- rapidly mutated into the glider's and tug's best hopes and chances for survival, cost-free inconveniences at absolute worst
- rendered hang gliding wide open to infiltration and control by the worst dregs and lunatics humanity had to offer
- precipitated the extermination of nearly all pockets of intelligence and decency in the sport
- sent tow equipment evolution into the sewer and rendered the market wide open for total crap
- demoted the standing of the guy on the glider from Pilot In Command to passenger / dope on a rope
- transferred control of the sport of hang gliding to a cartel of powered ultralight drivers
- interfered with the cleansing of the gene pool by occasionally defusing a lockout with a few feet to spare
- facilitated the global infestation of the easily reachable release
- crashed UNTOLD THOUSANDS of gliders - many lethally
- rendered AT gliders untowable in prime soaring conditions
- sent and helped send AT operations into permanent extinction
- fairly abruptly started becoming substantially less desirable
- slowly started becoming lethal again
I'm locking the "topic" as it's intended as a reference only but:
- count on frequent amendments
- do feel free to contact me regarding other relevant material
---
*Tost Flugzeuggerätebau
Weak links protect your aircraft against overloading.
- Use only the weak links stipulated in your aircraft TCDS or aircraft manual.
- Checking the cable preamble is mandatory according to SBO (German Gliding Operation Regulations); this includes the inspection of weak links.
- Replace the weak link immediately in the case of visible damage.
- We recommend that the weak link insert are replaced after 200 starts: AN INSERT EXCHANGED IN TIME IS ALWAYS SAFER AND CHEAPER THAN AN ABORTED LAUNCH.
- Always use the protective steel sleeve.
*Manned Kiting
The Basic Handbook of Tow Launched Hang Gliding
Daniel F. Poynter
1974
"A bad flyer won't hurt a pin man but a bad pin man can kill a flyer." - Bill Bennett
"Never take your hands off the bar." - Tom Peghiny
"The greatest dangers are a rope break or a premature release." - Richard Johnson
*Donnell Hewett - 1980/12
Now I've heard the argument that "Weak links always break at the worst possible time, when the glider is climbing hard in a near stall situation," and that "More people have been injured because of a weak link than saved by one." Well, I for one have been saved by a weak link and would not even consider towing without one. I want to know without a doubt (1) when I am pushing too hard, and (2) what will break when I push too hard, and (3) that no other damage need result because I push too hard.
In skyting we use a simple and inexpensive strand of nylon fishing line which breaks at the desired tension limit. Sure, it may get weaker through aging or wear and break too soon, but it cannot get stronger and fail to break. If it does break too soon, so what? We simply replace it with a fresh one.
A properly designed weak link must be strong enough to permit a good rate of climb without breaking, and it must be weak enough to break before the glider gets out of control, stalls, or collapses.
*Dennis Pagen - 1982/06-05
State College, Pennsylvania
Dear Donnell,
It was with great interest that I read your letter and publication on "Skyting". Your analysis of the forces involved in the towing situation satisfied my technical curiosity and let me know you have done your homework.
*Donnell Hewett - 1982/09
In addition to the above mentioned roll and yaw tendancies, there is some sideways force on the pilot due to the body line. This is illustrated below:
As can be seen, this sideways force tends to pull the pilot over to the correct side to make the glider turn naturally in the proper direction.
*Gil Dodgen - 1983/05
Editorial
A NOTE ON TOWING
The early days of hang gliding were marred by numerous towing accidents. During this period this aspect of our sport established a hopelessly bad reputation. And, indeed, last year, as you may have noted in Doug Hildreth's recent accident review, there was a towing fatality by a totally inexperienced Texas pilot.
Some time ago I received a series of four articles on a new towing system from Texas experimenter and inventor Donnell Hewitt. I ran the first in the series of four articles. Editors learn from experience and if I could roll back the calendar I would run all four at once in condensed form. In fact, what happened was that the first article - which made seemingly outrageous claims without outlining the actual technique or hardware - inflamed the then towing establishment. It seems that today's innovators become tomorrow's conservatives so I was bombarded with calls, some from the USHGA Board, telling me that this Mr. Hewitt was totally inexperienced, that he didn't know what he was talking about, and that I was contributing to the possible injury and death of unknown multitudes of innocent hang glider pilots.
I am not a tow pilot, and although Donnell's system made sense to me I was forced to discontinue the series. The essence of his system was a double bridle that connected to the glider and to the pilot. This system would thus pull the pilot back on line in the event that the glider was inadvertently turned off course from behind the vehicle. This would produce a self-correcting system avoiding the infamous "lockout" the factor which seemed to make towing so dangerous.
Well, it appears that Mr. Hewitt's system not only works but, as I've been told by pilots who have made literally thousands of land tows with it, it works beyond all the most optimistic expectations. One pilot told me, "It is virtually impossible to lock out even if one tries."
The possibilities are obviously incredible if a safe, standardized towing technique can be established. The sport of hang gliding at this point is essentially limited by the availability of flying sites. With land tow the entire country is opened up, and as we have seen by Willi Muller and Bruce Case's world class cross country flights over flat land, the potential is unlimited. In fact, there are certain safety advantages to flying over flat land. The turbulence created by jagged terrain is avoided and the dreaded downwind turn into the hill is eliminated.
In upcoming issues we will try to supply as much information as possible on this new aspect of the sport. Those with experience are invited to contact us about possible articles.
However, any new technique or equipment always produces unforseen problems. Towing must be approached with the most thoughtful and conservative attitude. As Garry Whitman pointed out to me recently, the only problem he has had has been with experienced pilots who won't listen to his instructions. And please remember, the equipment and methods described in this publication are based on the experience of the authors only and are not endorsed or recommended by the USHGA or Hang Gliding magazine.
With the kind permission of Donnell Hewitt we will publish the remaining three installments of his Skyting series in upcoming issues.
*USHGA Safety and Training Committee - 1985/07
USHGA Aerotow Guidelines
The FAA has granted the USHGA an exemption that allows aerotowing of hang gliders according to these guidelines. Aerotowing is a new and different way of flying hang gliders and must be done according to these guidelines for safety and legality.
I RATINGS
AEROTOW GLIDER PILOT: This is the rating that allows a pilot to be aerotowed without being observed by an aerotow instructor.
1) Must possess at least a USHGA Intermediate rating.
2) Demonstrate five aerotows under supervision of USHGA Certified Instructor qualified to teach towing. Each flight must demonstrate proper procedures, including smooth, clean launches, proper position in straight flight and turns.
3) Pilot must pass the oral test.
Until a pilot receives this rating, all aerotows must be sponsored by an under the guidance of an aerotow instructor.
AEROTOWING INSTRUCTOR: This is the rating that allows a pilot to teach other pilots to be aerotowed and to teach other pilots to be tug pilots.
1) Must hold a USHGA Instructor card for at least six months.
2) Successfully pass a towing instructor certification program, demonstrating capabilities in the form of aerotowed flights in different conditions and experience teaching pilots to be aerotowed.
TUG PILOT: This is the rating that allows a pilot to tow pilots with an aerotow rating or under the supervision of an aerotowing instructor. It is given by an aerotow instructor who has witnessed a pilot who has flown a minimum of ten aerotows, demonstrating proper procedures, including smooth takeoffs, straight flight and turns, and passed the oral test. Until a pilot receives this rating, all aerotows must be sponsored by and under the guidance of an aerotow instructor. A tug pilot cannot tow a pilot who has fewer than five tows.
II AEROTOWING EQUIPMENT
1) The tow line connection to the towing vehicle must be arranged so as not to hinder the control system of the towing vehicle.
2) A pilot-operational release must connect the tow line to the towing vehicle. This release must be operational with zero line force up to twice the breaking strength of the tow line.
3) A weak link must be placed between the tow line and the release at both ends of the tow line with the forward link ten percent stronger than the rearward weak link. The weak link must have a breaking strength less than 85% the weight of the hang glider and pilot combination, not to exceed 200 pounds.
4) A release must be placed at the hang glider end of the tow line within easy reach of the pilot. This release shall be operational with zero tow line force up to twice the rated breaking strength of the tow line.
5) A drogue device must be placed midway to 3/4 back from the tow vehicle on the tow line to prevent the tow line from reaching the tow vehicle propeller.
6) The tow line must be at least 150% as strong as the weak link in use.
THE AERO TUG: The ultralight used as a tug should have a wing loading so that its best climb speed is 25 to 38 mph (in thermal conditions, best climb speed must be over 30 mph). It must have enough power to tow a hang glider at a rate of climb of at least 300 feet per minute. The tug must have a concave rear view mirror so the tug pilot can see the glider at all times. The tug pilot should be able to operate the forward release without releasing the throttle or any of the flight controls.
THE AEROTOW GLIDER: The towed vehicle must meet or exceed the Hang Glider Manufacturers Association airworthiness standards. A pilot's first aerotowed flights should be with a glider familiar to the pilot with control bar wheels installed. A pitch enhancement device may be installed for improved pitch control on tow. Pitch devices must be installed and tuned according to the manufacturer's specifications. Extreme caution must be exercised when towing gliders possessing forward components that can contact the tow line (such as bowsprit gliders).
THE AEROTOW BRIDLE: The tow bridle should be tested to a tension of 300 pounds and should release easily at that tension. It should also operate properly with zero tension and be constructed so that it cannot release accidentally. Aerotow bridles should be of a type approved by the manufacturer of the aero tug system or an aerotow instructor.
III OPERATIONS
Aerotowing is complex and must be properly organized to be safe and efficient.
In practice, a particular site and weather pattern will have a standard routing and most pilots will know what to do. It is the launch director's responsibility to make sure everyone knows what to do. Considerations for establishing a routine include pilot skill, surface winds, winds aloft, runway direction, areas of turbulence, lift and sink, emergency landing zones to be used in case of line breaks or engine failures and separation between gliders, obstacles, tug and line. Training flights should be made in calm air.
PREFLIGHT PROCEDURES: Check the tug for adequate fuel supply. Preflight and test fly the tug. Preflight the line by stretching it out on the ground and inspecting its entire length including weak links, all knots, splices and fittings. Worn lines should be replaced. Test the tug release. Hook in to the glider and do a full hang check and then hook on to the tow line. The proper order for hooking in is as follows:
1) Hook in to the glider.
2) Hang check.
3) Hook on to the tow line.
If it becomes necessary to unhook:
1) Release the tow line.
2) Unhook from the glider.
Test the tow bridle release. Pilots are warned to turn their heads to avoid being struck by the release.
LAUNCH PROCEDURES: The tug pilot must take care to avoid causing problems for the glider pilot due to prop wash. Tug and glider pilot must have an established communication system for determining launch initiation. In all cases the glider pilot initiates launch. Slack line takeoffs should be avoided during training flights. Visual contact in the rear view mirror must be maintained at all times. The tug pilot should release the rope if there is any problem. The glider will lift off before the tug and the glider pilot will immediately transition to the base tube for optimal control and fly level about 12 feet above the ground until the tug lifts off and starts climbing.
AEROTOWING FLIGHT PROCEDURES: As soon as the tug lifts off and starts climbing, the glider will also climb and should remain in a position recommended by the tug pilot. If the glider is too high, the glider pilot should correct the relative position of the glider if necessary. Control inputs should be reduced under tow because energy exchange between tug and glider exaggerates response to control inputs.
In turns, the glider will maintain a position slightly inside the tug, so that it can fly at a better, slower climb speed. Glider speed varies with position in turns, with inside slower and outside faster. The glider pilot will tend to point at the tug because of the tow tension and should fly the glider so that its keel always points directly at the tug.
If arm signals are used, the following are suggested: A stationary arm signal means the glider pilot should move in the direction the tug pilot's arm is pointing. An arm pointed up means the glider should go up relative to the tug, down means the glider should go down, left-left and right-right. A waving arm means the glider pilot should release immediately. While minor deviations from the proper position are no problem, it is easier to maintain the proper position than to let the glider wander and have to make larger corrections. Major deviations from position can be cause for releasing. It is better to have the glider pilot release, but the tug pilot should also judge the situation and release if necessary. This is to be considered an emergency situation. If the tug pilot releases or the rope breaks, the glider pilot should release the rope or what is left of it before landing. In a situation where the glider is so far out of position as to be hazardous, release even at the cost of outlanding.
The normal release procedure is for the glider pilot to pull in to reduce line tension, check traffic to the right, then release. After releasing the glider pilot should turn to the right. The tug should turn left and descend to achieve maximum separation as quickly as possible. Both tug and glider should fly the predetermined landing patterns.
A site with lots of room and a nonabrasive surface may allow the rope to remain hooked to the tug to drop the rope on the first pass and then fly a short pattern and land.
AEROTOWING POSTFLIGHT PROCEDURE: The glider end of the rope should be checked for accidental knots and untied if necessary. Never tow with a knot in a line because they weaken the rope, cause premature wear and can be very difficult to untie. If the tug has released the rope, beware the prop when hooking it up and shut off the tug engine if safety requires it. Extreme caution should be exercised when operating with a rotating propeller. Prop clearing procedures should be followed at all times. Be especially vigilant to keep children, dogs and spectators well clear of operations at all times. Only the glider pilot and launch assistant should be within the vicinity of the glider during launch to avoid confusion.
*Rob Kells - 1985/09
Accident Report - Chris Bulger - 1985/07/17
It was late in the afternoon, and the conditions were smooth. A number of successful tows had been made that day without mishap. Kenny Brown, Mitch McAleer, and Jeff Huey each had clean tows to approximately 2500'. While Chris was towing John Pendry they climbed to between 1,000 and 1,500 feet.
Chris made a fairly sharp right turn which caused John to lock out to the left. John was fighting to get back behind the tow vehicle. At one point he started to recover from the lock out and then felt a "bump" (hard pull on the line). The trike tumbled, the single strands of 505 leech line that went from John's shoulder straps to the three-ring broke one at a time, and presumably the shackle pulled out of the trike release at the same time the second strand of 505 gave way.
The trike tumbled a second time, and broke a leading edge, and then on the third tumble Chris was thrown out and fell approximately 500' to his death. Exactly what happened will never be known but studying the physical evidence suggests several observations:
THE WEAK LINK:
It was one continuous strand of 205 leech line looped through the ring on the three-ring circus release (glider pilot end) and the tow rope, and fastened together with a fisherman's knot. This material is rated at 125 lbs. per strand by the manufacturer. The strength of the weak link would figure to be 4 X 125 = 500 lbs. minus the loss in strength due to friction and the knot. I have done several load tests with this material and duplicate hardware and found that the "weak link" was good for at least 400 lbs. Chris was telling me at breakfast that morning that Thevenot, when towing at the factory, doesn't use a weak link. In any case the weak link that was being used did not break. It is recommended that you never use a weak link good for more than 150 to 200 lbs. I have been using for years a single loop of 205 with three overhand knots and two bowlines to tie the ends together. Its breaking strength is between 210 and 215 lbs. It has always broken when necessary, but sometimes a little more time was required than I was comfortable with.
If you're towing, USE A WEAK LINK and test its breaking strength on numerous samples. Be sure it is breaking consistently at UNDER 200 lbs.
THE TRIKE RELEASE:
The trike was manufactured in Australia by Ricky Duncan. The trike release had been tested by the manufacturer for a straight pull of 300 lbs. They had always used 150-lb. weak links and had never had a release failure. Due to the increased load with this weak link it appears that the release on the trike did not malfunction. It was a steel pin on the end of a cable that went through two bolts with a shackle fitting in between. The cable was routed to a foot peddle at the nose of the trike. The trike inspection revealed that the pin was bent above the bottom bolt making release from the trike end impossible, and the cable was broken away from the foot pedal, indicating that Chris was trying hard to pin John but was unable to. So a release that was tested to 300 lbs. proved inadequate for a 350-lb. plus load at an angle up and to the side. It is of course also possible that the release was damaged on the ground by an impulse load caused by the rope snagging on something.
THE GLIDER
The glider was a Moyes GTR 180 which had been modified to increase wing area and airframe strength for the purpose of using with a trike. This particular glider had undergone continuing modifications as late as the day of the accident. There is no evidence that the glider was a contributing factor in the incident, but at the same time there is no data on file which establishes its level of airworthiness.
PILOT RELEASE:
It is my understanding that John did not have a lot of aero tow experience. He was locked out and putting everything he had into recovering. It's tough to let go when you're locked out and it has usually been the case that the better the pilot the more attempt is made to recover rather than release well before a lock out becomes severe, especially when on high tow.
NEVER underestimate the danger in towing, and never shortcut or ignore any safety procedures. Let's not let Chris Bulger's tragic death be for nothing.
*Doug Hildreth - 1990/09
1990/07/05 - Eric Aasletten - 24 - Intermediate - 2-3 years - UP Axis - Hobbs, New Mexico - Platform tow - Fatal / Head
Reasonably proficient intermediate with over a year of platform tow experience was launching during tow meet. Home-made ATOL copy with winch on the front of the truck. Immediately after launch, the glider pitched up sharply with nose very high. Apparently the angle caused an "auto release" of the tow line from the pilot, who completed a hammerhead stall and dove into the ground. Observer felt that a dust devil, invisible on the runway, contributed or caused the relatively radical nose-up attitude.
*Doug Hildreth - 1991/06
Pilot with some tow experience was towing on a new glider which was a little small for him. Good launch, but at about 50 feet the glider nosed up, stalled, and the pilot released by letting go of the basetube with right hand. Glider did a wingover to the left and crashed into a field next to the tow road. Amazingly, there were minimal injuries.
Comment: This scenario has been reported numerous times. Obviously, the primary problem is the lack of pilot skill and experience in avoiding low-level, post-launch, nose-high stalls. The emphasis by countless reporters that the pilot lets go of the glider with his right hand to activate the release seems to indicate that we need a better hands-on way to release.
I know, I know, "If they would just do it right. Our current system is really okay." I'm just telling you what's going on in the real world. They are not doing it right and it's up to us to fix the problem. Think about it.
*Dennis Pagen - 1997/01
Towing Topics
Let me begin with the accident involving Bill Bennett and Mike Del Signore which occurred in July (1996/07/25) in Ohio, since this accident seems to be the catalyst which started this recent flurry of discussion. As a good friend of Bill's and recipient of the verbal and written reports of eyewitnesses, I believe I can shed some light on the situation.
Bill was training pilots in aerotowing, tandem and as tug drivers at the time. Bill had credentials in all three disciplines and was ideally suited for the job. However, an extenuating circumstance may be that he was taking on a heavy load of personal responsibility, for he had been working all day supervising the operation as well as flying repeatedly as a tandem "passenger" while the trainees piloted the hang glider. Thus, fatigue could have been a factor in the accident.
However, perhaps more critical was the fact that during the flight that proved fatal, several factors were combined. First, Mike, while a very experienced ground-based tow pilot, was new to aerotowing. Second, Mike was not an experienced tandem pilot. Third, the tug pilot was inexperienced. Fourth the weak link was way too strong. Fifth, the arrangement of the tandem pilots was not ideal, and sixth, the release at the tug end may have malfunctioned.
A significant matter is the fact that Mike was by far the largest pilot Bill was flying with. Not only did this create a very high wing loading on the glider, but Bill was unable to reach the control bar according to some witnesses. Even if he could in normal flight, I believe he could not in the reported situation in which Mike was pushing full-out to climb behind the tug.
Witnesses reported Bill saying that the tow was too slow on their first flight together. Unfortunately, a witness who was standing with the tug pilot between flights indicates this message was never given to the tug pilot. It seems clear from Bill's comment and what happened subsequently that a slow tow combined with heavy loading is what initiated the fatal sequence.
Once the pilots were airborne they remained low on the tug and most likely passed through at least a portion of the tug's wake. This wake is very turbulent and requires constant, hard roll control with a nearly full push-out to climb above. This is not a desirable position to be in, especially close to the ground. The tug pilot can help in this situation by diving to increase the glider's speed. In this case, the inexperienced tug pilot didn't know the proper procedure and cut power to "let the glider catch up." Later he apparently dove to break the weak link, but by this time a lockout was in progress and speeding up makes it worse.
If a tug is going too slow to begin with, there is no way to climb above the wake and the only recourse is to release. I believe he tug's wake turbulence rolled or stalled the hang glider and a lockout rapidly ensued. I am sure Mike did not have the experience to make a quick and timely release decision, and anyway he had his hands full trying to control the glider. Bill was certainly monitoring what was taking place, but without being on the control bar he had no idea what forces and feedback were occurring. I expect the lockout progressed so fast that he had no chance to react once it got serious.
The bridle system used was like that shown in the photograph on page 20 of the September 1996 issue of this magazine. There was only a bottom release. The weak link was at the top end was tested after the accident to break at over 300 pounds (it was constructed from 205 Dacron line). Because of this doubling effect of the bridle, this would require a towline force of over 600 pounds to break. This is way too high. There is no known reason for the failure of the tug release since it was tested before and after the accident with a realistic tow force. However, correcting both of these matters - overstrength weak link and release failure -- would not have necessarily prevented this accident, for even if the glider was freed from the towline it may have been too low to recover from the lockout attitude.
In conclusion, let me point out that like most accidents, in this case a cascade of events occurred that got out of hand. I don't agree with the accident analysis in the October, 1996 issue that indicated that it was the failure of the pilots to release. I think the root cause was a series of problems as outlined above, and more specifically, our failure to educate pilots on all levels of towing. This includes towing administrators as well as pilots. To remedy this situation we recommend the following. (These are merely my suggestions and I'm sure many more items will be addressed in the USHGA Towing Committee.)
1) A pilot should be an experienced tow pilot before he or she is allowed to be pilot-in-command for the first 300 feet AGL in a tandem situation.
2) A training situation should not include an inexperienced pilot at both ends of the towline (tug or winch operator at one end and glider pilot at other end).
3) Tandem aerotowing should take place at five mph faster than solo towing for the first 300 feet.
4) Weak links should be tested for maximum load with the actual bridle setup to be used.
5) Pilots should be taught early emergency release procedures and should practice such as part of their training.
It should be made very clear to all pilots that tandem gliders are less responsive than solo gliders in general, and are thus more susceptible to wake turbulence-induced problems and lockouts. There has been some suggestion on the Internet that tests of the wake turbulence behind an aero-tug be conducted to check its magnitude and potential danger. This is probably unnecessary, for many pilots, including myself, have been in this wake turbulence. It is not overly upsetting to a responsive glider with an experienced pilot, but I, for one, would not like to be in the wake in a tandem glider near the ground. Tug pilots may have a tendency to resist diving down to help the hang glider in such a situation close to the ground because of obstructions and field limits. Thus, the safest procedure is for the glider pilot to release if he gets caught low in the first 100 feet of aerotow climb out. In the 12 different towing operations I have aerotowed with, I have never heard of or seen anyone practice low releases. Such practice, if carried out with safe limits, will go a long way toward training pilots to come off the line in a timely manner in case of trouble.
*Towing Aloft - 1998/01
A weak link is the focal point of a safe towing system.
Pro Tip: Always thank the tug pilot for intentionally releasing you, even if you feel you could have ridden it out. He should be given a vote of confidence that he made a good decision in the interest of your safety.
*Wallaby Ranch - 1998/02
The weak link is designed to act as a fuse, breaking the circuit when overloaded. In an excessive out-of position situation, the weak link will snap before the control authority of the glider would be lost. If you should have a weak link failure close to the ground, it will be important to immediately lower the nose of the glider, due to the relatively high angel of attack (angle of attack) while under tow and the sudden loss of energy upon release. Regain airspeed and land normally.
http://www.questairforce.com/aero.html
Aerotow FAQ
*Quest Air - 1999/01
Weak Link
The strength of the weak link is crucial to a safe tow. It should be weak enough so that it will break before the pressure of the towline reaches a level that compromises the handling of the glider but strong enough so that it doesn't break every time you fly into a bit of rough air. A good rule of thumb for the optimum strength is one G, or in other words, equal to the total wing load of the glider. Most flight parks use 130 lb. braided Dacron line, so that one loop (which is the equivalent to two strands) is about 260 lb. strong - about the average wing load of a single pilot on a typical glider. For tandems, either two loops (four strands) of the same line or one loop of a stronger line is usually used to compensate for nearly twice the wing loading. When attaching the weak link to the bridle, position the knot so that it's hidden from the main tension in the link and excluded altogether from the equation.
IMPORTANT - It should never be assumed that the weak link will break in a lockout.
ALWAYS RELEASE THE TOWLINE before there is a problem.
*Bill Bryden - 1999/06
Rob Richardson, a dedicated instructor, died in an aerotowing accident February 27, 1999 at his flight park in Arizona. He was conducting an instructional tandem aerotow flight and was in the process of launching from a ground launch vehicle when the accident occurred.
Rob had started to launch once but a premature tow line release terminated this effort after only a few meters into the launch roll-out. It is suspected the cart was rolled backwards a bit and the tow line was reattached to begin the launch process again. During the tug's roll-out for the second launch attempt, the tug pilot observed the glider clear the runway dust and then begin a left bank with no immediate correction. At that point he noticed that the launch cart was hanging below the glider and immediately released his end of the 240 ft. tow line. The tug never left the ground and tug pilot watched the glider continue a hard bank to the left achieving an altitude of approximately 25 feet. Impact was on the left wing and then the nose of the glider. Rob was killed immediately from severe neck and head trauma. Rob's body likely cushioned much of the student's impact. She was basically uninjured but suffered short term memory loss (not uncommon in hard crashes) and did not recall the events of the accident.
http://ozreport.com/3.066
Weaklinks
*Davis Straub - 1999/06/06
During the US Nationals I wrote a bit about weaklinks and the gag weaklinks that someone tied at Quest Air. A few days after I wrote about them, Bobby Bailey, designer and builder of the Bailey-Moyes Dragon Fly tug, approached me visibly upset about what I and James Freeman had written about weaklinks. He was especially upset that I had written that I had doubled my weaklink after three weaklinks in a row had broken on me.
I told him that I would be happy to publish anything that he wrote about weaklinks, but I never received anything from him or anyone else at Quest.
A few weeks later I was speaking with Rhett Radford at Wallaby Ranch about weaklinks and the issue of more powerful engines, and he felt that stronger weaklinks (unlike those used at Wallaby or Quest) were needed. He suggested between 5 and 10 pounds of additional breaking strength.
To compensate for the greater power of the 619 engine that Rhett has on his tug, he deliberately flew it at less than full power when taking off or in anything other than absolutely smooth conditions. He started doing this after he noticed that pilots towing behind his more powerful tug were experiencing increased weaklink breakage.
A number of the pilots at the US Nationals were using "strong links" after they became fed up with the problems there. These "strong links" were made with paraglider line and were meant to fool the ground crew into thinking that the pilot had a weaklink.
The problem with strong links (neither Bobby Bailey nor I was aware at the time of the US Nationals that pilots were doing this) is that they endanger the tug pilot. If the hang glider pilot goes into a lock out, and doesn't break the weaklink (because there isn't one), they can stall the tug. I assume that Bobby Bailey won't hear about the use of strong links at the US Nationals until he reads it here.
This is of course a problem that Quest Air brought on themselves by their mismanagement of the weaklink production process, but it could have had disastrous consequences both for the competing pilots as well as for the Quest Air tug pilots. Hopefully in future everyone will learn from this mistake.
I would suggest that the tug pilots at Quest Air get together will Rhett and come up with a new standard for weaklinks to be used with the Turbo tugs. That Quest Air tie their weaklinks with a shorter length to alleviate the problem of the weaklink catching the release. That they organize the weaklink tying process so that there is sufficient quality assurance.
http://ozreport.com/5.126
Flytec Dragonfly
*USAFlytec - 2001/07/14
Steve Kroop - Russell Brown - Bob Lane - Jim Prahl - Campbell Bowen
The tail section of the Dragonfly is designed so that it can accept in-line as well as lateral loads. Furthermore the mast extension, which is part of the tow system, is designed to break away in the event of excessive in-line or lateral loads. The force required to cause a breakaway is roughly equivalent to the force required to break the double weaklink used on the tail bridle. More simply put, the mast would break away long before any structural damage to the aircraft would occur.
*Bill Bryden - 2000/02
Dennis Pagen informed me several years ago about an aerotow lockout that he experienced. One moment he was correcting a bit of alignment with the tug and the next moment he was nearly upside down. He was stunned at the rapidity. I have heard similar stories from two other aerotow pilots.
http://www.kitestrings.org/post11731.html#p11731
http://ozreport.com/6.178
Update on Tandem Accident
*Martin Henry - 2002/09/04
Here is an update of the investigation into the August 17th 2002 dual fatality tandem flight at Fort Langley BC.
I would like to say that we know the cause of this accident, but it continues to be a mystery. What is known is the following.
This was a normal instructional flight, using a Double Vision Tandem glider, flown in the upper lower tandem configuration. The student had enough experience that he had moved to the bottom tandem position with the instructor using the top position. The glider was being towed by a Moyes Tug (912S modified) and was using a standard V bridal system with both upper and back up lower releases and a tow line length of around 300'. The flight plan includes a 1000-ft release altitude, for instructor/student training. From take-off to the 1000-ft altitude the flight appeared "normal".
Weather conditions were good. No unusual turbulence had been detected during earlier tows to 2500ASL.
At or near the release altitude the glider violently departed from tow in what appears to be severe left lock-out. The "lock-out" may or may not have been the result of loss of control or aircraft failure.
The tug pilot indicated that he had just completed a shallow right turn and the tow was "normal" then there was a sudden increase in tow pressure at which point the weak link at the tugs end failed. (The force of the event bent the upper unsupported section of the tugs bridal attachment point, at which point the tugs weak link failed).
At this point in time it is not known why the hang glider’s weak link did not fail. Inspection of the hang glider’s tow components confirm that the weak link was present and had not failed. (At the crash site the weak link was found released from the upper release, this may or may not be the result of being released by either of the pilots but may have been the result of releasing at impact).
After departure from tow, the hang glider entered a severe left "wing-over", followed by a very steep spiral decent. It is believed that during the initial stages of decent the hang glider became tangled in the towline with a substantial amount of towline becoming tangled in the left wing. At some point during this descent, at a very low altitude, the emergency parachute was deployed. Inspection of both the parachute and the deployment system indicates that a pilot (unknown) had successfully deployed the parachute but at too low an altitude to open. Next the glider "clipped" a tree then impacted at a steep angle in a pasture.
Damage at impact is extreme. It has been difficult to determine at what point any given component has failed. My preliminary evaluation of this crash indicates that the hang glider appears to have maintained its basic structural components until impact. Sail damage is so extensive it may not be possible to determine if a sail failure during the flight may have contributed to the accident.
During a careful inspection of the hang glider, a serious issue has been discovered that may or may not have contributed to this crash. The discovery of metal fatigue on the gliders landing gear/control bar combination has resulted in the need to post the following:
Important Airworthiness Notice.
The following notice applies to any Owner/Operators that are using Tandem Hang Gliders. This notice is not type specific but does apply to any gliders that have been fitted with any form of fixed wheels where the wheels are being used as the sole or primary landing system (castor type, slip on, or any other type that may be mounted to or over the stock or modified base tube).
Gliders fitting this description should not be flown until the following actions have been taken:
Any hardware associated with the mounting of wheels to the base tube should be removed and an inspection should be made to assess airworthiness of the base tube. Critical concerns include metal fatigue such as cracks in any of the components associated with this assembly. Particular attention should be paid to any areas of "sleeving" and or any areas where bolts or rivets may intersect such sleeving.
PLEASE NOTE: any suspicious damage should be completely evaluated. If over-sleeving is preventing proper inspection, sleeving must be removed to properly evaluate structural reliability.
Failure to inspect and correct any defect may result in catastrophic failure. Where practical, installation of an internal backup cable should be considered.
For any further information on this notification or for any individuals that may wish to contribute information pertaining to the accident currently under investigation, please contact Martin Henry.
*Lauren Tjaden - 2003/12/14
This fall at Ridgely, I had a weak link break at maybe fifty feet. I thought I was going to have to land in the soybeans - the very tall soybeans - when I looked at my angle. But, my glider stalled quite dramatically almost instantly (hard not to stall when you have a break), and dove towards the ground (a bit disconcerting from so low).
*Joe Gregor - 2004/09
Highly experienced mountain pilot (Mike Haas - 2004/06/26) aerotowing a newly-purchased glider experienced a lockout at low altitude. Witness reports indicate that the glider began oscillating immediately after leaving the launch dolly. The weak link broke after the glider entered a lockout attitude. Once free, the glider was reportedly too low (50-65' AGL, estimated) to recover from the unusual attitude and impacted the ground in a steep dive. The pilot suffered fatal injuries due to blunt trauma. There is no evidence that the pilot made an attempt to release from tow prior to the weak link break, the gate was found closed on the Wallaby-style tow release.
*Federal Aviation Administration - 2004/09
Title 14: Aeronautics and Space
PART 91--GENERAL OPERATING AND FLIGHT RULES Subpart D--Special Flight Operations
§ 91.309 Towing: Gliders and unpowered ultralight vehicles
- (a) No person may operate a civil aircraft towing a glider or unpowered ultralight vehicle unless--
-- (1) The pilot in command of the towing aircraft is qualified under §61.69 of this chapter;
-- (2) The towing aircraft is equipped with a tow-hitch of a kind, and installed in a manner, that is approved by the Administrator;
-- (3) The towline used has breaking strength not less than 80 percent of the maximum certificated operating weight of the glider or unpowered ultralight vehicle and not more than twice this operating weight. However, the towline used may have a breaking strength more than twice the maximum certificated operating weight of the glider or unpowered ultralight vehicle if--
--- (i) A safety link is installed at the point of attachment of the towline to the glider or unpowered ultralight vehicle with a breaking strength not less than 80 percent of the maximum certificated operating weight of the glider or unpowered ultralight vehicle and not greater than twice this operating weight;
--- (ii) A safety link is installed at the point of attachment of the towline to the towing aircraft with a breaking strength greater, but
not more than 25 percent greater, than that of the safety link at the towed glider or unpowered ultralight vehicle end of the towline and not greater than twice the maximum certificated operating weight of the glider or unpowered ultralight vehicle;
*Dennis Pagen - 2005/01
I am personally familiar with such a problem, because it happened to me at a meet in Texas. Soon after lift-off the trike tug and I were hit by the mother of all thermals. Since I was much lighter, I rocketed up well above the tug, while the very experienced tug pilot, Neal Harris, said he was also lifted more than he had ever been in his heavy trike. I pulled in all the way, but could see that I wasn't going to come down unless something changed. I hung on and resisted the tendency to roll to the side with as strong a roll input as I could, given that the bar was at my knees. I didn't want to release, because I was so close to the ground and I knew that the glider would be in a compromised attitude. In addition, there were hangars and trees on the left, which is the way the glider was tending. By the time we gained about 60 feet I could no longer hold the glider centered--I was probably at a 20-degree bank--so I quickly released before the lockout to the side progressed. The glider instantly whipped to the side in a wingover maneuver. I cleared the buildings, but came very close to the ground at the bottom of the wingover. I leveled out and landed.
Analyzing my incident made me realize that had I released earlier I probably would have hit the ground at high speed at a steep angle. The result may have been similar to that of the pilot in Germany. The normal procedure for a tow pilot, when the hang glider gets too high, is to release in order to avoid the forces from the glider pulling the tug nose-down into a dangerous dive. This dangerous dive is what happened when Chris Bulger (U.S. team pilot) was towing John Pendry (former world champion) years ago. The release failed to operate in this case, and Chris was fatally injured. However Neal kept me on line until I had enough ground clearance, and I believe he saved me from injury by doing so. I gave him a heart-felt thank you.
Additionally... On Wills Wing's website:Hang Gliding - 2005/02
Please do not attempt to aerotow any glider without first receiving instruction from a qualified aerotow instructor.
Master's Tips:
Aerotow Release Attachment Points for Wills Wing Gliders
by Rob Kells
The list below will give you a good starting point for attaching an upper aerotow release to our current production gliders. There are a number of other factors that may cause you to want to move it slightly forward or aft of the starting point.
Release point
The primary factors that determine where the tow point needs to be are
- the tow speed of the tug
- the glider's aspect ratio
- the pitch bar pressure at tow speeds
- the glider's top speed
- trim speed
- the pilot's weight
The proper placement of the tow point will trim the glider with light but positive pitch pressure while under tow.
VG Setting
All Wills Wing gliders equipped with VG are easiest to tow with the VG set to 1/2. This reduces the glider's pitch bar pressure, while at the same time damping the roll response to reduce the chance of oscillations on tow. Pilots at the light end of the recommended weight range may want to set the VG at 1/3 on.
Vertical Stabilizers
All gliders are easier to tow when a vertical stabilizer is added to the rear keel. This provides significantly better directional stability and vastly reduces the chance of oscillations.
Tow Bridles and Releases
These tow point positions assume the use of two spliced Spectra ropes to attach to the tow line. One is attached to a shoulder tow point on the harness with a weak link, and then is routed through a spliced loop in a second longer Spectra rope, and attached to the other shoulder via a back-up release. The longer rope is then routed through the tow ring and attached to the upper release with a proper weak link. The assumed tow speed is 32 miles per hour. Some trikes tow at significantly higher speeds. The higher the tow speed, the further forward the top release must be positioned to trim away pitch pressure. Under no circumstances should you attempt to aerotow behind a tug which has a tow speed that is near the steady state maximum top speed of your glider! We do not recommend releasing from the bottom release point on your shoulders when using a V-bridle. If the bridle or weak link gets caught on the tow rope ring after releasing at the shoulders, and the glider is being pulled only from the top point, it may become unstable in pitch on tow. Use the bottom back up release only if you have a top release failure.
Towing from only the shoulder attachments without a top release is generally referred to as "Pro tow". The Sport 2, U2s and Talons may be "Pro towed" without a top release, however this method is not as easy as using a two point release as described above. Towing without a top release will cause the base tube to be positioned much further back during tow, the glider will have increased pitch pressure, and lockouts are much more difficult to correct.
We find that the easiest way to secure the top release to the keel is to use a piece of spectra or perlon line. Start by making a loop around the keel and secure it with an overhand knot and safety half hitch in the desired location. Tie the other end of the line around the king post base secured with a bowline knot and safety half hitch, making sure that the forward loop will position the top release in the desired location.
Use a rapid link to attach the top release webbing to the line. This will make it easy to remove the release.
Always use an appropriate weak link with a finished length of 1.5 inches or less. Longer weak links are more likely to get tangled on the tow ring upon release. Carry a hook knife when towing.Note: The higher the top tow point the better. If the glider is equipped with a DHV (longer than Wills Wing standard length by 8 inches) it is better to tie the release to the keel rather than attach it to the hang loop.MODEL - TOP RELEASE LOCATION
Falcon: 140, 170, 195 - On keel, just below cross bar
Falcon: 225 - On keel, 3 inches in front of cross bar
Falcon: Tandem - On keel, just behind the rear of the front keel pocket
Eagle: 145, 164, 180 - On keel, 14 inches forward of back of bottom surface zipper (Must leave bottom surface unzipped 14 inches)
Sport: 2 135, 155 - On keel, at back of bottom surface zipper - Set VG to 1/2
U2: 145, 160 - On pilot’s hang loop or carabiner - Set VG to 1/2
Photo: Mark Vaughn
Somebody obviously screwed the pooch and truncated it off of the article.Talon: 140, 150, 160 - On pilot’s hang loop or carabiner - Set VG to 1/2
*
http://ozreport.com/9.032
The Worlds - weaklinks
*Davis Straub - 2005/02/07
For a couple of years I have flown with a doubled weaklink because, flying with a rigid wing glider, I have found that there is little reason to expect trouble on tow, except from a weaklink break.
http://groups.yahoo.com/group/skysailingtowing/message/4593
Weaklinks
*Peter Birren - 2005/02/08 19:22:49 UTC
What is the big issue? Re-launching? Oh, the wasted time! Oh, the hassle! Oh, the embarrassment! These are sure preferrable to Oh Shit!
http://groups.yahoo.com/group/skysailingtowing/message/4597
Weaklinks
*Donnell Hewett - 2005/02/08 23:28:13 UTC
4. The appropriate strength of a weaklink depends upon pilot skill. A skillful pilot can maintain control when a stronger weaklink breaks whereas a less skillful pilot cannot. As a general rule, a beginning pilot should limit his towline tension to ½-g and an experienced pilot to 1-g. Only highly experienced pilots qualified to perform aerobatics while on tow should use a 2-g or stronger weaklink while being pulled forward (such as when aerotowing).
5. The appropriate strength of a weaklink depends upon the type of towing system used. Different strength weaklinks should be used for foot-launched ground towing, platform towing, aerotowing, boat towing, etc. As a general rule, forward pulling systems such as aerotowing, foot-launch ground towing, etc. should use 1-g weaklinks or less. Consistently downward pulling systems such as platform launch can go as high as 2-gs.
http://ozreport.com/forum/viewtopic.php?t=553
Weak Links vs Strong, but foolproof release?
http://groups.yahoo.com/group/skysailingtowing/message/4624Justin Needham - 2005/02/09 23:03:22 UTC
Hi Davis.
Re your comment "why weaklinks". I had a scary incident back in the early 90's where a doubled up weakink (unbeknown to me) caused a bad accident.
A Swift pilot who had been towing on the same site had been doubling weaklinks to prevent early breakage, but not advising the flex wing pilots of his actions. We had all been clipping into the same line. My launch on this occasion was in medium length grass where the tug had slow acceleration. The tug pilot was inexperienced. The winds were pretty much zero. On my "all out", I guess a gentle thermal tailwind hit me from behind as I began to run. This was enough to prevent me from getting airborne. I ran a very long way till I could no longer keep up with the groundspeed. The glider wasn't taking my weight, and I was then forced to push out to try and avoid hitting the ground. Unfortunately even in deep ground effect mush, there was still not enough lift. The control frame hit down, followed immediately by the nose of the glider and then everything went crazy.
At this point, a normal weaklink would have broken instantly and I'd have been left embarrassed but (probably) healthy in a heap down the runway. On this occasion, the doubled link wouldn't break. I was accelerated along the ground, with a flattened control frame, with my face in the dirt and absolutely no ability to release since my arms were being flailed about. All I clearly recall, is shouting "stop stop stop" since I could do nothing else. I was in severe danger of breaking my neck, since my head was being caught up in all this as I did 20MPH+ across the ground.
The tug pilot was inexperienced, and for those few seconds was concentrating on getting airborne, not on looking at me. (Mistake number 2) After ploughing a furrow for ~ 75 meters, while my glider disintegrated about me, the tug pilot got the message and finally stopped.
Why didn't I use a trolley you ask? Well there was no trolley on site, and perhaps I was relying on my normal perfectly adequate nil wind launch technique a little too much. (Potential mistake number 3). It didn't seem an undue risk under the circumstances at the time, - we all take calculated risks every time we fly. Unfortunately this risk had no safety valve.
Now, as you may imagine, I'm paranoid about weaklinks and wouldn't under any circumstances (trolley or no trolley) ever consider a doubled one! I believe I was quite lucky not to get seriously injured, and I didn't even leave the ground.
Rgds,
Justin Needham, UK
Why Weaklinks?
justin.needham@nokia.com
2008/02/09 03:08
*
http://ozreport.com/forum/viewtopic.php?t=559
Protow vs. weaklink
Davis Straub - 2005/02/21 10:44:27 UTC
The force on the weaklink is equal to the force on the tow line divided in half further divided by the cosine of the (angle between the two legs of the protow line divided in half). So as I wrote in a message recently:
Let's do a little calculation to look at the hypothetical (totally hypothetical) tow pressures on a weaklink connected to the end of a protow bridle.
Angle 120 force 300 half force 150 150 resultant 300 300
Let's say the force is 300 lbs (foot-lbs). Let's say that the angle formed by the two legs of the protow bridle is 120 degrees (it is likely much less, but this is to illustrate a point). Then the resultant force on the weaklink is 300 lbs.Indeed, in this case it only allows 260 pounds.Paris Williams
At Quest, for solo tows, we use two strands (one loop) of a 130. Lb line on one end of a v-bridle, with the knots "buried" to try to remove them from the equation. You'd think this would allow for nearly 520 lb. Of actual tow force, though I never personally measured it and would guess that it's significantly less than this.
If the angle between the legs of the bridle is 60 degrees instead of 120 (totally depends on the length of the legs), then the force on the weaklink is 173 pounds (assuming a 300 pound tow line force).
Or, a 260 pound weaklink can handle 450 pounds of tow forces.
Cool, eh?
*Davis Straub - 2005/02/33 02:59:56 UTC
Angles
I'm doing the math now for the case of the tow rope off at an angle. It depends on the length of the protow.
Out soon.
http://www.chgpa.org/forums/viewtopic.php?f=2&t=229
Quest Friday, shoulder towing
*Lauren Tjaden - 2005/03/05 13:25:42 UTC
My understand is that since all the tow forces are on you (when towing from the shoulders), not you and your glider combined, that in a lockout it might be more difficult to recover since your shoulders will be pulled in the direction of the plane more strongly (someone please correct me if I am wrong, since I have limited experience with this, to say the least). Also, the bar position is further back so you have less leverage to push it back into position than if it was further ahead of you.
On the plus side, you?have less drag and less hassle in the air stowing your tow bridle.
I also feel it may be easier to pin off in case of a lockout because you have a bailey (for me, two of them, one on each side) and they are much closer to your center of gravity. Reaching that handle way out to the side can be challenging in a hard turn. The bailey is right there.
I would welcome hearing more expert opinions, as well.
http://www.chgpa.org/forums/viewtopic.php?f=2&t=358
finally!
*Lauren Tjaden - 2005/04/10 02:47:49 UTC
Pop! My weak link broke, and I involuntarily shuddered. The last time this happened, I found myself in a severe stall followed by an uncontrolled slipping dive, and brushed close to the ground before I recovered. But my visualization of what to do in this situation helped, because I pulled in so hard and fast Griffin's nose barely had time to rise. Hurray!
Soon I had a new weak link attached and ventured into the sky again.
http://ozreport.com/9.127
Robin's accident
*Davis Straub - 2005/06/14
Once the glider bounces off the ground, Robin is never able to get the glider lined up correctly behind Bobby Bailey and drifted continually to the left, locking out and crashing from a low altitude. If Bobby had released Robin at any time before the last two or three seconds he would likely not have crashed, at least not from a lockout.
http://www.chgpa.org/forums/viewtopic.php?f=2&t=242
VOX
*Paul Tjaden - 2005/03/12 14:54:17 UTC
I noticed that Jim Lamb uses two barrel releases and NO weak link.
http://ozreport.com/9.177
Another bad launch off the cart
*Davis Straub - 2005/08/28
And another good outcome that we can learn from.
In the second frame the left wing is dragging on the runway and the weaklink has broken. This is a good thing. The pilot is in trouble and you want that weaklink broken so that he isn't dragged down the runway. Notice that he hasn't moved his hands at all, and doesn't throughout this sequence of photos. The weak weaklink does the heavy lifting for him. Use a properly sized weaklink!
http://ozreport.com/forum/viewtopic.php?t=865
Tandem pilot and passenger death
Martin Henry - 2005/09/09 17:05:50 UTC
What is known, the event (2002/08/17 - William Woloshyniuk / Victor Cox) occurred at or near the departure from the tug. The departure from tow was reported (by the tug operator) to be a violent separation. The tug (Moyes) suffered a failed vertical pylon on the upper portion of the tug end V bridal, just prior to the tug end weak link failure.
*Mike Van Kuiken - 2005/10/13 19:47:26 UTC
The weak link broke from the tow plane side. The towline was found underneath the wreck, and attached to the glider by the weaklink. The glider basically fell on the towline.
http://www.chgpa.org/forums/viewtopic.php?f=2&t=1079
$15 pacifiers
Jim Rooney - 2005/09/21 17:41:35 UTC
I don't know that anyone else isn't bothered by it... I think it's more along the lines of many people do not wish to be the guinne pig for a new system. Even the simplest of systems fail... often in new and interesting ways.
How many unintended releases did you go through to get to this point? How many bad positions did it put you in? If the unknown isn't a huge factor in an experimental system, then we would have no unintended releases in the first place. You've accepted the risks involved in testing out a new system. You've decided that the potential rewards involved outweigh the risks involved... but you can't say there aren't risks.
Steve Kinsley - 2005/09/21 15:15:54 UTC
I am bothered by the current aerotow release options even though I have never really had a bad experience. If you were seriously crooked right off the cart are you confident you could really get to the release? I am an old guy and am no longer very confident in my abilities. That is why I have messed around trying to devise something where you hold a string in your mouth. Open your mouth and you are off. After much experimentation and many exasperated tug pilots seems to work fine. But with the exception of Tad, nobody else I know is bothered by this aspect of towing.
Steve Kinsley - 2005/09/22 00:26:45 UTC
If I had known Tad was going to make one I would have just waited for his. Although once into it I kinda got hooked on the project. The only real problems in the process were unintended releases but it never really put me in a bad position. I might make an exception for last weekend when I (mis) used Tad's for the first time and ended up dancing on the cart. Never thought about that. See.
I think the tough part in managing risk is keeping the perception of risk and the reality aligned. IMHO the perception of risk from a failed hangstrap is much greater than the actual reality. So I don't really care about backup hang straps. But I reached the opposite conclusion re aero releases -- a lot more dangerous than you think. In my view (at least for shoulder tow). Others could come to the opposite conclusion. Not enough data out there to resolve the issue.
Tad Eareckson - 2005/09/22 12:55:24 UTC
In the course of the development of my two point system I have had several premature releases related to pushing the envelope in the fields of tight and hair trigger.
Release systems incorporate weak links (and we all know what can happen when they don't). Consequently, from the moment the engine revs up to the point at which the pin is pulled one can suddenly find oneself in free flight mode with no warning whatsoever. Thus, one must launch and fly in such a manner that a weak link failure or premature release is not an issue. Happily, this is what you're supposed to be doing regardless.
Jim Rooney - 2005/09/22 14:05:50 UTC
Ok, as long as we're digging this deeply into it....
It is not merely a matter of inconvenience. I was there, and in my oppinion Steve came rather close to breaking his legs. I was getting ready to dial 911.
Sure, being on tow at the wrong time is an extremely bad thing. But don't tell us that being off tow at the wrong time is all sweet and wonderful. Yes, we prepare for it, but that doesn't make it a safe situation. It makes it a manageable situation. There are times where it's better to be on tow than off tow. Ask anyone that's dragged a dolly into the air.
Yes, your tow system failed... it didn't fail to release, it failed to work. Did it fail more safely than a lockout? Yes. But don't tell me that thing worked. You found an unforseen error. That's the problem... unforseen. You don't know what else is waiting for you. Oh, let me rephrase that more accurately, Steve found an unforseen error for you.
*Kevin Carter - 2005/09/24 21:49:39 UTC
One pilot in the Texas Open had three premature releases in a row with glider damage on all three and different degrees of pilot injury. I myself have had a low level release that caused minor injury.
When you are discussing the acceptable risk of a premature release.....take the blinders off man. It is a real risk that should be minimized and not taken lightly.
http://ozreport.com/forum/viewtopic.php?t=865
Tandem pilot and passenger death
*Davis Straub - 2005/10/15 05:50:52 UTC
In the pre-Worlds in Forbes, NSW, Australia in the late nineties, those of us flying the Icaro 2000 Laminars got them just before the meet began after we has been in the country for a while. I had been flying a Moyes Extra Light, king posted glider.
On the first day towing the Laminar I believe I had nine tows, but maybe it was only seven. During those terrible tows I had at least three barrel rolls.
http://ozreport.com/forum/viewtopic.php?t=1143
Death at Tocumwal
*Davis Straub - 2006/01/24 12:27:32 UTC
I'm willing to put the barrel release within a few inches of my hand.
http://ozreport.com/forum/viewtopic.php?t=2266
Nuno Fontes - Hang Gliding Towing Accident.
*Nuno Fontes - 2006/05/27
We were towing on the lee side of some thousand foot mountains. I had flown without problems an hour before.
I got to about a hundred feet and the glider was completely veered to the left due to the strong crosswinds from the right.
What made me hesitate and not release was having the right wing way up and being stalled and very low. I had the feeling I was going to be catapulted backwards if I released and had a clear notion I was going to hit dirt in a tailwind.
The best option seemed to be to resist the lock out and slowly bring the glider down, even if it was crooked, but another problem arose when the observer had the tow line cut when I was down to about fifty feet.
I had no chance. The glider that had been hanging on like a kite dead leafed to the ground. The left leading edge hit first, destroying it along with the nose plates. My body's impact point was the left shoulder and the left side of my head and neck.
I remained unconscious for about twenty minutes with a bloody face from what poured from my nose. The chopper arrived about an hour after the crash. I was already semi-conscious but in a lot of pain and having trouble breathing. I was hauled to Stanford (about half an hour flight time).
The toll: fracture and crushing of the upper humerus, several broken ribs, a lung pierced and collapsed by one of them, and broken C1 vertebra right by the artery. They considered surgery, but the no-surgery risk was lower - they feared a chip would rupture the artery.
http://www.ushpa.org/page/hg-tandem-aerotow-operations.aspx
HG Tandem Aerotow Operations
*Safety Notice - 2006/03/15
Experiences in hang glider tandem flight using aero-tow launch along with analysis of accidents and incidents that have occurred during such flight strongly suggest, for safety reasons, the following cautions be observed.
If the pilot of the tandem glider finds that he/she is too low behind the tug and slow enough that the glider will not climb without pushing out pass trim, then the pilot should pull in and release rather than trying to push out and climb to the tug altitude. Though pushing out to climb to the tug altitude has been a common practice usually accomplished without incident, there is a deep underlying danger in doing this. Should the tandem glider become unattached from the tug during this maneuver, the nose high attitude of the tandem glider attained while doing this will cause a very abrupt stall which will result in a much greater altitude loss than one would expect (possibly more than 750 ft.) The most extreme cases may result in structural failure of the glider.
Towing tandems requires extra awareness on the part of the tug pilots, particularly in the early part of the tow to help the tandem pilot avoid the development of critical situations. Prior to the start of the tow, proper tow speeds based on the gross weight of the tandem glider should be determined. Greater total weight will require correspondingly higher tow speeds. It is CRITICAL to understand that the towed hang glider is at risk when the tow is slow and the glider is low. When towing a tandem glider, the tug pilot should fly the appropriate airspeed to keep the tandem glider in the proper position and if there is any doubt the tug pilot should fly slightly faster and avoid flying slightly slow.. The tug pilot should avoid pulling up abruptly and leaving the tandem glider low. If the glider is low on tow, the tug pilot should attempt to speed up and to descend to the altitude of the towed glider, releasing the tow rope only as a last resort.
These points are crucial to the safety of aerotow tandem flight. However, this letter is addressed to all aerotow rated pilots and tug pilots, not just to tandem pilots. This is because in consulting with pilots about this issue, we found that this problem is exhibited under the same circumstances with solo gliders as well. Because of the lighter wing loading of the solo gliders, the reaction of a solo glider is not as severe, but can still be violent.
To insure that all AT rated tandem pilots are notified, we are asking that the AT-rated tandem pilots sign on to the USHPA web site (http://www.ushga.org) and fill out a form that states that they have read and understand the safety notice. Understand that we are not asking if you agree with the safety notice, but that you have read it and understand what it says. You will need to do this in order to have your tandem rating renewed.
David G. Broyles, Chairman of Safety and Training Committee
Steve Kroop, Chairman of Tow Committee
Paul Voight, Chairman of Tandem Committee
http://www.chgpa.org/forums/viewtopic.php?f=2&t=2467
weak links
Marc Fink - 2007/05/19 12:58:31 UTC
Tad,
The simple fact is that hundreds of thousands of tows using weaklinks in their present configuration successfully bely your contentions that we're all crazy for towing that way.
Simply put, your statements are irresponsible and are based on your personal interpretations.
I am a tow operator--as well as a "towee." I also do aerotow tandems. Using greenline or similar line, which generally tests at 125 lbs +- 50 lbs is widely accepted because it simply works well and relatively predicatably for the enormous range of conditions and applications in towing. If this weren't true, then accident rates would be much higher and these kinds of weaklinks would have been abandoned along time ago.
A 400lb load limit for a solo tow is absurd.
*Jim Rooney - 2007/07/22 22:30:28 UTC
I've heard it a million times before from comp pilots insisting on towing with even doubled up weaklinks (some want no weaklink). I tell them the same thing I'm telling you... suck it up. You're not the only one on the line. I didn't ask to be a test pilot. I can live with your inconvenience.
http://www.hanggliding.org/viewtopic.php?t=5089
The Good-The Bad-The Ugly....
*Socrates Zayas - 2008/01/14 05:22:38 UTC
Finally the radiography proved that she did have fractures but they were acute an to multiple places around the top of the humerus and the head of the humerus...
The nose didn't break although she may have hairline fractures to the septum as well...
her memory was really bad, she had a hard time remembering the date, day, names of her kids, number of kids, and other basic things... I was sacred....
The dolly hit a huge hole, maybe a rabbit hole, gopher, or just a hole-hole... either way it ripped the wheel right off the dolly
http://ozreport.com/12.081
Weaklinks - the HGFA rules
*Davis Straub - 2008/04/22 14:47:00 UTC
Here is the requirement from the 2007 Worlds local rules (which I wrote) for weaklinks:
Competitors must use appropriate aerotow bridles as determined by the Meet Director and Safety Director and their designated officials. Bridles must include secondary releases (as determined by the Safety Director). Bridles must be able to be connected to the tow line within two seconds. The only appropriate bridles can be found here:
http://OzReport.com/9.039#0
and:
http://ozreport.com/9.041#2.
Pilots who have not already had their bridles inspected during the practice days must bring their bridles to the mandatory pilot safety briefing and have them reviewed. Pilots with inappropriate bridles may purchase appropriate bridles from the meet organizer.
Weaklinks
Pilots must use weaklinks provided by the meet organizers and in a manner approved by the meet organizers. All weaklinks will be checked and use of inappropriate weaklinks will require the pilot to go to the end of the launch line to change the weaklink.
Weaklinks will consist of a single loop of Cortland 130 lb Greenspot braided Dacron Tolling line http://www.cortlandline.com/catalog/braid.html and should be placed at one end of a shoulder bridle. The tow forces on the weaklink will be roughly divided in half by this placement. Pilots will be shown how to tie the weaklink so that it more likely breaks at its rating breaking strength.
For many years a number of us (US pilots) have felt that #8 bricklayers nylon line was not an appropriate material to use for weaklinks as it is not as consistent in its breaking strength (as far as we are concerned) as the Greenspot line used in the US. At the 2008 Forbes Flatlands Greenspot for the first time was used as the standard weaklink material (thanks in large part to the efforts of Bobby Bailey). We applaud these efforts to improve the safety of aerotowing by using a better weaklink material.
If the weaklink is at one end of the bridle then there is little to no reason to replace the weaklink after each flight. The weaklink should be replaced if it shows any signs of wear as its strength may be reduced. The weaklink is constructed using "fisherman's knots."
A single loop of weaklink is used at the end of the V-bridle or the end of the pro tow bridle.
Pilots at the 2007 Worlds were not actually required to use the bridles pictures above unless their bridle couldn't be hooked up quickly to the carabineer at the end of the tow rope. They could have a weaklink (four strands) that connected their bridle to the carabineer. They just had to have the loops of the weaklink available to be hooked to by the ground crew. This would obviously require a carabineer at the end of the tow rope, and would leave the weaklink attached to the carabineer after the pilot releases, requiring that it be taken off by the ground crew before hooking up to the next pilot. Of course, a locking carabineer could be used.
It was required that pilots be able to be connected to the tow line quickly both in order to be fair to all pilots and get them in the air in time to compete with each other, as well as to promote safety. It is safer to have a simple uniform release/bridle system that the ground crew is familiar with and can determine if there is a problem. The simpler and more uniform the safer, system wide.
Getting pilots into the air quickly is also safer as it reduces the stress that pilots feel on the ground and keeps them focused on their job which is to launch safely and without hassling the ground crew or themselves. When we look at safety we have to look at the whole system, not just one component of that system. One pilot may feel that one component is unsafe from his point of view and desire a different approach, but accommodating one pilot can reduce the overall safety of the system.
I look forward to any response from the HGFA or other interested persons. Again, I have a direct personal and minor financial interest in the issues raised by this discussion, but no financial interest when it comes to weaklink material.
http://www.hanggliding.org/viewtopic.php?t=6911
Sunday flying at Florida ridge. -
*Socrates Zayas - 2008/05/21 23:53:23 UTC
10:30am Pilot change due to feeding schedule was made, Eric came out to tug me up along the south-west but more south then west. This puts my right over the right side of the hanger and the parking lot. This is a short section of the field but not all that bad as long as you have exit strategy in mind. Good! Because at about 10 seconds into that 1st flight I broke a weak link that I decided I would NOT double anymore after seeing my wife eat it a few months ago; it broke after hitting 800ft/min lift on the LZ!!! hell of a cycle... the TUG and I went up like rockets... but instantly at 200ft wasn't all that bad, I flew that glider into a nice foot landing right by the cars.
2nd try:
This time the wind seemed H & V (heavy and variable), nothing that I haven't been known for flying in, in the past so we decided that this time we would head South-East, but this buts us at an even shorter end of the field. The only thing there is an Orange Orchard and well that's what you have...
So the Tug and I decided that a bit more speed would be beneficial to both of us and we took off... the cycle was nice... nothing out of the ordinary, and just as the TUG flew over the fence line of the Oranges, it happened the link broke, it was as if it didn't even break, I though it was a release, like a slip instead of a break, (so did the pilot later wen we discussed this.) but then AXO and Ralph and I found the release and there she was broken...
I was flying nice, I had good speed due to the fast tug and then my gaining flight, I thought "s--- it broke again, damn, I don't want to land between those trees, they don't even have the kees to the gate anymore" so I coordinated a turn to the right cross wind toward the RVs and camp-fire spot... Unfortunately just to the right of those things are 75-100ft trees, and I was just not seeing the tidal view of the wind as it passed those structures: YOU SHOULD ALL KNOW THIS AS MECHANICAL ROTOR"...
I had speed to fly according to the 5030 it was 30 but not "chicken hawk fly through anything speed" that you all know me for... so the rest is story book!
I got chewed up buy the ROTOR, SHADOW- AND the THERMALS that where being blown down due to the wind velocity....
The Outcome: My left wing was raised to about 80 degrees and I was sent into a right slip, at 50-40ft... now do that math! A U2 has a wingspan of about 38ft? so I had how much time? YEAH.... that is the problem... not enough energy to help me lift the nose and I didn't turn Hulk fast enough to force the glider to level for a belly floop... instead it was as that video but worse cause that dude looked like he locked out... I slipped at 40ft and then cartwheeled...
http://www.chgpa.org/forums/viewtopic.php?f=2&t=3380
Lauren and Paul in Zapata
*Lauren Tjaden - 2008/07/21 14:27:04 UTC
Zapata has delivered as promised, day after day with howling winds and good lift, where flights of over 100 miles (and much more) are possible.
Yesterday I chased Paul again. The tow rope weak link broke when Paul locked out and the weak link he got from Tad did not break. Russell said it was about the worst he has ever had his tail pulled around. Anyhow, I would advise against those weak links, though Tad's barrel releases do seem better able to release under stress. After Russell got a new rope and Paul recovered, he was late leaving and got trapped under some cirrus.
http://groups.yahoo.com/group/skysailingtowing/message/6726
Weaklinks
*Peter Birren - 2008/10/27 23:41:49 UTC
My take is more like what's on http://www.birrendesign.com/towing_B.html
No dolly... foot launched static tow.
You trying to tell me the pilot had time to release? Not a prayer.
I know about this type of accident because it happened to me, breaking 4 ribs and my larynx... and I was aerotowing using a dolly. The sh*t happened so fast there was no room for thought much less action. But I wasn't dragged because the weaklink did its job and broke immediately on impact.
You're focusing on AT but there's a lot more towing going on then at the flat/smooth-ground country club sites. On a crowned country road, off the back of a truck or trailer... ain't a place for a dolly or a threaded bridle of any type.
If your belief is that the weaklink is there mainly to protect the equipment and break before the glider breaks, I suggest you try to break one while being towed. With a 1.4G link, which in my case is about 385 pounds, I may as well not even bother because a slightly worn towline will break at about that tension.
No, you will not be happy with the result of a weaklink breaking should the pilot stumble and the glider impact the ground, but it's still better than being dragged until the tug stops (or in the case of static towing, the vehicle stops and the tension on the towline eases).
Imagine if you will, just coming off the cart and center punching a thermal which takes you instantly straight up while the tug is still on the ground. Know what happens? VERY high towline forces and an over-the-top lockout. You'll have both hands on the basetube pulling it well past your knees but the glider doesn't come down and still the weaklink doesn't break (.8G). So you pull whatever release you have but the one hand still on the basetube isn't enough to hold the nose down and you pop up and over into an unplanned semi-loop. Been there, done that... at maybe 200 feet agl.
Now maybe if I'd pushed out quickly, real quick-like, the weaklink might have broken. That, however, would have possibly also put the tug pilot and plane in jeopardy if it didn't break.
Scenario: at a static tow site, driver takes his eyes off the gauge to watch the pilot in the rear view mirror. When he looks back, the gauge is reading zero, so he steps on the gas... but the needle had gone all the way around to about 350 lbs and here he was giving more tension. Pilot stuff the bar 'cuz to let go as low as he was would be riskier. Pilot rode it out until the .8G weaklink broke, holding the bar to his knees and riding it "over the top" to safe, level flight. (shoulda seen the pilot's eyes... big as the proverbial saucers.)
So if the 914 can only pull .5G, then why in Heaven's name do you need a 1.4G weaklink?
Nice that you've got a good place to aerotow with good dollies and all, but your "strong link" will have brought more hurt onto the pilot who crashed because it won't break soon enough. As for my incidents and evidence, the above stories should be enough but, if not, I can provide several others where the main thing proved (to me and others on-site) is that a less-than-1G weaklink is MUCH better than a strong link.
http://www.chgpa.org/forums/viewtopic.php?f=2&t=3600
Weak link question
Danny Brotto - 2008/11/04 12:49:44 UTC
I came out of the cart rolled and yawed to the right with the upwind wing flying and the downwind wing stalled. It was rather dramatic. If I had released or if the weak link had broken, the downwind wing would have further stalled and I would have cartwheeled into terra firma in an unpleasant fashion. I held on tight gaining airspeed until the downwind wing began flying, got in behind the tug, and continued the flight.
Sunny later told be he was about to give me the rope and I thanked him to no end that he didn't.
Brian Vant-Hull - 2008/11/13 19:18:04 UTC
Yes, it will take something else. But the approach you always slide into is not it. I think Matthew pointed out what needed to be done. But if you write articles nobody will listen unless you write with some humility.
Jim Rooney - 2008/11/20 22:25:38 UTC
Something to bear in mind... the tug's weaklink is three strand.
For clarity... A normal single loop weaklink would be considered two. A tandem double loop is considered four.
In the tandem setup, the "weaklink" in the system is at the tug end, not the glider.
Ya'll seem to be missing this.
Once you go beyond three strand... you're not using a weaklink. If the weaklink goes, you're getting the rope.
Paul found this out the hard way in Texas.
Theory's wonderful and all, but reality is not forgiving.
Ask yourself... are you willing to bet your life on your theory?
Dress accordingly.
Jim Rooney - 2008/11/22 22:31:35 UTC
Nail on the head Brian!
The simple fact is this. The only reason anyone even gives Tad the time of day is that they want to believe him. Why? Because they don't like to be inconvenienced by a weaklink break. That's it.
Sure, everyone digs around for other reasons to believe, but at the heart of it, it's convenience.
No one is actually scared to fly with a standard weaklink. They may say they are, but deep down inside, they're not. BTW, this weaklink as a lifeline comment... any tow pilot that takes you over something you can't get out from should be shot. It is one of the cardinal rules of towing. Again, "I wana believe" rationalization.
Tad loves to speak of himself as a scientifically minded person. Yet he ignores a data pool that is at minimum three orders of magnitude higher than his. It is thus that I ignore him.
Jim Rooney - 2008/11/24 05:18:15 UTC
Well, I'm assuming there was some guff about the tug pilot's right of refusal?
Gee, didn't think we'd have to delve into "pilot in command"... I figured that one's pretty well understood in a flying community.
It's quite simple.
The tug is a certified aircraft... the glider is an unpowered ultralight vehicle. The tug pilot is the pilot in command. You are a passenger. You have the same rights and responsibilities as a skydiver.
It's a bitter pill I'm sure, but there you have it.
BTW, if you think I'm just spouting theory here, I've personally refused to tow a flight park owner over this very issue. I didn't want to clash, but I wasn't towing him. Yup, he wanted to tow with a doubled up weaklink. He eventually towed (behind me) with a single and sorry to disappoint any drama mongers, we're still friends. And lone gun crazy Rooney? Ten other tow pilots turned him down that day for the same reason.
*Jim Rooney - 2008/11/24 20:34:53 UTC
Something else occurred to me...
There seems to be the impression that I think that because I fly so much, that I "can handle more". In fact, you have the impression that I'm so comfortable with this notion, that hell, I'll take someone else along.
Not at all.
I can handle less tandem. I have less safety devices tandem... in addition to a lesser weaklink setup (read stronger glider link) the tandem parachute is slower to deploy (must be used higher) and I have more weight to throw around (solo gliders are more easily maneuvered). I also have a passenger, and who knows if they're going to start grabbing sh*t? The deck is stacked higher against me tandem.
What I have is the understanding that I can't fly in the same crap that I could solo.... because my margins are lower. I have a familiarity that allows me to know when to STOP FLYING... which is always WAY sooner than I would solo. That's what flying every day with the same people and equipment does for me.
http://www.chgpa.org/forums/viewtopic.php?f=2&t=3648
Oh no! more on weak links
*Carlos Weill - 2008/11/30 19:24:09 UTC
Incident 1
On June of 2008 during a fast tow, I noticed I was getting out of alignment, but I was able to come back to it. The second time it happen I saw the tug line 45 deg off to the left and was not able to align the glider again I tried to release but my body was off centered and could not reach the release. I kept trying and was close to 90 deg. All these happen very quickly, as anyone that has experienced a lock out would tell you. I heard a snap, and then just like the sound of a WWII plane just shut down hurdling to the ground, only the ball of fire was missing. The tug weak link broke off at 1000ft, in less than a second the glider was at 500ft. At that point I realized I had the rope, so I drop it in the parking lot.
Mistake #1 Did not stay behind the tug
Mistake #2 Did not release earlier
Mistake #3 Did not use the secondary
Incident 2
As a background, after release I wrap the bridle on my hand to stow it away. The bridle is the 3-point brake release in the hangloop carabiner. More than 18months ago 2007, under during a turn when tow forces were too strong, my weak link broke. But bridle was still attached to the tug because the bridle was coiled and had wrapped itself around the carabiner. However I had left the weak link intended for pro-tow on the harness and it broke. This happened in no more than 2 seconds.
Since then I when I set-up I make sure the bridle has no twists and still keep the pro-tow weak link.
I welcome any face-to-face questions or comments on these incidents. Anyone who wants recommendations for their towing or training, you have a great pool of knowledge in the tow parks especially from the ones that do it regularly and have the experience in the tug and behind the tug.
http://ozreport.com/forum/viewtopic.php?t=15716
weak links
*Martin Henry - 2009/04/26 16:23:56 UTC
The reason I thought I would post is, well your very caught up in your end of the towline you seemed to be in a bit of a battle with the guy (or gal?) on the other end of the line. I have absolutely no challenge to your 1.4 mass weak link (Mainly because there is only so much time I can dedicate to string...) but... If the guy on the front end of the line does not like it, then I think you should respect their side of the argument?
Trike Tug pilots (most), Bailey Tugs with the smaller two strokes or anything that is simply underpowered have a pretty small margin of safety when it comes to the towing envelope. It's a complicated balance. I've heard the expression, "it's like flying two aircraft at once". Getting your tail hauled up, down, left and right buy less then cooperative customer can be down right nerve wracking. If your tug pilot wants you on a "weak" link, you should respect his wishes. If you don't like it, find a tug pilot that can handle the challenge. If he's a lousy tug pilot, he will sooner or later be out of business, If he's good, pilots will line up to be towed. My point there are two aircraft involved. If your being towed up by a big 914T your tug pilot might be able to muscle his way out of a problem, but if he's driving a wheeze two stroke he simply may not have the power to put up with much trouble caused by a strong weak link.
For a sad example of what can happen to a tug when things go wrong...
In Washington State a few years back a Sailplane operation had Tug go down. During the roll, the Spoilers "popped" open on the two seater sailplane (with student at the controls). The Tug pilot sensed a problem as the tow progressed... things where simply not happening as they should. He glanced back and saw the spoilers open. He should have given the glider the rope. He didn't, he powered hard into the tow and got on the radio and screamed at the student to get his spoilers closed. There was plenty of energy building and the student realized his error and slammed the spoilers shut. The glider, now with speed, ballooned rapidly and the student did not react fast enough to compensate, shooting way too high. The high tow position, Tug at full power (trying to power his way out of the problem) the glider was pitching the tug down. The rope/weak link failed. The Tug still low to the ground at full power, close to stall, nose down, drove straight into the rough ground off the end of the runway and the Tug pilot was killed.
Flying a Tug with a heavy customer at the end of the towline is a ballet dance with a fat lady, you have to do it right or somebody could get killed.
http://groups.yahoo.com/group/skysailingtowing/message/7066
AT SOPs - proposed revisions
*Peter Birren - 2009/05/10 01:33:57 UTC
If you want a truly foolproof release, it's got to be one that eliminates the pilot from the equation with a release that operates automatically.
http://groups.yahoo.com/group/skysailingtowing/message/7230
Towing question
*Martin Henry - 2009/06/26 06:06:59 UTC
PS... you got to be careful mentioning weak link strengths around the forum, it can spark a civil war
http://www.hanggliding.org/viewtopic.php?t=11497
Aerotow release options?
*Jack Axaopoulos - 2009/07/04 12:13:01 UTC
Bullshit.
a) only the pilot can let the angle of attack increase when you lose tension. Thats 100% on the pilot. You are simply wrong and misleading again.
b) "And if your angle of attack was way too high to begin with..." Which should never be the case or youre making a pilot error. Again, you are misleading people.
This is the problem I have with you. You attempt to fallaciously attribute pilot errors to issues of mechanical towing devices or other things.
Sorry... but if you suddenly lose power, your nose just doesnt pop
http://www.hanggliding.org/viewtopic.php?t=14230
pro tow set-up
*Ryan Voight - 2009/11/03 05:24:31 UTC
It works best in a lockout situation... if you're banked away from the tug and have the bar back by your belly button... let it out. Glider will pitch up, break weaklink, and you fly away.
During a "normal" tow you could always turn away from the tug and push out to break the weaklink... but why would you?
Have you never pondered what you would do in a situation where you CAN'T LET GO to release? I'd purposefully break the weaklink, as described above. Instant hands free release
http://ozreport.com/13.238
Adam Parer on his tuck and tumble
*Adam Parer - 2009/11/25
Due to the rough conditions weak links were breaking just about every other tow and the two tugs worked hard to eventually get everyone off the ground successfully.
http://www.paraglidingforum.com/viewtopic.php?t=28697
Weak links why do we use them. in paragliding.
*Forum Moderators - 2010/02/24 22:02:46 UTC
Tad Eareckson
We, the Moderators, feel that weak links are an important topic. In our view Tad Eareckson's posts have discouraged others from taking part in this discussion, so, after several warnings, he has been banned. His most recent post, after this topic was locked, is here. We are happy to lift the ban if we come to the view that Tad has further positive contributions to make - please contact us by PM or by email if you feel that this is the case.
http://www.hanggliding.org/viewtopic.php?t=18777
Accident - Broken Jaw - Full Face HG Helmet
http://groups.yahoo.com/group/TTTFlymail/message/11545Keith Skiles - 2010/08/28 05:20:01 UTC
Last year, at LMFP I saw an incident in aerotow that resulted in a very significant impact with the ground on the chest and face. Resulted in a jaw broken in several places and IIRC some tears in the shoulder.
Cart stuck incidents
*Keith Skiles - 2011/06/02 19:50:13 UTC
I witnessed the one at Lookout. It was pretty ugly. Low angle of attack, too much speed and flew off the cart like a rocket until the weak link broke, she stalled and it turned back towards the ground.
http://www.hanggliding.org/viewtopic.php?t=18868
Almost lockout
*Ryan Voight - 2010/09/07 02:50:00 UTC
Weak link in truck towing WILL (read: should) still break in a lockout situation... but as everyone has already pointed out, it takes a lot longer because the glider can continue to pull line off the winch.
There is a limit to how fast line can come off the winch though... so the forces still build up, and the weaklink still fails.
http://www.youtube.com/watch?v=r1LbRj-NN9U
Mitch teaches weak link break strategy
*Mitch Shipley - 2011/03/20
So... The angle of attack on tow is angle between the force, the glider, and the wind. All that stuff.
If you take this away that angle goes from there to now there and the... You're stalled. You're stalled.
http://www.chgpa.org/forums/viewtopic.php?f=2&t=4931
Zapata
*Pete Lehmann - 2011/06/24
Blood on the Tracks
And then there's my weak link break. I had been looking forward to attempting an unusual eighty mile flight to the south east along the Mexican border towards McAllen. But the instant I came off the cart my weak link broke. That shouldn't have been a problem as I had good speed to transition to a landing. However, I had zipped up my harness a bit too far and couldn't unzip it in the seconds available to me.
Still in my harness, I opted to belly land on the runway. Unfortunately the repaved runway has an extraordinarily coarse texture, that of a heavy grit sand paper, which resulted in my harness and knee being shredded. The harness can be fixed with Shoe Goo, but the knee required three stitches to pull together the resulting mess. The doctor who treated me at the clinic was sufficiently impressed by it to take some pictures for his colleagues. I was extraordinarily lucky, and can walk well and should be flying in a couple of days.
http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?
Jim Rooney - 2011/08/26 02:44:10 UTC
See, in truck towing, a weaklink does next to nothing for you (unless the line snags).
This is because you're on a pressure regulated system... so the forces never get high enough to break the link.
This is not the case with an aerotow.
This is why the weaklink exists.
The forces of an aerotow can get high enough to tear the wings off the glider.
This is no exaggeration... it can be done.
Marc Fink - 2011/08/28 21:11:09 UTC
I once locked out on an early laminarST aerotowing. went past vertical and past 45 degrees to the line of pull-- and the load forces were increasing dramatically. The weaklink blew and the glider stalled--needed every bit of the 250 ft agl to speed up and pull out. I'm alive because I didn't use a stronger one.
So how about wheels and single hang straps (seeing how we've exhumed the dead horses)?
Jim Rooney - 2011/09/02 19:41:27 UTC
Yes, go read that incident report.
Please note that the weaklink *saved* her ass. She still piled into the earth despite the weaklink helping her... for the same reason it had to help... lack of towing ability. She sat on the cart, like so many people insist on doing, and took to the air at Mach 5.
That never goes well.
Yet people insist on doing it.
---
(Keith Skiles - 2010/08/28 05:20:01 UTC-2011/06/02 19:50:13 UTC)
Davis Straub - 2011/09/03 01:39:55 UTC
I think that I know the one that is being referred to.
The problem was an inexperienced female student put on a cart that had the keel cradle way too high, so she was pinned to the cart. The folks working at Lookout who helped her were incompetent.
*Cragin Shelton - 2011/09/03 23:57:33 UTC
Nice Reference CitationDo you REALLY think that there has been no progress in knowledge about the practical applied physics and engineering of hang gliding in 37 years? OR that an early, 3+ decade old, information book written by a non-pilot is a solid reference when you have multiple high experience current instructors involved in the discussion?Manned Kiting
The Basic Handbook of Tow Launched Hang Gliding
Daniel F. Poynter
1974
"A bad flyer won't hurt a pin man but a bad pin man can kill a flyer." - Bill Bennett
"The greatest dangers are a rope break or a premature release." - Richard Johnson
http://www.ushawks.org/forum/viewtopic.php?f=2&t=818
Peter (Linknife) Birren
Peter Birren - 2011/11/27 02:13:08 UTC
No, I'm not going to comment on Arlan's accident and you really ought to quit as well because neither you nor I were there. The difference is that you have no trouble talking out your ass about that which you know nothing about. I could, however, speculate on several scenarios from having spoken at great length with the tug pilot and eyewitnesses. How many of those at the site did you speak with?
Tad Eareckson - 2011/11/27 04:47:34 UTC1. And yet ANOTHER never fails indicator that you're dealing with someone with a brain half the size of a walnut.No, I'm not going to comment on Arlan's accident and you really ought to quit as well because neither you nor I were there.
"If you weren't looking up through a telescope while the Columbia broke and burned up during reentry you couldn't POSSIBLY have any idea what went wrong and why."
2. ARLAN didn't have an ACCIDENT. Arlan ran a dangerous operation using dangerous equipment out of compliance with USHGA/FAA regulations and got his student killed in the course of a NOTHING, ROUTINE, tandem training flight. The fact that he got killed too was incidental to the real tragedy.Yeah dickhead? Then why don't you start telling me what I've got wrong, disgrace me in front of my cult members, and start bringing them back to The True Path of USHGA Righteousness?The difference is that you have no trouble talking out your ass about that which you know nothing about.Why bother? You weren't there so getting eyewitness accounts could serve no possible purpose in enhancing your understanding of the situation.I could, however, speculate on several scenarios from having spoken at great length with the tug pilot and eyewitnesses.1. Those at the site at the time? NONE.How many of those at the site did you speak with?
2. So how did what they told you off the record differ from what they put in print?
3. In other words, when were they telling the truth and when were they lying?
4. What were their reasons for lying and/or suppressing accurate information about the crash?
5. What are your reasons for not having publicized your conclusions about why this double killing took place? Did the eyewitnesses swear you to secrecy before whispering their true accounts? Or does USHGA recall your Safety Award if you don't go along with the whitewashes and coverups?
6. Ya wanna start by explaining why the front end weak link blew before the glider's - when neither aircraft was in immediate danger - when the Standard Operating Procedures state that it should be a hundred pounds over?
P.S. Bob, you wanna help him out a bit here? Tell that he should just ignore the questions to which the answers will be inconvenient? Show him how to break through walls to extract himself from the corners he's painted himself into? I'm certain he'll be eternally grateful.
Bob Kuczewski - 2011/11/27 14:49:31 UTC
Peter, I do think you should pretty much ignore Tad at this point. Tad doesn't really want to make progress in this sport. If he did, then he'd be doing what I've suggested above. Furthermore, I believe Tad is motivated more by some sort of twisted revenge than by any desire to actually improve the sport. So you cannot have a calm and rational discussion with him if you're one of his chosen targets for that revenge. Additionally, Tad has far more free time on his hands than any of us, so we're all at a disadvantage when trying to debate him ... whether we're right or wrong. Tad's single-minded pursuit of revenge combined with his abundance of free time may end up being the downfall of the US Hawks forum if we don't figure out a way to deal with it. I'm open to suggestions.
*Warren Narron - 2011/11/27 16:52:45 UTC
I've already said that Peter doesn't need any encouragement to ignore uncomfortable questioning. Peter Birren came on to this site 'swinging a big club' using vulgar language in an arrogant mannor. I didn't see him being called down or people being advised to ignore him.
Now that Birren has argued his way into a corner, he is given a free pass to skip merrily down the road past the very bodies he can now refuse to talk about?
Let Peter Birren, answer the questions.
He came here looking for a fight, let him fight.
If he knows something in contrast to the politically expedient story that we have heard, then he needs to say it. Come out of the box Peter, and answer the questions.
http://ozreport.com/forum/viewtopic.php?t=26134
Whipstall almost tumble
*Mike Bomstad - 2011/12/26 08:33:15 UTC
Well, how about a weak link...
Blue Sky Scooter Towing Method
*Steve Wendt - 2012/03
But with the towline we use a standard weak link like we would for aerotow... Uh... This... In this particular case it's 130 greenline, 130 pound test.
...
When I'm operating the scooter, people a lot of times ask me how much tension is on the line. My answer is, I don't know. I don't think we NEED to know. We don't need to be looking at a gauge if my gauge is right in front of me. It's my student. If my student is too high off the ground, there's too much line tension. I have to reduce the power.
And I never cut the power, it's always reduced gradually, increase the power gradually.
http://www.hanggliding.org/viewtopic.php?t=25536
Whoops! Snapped another tip wand :-O
NMERider - 2012/03/14 15:17:14 UTC
Jim Rooney threw a big tantrum and stopped posting here.
His one-technique-fits-all attitude espoused on the Oz Report Forum has become tiresome to read. It does not work in the fucked-up world of XC landings and weary pilots.
*Christopher LeFay - 2012/03/15 05:57:43 UTC
January's canonization of Rooney as the Patron Saint of Landing was maddening. He offered just what people wanted to hear: there is an ultimate, definitive answer to your landing problems, presented with absolute authority. Judgment problems? His answer is to remove judgment from the process - doggedly stripping out critical differences in gliders, loading, pilot, and conditions. This was just what people wanted - to be told a simple answer. In thanks, they deified him, carving his every utterance in Wiki-stone.
http://www.kitestrings.org/post2230.html#p2230
*HIGHER EDUCATION - 2012/06
TIE A (BETTER) WEAK LINK
by Drs. Lisa Colletti and Tracy Tillman
TRACY: Unlike the FAA's relatively clear-cut legal rules, the practical aspects of weak link technology and application are not so clear-cut. For some people, talking about weak links is more like talking about religion, politics, or global warming--they can get very emotional about it and have difficulty discussing it logically, rationally, or with civility.
LISA: So let's try to talk about it rationally, logically, and practically here.
TRACY: Based on several decades of experience and hundreds of thousands of tows conducted by numerous aerotow operators across the county, the de facto standard has become use of a 260 lb. weak link made as a loop of 130 lb. green spot IGFA [ref 12] Dacron braided fishing line attached to one end of the pilot's V-bridle. It is a de facto standard, because it works for most pilots and gliders and is usually near the USHPA recommendation of a nominal 1G weak link for most pilots. For example, a mid-size Sport 2 155 with a pilot who has a hook-in weight that is in the middle of the recommended weight range will weigh about 260 lbs., so a loop of 130 lb. line is just right. This strength of line also meets FAA requirements for most sizes of gliders and weights of hang glider pilots. Lighter green spot line is available for very light pilots, and heavier line is also available for heavier pilots, tandems, and the tug.
TRACY: Historically, a 520 lb. double loop of 130 lb. green spot line has been the de facto standard for weak link used on the V-bridle for both the tandem and the tug. Technically, this can be legal if the V-bridle on the tug is longer and has a more acute angle than the V-bridle on the glider, which results in a vector angle that effectively makes the weak link on the tug act slightly stronger than the weak link on the glider. There has been a trend lately for some tandem operators to go with about a 400 lb. weak link on both the tandem glider and tug V-bridles, rather than 520 lbs., to help protect the equipment from large stresses. If tandem operators think that, practically, a 520 lb. double loop weak link is too much for a tandem, it is way too much for a solo pilot.
Solo hang glider pilots should not place a 520 lb. double loop weak link on their V-bridle, unless they get specific approval from the tow operator. It could be hard on the equipment and could be illegal if the tug is using a weaker weak link. It is also far beyond USHPA's nominal 1g recommendation.
LISA: You and I have flown sailplanes for almost as long as we have flown hang gliders. We own two sailplanes and have two airplanes that we use for towing full-size sailplanes. In all the time that we have flown and towed sailplanes, we have not experienced or even seen a sailplane weak link break.
LISA: It's not that it doesn't happen, but it is a rare occurrence. Russell Brown, a founder of Quest Air in Florida and a well-known Dragonfly tug pilot, is also a sailplane pilot, tug pilot, and A&P mechanic for a large commercial sailplane towing operation in Florida. He told us that, like us, he has never seen a sailplane weak link break, either. Russell owned the first 914-powered Dragonfly ever made--he helped us build the second one, which we still fly. He is the one who, many years ago, showed us the method for making a WT weak link and suggested we use polypropylene rather than Spectra for hang glider V-bridles.
TRACY: Dr. Lionel D. Hewitt, professor of physics and developer of the 2-to-1 center-of-mass Skyting bridle for surface towing, is well respected for his knowledge of towing, bridles, and weak links [ref 4]. His position on weak link strength for aerotowing of hang gliders seems to be consistent with ours. He has acknowledged that we especially need to avoid inadvertent weak link breaks while aerotowing, because much of aerotowing takes place over unlandable terrain. That, along with recognizing that towing pressures vary considerably while on aerotow, has led him to suggest the use of a weak link that breaks in the neighborhood of 1.5G of towline pressure [ref 16]. This is near to what actually results when a USHPA-recommended nominal 1G weak link is placed at the top end of a V-bridle used for aerotowing.
LISA: Actually, that is our expectation of performance for weak links on hang gliders here at Cloud 9, too. Primarily, we want the weak link to fail as needed to protect the equipment, and not fail inadvertently or inconsistently. We want our weak links to break as early as possible in lockout situations, but be strong and reliable enough to avoid frequent weak link breaks from turbulence. It is the same expectation of performance that we have for the weak links we use for towing sailplanes.
LISA: Without shock absorption, a Spectra bridle acts somewhat like an impact wrench on the weak link.
LISA: Finally, everyone should know that thorough aerotow training and currency results in a more proficient aerotow pilot who can tow more smoothly and can stay more precisely in the center of the cone of safety [ref 18]. When hang glider pilots can fly their gliders on tow as smoothly as a sailplane flies on tow, it is less likely that they will experience an inadvertent weak link break. Is that it for this article?
TRACY: We could get into details of lab testing weak links and bridles, but this article is already getting long. That would be a good topic for an article in the future. Besides, with our backgrounds in formal research, you and I both know that lab tests may produce results with good internal validity, but are often weak in regard to external validity--meaning lab conditions cannot completely include all the factors and variability that exists in the big, real world.
What we have covered in this article is practical information and knowledge gleaned from the real world of aerotowing, developed over decades and hundreds of thousands of tows by experts in the field. This information has practical external validity. Hopefully, someone will develop methods and technology that work better than what we are using as standard practice today. Like the methods and technology used today, it is unlikely that the new technology will be dictated onto us as a de jure standard. Rather, to become a de facto standard, that new technology will need to be made available in the marketplace, proven in the real world, and then embraced by our sport.
---
This article was peer-reviewed and approved for publication by the USHPA Towing Committee.
http://www.hanggliding.org/viewtopic.php?t=27393
Pro towing: 1 barrel release + weak link or 2 barrel release
*Juan Saa - 2012/10/18 01:19:49 UTC
Boca Raton
The normal braking force in pounds for a weak link is around 180, at least that is the regular weak link line used at most aerotow operations. By adding a second weak link to your bridal you are cutting the load on each link by half, meaning that the weak link will not break at the intended 180 pounds but it will need about 360.
If that is what you use and is what your instructor approved then I have no business on interfering, i dont know if you are using the same weak link material but there shoul be only ONE weak link on a tow bridle for it to be effective in breaking before higher loads are put into you and the glider should the glider gets to an attitude or off track so much that the safety fuse of the link is needed to break you free from the tug.
I made the same mistake on putting two weak links thinking that I was adding protection to my setup and I was corrected by two instructors on separate occacions at Quest Air and at the Florida RIdge.
http://ozreport.com/forum/viewtopic.php?t=30971
Zach Marzec
Paul Tjaden - 2013/02/07 23:47:58 UTC
When the lift/turbulence was encountered, the weak link on the tow line broke as the nose of the glider pitched up quickly to a very high angle of attack. Apparently, the glider stalled or possibly did a short tail slide and then stalled and then nosed down and tumbled. Eye witnesses said the glider tumbled twice and then struck the ground with the base tube low. Due to the extremely low altitude, there was no time for the pilot to deploy his reserve parachute.
Zach was conscious immediately after the accident but died in route to the hospital.
Beyond these facts anything else would be pure speculation. I have personally had numerous weak link breaks on tow, both low and high, after hitting turbulence and have never felt in danger of a tumble. I have witnessed countless others have weak link breaks with no serious problems. We train aero tow pilots how to handle this situation and I am certain that Zach had also encountered this situation many times before and knew how to react properly. Apparently, Zach simply hit strong low level turbulence, probably a dust devil that could not be seen due to the lack of dust in Florida, the nose went too high and he tumbled at a very low altitude.
Strong dust devils in Florida definitely do exist even though they are rare. My wife had a near miss when she encountered a severe dusty a couple years ago and I almost lost a brand new $18,000 ATOS VX when it was torn from its tie down and thrown upside down.
I wish I could shed more light on this accident but I am afraid this is all we know and probably will know. Zach was a great guy with an incredible outlook and zest for life. He will be sorely missed.
Mark Frutiger - 2013/02/08 19:12:21 UTC
Zack hit the lift a few seconds after I did. He was high and to the right of the tug and was out of my mirror when the weak ling broke. The load on the tug was not excessive as with a lockout, but I was not surprised when the weak link broke. I was still in the thermal when I caught sight of Zack again. I did not see the entry to the tumble, but I did see two revolutions of a forward tumble before kicking the tug around to land. The thermal was still active in the area that I had just launched from so I did a go round and landed on a runway 90 degrees cross to the direction we were towing in.
I would be more than happy to answer any questions pertaining to what I saw and experienced, but I prefer not to engage in speculation at this point.
*Jim Gaar - 2013/02/13 17:57:05 UTC
Former Flight Park Manager
Because it has the best known and accountable safety record (in my personal books anyway).
http://ozreport.com/forum/viewtopic.php?t=31052
Poll on weaklinks
Jim Rooney - 2013/03/04 19:31:36 UTC
We all play by the same rules, or we don't play.
...
The law of the land at comps was 130lb greenspot or you don't tow. Seriously. It was announced before the comp that this would be the policy. Some guys went and made their case to the safety committee and were shut down. So yeah, sorry... suck it up.
Jim Rooney - 2013/03/05 21:40:02 UTC
I'm not saying that you've claimed that a stronger weaklink allows for a greater AOA... I'm telling you that it does.
You know this.
I'll spell it out anyway...
Increases in AOA increase the load factor... push it beyond what the weaklink can stand and *POP*, you're off tow.
Increase the load factor that the weaklink can withstand and you increase the achievable AOA.
This ain't truck towing. There is no pressure limiting mechanism. Push out and you load the line. Push out hard and you'll break the weaklink... that's the whole idea.
You want to break off the towline? Push out... push out hard... it will break.
As others have pointed out, they've used this fact intentionally to get off tow. It works.
You want MORE.
I want you to have less.
This is the fundamental disagreement.
You're afraid of breaking off with a high AOA? Good... tow with a WEAKER weaklink... you won't be able to achieve a high AOA. Problem solved.
I'm sorry that you don't like that the tug pilot has the last word... but tough titties.
Don't like it?
Don't ask me to tow you.
Go troll somewhere else buddy.
I'm over this.
*Jim Rooney - 2013/03/07 06:40:02 UTC
So... if it's *only* purpose is to prevent your glider from breaking apart... which is complete and utter bullshit... but if that was it's only purpose... why then do we have them at all?
Your glider will tear the rope apart before it breaks.
It will tear the towmast off the tug before it breaks.
Your glider is capable of amazing feats of strength... it is in no danger of folding up on you.
http://www.ushawks.org/forum/viewtopic.php?f=2&t=1563
Platform Launching (PL) Draft suggestions needed
*Bob Kuczewski - 2014/06/06 17:50:48 UTC
As another suggestion, I think the notions of balance and pilot choice should be introduced at some point. The curve of injuries as a function of weak link strength probably looks something like this:
That means there's danger on either end ... and even at the lowest (best) possible point!!
However, the shape of that curve for any particular pilot is based on their choice of equipment, conditions, and their own pilot skill. A pilot with good skills at recovering from weak link breaks (as Bill mentioned above) will be operating with a curve that's much lower (less chance of injury) on the left side than a pilot with poor skills at recovering from weak link breaks. Similarly, a pilot using a good quality release will be operating with a curve that's lower on the right side than a pilot using a poor release.
In the end, I think the best weak link strength will be based on the combination of equipment, conditions, and pilot skill. So one of the goals of this chapter should be to show the full range of those issues so the individual pilot can be educated as to how to weigh them in making their own choice of weak link strength. It's important to remember that the safest weak link strength may differ between two pilots even if they have the same weight, equipment, and conditions. Their skills matter, and I think that is very well said in Bill's post.
Great topic and discussions Bill, Sam, Mike, and Charlie!!!
http://www.chgpa.org/forums/viewtopic.php?f=2&t=6326
An OK Day at Ridgely
*Matthew Graham - 2014/06/09 01:51:11 UTC
It was pretty quiet at Ridgely when we arrived at noon. Brian VH and Felix were there-- and Sammy (sp) and Bertrand... and Soraya Rios from the ECC. She was not flying.
Felix test flew Bertrand's T2C for about an hour and loved it. Brian had a short flight on a Falcon. I got on the flight line at a little after 1pm behind Sammi. She had a sledder. Then the tandem glider called rank and went ahead of me. The tandem broke a weak link and it took a while to sort out a new weak link. I finally towed around 1:30 and also broke a link at 450'. Back to the end of the line. Actually, my wife Karen let my cut in front of her. Bertrand and Sammi towed again. Each having sledder. The cirrus had moved in and things did not look good. Again I arrived at the front of the line only to have the tandem call dibs. And then the tug needed gas. I thought I would never get into the air...
http://www.hanggliding.org/viewtopic.php?t=31747
Lockout
*Davis Straub - 2014/09/01 15:22:41 UTC
I can tell you that I fly with a 200lb weaklink on one side of my 750lb pro tow bridle. I am happy with it.
http://www.chgpa.org/forums/viewtopic.php?f=2&t=6833
Highland Saturday 31th
John Middleton - 2015/11/01 15:15:56 UTC
On my first tow the weak link broke at 1000 and I tried to survive but only extended for a couple of minutes before landing.
(Final day of 2015 Highland Aerosports flight ops. Well done, guys. See ya next spring.)Knut Ryerson - 2015/11/01 21:29:32 UTC
Yes. nice day at Highland on Saturday. Arrived for once early, 10 a.m. and was towed up at 1:09 PM and flew for 52 minutes. Reached 3269 feet and bounced around there in broken up lift. Got cold and bored and branched out SW to find more lift. Fiinally was forced to land, though was cold. Never felt good on the tow, but must have done something right during the flight it self, because I were able to stay up. Did not have a strong landing too and bent a down tube
*
http://www.myrepublica.com/news/9714
My Republica - Seti flashflood alert pilot dies in Ultralight crash
*Santosh Pokharel - 2016/11/23 20:20
POKHARA, Nov 23: Russian pilot Alexandr Maximov, who had helped minimize considerable damages by timely alerting the locals about massive incoming flash flood in Seti River nearly four years ago, died in an unfortunate ultra-light aircraft crash in Pokhara on Wednesday morning. He was 62.
The ultra-light aircraft he was piloting lost its balance shortly after it took off and crashed near the runway. Police and sources at the Avia Club in Pokhara, where he worked as senior pilot and trainer, informed that he breathed his last while undergoing treatment at a local hospital.
A Canadian woman, Jilleni Volker, who was traveling in the ill-fated aircraft with the call sign 9N-ALL, was injured in the accident that took place at the club's own Lauruk-based airfield in Kaski district. She sustained severe injuries in the crash and is currently undergoing treatment at a Pokhara-based hospital, according to the police.
"Preliminary investigation shows that the ultra-light aircraft lost its balance and crashed after a rope tied to a hang-glider snapped while being pulled by the aircraft,” informed Inspector Mohanmani Adhikari of Baidam Police Post, adding that massive amount of blood loss due to head injury ultimately led to the death of the pilot.
Having over 5,000 hours of flight experience in Pokhara, Maximov was considered an experienced pilot who had been flying the ultra-light aircraft in Nepal for the past 14 years.
He was also the first to fly "Danphe", an ultra-light aircraft engineered by a team of Nepali youths for the first time in the country.
Maximov has a huge contribution in producing quality Nepali pilots. "His untimely death is an irreparable loss to all of us," said Santa Lamichhane, a pilot working at the Avia Club.
"He was an excellent mentor and a very good person. We have lost our main instructor and an awesome colleague."
http://airtribune.com/2019-big-spring-nationals/info/details__info
http://airtribune-production.s3.amazonaws.com/media/contest/files/2019/07/GTxd6mT4AIn8.pdf
*2019 Big Spring Nationals - 2019/07
Weaklinks of 140 and 200 pounds will be available and provided by the organizers. Weaklinks provided by the organizers must be used by the competitors.
http://ozreport.com/forum/viewtopic.php?t=60556
My launch on Tuesday
*Mick Howard - 2019/08/21 16:24:23 UTC
Setting the appropriate angle of attack reduces the likelihood of popping up above the tow plane on take-off This is the other extreme often seen when pilots hold their weight back (pushed out) as they leave the cart. This is a concern to tow pilots who have to maintain control close to the ground while the tail is being picked up and is a concern when pilots pop up high and break the weak link, then stall and crash because of the high angle of attack and immediate loss of airspeed.