Landing on Tow - YouTube link.

This was discussed here recently. JS was kind enough to drop by Jean
and share his experience with the instructors of the LVVSA. Here's a
link.
http://www.youtube.com/watch?v=QT_IkCb4Tzk

I wonder how this would go in a Nimbus 4D? Any opinions? ;

On Nov 10, 1:31*am, Bob wrote:
I wonder how this would go in a Nimbus 4D? Any opinions? ;

You'd have to approach with the airbrakes out to keep from over-
running the towplane.

I have to take umbrage at practicing something that is such an
incredibly rare event.

I have never even heard of a single tow rope release failure (but I am
sure that they have happened) let alone a double release failure.
Practicing slack rope and rope break (basically a single failure)
recoveries is important. But we simulate these at a decent altitude
which allows time and height to recover in case of something going
badly. Practicing what this video shows invites trying to recover at
the worse possible time - just a few feet above the ground. Would you
practice a much-more-likely-to-occur spin ... but at 100 feet?

Anyone know of a real life double release failure?

My $1.99.

- John DeRosa

On Nov 10, 9:36*am, ContestID67 wrote:
I have to take umbrage at practicing something that is such an
incredibly rare event.

I have never even heard of a single tow rope release failure (but I am
sure that they have happened) let alone a double release failure.
Practicing slack rope and rope break (basically a single failure)
recoveries is important. *But we simulate these at a decent altitude
which allows time and height to recover in case of something going
badly. *Practicing what this video shows invites trying to recover at
the worse possible time - just a few feet above the ground. *Would you
practice a much-more-likely-to-occur spin ... but at 100 feet?

Anyone know of a real life double release failure?

My $1.99.

- John DeRosa

I have NOT had a double release failure but I have had a single, at
the glider end, in a SGS 2-33. We were never able to duplicate or
determine the cause. Hasn't happened again. The glider had a
Schweizer release as did the tow-plane.

Our club has done significant testing on release forces for both TOST
and Schweizer hook systems (we have tow-planes with both) at various
angles and loads. I'll see if we have details and reports that can be
shared here. I'm sure it will be interesting to all.

But back to topic; I agree that it seems incredibly rare, the question
is: Does practicing something potentially dangerous present a greater
danger than the actual event? This is the premise behind the
avoidance of spin training in the US as well as the virtual ban on
practicing single engine failures (of twin-engined aircraft) on
liftoff.

A discussion of the options and developing a good understanding of the
elements of the process may be the safest approach. As a pilot of
many hours I have experienced several "eventualities" including failed
engines in various stages of flight and extreme icing. We don't
really train to specific circumstances but rather to the understanding
of principles surrounding a situation. With an understanding of those
principles and some basic intelligence most pilots can chose a
reasonable course of action.

I know that most accidents fly in the face of the previous statement,
however the crux of the statement is "an understanding of those
principles". I'm a full-time flight instructor and teach
international students as well as US pilots in SEL, MEL and gliders.
I've been doing it for 15 years and have worked with close to a
thousand individuals. I have seen that in most cases individual try
to learn "just enough". It is a very rare individual that digs into
the library of materials I offer or even researchs the web pages that
are available. In defense of gliders pilots: they seem to be more
interested, as a group, in gaining knowledge for knowledges sake and
thus are better at understanding the principles.

Rather that rattle on longer. Summary: teach the principles, practice
in safe scenarios, review frequently.

ContestID67 wrote:
I have to take umbrage at practicing something that is such an
incredibly rare event.

I have never even heard of a single tow rope release failure (but I am
sure that they have happened) let alone a double release failure.
Practicing slack rope and rope break (basically a single failure)
recoveries is important. But we simulate these at a decent altitude
which allows time and height to recover in case of something going
badly. Practicing what this video shows invites trying to recover at
the worse possible time - just a few feet above the ground. Would you
practice a much-more-likely-to-occur spin ... but at 100 feet?

Anyone know of a real life double release failure?

My $1.99.

- John DeRosa

I think practicing this is pretty darn stupid, why risk a collision
between two perfectly fine aircrafts during decent and ground roll ?

The risk of a slippery glass glider catching up with the towplane during
decent is simply not worth it.

Better things to practice that have a much higher probability includes;
tow plane power loss (at safe height, do wing rocking - glider pilot
should react correctly, i.e release), spin entry/recovery, air brake
deployment during tow at safe height, landing with full airbrakes
deployed and of course, procedures for rope break at various heights,
etc etc

Being an instructor myself, I had a very interesting ride with a
(talented) student when I pulled the release handle to simulate rope
brake at around 330ft/110m in strong straight side-wind (i.e. 90 degrees
from takeoff direction).

The student turned around to land downwind, which was OK. But he turned
the wrong way since he didn't turn into the wind. Since we were
practising at a very large airfield I let him continue and he corrected
his position before landing since he was well off the centerline once
the turn was finished.

The student realized his mistake at an early stage but did the right
thing and continued the turn instead of consuming height trying to
reverse the turn. This particular student will NEVER do this mistake
again since he got to experience what happens when doing it the wrong way.

An example of practicing a probable scenario that at a fairly low risk
gives much in return for the student.

Double release failure ?! Bah !

/AndersP

On Nov 10, 12:31*am, Bob wrote:
I wonder how this would go in a Nimbus 4D? Any opinions? ;

In a 2C it would be terrifying. A 4D has to be worse.

I also note the Pawnee was making a low, power-on approach which had
it below the power-off glide path to the runway - something most light
airplane pilots are taught not to do.

Lets talk about an alternative procedure with a typical glider like a
G103. The 103 POH specifies max weak link as 1662 Lbs and the max
weight as 1278. 1662/1278 = a 1.3 G momentary jerk that would be
required to break the link. Open the spoilers with slack in the tow
rope and 1.3G is easy to achieve.

Of course, the glider might be flown lighter if solo which could have
a flying weight as low as 992 Pounds. 1662/992 = 1.7G - still easy to
achieve with a little slack and spoiler. 103's are just as likely to
be flown over gross weight in many clubs. Also many operations sue an
old, worn piece of rope as a weak link that is likely to be weaker
than 1662 Lbs.

I'm convinced just breaking the weak link is the safer procedure in
the extremely unlikely case of a double release failure. It can't be
hard - students do it all the time.

I'm convinced just breaking the weak link is the safer procedure in
the extremely unlikely case of a double release failure. *It can't be
hard - students do it all the time.

When this subject last came up some time ago, we had an informal poll
at our club of a mix of experienced cross-country and aerobatic pilots
and every one said they would opt for breaking the weak link at
altitude rather than try an on-tow landing.

Not one of us thought that trying a coordinated landing would be safer
than breaking the link. Not one!

Yet some seem to believe that we should train low-time students to do
this maneouver. Why?

Mike

In message , AndersP
writes
snip

The risk of a slippery glass glider catching up with the towplane
during decent is simply not worth it.
Snip

Opening the airbrakes works very well at stopping the glider catching up
the towplane... Descending on tow (though not all the way down) was one
of the things I had to do on my final flight before going solo.

--
Surfer!

On Tue, 10 Nov 2009 11:48:59 -0800 (PST), bildan
wrote:

On Nov 10, 12:31*am, Bob wrote:
I wonder how this would go in a Nimbus 4D? Any opinions? ;

In a 2C it would be terrifying. A 4D has to be worse.

Add the Schleicher open class gliders to that list.


I'm convinced just breaking the weak link is the safer procedure in
the extremely unlikely case of a double release failure. It can't be
hard - students do it all the time.

Basically a good idea... but...

.... unfortunately there are many gliding operations which do not use
weak links at all - especially in the French Alps where the area in
the vicinity of the airport is unlandable and a weak link break would
result in the certain destruction of the glider.