Most recent tow plane crash.

[waltco...@aol.com]

General Aviation Accident...
(6/May/2022)
- New Zealand 🇳🇿 :
A Piper PA-25-235 Pawnee B, owned by the Wanganui Manawatu Gliding Club, registration ZK-CIG, impacted trees during a glider-tow takeoff attempt at Feilding Aerodrome (NZFI), Bunnythorpe, New Zealand.
The airplane sustained substantial damage and the sole pilot onboard was seriously injured.
Preliminary information indicates the glider "got too high" on departure. The tow plate was in such a position that the pilot of the Pawnee could not recover. The glider was released and was able to land safely, but the Pawnee impacted trees.

(perhaps a turboencabulator malfunction?)

Walt

[Birdie4120]

[waltco...@aol.com]

On Monday, July 11, 2022 at 5:53:02 PM UTC-4, Lhmc...@mac.com wrote:
> That is terrible. I hate reading about these things. I wish the tow pilots could release via a trigger or similar right on the joy stick. I see my first duty on tow as to not hurt the tow pilot.On Monday, July 11, 2022 at 10:23:23 AM UTC-4, waltco...@aol.com wrote:

Believe me, tow pilots wish for the same. It would at least be nice if all tow planes were equipped with releases that would work under all conditions and release handles easily accessible. When the SHTF the pilot initially is busy trying to control the aircraft, the though of releasing follows closely.

Walt

[Dan Marotta]

I agree with the concept, but a trigger on the stick is a bad idea. It
wouldn't be very long before a glider was cut loose accidentally. A big
red (guarded) button on the panel would suit me just fine!

Dan
5J

[R]

The Tow pilot passed away in May.

R

[waltco...@aol.com]

On Tuesday, July 12, 2022 at 5:51:57 PM UTC-4, R wrote:
> The Tow pilot passed away in May.
>
> R

That make THREE tow pilots to die as a result of kiting since my departure.

Walt

[Stéphane Vander Veken]

We had a kiting accident in Belgium two weeks ago. The pilot of the (rented) Pawnee with Schweizer hook was unable to release before the glider did (manually or via the automatic release of the winch hook) and had insufficient height to round out correctly out of the dive. He was horizontal but in a stall when he crashed in the corn field just passed the end of the runway. As this field was a bit lower, he was able to walk away from the burning wreck, with a broken nose and finger. Makes one believe in miracles...

[Mark Mocho]

Makes one believe in miracles...

One of which is NOT the Schweizer release mechanism.

[Tony]

On Sunday, July 17, 2022 at 11:46:44 AM UTC-4, Mark Mocho wrote:
> Makes one believe in miracles...
> One of which is NOT the Schweizer release mechanism.

I think the Schweizer hook is overly maligned - this is worth watching:
https://youtu.be/b-XMaLKl4c4

[bluej...@gmail.com]

The AC-43 minimum length of the " tow-hitch release handle" in the towplane is a significant factor in how much leverage you have when trying to release a kiting glider. As has been mentioned before in other threads, the short handle on the floor is hard to reach when you're nose down and hanging in the straps. The physics of the situation may make it nearly impossible to pull hard enough, regardless of the proving tests in the YouTube video posted early.

The minumum 5:1 ratio specified in AC-43 is fine for dropping banner or releasing a glider under normal loads, but a higher ratio would make a significant difference. The Pawnees have a great dump handle that shouldn't get tossed when they are stripped of their spray equipment. They make great, long and easy to operate, release handles with a major mechanical advantage over the short handles you see out there. BobY repurposes the dump handle when he rebuilds his Pawnees and everyone likes it more than the reach-for-the-floor handles.

PA

[Hank Nixon]

We have mounted the Schweizer hook inverted and use a release handle that is about 4 inches longer and bent up instead of down. The handle is easily reached with no bending or searching as it is just below seat level. FWIW
UH

[waltco...@aol.com]

On Sunday, July 17, 2022 at 10:58:39 AM UTC-4, Stéphane Vander Veken wrote:
> We had a kiting accident in Belgium two weeks ago. The pilot of the (rented) Pawnee with Schweizer hook was unable to release before the glider did (manually or via the automatic release of the winch hook) and had insufficient height to round out correctly out of the dive. He was horizontal but in a stall when he crashed in the corn field just passed the end of the runway. As this field was a bit lower, he was able to walk away from the burning wreck, with a broken nose and finger. Makes one believe in miracles...

There is sufficient evidence that the Schweizer hook is problematic when under extreme pressure and that the handle, down on the floor and not instantaneously available to the pilot and with a lack of mechanic advantage adds to this problem. I don't believe in miracles, I believe in taking action and getting things done, getting things changed to improve conditions and survivability.

Walt Connelly

[waltco...@aol.com]

On Sunday, July 17, 2022 at 2:50:45 PM UTC-4, sgs...@gmail.com wrote:

There is sufficient evidence that the TOST system is safer and more reliable. Now, if you were going to fly a Pawnee with a conventionally installed Schweizer release and handle and KNEW you would have a low level kiting incident, would you do it anyway?

Walt Connelly

[waltco...@aol.com]

Makes sense to do something that improves the survivability of the tow pilot. Of course you will hear the chorus of those who will say you can't change anything in the cockpit without permission from the FAA. They won't approve this and that, you have to make out this and that request, submit it and get permission before you can change anything. REALLY? I remember how quickly the handle that was (MIGHT I SAY) Improperly and perhaps illegally installed in the Pawnee I was flying got turned around to its originally approved position? All involved know how and why.

Walt Connelly

[Stéphane Vander Veken]

The Pawnee involved in our accident had a very long release handle, according to another of our tow pilots.

In another club, there was a similar kiting incident with a Husky ten years ago, but the pilot was able to release because the aircraft had a Tost retractable towing cable with a guillotine. So the cable was cut, not released. As far as I know, the Schweizer hook is far from ideal when the towing cable is under high tension. But the French Aerazur hook (no longer in production) wasn't much better, and there have been accidents with Tost hooks too. In the case of the Tost hooks, it has been suggested that the design of the release mechanism in some gliders and tugs augmented the necessary force instead of reducing it.

[waltco...@aol.com]

On Monday, July 18, 2022 at 8:57:00 AM UTC-4, Stéphane Vander Veken wrote:
> The Pawnee involved in our accident had a very long release handle, according to another of our tow pilots.
>
> In another club, there was a similar kiting incident with a Husky ten years ago, but the pilot was able to release because the aircraft had a Tost retractable towing cable with a guillotine. So the cable was cut, not released. As far as I know, the Schweizer hook is far from ideal when the towing cable is under high tension. But the French Aerazur hook (no longer in production) wasn't much better, and there have been accidents with Tost hooks too. In the case of the Tost hooks, it has been suggested that the design of the release mechanism in some gliders and tugs augmented the necessary force instead of reducing it.

Very LONG is a subjective measurement. Sometimes it's not the length but the pivot point and the mechanical advantage that count.

It is true that the Schweizer hook is far from ideal (an understatement) and the TOST system is not foolproof but flying with a system that is known to have the greatest chance of failure is foolish. Nothing is 100 percent other than death and taxes and kiting at a low level has a good chance of causing one (death) and eliminating the need to pay the other. (taxes) All this being said there is a point at which if a kiting occurs and it occurs fast enough THE TOW PILOT IS GONNA DIE. When it happens that someone in the line has standing , a good lawyer will take a commercial operation or club to the cleaners.

Walt

[youngbl...@gmail.com]

I have a different opinion on the whole tow release scenario. I have use all of the mentioned tow release mechanisms available, Tost, Schweizer, Pacific Aero, and a couple of home made contraptions. Do not think that the Tost is without problems, the Schweizer is ok, but with the proper release handle and the Pacific Aero is a very good release that works well.
The main problem is that the release handle must be easily within the reach of the struggling tow pilot. I have flown tow planes that it was impossible to reach the release during an emergency. With the Pawnee in mind, keep the hopper release handle and modify it to work as the release handle and you may be surprised at how effective it will be. OBTP

[Ramy]

If all tow pilots would have refused to tow with anything less than acceptable tow release, we would have less tow kiting accidents. The reality is that many tow pilots either not fully aware or not too worried about this issue.

Ramy

[youngbl...@gmail.com]

Ramy, you are 100% correct, more tow pilots must be more cognizant of the surprise tow and how to save yourself in that all too often emergency. Not only am I getting more grumpy in my golden years, but also more cognizant of the emergency situation that one could and possibly will be faced with. Getting to that ever important release or dump handle can and will save your life. OBTP

[2G]

A bad kiting situation is going to put the tow plane in a negative G maneuver, making it all that much harder to find a release lever, in a situation where time is of the essence. Don't think so? Next time w/o a glider on tow, and at altitude, do a HARD pushover and see if you can even find the tow release lever (in a second or two - after that it is game over).

Tom

[waltco...@aol.com]

On Monday, July 18, 2022 at 9:03:57 PM UTC-4, Ramy wrote:

All previous comments are true. The bottom line though is "you don't know what you don't know." I had heard of the difficulty releasing in an emergency, it isn't until your find yourself beyond 60 degrees nose down and wings rotated 90 degrees to the left, pulling on the release (an improperly installed and perhaps illegally rearranged release) that it hits home. The manager of the place told me I was the first tow pilot he knew personally who experience a kite and an inability to release. Perhaps a long enough release handle would bring with it enough mechanical advantage to actuate the Schweizer release system but then again, perhaps NOT? Yes, the Tost system is not perfect but the design avoids the pitfall of the Schweizer system. Had I had my hand on the release when the student f00ked up I couldn't have have pulled it fast enough to release before I was nose down, it happens in the wink of an eye.

Remember, you have the right to refuse to tow anyone whom you feel isn't up to par, on two occasions I should have exercised this right. You are potentially saving your life, a tow plane and some bad press for your Gliderport.

Walt

[cschra...@gmail.com]

At least one operation I know has guillotines to cut the rope if the release doesn't work. If you had that it doesn't matter what happens you can cut the rope.
- Chris Schrader

[waltco...@aol.com]

On Wednesday, July 20, 2022 at 12:41:39 PM UTC-4, cschra...@gmail.com wrote:
> At least one operation I know has guillotines to cut the rope if the release doesn't work. If you had that it doesn't matter what happens you can cut the rope.
> - Chris Schrader

I'm not familiar with guillotine set ups but I would imagine it is one or the other. A release OR a guillotine. When things are going bad down low you don't want to be wasting time releasing if you can cut the line. I'm sure there are occasions when the guillotine doesn't work properly too.

Walt

[Ramy]

The Byron tow plane had guillotine instead of tow release. This is common for retractable tow ropes. The rope was cut, but it was too late.

Ramy

[waltco...@aol.com]

As I have said, there is a point in the tow that no matter what kind of release one has, no matter if their hand is on the lever, the tow pilot will be in an unrecoverable position. Had the handle been in my hand I could not have pulled it before I found myself nose down and wings turned 90 degrees to the left.

The answer is an all encompassing one my friends. Training is where one starts, not just telling but TEACHING the student to keep their eyes on the tow plane, there is a difference. Not just telling but TEACHING the student to release immediately if they lose sight of the tow plane. This being said there are certain types who will never get it, you went to high school with them, college too. The type of release and the handle just give the tow pilot an escape if the event happens high enough.

Then again as I have pointed out, if you can't trust a CFIG to do things right, how can you trust a student or a certified pilot?

Walt

[kirk.stant]

Any statistics on the kind of gliders that are involved in kiting accidents/incidents?

Our club's Pawnees have Tost reels with guillotines - which I like a LOT more than the Elmira Death Hook!

And yes, we do ops check the guillotines whenever we replace the rope. They are surprisingly easy to use - probably easier with the rope in tension. Release handle is right in front of the throttle at same level.

Kirk
66

[2G]

Unfortunately, the Tost reel system is not a solution to the kiting problem as a fatal accident last year involved this system. The problem is that if the kiting occurs at low altitude (<500 ft) the tow pilot has very little time to react to the kiting and cut the rope. I have advocated an electronic system to sense the upset and trigger the guillotine, but do not have access to the test beds (tow planes) necessary to develop such a system.

BTW, such a system would (redundantly) monitor the elevator position, pitch angular rate, altitude and airspeed to determine if an upset was occurring.

Tom

[Martin Gregorie]

Avoiding False Positive kiting indications in turbulent conditions could
be quite an 'interesting' problem to solve. It might also pay to track
height AGL and disable the anti-kiting sensor above, say, 2000 ft AGL.


--

Martin | martin at
Gregorie | gregorie dot org

[youngbl...@gmail.com]

I regard to several comments about kiting and loss of control. I make a lot of tows, probably 1500 in the last 12 months and over the past years have made probably 5K plus, so maybe I might just have the experience necessary to make my observations. Kiting is a product of poor teaching and poor understanding of the consequences. The recent post shown on this forum should be shown to every new and even seasoned glider pilots. The pilot should be cognizant of any out of position tow parameter and react quickly. Yes, I have looked at the ground from 200 or less feet and had things work in my favor so that I did not have that catastrophic ending. If you think the Tost is the solution to the problem then think again, the safety net is being able to get to the release and act quickly, it may just save your life. Old Bob, The Purist.

[2G]

As in all accident prevention scenarios, the first priority is to avoid the accident in the first place, and thorough training leads the list. Sometimes, however, the training is over-ridden by some exigent event or there is no training at all. Or, as they say, shit happens. The tow pilot may never have experienced an upset before, and is slow to recognize it. After all, students can be all over the place, anyhow. It would be like the driver of a car manually initiating the air bag deployment.

Whatever the reason, an automatic system would solve the problem. It would only be armed at low altitudes, say 1000-2000 ft. The tow pilot could recover from an upset above that altitude. I envision it monitoring both elevator position and pitch rate; if the elevator is commanding full-up and the plane is pitching down some external force beyond the pilot's control is causing it. The same is true for a pitch up while the elevator is full down. Once a preset pitch angle is exceeded with these conditions the system would activate.

Tom

[waltco...@aol.com]

Yes, the Tost system is not the solution but it is better than the Schweizer hook, and the tow pilot has a right to an adequate escape mechanism when the glider pilots screws the pooch. I agree that easy access to the handle is paramount along with a MORE than adequate mechanical advantage regardless of the hook mechanism. There should be no argument or fight with the FAA OR obstinate aircraft mechanics when there is a logical solution to the problem. Make the f00king handle longer and instantly accessible. There is NO one answer, it is an all encompassing approach which is needed as I have said in the past.

Walt

[waltco...@aol.com]

Anything is accomplishable with enough time and money but when you have push back about inverting the Schweizer hook or lengthening the release handle how ready do you think the commercial operator or club will be to accept your solution?

Walt

[Dan Marotta]

How complex is the Schweizer tow hook STC? Would it be all that
difficult to simply invert the drawing, include a paragraph about no
change in operation and vastly increased safety and get a new STC created?

Admittedly, I know nothing of the process to get an STC approved, but
isnm't there the capability for a field approval via Form 337 for a
one-time installation on your tug?

Dan
5J

[Larry Suter]

WRT training, our club has added an Emergencies section to our pre-solo written test in addition to the topics required by 61.87. Questions germane to kiting are:

3- Your canopy pops open on aerotow. You should
a- use both hands to immediately close the canopy
b- fly the plane to a safe altitude with the canopy open, then do a safe landing using one hand on
the stick and the other on the spoilers like you normally do. Leave the canopy open; don’t try to
use one hand to hold it. The glider will fly perfectly well with an open canopy
c- do nothing; this is not an emergency

5- According to the Glider Flying Handbook, “One of the most dangerous occurrences during aerotow is
allowing the glider to fly high above and losing sight of the towplane.” This is because (circle all correct):
a- The tension on the towline caused by the glider pulls the towplane tail up, lowering its nose.
b- If the glider continues to rise, pulling the towplane tail higher, the tow pilot may not be able to
raise the nose.
c- Ultimately, the tow pilot may run out of up elevator authority
d- In some towhook systems, the high pressure loading on the towhook causes towhook seizure,
and the tow pilot may not be able to release the towline from the towplane.
e- This situation can be critical if it occurs at altitudes below 500 feet above ground level (AGL).

6- On aerotow you suddenly realize you’ve lost sight of the towplane. You should:
a. release immediately because the abnormally large upward pull can upset the towplane
b. pitch down, dive on the towplane and worry about the slack rope later
c. do nothing; this is not an emergency

At the conclusion of the test, we review all incorrect answers with the student before authorizing that student to conduct a solo flight.

Larry

[waltco...@aol.com]

Congratulations on reacting properly to a serious problem, not every glider facility will do the same. I would add to these comments telling the student WHY they should react as suggested and that is because YOU COULD KILL THE TOW PILOT.

Walt Connelly