Towing Aloft

[Tad Eareckson]

A weak link is the focal point of a safe towing system.

And thus, obviously, the focal point of this entire stupid book.

http://www.hanggliding.org/viewtopic.php?t=11497
Aerotow release options?

Adi Branch - 2009/07/02 12:50:02 UTC

I have to chirp in on this.. I know I'm a noob and all that, but Tad seems to be talking sense to me. From what I can gather the US has some quite different (dated?) ways of doing things which it appears are not used here in the UK, and some of the reasons I've heard cited for not using these methods relate directly to accidents in the US.

For instance, the idea of tying your own weak link is absolute nuts to me, as is using a bit of string for the job! Over here it's aluminium only (sailplane style link) and if I turned up with a bit of tied string, I'd be shown the exit road.

And not one single solitary reference to Tost weak links in the entire stupid book. Only bits of tied string and volumes about how to tie, test, not drag, and replace them, select them for lockout protection, and...

I witnessed a tug pilot descend low over trees. His towline hit the trees and caught. His weak link broke but the bridle whipped around the towline and held it fast. The pilot was saved by the fact that the towline broke!

...configure them in violation of USHGA towing regulations so they don't work when you actually need them to.

[Tad Eareckson]

EMERGENCY PROCEDURES

A few emergencies can occur in the release phase of aerotowing. These are only true emergencies if you are not prepared, so let's prepare now.

Emergency Release

First we should point out the situations that demand a release by either the hang glider pilot or the tug pilot.

The hang glider pilot must release if:
1. Anything prevents him or her from controlling the glider.
2. The hang glider reaches a position relative to the tug at which it is not responding to corrective controls.
3. The pilot's health condition becomes problematical.

The tug pilot must release if:

1. A problem exists with the tug which makes it riskier to continue towing than to release.
2. The hang glider becomes misaligned to the point that control is hampered.
3. The hang glider doesn't respond to repeated release signals.
4. The tug pilot's health condition becomes problematical.

A few emergencies can occur in the release phase of aerotowing. These are only true emergencies if you are not prepared, so let's prepare now.

- When IS "the release phase of aerotowing"? Is it at a couple thousand feet when you get the signal? At a couple thousand feet there ARE NO emergencies - whether you're prepared or not. True emergencies tend to happen below two hundred feet and sometimes it doesn't matter a whit whether you're prepared or not - your best bet for survival is to never let yourself get into a situation in which an emergency can develop. You do that by using a driver who knows what the fuck he's doing, having streamers along the runway, knowing what a weak link is, and never going up with the kind of shit equipment you bastards describe, illustrate, and endorse in this stupid book.

- The release phase of aerotowing can be any time you're connected to a tug with its engine spinning fast enough to pull you forward and can come upon you so fast you don't even have time to think.

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.

- Bullshit.

The hang glider pilot must release if:
1. Anything prevents him or her from controlling the glider.

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.

Like when you're "pro towing" soon after liftoff when you've hit the mother of all thermals ('Cause you didn't have streamers along the runway, right?), are standing on your tail and going up like a rocket, have pulled in all the way, can't get the nose back down, and have hangars and trees on the left - the way the glider is tending?

2. The hang glider reaches a position relative to the tug at which it is not responding to corrective controls.

http://www.chgpa.org/forums/viewtopic.php?f=2&t=3600
Weak link question

Danny Brotto - 2008/11/04 12:49:44

I had the Axis on the cart with the AOA a bit high, launching to the west, with a moderate ninety degree cross from the left. 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.

Like when you're in a moderate ninety degree left cross and slow, rolled and yawed to the right with the upwind wing flying and the downwind wing stalled, and your driver's about to give you the rope?

3. The pilot's health condition becomes problematical.

Oh my God!!! I think I'm having a heart attack!!! I know there's a procedure for dealing with this situation in the excellent book, Towing Aloft, by Dennis Pagen and Bill Bryden. If only I could remember what it was!

The tug pilot must release if:

1. A problem exists with the tug which makes it riskier to continue towing than to release.

Name a situation in which it ISN'T riskier to continue towing than to release - especially at launch when the glider's in bad enough shape that there's a one hundred percent certainty that he'll crash as a consequence of you cutting him loose.

2. The hang glider becomes misaligned to the point that control is hampered.

Whose control?

Yours?

- When ISN'T a tug's control being hampered by having another plane on the back end of its towline?

- "Well the glider has become misaligned to the point that my control is hampered. I've got plenty of margin, I'm not in any immediate danger, and if I cut the glider loose I'll kill him. But that's OK because the excellent book, Towing Aloft, by Dennis Pagen and Bill Bryden, says if my control is being hampered I MUST cut him loose."

The glider's?

Bill Bryden - 1999/06

1999/02/27 - 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 foot towline. 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.

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

Who the fuck are you to determine from looking in a mirror from 250 away what the glider's control situation is and that you get to override his decision to stay on tow and get back into position?

3. The hang glider doesn't respond to repeated release signals.

Why is this under the "Emergency Release" procedures heading?

- If it's an emergency for the:

-- tug you don't signal him - you dump him

-- glider it's your job to stay in front of him while he deals with it as best he can. If getting off tow were in his best interest he'd have done that already.

- Has anyone in the history of hang glider aerotowing NOT responded to a release signal?

4. The tug pilot's health condition becomes problematical.

Oh my God!!! I think I'm having a heart attack!!! I know there's a procedure for dealing with this situation in the excellent book, Towing Aloft, by Dennis Pagen and Bill Bryden. If only I could remember what it was!

[Tad Eareckson]

http://www.hanggliding.org/viewtopic.php?t=25330
Lessons at Wallaby - What to Read Beforehand?

momentum - 2012/02/23 03:18:01 UTC
Vancouver

Hello all,

So after wanting to get into hang gliding for a while, I've finally committed to ten days of lessons at Wallaby. My question is, what should I read beforehand to maximize my experience? I already have Dennis Pagen's book, which has been very instructional. I'm just wondering if there is any other literature I should be familiar with before my lessons start in three weeks.

Thanks!

Nah, just read Dennis's book. The total bullshit in there is based on and thus totally consistent with the total bullshit you'll get in your lessons at Wallaby. And the import thing is that you feel safe, relaxed, confident, and trusting in your program - just like Jeremiah Thompson was all the way up to the last tandem flight before he was gonna solo.

Bob Flynn - 2012/02/23 04:14:57 UTC
Jacksonville, North Carolina

Don't overload yourself too much with book learning yet. Go.....have.....fun! Listen to your instructor and try to accomplish the goals he sets but mostly have fun. That's when you learn at the best pace. Go ahead and read up on Dennis's book. But your first lessons need to be fun.

Yeah Bob, just as long as he isn't too concerned about WHAT he's learning.

If he's interested in anything from the NONfiction departments - and his prospects for long term survival...

FAA Glider Flying Handbook
Manned Kiting
fatality reports
incident reports
Kite Strings

Or he could just go tow with Joe Street. Wouldn't even hafta cross the border - just drive along it most of the way east.

[Steve Davy]

This thread needs to be on the first page.

[Tad Eareckson]

Seems only fair. The crime against humanity which is its subject is on the first page of the publications listed at USHPA's store.

[Zack C]

I (or Tad) can sticky the topic (so it'll always appear first), but it's already high on the Google rankings for 'Towing Aloft'.

Zack

[Tad Eareckson]

Nah, don't make it a sticky. The book's already sticky enough to suck in and kill large mammals at a rate that dwarfs anything the La Brea Tar Pits were ever able to manage.

[Tad Eareckson]

I - TOWING BRIDLES

A bridle is a system of lines, such as webbing or rope, that connects a towline to the pilot and glider. It is a necessary part of the towing safety equipment, for just as a different form of bridle permits you communication over a horse with its superior strength, the modern tow bridle allows you to handle the increased forces of a glider during a tow. Retaining effective control while under tow is critical to a pilot's safety.

Single-Point Bridle

An optional type of bridle for use by experienced pilots on advanced gliders is the single-point bridle. This bridle consists of the simple shoulder line described above and all towing forces are on the pilot's harness shoulder straps. With this method, the pilot is pulled forward through the control bar somewhat so the control bar is not in it's normal trim free flying position (see figure 7-14). This matter is explained in more detail in Chapter 9 on flying under aerotow and in Appendix I.

The main benefits of the single point bridle is its simplicity and its tendency to reduce yawing of the glider under tow. The latter effect results from the fact that the location of the forces on the glider is similar to that when in free flight. Another advantage is that it is short and thus easier to tuck away into your harness. One drawback to single point is that it is not easy to incorporate a secondary release so a hook knife must be handy in flight.

A single-point bridle system:
- Is simpler.
- Reduces yawing.
- Results in more shoulder line pressure.
- Does not have a secondary release.
- Requires a more rearward than normal bar position.

Figure 7-14: Single-Point Bridle System

Bridle attached to harness shoulder straps
Release
Towline
Base bar is further back in trim position because pilot is pulled forward

NOWHERE is there even a HINT of a mentioned that...

Dennis Pagen - 2005/01

Thirdly, experienced pilots should be aware that towing only from the shoulders reduces the effective pull-in available to prevent an over-the-top lockout.

...towing only from the shoulders reduces the effective pull-in available to prevent an over-the-top lockout.

And this has been a determining factor in two aerotow fatalities.

[Tad Eareckson]

All towing casualties referenced in Towing Aloft...

There have been fatalities in both hang gliding and paragliding with hand towing due to lockouts.

Two fatalities have occurred in the past five years directly related to failures of very poorly constructed and maintained releases. For the sake of safety, only use releases that have been designed and extensively tested by reputable manufacturers.

In recent years, two serious lockout accidents occurred with surface based towing: one resulting in a fatality and the other a very serious injury. In both of these events the line tension was being monitored directly and it never exceeded 120-130 pounds, well below the breaking point for the weak links!

Three recent aerotowing accidents have occurred--one fatal. The common thread in all three was a lockout and the use of a much too heavy weak link.

In Pennsylvania, an airstrip lined with trees was used for aerotowing. The wind was crossing nearly sixty degrees one day about 10 mph. A pilot launching from a dolly behind a trike got a wing lifted just as he reached flying speed. He became airborne in a strict right turn. He tried to correct but struck a tree about twenty feet up. The weak link broke and he slipped to the ground, demolishing his glider and breaking his hip. His later comment was "I only needed a couple more feet of clearance and I was home free!"

Analysis...

- You can:

-- get killed in a hang or paraglider if you use people to pull the other end of the string (but probably not if you use a boat, snowmobile, scooter, winch, truck, ultralight)

-- only get killed on equipment that you make yourself - you'll be fine with anything a flight park sells you

- A light weak link can:
-- not save you from a lockout
-- save you from a lockout

- Don't fly into trees.

- Otherwise... you're good to go.

[Tad Eareckson]

Lockouts will only occur under a combination of:
- Poor equipment,
- Poor skills or
- Poor conditions

Remember the two main dangers in any towing are lockout and structural failure. Lockouts are hard to get into (although not impossible) and are prevented along with failure by the force limiting effects of the weak links.

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.