Parowan Fatal Crash

Points taken, but having said that, how well will pilots react if they
unexpectedly get into a spin or a spiral dive? Normally you gird your
loins up first before doing a deliberate spin! It has only happened to me
once while solo flying (a spin), and I have to admit that that it took me
a second or two to twig what was going on. I have also seen a K6E flown by
a very experienced instructor returning to the airfield looking as though
it had been on a bombing raid, with lots of torn fabric and other damage
after a loss of control in a rough thermal.

Derek Copeland

At 11:17 02 July 2009, T8 wrote:
On Jul 2, 6:45=A0am, Gregg Leslie wrote:
How about some sympathy for the families...

GL

Yes, thank you Gregg.

For the rest of you guys... c'mon. You want to discuss elementary
spin recovery technique, fine. Start your own thread. Please don't
do it in the context of a couple of tragic accidents.

We don't know what happened. I do know that the one of these guys I
knew personally had a lot more flight experience in all sorts of
aircraft, from hang gliders to turbo-twins than most of the noisy
pundits here. If he failed to apply appropriate corrective actions, I
suspect it is most likely because he was incapacitated. Lack of
knowledge or skill wasn't the problem.

I'm with Ramy, these accidents are disturbing.

-Evan Ludeman / T8

On Jul 1, 10:54*pm, Heinz wrote:
On Jul 1, 2:32*pm, bildan wrote: Any attempt to turn will trip an asymmetric stall which will develop
into a spin in less than a second. * *Just before the glider spins,
everything "looks" normal. *(Except, of course, for the ridiculously
low airspeed, sloppy controls, absence of wind noise etc...) *Several
high time glider pilots doing a BFR with me didn't see this one coming
and were visibly shaken by their 'inadvertent spin'.

What happens next is crucial. *If the pilot does nothing, the glider
is likely to transition into a spiral dive. *

I do not understand this last sentence. What converts a spin into a
spiral dive? What is the aerdynamic/physics here?
Heinz

Most modern gliders are very spin resistant and won't stay in a spin
unless the controls are held in the pro-spin position - full up
elevator and into the spin rudder. This is unlikely in an inadvertent
spin so the usual scenario is a initial wing drop and a quarter turn
auto-rotation transitioning into a spiral dive. If the pilot is
behind the glider and applies spin recovery control inputs - forward
stick and anti-spin rudder - after the glider has made this
transition, it gets "interesting".

There is way too much speculation on this thread.

The report from the tow pilot who witnessed the Parowan crash does not
suggest any kind of stall-spin, at least not one caused by pilot's
actions. But I'm not going to speculate, just wait for the accident
report.

From Parowan,

ted/2NO

On Jul 2, 5:17*am, T8 wrote:
On Jul 2, 6:45*am, Gregg Leslie wrote:

How about some sympathy for the families...

GL

Yes, thank you Gregg.

For the rest of you guys... c'mon. *You want to discuss elementary
spin recovery technique, fine. *Start your own thread. *Please don't
do it in the context of a couple of tragic accidents.

We don't know what happened. *I do know that the one of these guys I
knew personally had a lot more flight experience in all sorts of
aircraft, from hang gliders to turbo-twins than most of the noisy
pundits here. *If he failed to apply appropriate corrective actions, I
suspect it is most likely because he was incapacitated. *Lack of
knowledge or skill wasn't the problem.

I'm with Ramy, these accidents are disturbing.

-Evan Ludeman / T8

These accidents are very disturbing for all of us. Of course we
sympathize with the families. We are all family. These discussions
mean no disrespect whatsoever. We don't yet know the cause of any of
these accidents and may never know the exact cause but incapacitation
is always a possibility.

Discussing the general subject of what causes accidents is one way
pilots cope. It's an attempt to put tragedies into some sort of
rational framework we can deal with.

The biggest mistake we can make as a group is to never discuss
accidents since they are a powerful learning opportunity.

At 21:32 01 July 2009, bildan wrote:

The people who taught me the killer spin were my students. As in, "I
didn't know a glider would do that."

I suppose I shouldn't laugh, but this really is sort of funny. It's
also one reason I don't think I could stand the stress of instructing.

These spins require a set up. First, fly at minimum controllable
airspeed for at least 30 seconds. Try to let the glider slowly and
smoothly enter "mushing flight". In "mushing flight" the glider is
not quite stalled but the airflow over the wing has become unstable.
Any disturbance will trip it into a full stall.

My experience in BFRs has been that instructors consistently approach the
subject of spins in just this way. Not the full back stick and then kick
rudder approach, but something realistic. Usually simulating the turn to
final when too slow, afraid to bank sufficiently hard, and then pushing
the turn with rudder. Down goes the wing.

Jim Beckman

On Thu, 02 Jul 2009 13:45:02 +0000, Jim Beckman wrote:


My experience in BFRs has been that instructors consistently approach
the subject of spins in just this way. Not the full back stick and then
kick rudder approach, but something realistic. Usually simulating the
turn to final when too slow, afraid to bank sufficiently hard, and then
pushing the turn with rudder. Down goes the wing.

The two usual scenarios used at my club a

- a slow, under-banked, over-ruddered turn as if you're trying to
stretch a low approach. Its interesting how much you have to abuse
a Puchacz to get it to spin off a fairly wide turn in this setup.

- a simulated winch cable break followed by a too-slow push-over
and a turn as soon as a normal gliding attitude has been established.
The Puchacz departs *really fast* from this demo.

If I sound like I'm harping on the Puchacz its because thats what we use
for spin training. Following up on Bildan and single seaters, I think it
depends on the glider. From my own experience:

- Discii and Pegasii can be spun fairly easily and will stay in at
least one turn without any spiral diving tendency. Recovery is normal.

- ASW-20s spin readily and, even in zero flap may depart in a
turbulent thermal with little or no warning. They often auto-recover
as soon as the flaps are fully negative.

Speed gain and height loss from even an incipient (1/4 turn) spin
are both surprisingly high: entry from a 45 degree bank at 45 kts,
exit 300 feet lower at 80kts. By contrast a Puchacz can be spun
one full turn in each direction and only loose 800 ft overall.

- SZD Juniors can be spun fairly easily and, at around 70kg pilot weight,
self-recover after 2.5 turns without any spiral diving tendency.
Pilots who are either heavier or lighter than the medium weight
band should read the manual before spinning one because they have
three behaviors depending on pilot weight.

- the most spin resistant glider I've flown is a Std Libelle. Its
spin and recovery is benign once you get it to go: first time I
tried to spin mine, nothing happened. I had to really try hard
before it would depart.

The ASW-20 is the only type on my list that has departed unexpectedly.


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

Two experienced contest pilots, in two seperate contests 1000 miles
appart, suddenly plunge to the ground out of control at almost the
same time. This is not only very disturbing, it is down right spooky!

The discussions about spins and spiral dives are great and very
important, and I already made a note to myself to practice some more
spins in my glider, but I don't buy it as the cause of those
accidents. Both pilots had plenty of altitude to recover even without
immediate proper recovery technique.

Ramy

T8 wrote:
On Jul 2, 6:45*am, Gregg Leslie wrote:
How about some sympathy for the families...

GL

Yes, thank you Gregg.

For the rest of you guys... c'mon. You want to discuss elementary
spin recovery technique, fine. Start your own thread. Please don't
do it in the context of a couple of tragic accidents.

We don't know what happened. I do know that the one of these guys I
knew personally had a lot more flight experience in all sorts of
aircraft, from hang gliders to turbo-twins than most of the noisy
pundits here. If he failed to apply appropriate corrective actions, I
suspect it is most likely because he was incapacitated. Lack of
knowledge or skill wasn't the problem.

I'm with Ramy, these accidents are disturbing.

-Evan Ludeman / T8

On Jul 2, 11:05*am, Ramy wrote:

accidents. Both pilots had plenty of altitude to recover even without
immediate proper recovery technique.

Ramy

Ramy -

1) Wasn't the Parowan crash at the top of a tow? I read a report that
implied it was only at 2000' AGL or so - not a whole lot of altitude
if you do not use proper recovery technique.

2) See the comments about spiral dives. Failure to recover from that
is a much worse outcome than failure to recover from a spin (with
relatively low speeds and low g-forces, compared to a spiral dive)

3) Remember we're all speculating. We can say that a spin-type of
event may have been part of the accidents, based on eyewitness
reports. BUT we don't know what caused them. Anything from a
mechanical failure to a medical condition could have complicated
matters or explained the lack of recovery. This is where we have to
sit back and wait for the NTSB - as tough as that is...

Take care,

--Noel

While this board will not be able to determine the reason for these
accidents, I find the speculation very educational and see no harm in
it so far.

As a compulsive reader of NTSB reports I recall very few that describe
a spin right off tow but there is at least one:

http://www.ntsb.gov/ntsb/brief.asp?e...08X06614&key=1

It is interesting, tragic, and informative as to the effects of
attempting to fly an L13 that 1.4" behind the aft limit.

Brian


3) Remember we're all speculating. *We can say that a spin-type of
event may have been part of the accidents, based on eyewitness
reports. *BUT we don't know what caused them. *Anything from a
mechanical failure to a medical condition could have complicated
matters or explained the lack of recovery. *This is where we have to
sit back and wait for the NTSB - as tough as that is...

Take care,

--Noel

Prelimary NTSB Reports for the Parowan and Ephrata fatal accidents -
not much content at this time.

http://www.ntsb.gov/ntsb/brief.asp?e...29X04921&key=1
http://www.ntsb.gov/ntsb/brief.asp?e...29X83644&key=1