Spin

There are no worldwide standards but rather local procedures (depending on
the terrain) with daily adjustments (depending on wind conditions).

--
Bert Willing

ASW20 "TW"


"Janos Bauer" a écrit dans le message de
...

If standard rules (e.g. landing straight ahead after this low cable
break) had been performed nothing seriously would have happened.

What are the standards altitudes for such incident? Here are the list
I learnt: 50 straight landing, 50&100 one 180 degree turn, 180 two
turns or small circle. Of course in strong wind I would increase these
values.


/Janos

I once watched a pilot turn an ASW 20 through 360 degrees after a 75
foot rope break. With each successive 90 degree turn, I heaved a sigh
of relief, until he rolled into the next one. The pilot made three 90
degree left hand turns, at one point dropping slightly below the level
of the runway, until he was lined up to land across the runway. He
made his last 90 degree right turn in ground effect, using rudder
only. I didn't see much of the touchdown or rollout, as I was running
for life and limb. The glider was undamaged. The pilot, on the other
hand...

To my knowledge, he never flew another glider.



"Bill Daniels" wrote in message ...
"CV" wrote in message
...
Fredrik Thörnell wrote:
What does the commentator say about 18 meter (high?) something? Or is

He is saying that the cable broke at 80 meters height. (200 odd feet)
CV

Perhaps someone familiar with the incident could explain why the pilot tried
to turn back from a height of 80 meters. I would expect that, with a wire
break at 80 meters, the pilot would have 75% or more of the airfield
straight ahead for a safe landing. In fact, a 180 degree turn from an 80
meter wire break would leave no place to land at most winch sites.

Bill Daniels

Sorry, meters.

/Janos

Todd Pattist wrote:
Janos Bauer wrote:


What are the standards altitudes for such incident? Here are the list
I learnt: 50 straight landing, 50&100 one 180 degree turn, 180 two
turns or small circle. Of course in strong wind I would increase these
values.


Units? Meters or feet?

Todd Pattist - "WH" Ventus C
(Remove DONTSPAMME from address to email reply.)

Please would someone post a url if this clip is online.

Thanks



At 15:36 05 February 2004, Todd Pattist wrote:
Janos Bauer wrote:

Sorry, meters.

Thanks. I thought it was meters, but I wanted to be
sure.
Todd Pattist - 'WH' Ventus C
(Remove DONTSPAMME from address to email reply.)

David Pye
Kent Gliding Club
Charing

Mob: 07946-302975
Home: 01732-873088
East Malling, Kent, UK

At 23:12 05 February 2004, David Pye wrote:
Please would someone post a url if this clip is online.


http://www.fsv-unterjesingen.de/DnLoads/Seilriss.avi

He made his last 90 degree right turn in ground effect, using rudder
only. I didn't see much of the touchdown or rollout, as I was running
for life and limb. The glider was undamaged. The pilot, on the other
hand...

To my knowledge, he never flew another glider.

A turn at low speed with rudder only is an invitation for a spin.
At low altitude, it will usually end exactly the way we saw in this video,
with the glider spinning right into the ground.

If your collegue performed that last turn at very high speed the glider
wouldn't turn with rudder only.
If it was at low speed, and below 2 feet altitude, one of the wingtips
certainly touched first and it wasn't very pretty.

If he was above 2 feet, the result would have been some glider damage.

Bert Willing wrote:

There are no worldwide standards but rather local procedures (depending on
the terrain) with daily adjustments (depending on wind conditions).

--
Bert Willing

ASW20 "TW"

"Janos Bauer" a écrit dans le message de
...

If standard rules (e.g. landing straight ahead after this low cable
break) had been performed nothing seriously would have happened.

What are the standards altitudes for such incident? Here are the list
I learnt: 50 straight landing, 50&100 one 180 degree turn, 180 two
turns or small circle. Of course in strong wind I would increase these
values.


I had a reminder last summer during a check flight on a new field, and
then tried to pass the message to my first students during my first flights
as instructor: as long as landing straight ahead is possible, do it, don't
try anything else. If it is not possible, then you should have a height
sufficient for an abbreviated pattern. What I would like to add is some
rule of thumb for estimating if landing straight ahead is possible, not
based on looking on instruments if possible, like "First push the stick
in order to reach a normal flight attitude and speed. Then if you can see
the last 300m of the runway, you can land ahead". The value of 300m is
of course subject to discussion and change. The advantage of such a strategy
is that it could be well planned before take-off by having a well-known ground
feature mark the point you must see for deciding to land straight ahead.

Janos Bauer wrote:

What are the standards altitudes for such incident? Here are the list
I learnt: 50 straight landing, 50&100 one 180 degree turn, 180 two
turns or small circle. Of course in strong wind I would increase these
values.

I have been VERY surprised a few times by the effect of a slight
tailwind on my rope break practice. Since then I pay a lot
more attention to when the towplane rotates. If he rotates
much further down the strip, then I know I have either
a tailwind, heavy glider, high density altitude, etc.

Of course this assumes the towplane pilot rotates at the same speed
each time (in my experience they are very consistent).

In the cases when this happens
I know we ain't doin' very much "up" for the amount
"forward." So I SWAG a higher 180 altitude (maybe 300 or 400 feet).
The worst was an open canopy L-13 with two people on a hot
day with a 3-5 knot tailwind and only 180hp towplane. I dunno
if even 400 feet AGL woulda been enough.

Anybody else use the point of towplane rotation as
a hint?

I've wondered why airliners don't have some spot on the
ground (GPS) some distance down the runway, and abort
at that spot if they haven't reached a certain airspeed.
Seems simpler than doing all them calculamications for
wind, density altitude, etc. which may have changed since
you did them. Why not observe instead of predicting?

It doesn't work if you have ice/frost on the wings,
or if the ASI malfunctions (reads too high AS),
or you're misconfigured, but otherwise it seems to make
sense to me...

Of course when's the last time anybody de-iced a towplane or
glider, for goodness sakes! ;O

Arnold Pieper wrote:
He made his last 90 degree right turn in ground effect, using rudder
only. I didn't see much of the touchdown or rollout, as I was running
for life and limb. The glider was undamaged. The pilot, on the other
hand...

To my knowledge, he never flew another glider.

A turn at low speed with rudder only is an invitation for a spin.
At low altitude, it will usually end exactly the way we saw in this video,
with the glider spinning right into the ground.

I wonder if this was use of rudder, or coarse use of rudder.
I suspect the steep bank and different wing airspeeds set it up,
and then an accelerated use of rudder caused the wingtip speeds
to be that much more (a skidding stab at the rudder seems like
it would have a different effect than slowly putting in rudder).


If your collegue performed that last turn at very high speed the glider
wouldn't turn with rudder only.
If it was at low speed, and below 2 feet altitude, one of the wingtips
certainly touched first and it wasn't very pretty.

I've done quite a few turns with level wings and using rudder
to turn below 2 feet. I've done it both on the takeoff
roll (to line up from being way off) behind the towplane, and
after landing to line up with the takeoff runway (about
120 degrees left).

In the first case I probably should have simply released immediately.
In the second case I should have stopped straight ahead.
Not because this was necessary (it wasn't, since de facto
everything worked out fine) but because it would
be better practice for flying a higher performance glider,
where both of these circumstances could possibly create a
ground loop.

The competition pilots stay REAL straight at low airspeeds.
I suspect a few ground loops have convinced them not to
put in adverse yaw (and rudder to turn) during taxi.

Mark, I think Janos was talking about winch launch. The land ahead/turn
height for winch launch depends greatly on the winch site although at 25% of
the altitude expected without a wire break, say 500 feet or 150 meters, a
landing straight ahead on the runway should be possible. The ideal,
available at most sites, is an overlap between the two options where a 360
degree turn with a landing into the wind can be made from 300 feet AGL and a
straight ahead landing can be successful at 450 feet.

For airtow, there are certainly conditions where a low altitude rope break
will not allow the glider to get back to the airfield. Tailwinds, high
density altitudes and heavy gliders make conditions worse for rope breaks.
I have often been at 1000'AGL (300 Meters) before I felt comfortable about a
return to the runway. Under these conditions, airtow weak link strength
becomes a life or death matter.

Conditions like these make me far more comfortable with winch launch where I
can be sure of landing the glider on the airfield without a scratch.

Bill Daniels


"Mark James Boyd" wrote in message
news:4023f76a$1@darkstar...
Janos Bauer wrote:

What are the standards altitudes for such incident? Here are the list
I learnt: 50 straight landing, 50&100 one 180 degree turn, 180 two
turns or small circle. Of course in strong wind I would increase these
values.

I have been VERY surprised a few times by the effect of a slight
tailwind on my rope break practice. Since then I pay a lot
more attention to when the towplane rotates. If he rotates
much further down the strip, then I know I have either
a tailwind, heavy glider, high density altitude, etc.

Of course this assumes the towplane pilot rotates at the same speed
each time (in my experience they are very consistent).

In the cases when this happens
I know we ain't doin' very much "up" for the amount
"forward." So I SWAG a higher 180 altitude (maybe 300 or 400 feet).
The worst was an open canopy L-13 with two people on a hot
day with a 3-5 knot tailwind and only 180hp towplane. I dunno
if even 400 feet AGL woulda been enough.

Anybody else use the point of towplane rotation as
a hint?

I've wondered why airliners don't have some spot on the
ground (GPS) some distance down the runway, and abort
at that spot if they haven't reached a certain airspeed.
Seems simpler than doing all them calculamications for
wind, density altitude, etc. which may have changed since
you did them. Why not observe instead of predicting?

It doesn't work if you have ice/frost on the wings,
or if the ASI malfunctions (reads too high AS),
or you're misconfigured, but otherwise it seems to make
sense to me...

Of course when's the last time anybody de-iced a towplane or
glider, for goodness sakes! ;O