Winch Launch Fatality

1. Nose way down NOW!
2. Get a safe airspeed ASAP!
3. Decide on the landing option (Straight or circle.)
4. Execute landing option - concentrate on airspeed and coordination.
5. Pull the release - maybe.

Move 5 up to 2 and I'll agree with your sequence. Three reasons:
(a) you're going to wait some seconds for the airspeed to build so
* * pulling it at this point doesn't delay any other actions.

(b) Your hand is on or very near the release, so just do it.

(c) As I said above, you may be faced with a power fade rather than
* * a cable break and the cable may still be on. Now, we know that
* * back-release works for a straight backward pull, but what if
* * its a high power fade and you get airspeed and turn. Would you
* * still expect the cable to back release at an angle to the flight
* * path?

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

OK, maybe, as long as it isn't priority 1 - but now you are
introducing a power fade which is a different animal. Power fades are
demonstrated and practiced along with simulated rope breaks just so
pilots know the difference. No one has ever said, "Wow, that's
confusing - how do you tell the difference?"

(C.) However, this one deserves serious consideration. A break is an
obvious "thump" and an upward surge. (Spectra/Dyneema rope generates
a much more obvious thump than steel.)

Assuming the pilot is monitoring airspeed, a power fade means the nose
will coming down and be down to a normal glide attitude and airspeed
as power is totally lost - just as at the top of a normal launch. It
will be managed as if it were a normal launch with a normal release
pull - just at a lower height. Just as with a normal launch, the
winch driver will be alert to the rope not detaching from the glider
and fire the guillotine

For a winch power loss to be confused with a rope break, the power
failure would need to be a rare kind - some sort of explosive loss of
mechanical integrity or seizing up of the winch. But, if the rope is
still attached at the winch, there won't be the upward surge.

On Tue, 23 Jun 2009 14:42:24 -0700, bildan wrote:

OK, maybe, as long as it isn't priority 1 - but now you are introducing
a power fade which is a different animal.

They aren't taught as distinct happenings here - just as winch launch
failures. I agree that they are seldom confused, but the actions to be
taken after a cable break or after a power fade is recognised are the
same: (1) nose down to establish approach speed, (2) make sure cable is
off (3).....

No one has ever said, "Wow, that's confusing - how do you
tell the difference?"

....and I didn't say or imply that anybody confuses the two.

(C.) However, this one deserves serious consideration. A break is an
obvious "thump" and an upward surge. (Spectra/Dyneema rope generates a
much more obvious thump than steel.)

Even when it breaks at the winch end? I wouldn't know - I've not yet
flown on the stuff.

Assuming the pilot is monitoring airspeed, a power fade means the nose
will coming down and be down to a normal glide attitude and airspeed as
power is totally lost - just as at the top of a normal launch.

If its a slow fade the airspeed may easily be lower than approach speed.
IME a slow fade is harder to recognize and deal with than a sudden cut or
a break.


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

(Spectra/Dyneema rope generates a much more obvious thump than steel.)

Even when it breaks at the winch end? I wouldn't know - I've not yet
flown on the stuff.

It doesn't matter where it breaks - the whole rope weighs around 30
Lbs so the feel in the glider is the same.


Assuming the pilot is monitoring airspeed, a power fade means the nose
will coming down and be down to a normal glide attitude and airspeed as
power is totally lost - just as at the top of a normal launch.

If its a slow fade the airspeed may easily be lower than approach speed.
IME a slow fade is harder to recognize and deal with than a sudden cut or
a break.

Not if the pilot is controlling, or just monitoring, the airspeed.
The pilot will lower the nose appropriately to maintain the selected
airspeed. When the power is all gone, the glider will be gliding at
the selected speed - a perfect recovery even if the pilot didn't
recognize the power failure. Lowering the nose is the signal for more
speed so it works in all cases.