Does anyone use a tug tow hook that releases automatically whenglider kites?

Chris Rollings wrote:

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�.

I was the pilot of a tug involved in exactly the scenario described by
Chris above. The culprit was a K6 using a belly hook, and the only
reason I am here to tell the tale is that it occurred at 400ft. It was
actually a dual tow with the K6 on the short rope and a K13 on the
long rope in low-tow position. The K6 had recovered from some earlier
excursions, but all seemed to be going well before it happened.

The "up-ending" was instantaneous, there was no way to have reached
any type of release before the rope broke, and in any case I can
assure you that when descending vertically on full throttle at 400ft,
your first reaction it to close the throttle.

Our CFI in the K13 said he hadn't seen the underside of a PA18 in plan
form quite so close before.

In those days we used to store spare ropes and things behind the rear
seat of the PA18, and my situation was not improved by the whole lot
coming forward and landing on my head and all over the cockpit.

A good friend of mine later died towing a K6 with a PA18, which
incident quite probably was the trigger for Chris' investigations.

Ain't no doubt about how quickly the tug gets upset when the glider decides
to fly hither and yon.

My event involved a highly experienced retired FAA guy with type ratings in
every aircraft imagineable. It was his first flight in a borrowed HP-14
and, during the departure turn at about 700' AGL he flew high and wide to
the right, outside of the turn. Before I could reach the release lever,
he'd turned hard left and dove across the tail of the Pawnee wrapping the
tow rope around his left wing and, after it cut the top and bottom skins of
the wing clear to the spar, cutting the rope in two in the middle. The
final yank on the rope caused the tug to yaw hard right and pitch slightly
up (from about 45 degrees down).

Not realizing how close he'd come to killing us both, he proceeded to have a
nice 4-hour flight. After landing he asked our line guy to help with
derigging. That's when Steve called him to the left side of the glider and
pointed out the damage.

I had a few words with him, too.

"Colin Wray" wrote in message
...
Chris Rollings wrote:

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 â?oGâ??. 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 â?oGâ??.

I was the pilot of a tug involved in exactly the scenario described by
Chris above. The culprit was a K6 using a belly hook, and the only
reason I am here to tell the tale is that it occurred at 400ft. It was
actually a dual tow with the K6 on the short rope and a K13 on the
long rope in low-tow position. The K6 had recovered from some earlier
excursions, but all seemed to be going well before it happened.

The "up-ending" was instantaneous, there was no way to have reached
any type of release before the rope broke, and in any case I can
assure you that when descending vertically on full throttle at 400ft,
your first reaction it to close the throttle.

Our CFI in the K13 said he hadn't seen the underside of a PA18 in plan
form quite so close before.

In those days we used to store spare ropes and things behind the rear
seat of the PA18, and my situation was not improved by the whole lot
coming forward and landing on my head and all over the cockpit.

A good friend of mine later died towing a K6 with a PA18, which
incident quite probably was the trigger for Chris' investigations.

On Wednesday, February 12, 2014 12:03:17 PM UTC-5, Dan Marotta wrote:
Ain't no doubt about how quickly the tug gets upset when the glider decides

to fly hither and yon.



My event involved a highly experienced retired FAA guy with type ratings in

every aircraft imagineable. It was his first flight in a borrowed HP-14

and, during the departure turn at about 700' AGL he flew high and wide to

the right, outside of the turn. Before I could reach the release lever,

he'd turned hard left and dove across the tail of the Pawnee wrapping the

tow rope around his left wing and, after it cut the top and bottom skins of

the wing clear to the spar, cutting the rope in two in the middle. The

final yank on the rope caused the tug to yaw hard right and pitch slightly

up (from about 45 degrees down).

Yikes. Over confidence and diminished capacity are a bad combination.

Annual flight reviews would head off more accidents than better tow hooks.

Now don't try to increase the number of "flight reviews" we must endure,
Young Grasshopper.

It's more about currency than reviews. Fly more and you'll be amazed at how
much more competent and knowledgeable you are.

"son_of_flubber" wrote in message
...
On Wednesday, February 12, 2014 12:03:17 PM UTC-5, Dan Marotta wrote:
Ain't no doubt about how quickly the tug gets upset when the glider
decides

to fly hither and yon.



My event involved a highly experienced retired FAA guy with type ratings
in

every aircraft imagineable. It was his first flight in a borrowed HP-14

and, during the departure turn at about 700' AGL he flew high and wide to

the right, outside of the turn. Before I could reach the release lever,

he'd turned hard left and dove across the tail of the Pawnee wrapping the

tow rope around his left wing and, after it cut the top and bottom skins
of

the wing clear to the spar, cutting the rope in two in the middle. The

final yank on the rope caused the tug to yaw hard right and pitch
slightly

up (from about 45 degrees down).

Yikes. Over confidence and diminished capacity are a bad combination.

Annual flight reviews would head off more accidents than better tow hooks.

On Thursday, February 13, 2014 10:39:33 AM UTC-5, Dan Marotta wrote:
Now don't try to increase the number of "flight reviews" we must endure,
Young Grasshopper.

Due to lax enforcement, flight reviews for glider pilots are already in effect voluntary.

I'm suggesting that pilots who know that their capacities are in decline, might in an ideal world, volunteer for 'early' flight review. I realize that a primary symptom of cognitive decline is an inability to recognize or acknowledge that decline (and irritation with anyone who raises the point).

If that "expert pilot" who nearly killed you on tow, had taken a timely flight review, the whole incident might never had happened.

Experts inevitably grow incompetent over time and some of them continue to fly.

Now I understand your point. That pilot had a lot of type ratings,
airliners and such. He was a neophyte glider pilot who was given the use of
a glider that he had no business flying. Of course, I didn't know that at
the time.


"son_of_flubber" wrote in message
...
On Thursday, February 13, 2014 10:39:33 AM UTC-5, Dan Marotta wrote:
Now don't try to increase the number of "flight reviews" we must endure,
Young Grasshopper.

Due to lax enforcement, flight reviews for glider pilots are already in
effect voluntary.

I'm suggesting that pilots who know that their capacities are in decline,
might in an ideal world, volunteer for 'early' flight review. I realize
that a primary symptom of cognitive decline is an inability to recognize or
acknowledge that decline (and irritation with anyone who raises the point).

If that "expert pilot" who nearly killed you on tow, had taken a timely
flight review, the whole incident might never had happened.

Experts inevitably grow incompetent over time and some of them continue to
fly.

On Thursday, February 13, 2014 8:40:08 PM UTC-5, Dan Marotta wrote:
He was a neophyte glider pilot who was given the use of
a glider that he had no business flying.

I would expect most neophyte glider pilots to land soon and inspect for damage after wrapping the tow rope around the wing and jerking loose. You might see why I concluded that this guy had more issues than inexperience in a glider.

His inexperience on tow may have lead to entanglement with the rope, but what reasonable person would elect to fly a potentially damaged aircraft for four hours?