TOW PLANE Accident

On Tuesday, October 31, 2017 at 1:38:34 PM UTC-6, Richard Garrity wrote:
Skyline Soaring Club has suffered a tragic loss of a member in the crash of our tow plane. The accident occurred on October 7th while towing an ASK21. The glider released at very low altitude and returned safely to the airport. The NTSB is investigating and factual information is shown on their web site. Our flight operations resumed on October 21st after a Safety Meeting and a club Memorial at our hangar. Our sport has its own hazards and we must be constantly vigilant! Skyline Soaring with the strength of its 100+ members will continue with its mission to support soaring! The Club is reaching out to all in our community for any assistance in replacing our tow plane. We know that word of mouth is the best way to hear of a suitable tow plane that maybe becoming available. Your thoughts and ideas will be appreciated. Please contact me directly by phone or email. Thank you...

Dick Garrity
SSC Board Member
410 268 7069


Dick:

Although I understand when you say a 1000hr pilot is a pro, I take exception to the description. Being a professional pilot has far more to do with the attitude and discipline one takes with them into the cockpit. I've flown (as a CFI) with low time students who are totally focused on the relationship between them selves and the tow plane. I also tell my new tow pilots (as the chief tow pilot) the last thing you should do before moving the power lever to the maximum enthusiasm position is to review what you will do in the event of an untoward move by the glider pilot and last to look at the tow rope release lever before departing.

Exactly why we use low tow as much as possible in Australia. Ive never done a high tow. I cannot see any good reason to high tow.
That said, there are other factors in the report, age and a heart condition. Perhaps you lot would be better to stop second guessing and pushing your opinions
over this tragedy.

On Saturday, February 23, 2019 at 10:22:10 PM UTC-7, Charlie Quebec wrote:
Exactly why we use low tow as much as possible in Australia. Ive never done a high tow. I cannot see any good reason to high tow.
That said, there are other factors in the report, age and a heart condition. Perhaps you lot would be better to stop second guessing and pushing your opinions
over this tragedy.

We infrequently do low tow here in the US. High tow keeps the tow plane on the horizon, at the same level as you. If you are doing a long tow cross country though, then low tow is used more frequently here. There are also different hazards to the low tow position, so what you save on one hand, you give up with the other.

As to the mention of heart condition in the report, it did mention he had coronary plaque build-up. But none of these were sufficient to cause a heart attack. No no evidence for a heart attack was found on the autopsy. He did have a big heart though, but that is unlikely to have caused a sudden incapacitation of the tow pilot.

The bottom line from this report, is that the glider pilot was distracted, got high, and up-ended the tow plane too close to the ground. The rope broke before the glider pilot released. I will do my best not to do this to any tow pilot.

Many years ago the late Chris Rollins, while CFI at Booker GC in the UK, did some controlled testing of glider "kiting" behind tugs. He posted something about it on URAS he

https://groups.google.com/forum/#!ms...g/Uz0Ga95XVCsJ

It makes interesting and sobering reading.

On Friday, 8 March 2019 15:26:18 UTC, Paul Kaye wrote:
Many years ago the late Chris Rollins, while CFI at Booker GC in the UK, did some controlled testing of glider "kiting" behind tugs. He posted something about it on URAS he

https://groups.google.com/forum/#!ms...g/Uz0Ga95XVCsJ

It makes interesting and sobering reading.

Some excerpts:

"Third test: Terrier Tow-Plane, K 8b on C of G hook. I pitched the glider
about 25 degrees nose up. The glider continued to pitch up fairly rapidly
(as at the start of a winch launch) and substantial forward movement of the
stick only slightly slowed the rate of pitch. The glider achieved about 45
degrees nose up, speed increased rapidly from 55 knots to about 75 knots
and the glider was pulled back towards level flight (again as at the top of
a winch launch). I released at that point. The entire sequence of events
occupied a VERY short period of time (subsequently measured as 2 - 3
seconds). The Tow Pilot reported a marked deceleration and start of
pitching down which he attempted to contain by moving the stick back; this
was followed immediately by a very rapid pitch down accompanied by
significant negative “G�. The tow-plane finished up about 70 degrees
nose down and took about 400 feet to recover to level flight. We both
found the experience alarming, even undertaken deliberately at 4000 feet.
Our conclusion was that the combination of the initial pitch down and the
upward deflection of the elevator caused the horizontal stabilizer/elevator
combination to stall and the abrupt removal of the down-force it provided
caused the subsequent very rapid pitch-down and negative “G�. "

"These tests were repeated a few years later with a PA18 – 180 as the
tow-plane, Brian Spreckley flying it. The third test described above was
repeated and photographed from a chase plane using a 35 mm motor drive
camera on automatic (this took a frame every half second – video
camcorders of small size were not readily available then). The photo
sequence started with the glider in a slightly low normal tow position and
starting to pitch up, the second frame has the glider about 30 degrees nose
up and about 20 feet higher than previously in the third frame it is about
45 degrees nose up and has gained another 30 feet or so, the tow-plane is
already starting to pitch down, in the fourth frame the glider is about 100
feet higher than its original position and the climb is starting to
shallow, the tow-plane is about 50 degrees nose down, the final frame shows
the tow-plane about 70 degrees nose down and the glider almost back in
level flight , almost directly above it (that was about the point that I
pulled the release).

Sufficiently alarmed by events, Brian Spreckley had been trying to pull the
release in the tow-plane earlier and found that it would not operate until
my releasing at the glider end removed the tension from the rope.
Subsequent tests on the ground showed that the Schweizer hook fitted to the
tow-plane, whilst perfectly satisfactory under normal loads, was jammed
solid by the frictional loads when subject to a pull of around 700 lbs with
a slight upwards component – not something that a normal pre-flight check
would reveal. "

On Friday, March 8, 2019 at 9:39:11 AM UTC-6, Paul Kaye wrote:
On Friday, 8 March 2019 15:26:18 UTC, Paul Kaye wrote:
Many years ago the late Chris Rollins, while CFI at Booker GC in the UK, did some controlled testing of glider "kiting" behind tugs. He posted something about it on URAS he

https://groups.google.com/forum/#!ms...g/Uz0Ga95XVCsJ

It makes interesting and sobering reading.

Some excerpts:

"Third test: Terrier Tow-Plane, K 8b on C of G hook. I pitched the glider
about 25 degrees nose up. The glider continued to pitch up fairly rapidly
(as at the start of a winch launch) and substantial forward movement of the
stick only slightly slowed the rate of pitch. The glider achieved about 45
degrees nose up, speed increased rapidly from 55 knots to about 75 knots
and the glider was pulled back towards level flight (again as at the top of
a winch launch). I released at that point. The entire sequence of events
occupied a VERY short period of time (subsequently measured as 2 - 3
seconds). The Tow Pilot reported a marked deceleration and start of
pitching down which he attempted to contain by moving the stick back; this
was followed immediately by a very rapid pitch down accompanied by
significant negative “G�. The tow-plane finished up about 70 degrees
nose down and took about 400 feet to recover to level flight. We both
found the experience alarming, even undertaken deliberately at 4000 feet.
Our conclusion was that the combination of the initial pitch down and the
upward deflection of the elevator caused the horizontal stabilizer/elevator
combination to stall and the abrupt removal of the down-force it provided
caused the subsequent very rapid pitch-down and negative “G�. "

"These tests were repeated a few years later with a PA18 – 180 as the
tow-plane, Brian Spreckley flying it. The third test described above was
repeated and photographed from a chase plane using a 35 mm motor drive
camera on automatic (this took a frame every half second – video
camcorders of small size were not readily available then). The photo
sequence started with the glider in a slightly low normal tow position and
starting to pitch up, the second frame has the glider about 30 degrees nose
up and about 20 feet higher than previously in the third frame it is about
45 degrees nose up and has gained another 30 feet or so, the tow-plane is
already starting to pitch down, in the fourth frame the glider is about 100
feet higher than its original position and the climb is starting to
shallow, the tow-plane is about 50 degrees nose down, the final frame shows
the tow-plane about 70 degrees nose down and the glider almost back in
level flight , almost directly above it (that was about the point that I
pulled the release).

Sufficiently alarmed by events, Brian Spreckley had been trying to pull the
release in the tow-plane earlier and found that it would not operate until
my releasing at the glider end removed the tension from the rope.
Subsequent tests on the ground showed that the Schweizer hook fitted to the
tow-plane, whilst perfectly satisfactory under normal loads, was jammed
solid by the frictional loads when subject to a pull of around 700 lbs with
a slight upwards component – not something that a normal pre-flight check
would reveal. "

Thanks Paul, very instructive. Makes me wonder why that Schweizer tow-hook is still legal and widely used.

On Friday, March 8, 2019 at 1:05:48 PM UTC-5, wrote:
On Friday, March 8, 2019 at 9:39:11 AM UTC-6, Paul Kaye wrote:
On Friday, 8 March 2019 15:26:18 UTC, Paul Kaye wrote:
Many years ago the late Chris Rollins, while CFI at Booker GC in the UK, did some controlled testing of glider "kiting" behind tugs. He posted something about it on URAS he

https://groups.google.com/forum/#!ms...g/Uz0Ga95XVCsJ

It makes interesting and sobering reading.

Some excerpts:

"Third test: Terrier Tow-Plane, K 8b on C of G hook. I pitched the glider
about 25 degrees nose up. The glider continued to pitch up fairly rapidly
(as at the start of a winch launch) and substantial forward movement of the
stick only slightly slowed the rate of pitch. The glider achieved about 45
degrees nose up, speed increased rapidly from 55 knots to about 75 knots
and the glider was pulled back towards level flight (again as at the top of
a winch launch). I released at that point. The entire sequence of events
occupied a VERY short period of time (subsequently measured as 2 - 3
seconds). The Tow Pilot reported a marked deceleration and start of
pitching down which he attempted to contain by moving the stick back; this
was followed immediately by a very rapid pitch down accompanied by
significant negative “G�. The tow-plane finished up about 70 degrees
nose down and took about 400 feet to recover to level flight. We both
found the experience alarming, even undertaken deliberately at 4000 feet.
Our conclusion was that the combination of the initial pitch down and the
upward deflection of the elevator caused the horizontal stabilizer/elevator
combination to stall and the abrupt removal of the down-force it provided
caused the subsequent very rapid pitch-down and negative “G�. "

"These tests were repeated a few years later with a PA18 – 180 as the
tow-plane, Brian Spreckley flying it. The third test described above was
repeated and photographed from a chase plane using a 35 mm motor drive
camera on automatic (this took a frame every half second – video
camcorders of small size were not readily available then). The photo
sequence started with the glider in a slightly low normal tow position and
starting to pitch up, the second frame has the glider about 30 degrees nose
up and about 20 feet higher than previously in the third frame it is about
45 degrees nose up and has gained another 30 feet or so, the tow-plane is
already starting to pitch down, in the fourth frame the glider is about 100
feet higher than its original position and the climb is starting to
shallow, the tow-plane is about 50 degrees nose down, the final frame shows
the tow-plane about 70 degrees nose down and the glider almost back in
level flight , almost directly above it (that was about the point that I
pulled the release).

Sufficiently alarmed by events, Brian Spreckley had been trying to pull the
release in the tow-plane earlier and found that it would not operate until
my releasing at the glider end removed the tension from the rope.
Subsequent tests on the ground showed that the Schweizer hook fitted to the
tow-plane, whilst perfectly satisfactory under normal loads, was jammed
solid by the frictional loads when subject to a pull of around 700 lbs with
a slight upwards component – not something that a normal pre-flight check
would reveal. "

Thanks Paul, very instructive. Makes me wonder why that Schweizer tow-hook is still legal and widely used.

I do not wonder why, I know why. It is largely a "we've always done it this way" attitude and a financial consideration. The cost of retrofitting a tow plane with a Tost system and a release handle up where the tow pilot can reach it in the seated, upright position WITH adequate mechanical advantage to effect a release is a few thousand dollars, not something some are willing to spend.

The FAA in their own Advisory Circular, date 3/3/08 AC No 43.13-2b, Page 76, Par 808 states as follows:

“When the glider under tow operates above a certain angle to the tow plane, the ring may slide upwards on the hook, causing excessive load on the hook and difficulty in releasing the tow rope ring.�

The Soaring Society of America thru their Soaring Safety Foundation, Tow Pilot Training course additionally acknowledges IN RED as follows:

“If at any time the nose of the tow plane is pulled to a dangerously high or low pitch attitude, - PULL THE RELEASE!�

It goes on to say:

“Depending on the installation of the tow hitch, it may be possible for the release mechanism to become jammed due to the excessively high position of the glider, (American style hook).�

What they mean by “depending on installation of the tow hitch,� is that if you install it upright instead of inverted it may be possible for the release mechanism to become jammed due to the excessively high position of the glider.

The SSA and the FAA are well aware of this situation and have been for many, many years and yet the system remains approved. I can assure you that not all kiting incidents are slowly developing situations. I've been there at just above 300 feet when in the blink of an eye you find yourself nose down before you could even think of releasing. The gentleman who died in this tow plane incident was probably 100 feet below the level at which mine started. In both cases our tow ropes broke, the glider pilot didn't release. I had barely enough room to recover, he did not.


Walt Connelly
Former tow pilot
7000 tows

On Saturday, March 9, 2019 at 8:24:04 AM UTC-5, wrote:
I can assure you that not all kiting incidents are slowly developing situations. I've been there at just above 300 feet when in the blink of an eye you find yourself nose down ***before you could even think of releasing***..

[emphasis added]

Right. So after all the brouhaha and threats to write the FAA about our equipment, it turns out that in at least one of the events that got you goin', you say the hook/release doesn't matter because you didn't even have a chance to respond. Would you care to clarify?

Btw, how long was your rope?

T8

Though the final report w/any probable cause is scheduled for this Wednesday (3/13), there are a few details that perplex me. Video analysis (segment #2)indicates the spoiler handle starts to move aft at (in seconds?) 5.14s, then is near full aft by 9.21s until 11.13s when it "starts to move forward". Near the end of the epoch, the release handle moves several inches, then dangles, coincident with a snapping sound. The glider PIC reported deploying brakes when he saw the towplane below to the right with slack in the line. He stated,"and the[n] released the towrope." Partial to full brake handle aft for about 6 seconds, most while tug/glider still connected it seems (tho maybe wrong). Witnesses told the PIC they didn't think he pulled the tug's tail up; some of the written docs bear this out. Video stills recorded the tug's elevator position.

The post by Ouroboros was enlightening.
https://www.reddit.com/r/Gliding/com...e_immediately/

On Sunday, March 10, 2019 at 5:01:48 PM UTC-7, Duster wrote:
Though the final report w/any probable cause is scheduled for this Wednesday (3/13), there are a few details that perplex me. Video analysis (segment #2)indicates the spoiler handle starts to move aft at (in seconds?) 5.14s, then is near full aft by 9.21s until 11.13s when it "starts to move forward". Near the end of the epoch, the release handle moves several inches, then dangles, coincident with a snapping sound. The glider PIC reported deploying brakes when he saw the towplane below to the right with slack in the line. He stated,"and the[n] released the towrope." Partial to full brake handle aft for about 6 seconds, most while tug/glider still connected it seems (tho maybe wrong). Witnesses told the PIC they didn't think he pulled the tug's tail up; some of the written docs bear this out. Video stills recorded the tug's elevator position.

The post by Ouroboros was enlightening.
https://www.reddit.com/r/Gliding/com...e_immediately/

Where are you able to see the video footage?

BG