Recognizing and reacting to tow plane engine failure

On Friday, October 24, 2014 10:40:08 AM UTC-4, John Carlyle wrote:
I've experienced simulated power failures and simulated rope breaks just after I'm flying but the tow plane isn't.

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The simulated tow plane power failure was not a piece of cake. It took a few seconds to figure out that something was wrong, find the release and transition to landing mode.

The case of the towplane being on the ground and aborting takeoff when the glider is flying in ground effect is problematic.

If the runway has poor straight ahead landing options (I mean poor options for landing after a 100 AGL engine failure), then aborting takeoff before the towplane leaves the ground, even for an unconfirmed engine/pilot problem, is understandable. But the glider having much less drag is fated to fly past the tow plane (if it avoids collision).

Is it possible for the glider to turn fast enough to avoid colliding with the towplane? What happens when a glider touches a wingtip to the ground at 40 knots?

At what velocity does the glider have enough energy to fly over top of the towplane? Or is that impossible?

Any experiences/thoughts?

Its all "communication"..

But the whole point of the "turn" signal is that the tow pilot doesn't need to or try to "fight" it.

So which signals do you use radio for and which signals do you use the standard accepted signal?

Do you brief glider pilots as to which signals you do not respond to and which you do?

Has the SSA changed/adopted the accepted signal for "tow plane please turn" to now a "radio signal"?

When the tow plane rudder hits the stop, what happens? It snap rolls!!!??

Cookie





On Sunday, October 26, 2014 6:48:57 AM UTC-4, Bruce Hoult wrote:
On 2014-10-26 09:45:47 +0000, Cookie said:

Ok...and signalling a turn by moving out to the side will not make the
towplane hit its rudder stops either ...so what's the problem?


Shall we now replace all 17 of the "standard American soaring
signals"...with "use radio"?

Cookie


If boxing the wake causes the towplane to reach control stops then you
are doing it WAY WRONG and should expect to wear the rope, yes.

If it's mere communication ... like wagging your wings ... that's one
thing. If it's physically pulling the tail around against the tow pllot
attempting to maintain his intended heading then that's quite another.

So, you're saying the rudder won't even be near the stop on a typical box the wake, or "please turn" signal....so what's the problem?


Cookie





On Sunday, October 26, 2014 7:03:30 AM UTC-4, Bruce Hoult wrote:
On 2014-10-26 09:45:47 +0000, Cookie said:

Ok...and signalling a turn by moving out to the side will not make the
towplane hit its rudder stops either ...so what's the problem?


Shall we now replace all 17 of the "standard American soaring
signals"...with "use radio"?

Cookie


If boxing the wake causes the towplane to reach control stops then you
are doing it WAY WRONG and should expect to wear the rope, yes.

Btw:

Pawnee wingspan 36 ft 2 in. So out at his wingtip you are 5.5 m off
center. On a 60m rope that's 5.3 degrees angle on the rope.

If the glider weighs 600 kg and has a 30:1 L/D at towing speed then
there will be 20 kg of pull in the rope from drag, plus (at 600 fpm, 3
m/s climb and 70 knots 38 m/s airspeed) another 48 kg pull from
climbing. Total 68 kg. About 6 kg of which will be sideways pull on the
tail.

Anyone want to figure out how much rudder deflection it takes to
produce 6 kg sideways force at 70 knots? It won't be a lot.

On 2014-10-26 13:20:35 +0000, Cookie said:

Its all "communication"..

But the whole point of the "turn" signal is that the tow pilot doesn't
need to or try to "fight" it.

So which signals do you use radio for and which signals do you use the
standard accepted signal?

Do you brief glider pilots as to which signals you do not respond to
and which you do?

Has the SSA changed/adopted the accepted signal for "tow plane please
turn" to now a "radio signal"?

When the tow plane rudder hits the stop, what happens? It snap rolls!!!??

Cookie





On Sunday, October 26, 2014 6:48:57 AM UTC-4, Bruce Hoult wrote:
On 2014-10-26 09:45:47 +0000, Cookie said:

Ok...and signalling a turn by moving out to the side will not make the
towplane hit its rudder stops either ...so what's the problem?


Shall we now replace all 17 of the "standard American soaring
signals"...with "use radio"?

Cookie


If boxing the wake causes the towplane to reach control stops then you
are doing it WAY WRONG and should expect to wear the rope, yes.

If it's mere communication ... like wagging your wings ... that's one
thing. If it's physically pulling the tail around against the tow pllot
attempting to maintain his intended heading then that's quite another.

In this country there are two standard accepted non-radio signals from
the towplane, and one from the glider:

From towplane:
- release immediately
- check your airbrakes

From glider:
- I am unable to release

Anything else is prearranged before takeoff, or else in flight over the radio.

The SSA has no influence here.

On Sunday, October 26, 2014 8:59:46 AM UTC-4, son_of_flubber wrote:
The case of the towplane being on the ground and aborting takeoff when the glider is flying in ground effect is problematic.

If the runway has poor straight ahead landing options (I mean poor options for landing after a 100 AGL engine failure), then aborting takeoff before the towplane leaves the ground, even for an unconfirmed engine/pilot problem, is understandable. But the glider having much less drag is fated to fly past the tow plane (if it avoids collision).

Is it possible for the glider to turn fast enough to avoid colliding with the towplane? What happens when a glider touches a wingtip to the ground at 40 knots?

At what velocity does the glider have enough energy to fly over top of the towplane? Or is that impossible?

Any experiences/thoughts?

I don't understand why you call low level tow plane engine failure "problematic". I've seen two actual low level engine failures in ten years of glider flying (to be specific, the glider was flying and the tow plane was not). Tow planes lead a rough life and engine failures do happen, a lot more than we'd like.

Your comment "the glider is fated to fly past the tow plane" is exactly why (1) you need to prepare for this and (2) you need to see this situation for real. Yes, you can turn to avoid the tow plane if (and only if) you recognize that you must do so soon enough. If you touch a wingtip at 40 kt you will be in for Mr. Toad's wild ride - hopefully you and the glider will not need major repairs. I wouldn't even think about trying to fly over the tow plane - but then the runways I fly from have lots of good grass on their sides.

Again, the point I was trying to make is that a low level tow plane engine failure does happen and that experiencing one (albeit simulated) was a completely different affair from what I had imagined from reading about them. You have to be alert, and you must react quickly.

-John, Q3

No...there are 17 accepted signals...none require radio...that's the beauty of signals.......

who put you in charge?


Cookie



On Sunday, October 26, 2014 9:59:21 AM UTC-4, Bruce Hoult wrote:
On 2014-10-26 13:20:35 +0000, Cookie said:

Its all "communication"..

But the whole point of the "turn" signal is that the tow pilot doesn't
need to or try to "fight" it.

So which signals do you use radio for and which signals do you use the
standard accepted signal?


In this country there are two standard accepted non-radio signals from
the towplane, and one from the glider:

From towplane:
- release immediately
- check your airbrakes

From glider:
- I am unable to release

Anything else is prearranged before takeoff, or else in flight over the radio.

The SSA has no influence here.

http://www.soaringsafety.org/pilots/ic7.htm


Gee...look at the first signal....

I suggest you contact the soaring safety foundation and have this situation rectified immediately!

Cookie


In this country there are two standard accepted non-radio signals from
the towplane, and one from the glider:

From towplane:
- release immediately
- check your airbrakes

From glider:
- I am unable to release

Anything else is prearranged before takeoff, or else in flight over the radio.

The SSA has no influence here.

I'm with you cookie. Radio communications often get stepped on or are somehow compromised... The STANDARD AMERICAN SOARING SIGNALS are not.

Boggs

On Sunday, October 26, 2014 11:09:11 AM UTC-4, Waveguru wrote:
I'm with you cookie. Radio communications often get stepped on or are somehow compromised... The STANDARD AMERICAN SOARING SIGNALS are not.

Boggs

Thank you!

Cookie

On Sunday, October 26, 2014 8:59:46 AM UTC-4, son_of_flubber wrote:
The case of the towplane being on the ground and aborting takeoff when the glider is flying in ground effect is problematic.

On Sunday, October 26, 2014 10:27:28 AM UTC-4, John Carlyle wrote:
I don't understand why you call low level tow plane engine failure "problematic".

Problematic
noun
1. a thing that constitutes a problem or difficulty.

The problem is obvious: the glider pilot has very little time avoid collision.

jc:

I've seen two actual low level engine failures in ten years of glider flying (to be specific, the glider was flying and the tow plane was not).

Was there a collision?

I've seen the aftermath of one such aborted takeoff. The tow plane and glider collided (no human injuries).

What is the success rate for this maneuver?