Fatal Towplane Accident 5-9-20

On Wednesday, May 13, 2020 at 8:23:35 PM UTC-7, Ramy wrote:
The glider was a 1-26.

Ramy

Too bad. A 1-26 flies fine without a canopy. I have purposefully opened the canopy of a 2-33, unbuckled and stood up to untangle the yaw string, and though flying slower than on tow it wasn't terribly dramatic. Perhaps if training in 2-33s opening the canopy to experience it should be part of the course. It is the surprise and fear of the unknown which certainly contributes to the loss of concentration.

An artificial horizon and electric guillotine is a complex solution. Is the tow rope at a sufficient angle in these situations to simply position a sharp knife above the rope such that it cuts itself if the angle is too high? Surely that has been thought of and rejected for good reasons?

On Thursday, May 14, 2020 at 9:47:50 AM UTC-7, jfitch wrote:
On Wednesday, May 13, 2020 at 8:23:35 PM UTC-7, Ramy wrote:
The glider was a 1-26.

Ramy

Too bad. A 1-26 flies fine without a canopy. I have purposefully opened the canopy of a 2-33, unbuckled and stood up to untangle the yaw string, and though flying slower than on tow it wasn't terribly dramatic. Perhaps if training in 2-33s opening the canopy to experience it should be part of the course. It is the surprise and fear of the unknown which certainly contributes to the loss of concentration.

An artificial horizon and electric guillotine is a complex solution. Is the tow rope at a sufficient angle in these situations to simply position a sharp knife above the rope such that it cuts itself if the angle is too high? Surely that has been thought of and rejected for good reasons?

" I have purposefully opened the canopy of a 2-33, unbuckled and stood up to untangle the yaw string, " Until this moment, I had considered you the smartest guy on this news group. And for a yaw string??? I haven't actually looked at one in years, my butt and damaged lower back give me much feed back. But seriously, other than unbuckling, airplanes, gliders, helicopters can all fly without windows or doors (check POH for which doors). I witnessed a piper arrow crash due to a door coming ajar on take off. I too have opened canopies on 2-33's (pumpkin drops) and even on a Grob 103, front canopy to clear the hot air. In risk v rewards annuals, a yaw string is just not worth unbuckling for, i.e., dying.

An artificial horizon and electric guillotine is a complex solution. Is the tow rope at a sufficient angle in these situations to simply position a sharp knife above the rope such that it cuts itself if the angle is too high? Surely that has been thought of and rejected for good reasons?


I'd been thinking along the same line. I don't think it's quite that simple though. No matter how sharp the blade, it won't cut a line that is merely kissing against it. The blade needs to be hot enough to melt through the line or actively sawing. And, obviously it has to all happen very quickly..

How about this: Imagine two permanent magnets (strong magnets) that when joined together create a magnetic junction in the tow line just a bit aft of the tugs two hook. Similar to the knife blade idea, a horizontal bar is mounted off the back of the tow plane above the tow rope such that when the rope raises to a critical angle, the bar presses along the alignment between the two magnets. The relatively small orthogonal force exerted at the magnetic juncture will have a leverage effect to pry the magnets enough to break the magnetic circuit. To improve and optimize the leverage action on the magnets, each may have an attached bar of defined length that is rigidly affixed such the tow line attachment point is positioned at the distal end of these leverage bars. In fact, the tug side's lever bar may have a ring at the end to be attached directly to the tug's tow release. The tug will be instantly freed predicated on the existence of a strong enough pull on the line above the critical angle of bar contact.

On Thursday, May 14, 2020 at 9:47:50 AM UTC-7, jfitch wrote:
On Wednesday, May 13, 2020 at 8:23:35 PM UTC-7, Ramy wrote:
The glider was a 1-26.

Ramy

Too bad. A 1-26 flies fine without a canopy. I have purposefully opened the canopy of a 2-33, unbuckled and stood up to untangle the yaw string, and though flying slower than on tow it wasn't terribly dramatic. Perhaps if training in 2-33s opening the canopy to experience it should be part of the course. It is the surprise and fear of the unknown which certainly contributes to the loss of concentration.

An artificial horizon and electric guillotine is a complex solution. Is the tow rope at a sufficient angle in these situations to simply position a sharp knife above the rope such that it cuts itself if the angle is too high? Surely that has been thought of and rejected for good reasons?


A common problem most tow plans have is the lack of a good way to see the glider. The mount rearview mirror at some distance from them on the wing struts and various places. Most tow pilots I have taked to say the field of view is very limited and they mostly use them while taking out the slack be fore launch. I todays world we back up cameras on out cars with overlays to help use back up. If we used a camera looking back, the tow pilot could see the glider easily. The screen could have a box the glider must be within. If not cut the rope. Addition software could also be implemented to cut the rope for them.

A second idea is a tension sensor. if there is a sustained high pull on the rope as you get with a kiting event. An alarm could go off or the rope automatically cut. Slack rope jerks are very short in duration and could easily be ignored.

John Scott was a very good friend of mine and I feel very sad for his loss and at the same time a bit upset at the glider pilot for not doing one of the most fundalmental things we teach students. If you can not see the tow plane " release immediately" people loose sight of the towplane long before things go completely bad.

there is addition video taking by the airport cameras that show the entire accident sequence. Some day when the NTSB gives its report, we will get a chance to see this maybe.

The tow rope was found 100 yards beyond the towplane in a small pile indicating it came down vertically. The glider over flew the towplane as it was about to crash or even after and caused the plane to flip over. This trapped the pilot inside where he burnt to death.

Negative G's could have prevented the pilot from reaching the release under his seat in the most dynamic period of energy transfer to the gliders speed and altitude. IT is this on set of this critical time is when the rope need to be cut.

The pull on the Schwiezer tow hook would have been nearly straight down and could have also been jabbed. Years of doing winch launches in a 1-26 and 2-33 say you need to push over to help reduce the release forces to open the release.

Tow pilots do the most dangerous part of getting us into the air many times each day. We in the glider do less. We need to find solutions to prevent another kiting fatality.

Buzz