tow rope brake practice crash, what can we learn...

On Jul 13, 8:52*pm, Kevin Christner wrote:
On Jul 11, 5:38*pm, wrote:
Can anyone tell me if they've had an actual rope break below ~200 or
even ~400ft. *I have never, ever heard of one.

KJC

Actual rope breaks are pretty rare, but I think what you are trying
ask is who has had a PTT (Premature Termination of Tow) below between
200 and 400 feet. These are much more common.

Last month I terminated a tow at about 200 feet by pulling the
release. The tow plane wasn't climbing and I didn't know why. I
released and returned to the runway before we got too far away from
the runway to do so. Not a big deal since I practice this regularly
and it was a training flight anyway. Turned out the towplane was
experiencing carb ice and was fine after applying the carb heat.

I have hit turbulance on tow in my glider and got a slack rope
condition that caused a back release at about 400 feet.

The previous owner of my glider had the canopy depart the glider at
about 200 feet resulting in a broken rope and a 180 turn back to the
runway.

Brian
CFIIG/ASEL

On 7/14/2011 5:40 AM, T8 wrote:
On Jul 13, 10:52 pm, Kevin
wrote:

Can anyone tell me if they've had an actual rope break below ~200 or
even ~400ft. I have never, ever heard of one.

I had a rope break at 150' on my seventh student solo flight. I'm
glad we covered this in pre solo training.

-Evan Ludeman / T8

Per Kevin's question, "I have not," and until reading of Evan's experience,
nor had I ever heard of one since beginning participating in soaring in 1972.

That noted, I *did* experience a rope break in 1975 (15-meter glass), so weird
it stuck firmly in memory. Above 1k agl in benign air, the tug smoothly began
accelerating away/up from me, as what seemed like the entire rope sank out of
sight below. Being overhead the runway, I had no hesitation in pulling the
release (though it had probably already back released), lowered the gear
(there being no hope of remaining aloft in the flat conditions) and landed.
Subsequent inspection revealed the rope had parted where it exited a small
'bell-mouth' at the rear of the fuselage, feeding into a winch...meaning at a
portion of the rope neither wing runner or glider pilot would ever be likely
to see. What seemed weird about it to me was the rope had withstood the
(presumably far) larger tension of accelerating the glider from rest, while
parting under a very light, essentially steady-state load.

If it happens it must be possible. The same thought applies to relatively
perplexing accidents as the recent Montana 2-32 crash. Thoughtful pilots will
draw some appropriate-to-them conclusions...

One of my long-standing conclusions is I *can* screw up. Anywhere in a flight.
Hence I try to fly accordingly, especially where the margins are thin.

Bob W.

On Jul 14, 8:43*am, Berry wrote:
Far worse than the CFI-G in our club who was constantly warning students
about loss of airspeed due to turning downwind...


Many people argue that this is not real and base their argument on the
fact that the glider is moving in the air so the glider does not see
the wind speed difference. While that's true it ignors the very
important point that a pilot will, particularly at low altitude, and
particularly if not monitoring the ASI and yaw string, tend to make
control inputs based on the observed movement of the glider over the
ground.

The effect is real. If you haven't experienced it be thankful. The
two fatal accident after rope breaks in strong wing conditions may be
related to this.

Andy

On Thu, 14 Jul 2011 12:52:15 +0000, Walt Connelly wrote:

There are two things important here.
1. The importance of being ready to handle the rope break by practice.

No argument here.

Which direction do you turn?

This is an obvious question when winching and the answer is always the
same: downwind if there's any crosswind, because that opens the circuit
out at minimal cost.

I almost asked about it earlier in the thread and then decided that was
obvious - you'd turn the same way as usual because that's what the tow
pilot is expecting. So, is this the correct answer and, if not, what is?

If a current, experienced pilot blows it at a critical
moment, what's going to happen to the guy who flies twice a year?

At my club he'd be given a mandatory check flight if he hadn't flown for
more than a month and rocked up expecting to fly solo.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Jul 14, 9:57*am, Martin Gregorie
wrote:

I almost asked about it earlier in the thread and then decided that was
obvious - you'd turn the same way as usual because that's what the tow
pilot is expecting. So, is this the correct answer and, if not, what is?

With a crosswind and only the takeoff runway as a landing option the
choice should usually be into the wind.

A turn into a crosswind will reduce the deviation of the glider from
the extended runway centre line and reduce the distance required to
return to the runway centre line for landing. It therefore reduces
the altitude loss for the course reversal.

Imagine a 90 deg cross wind that equals the glider's airspeed. A turn
into wind can be accomplished on the runway extended center line. Now
consider how far the glider must go to complete the turn if made
downwind.

Andy

On Thu, 14 Jul 2011 10:13:53 -0700, Andy wrote:

On Jul 14, 9:57Â*am, Martin Gregorie
wrote:

I almost asked about it earlier in the thread and then decided that was
obvious - you'd turn the same way as usual because that's what the tow
pilot is expecting. So, is this the correct answer and, if not, what is?

With a crosswind and only the takeoff runway as a landing option the
choice should usually be into the wind.

A turn into a crosswind will reduce the deviation of the glider from the
extended runway centre line and reduce the distance required to return
to the runway centre line for landing. It therefore reduces the
altitude loss for the course reversal.

Imagine a 90 deg cross wind that equals the glider's airspeed. A turn
into wind can be accomplished on the runway extended center line. Now
consider how far the glider must go to complete the turn if made
downwind.

I initially thought into wind, i.e. opposite to what I'd mentally run
through in my pre-winch-launch eventualities, was the answer.

Then it occurred to me that, if the cross wind was such that turning into
it caused you to turn opposite to the local aero tow release convention
and the tow pilot wasn't looking or was dealing with a situation at his
end that had forced the tow to be abandoned, you could easily end up in
conflict with the tow plane. Not a good place to be.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

In article
,
Andy wrote:

On Jul 14, 8:43*am, Berry wrote:
Far worse than the CFI-G in our club who was constantly warning students
about loss of airspeed due to turning downwind...


Many people argue that this is not real and base their argument on the
fact that the glider is moving in the air so the glider does not see
the wind speed difference. While that's true it ignors the very
important point that a pilot will, particularly at low altitude, and
particularly if not monitoring the ASI and yaw string, tend to make
control inputs based on the observed movement of the glider over the
ground.

The effect is real. If you haven't experienced it be thankful. The
two fatal accident after rope breaks in strong wing conditions may be
related to this.

Andy

Slaps head: I knew I should not have mentioned the "downwind turn".

Originally Posted by Andy[_1_]

On Jul 14, 9:57*am, Martin Gregorie
wrote:

I almost asked about it earlier in the thread and then decided that was
obvious - you'd turn the same way as usual because that's what the tow
pilot is expecting. So, is this the correct answer and, if not, what is?

With a crosswind and only the takeoff runway as a landing option the
choice should usually be into the wind.

A turn into a crosswind will reduce the deviation of the glider from
the extended runway centre line and reduce the distance required to
return to the runway centre line for landing. It therefore reduces
the altitude loss for the course reversal.

Imagine a 90 deg cross wind that equals the glider's airspeed. A turn
into wind can be accomplished on the runway extended center line. Now
consider how far the glider must go to complete the turn if made
downwind.

Andy

I can imagine a 90 degree crosswind that equals the gliders speed but I wouldn't be taking off under those conditions. If the wind is that strong I would need to be pointing very much into wind. Had takeoffs and landing in both my Ventus a and Nimbus 3D at 18 - 21 knots at 45 degrees to runway and out landing field alike and there wasn't much directional control left.

Your illustration has little practical value.

Subject to local variations I would agree with Martin that a downwind turn in crosswind conditions is often the better option as it enables you to fly a teardrop pattern to the centreline more easily.

Cheers
Colin

On Jul 14, 10:13*am, Andy wrote:
On Jul 14, 9:57*am, Martin Gregorie
wrote:

I almost asked about it earlier in the thread and then decided that was
obvious - you'd turn the same way as usual because that's what the tow
pilot is expecting. So, is this the correct answer and, if not, what is?

With a crosswind and only the takeoff runway as a landing option the
choice should usually be into the wind.

A turn into a crosswind will reduce the deviation of the glider from
the extended runway centre line and reduce the distance required to
return to the runway centre line for landing. *It therefore reduces
the altitude loss for the course reversal.

Imagine a 90 deg cross wind that equals the glider's airspeed. *A turn
into wind can be accomplished on the runway extended center line. *Now
consider how far the glider must go to complete the turn if made
downwind.

Andy

We have parallel runways, gliders on one side, powered traffic on the
other, with opposite side traffic patterns that separates power from
glider traffic.

We always brief to turn away from the other runway to avoid a possible
headon with traffic you may not have heard on the radio.

T

On Jul 15, 4:43*am, Andy wrote:
While that's true it ignors the very
important point that a pilot will, particularly at low altitude, and
particularly if not monitoring the ASI and yaw string, *tend to make
control inputs based on the observed movement of the glider over the
ground.

The effect is real. *If you haven't experienced it be thankful. *The
two fatal accident after rope breaks in strong wing conditions may be
related to this.

Don't you people have ridges?

I don't think anyone would be likely to get to solo here without being
very aware that the direction the glider is pointing has little to do
with the direction it is moving, and having experienced this a number
of times in 20+ knots winds, at low level, while doing a lot of 180
degree turns, with the instructor pointing it out if the string didn't
stay in the middle.