Landing with one spoiler

On Thu, 29 Sep 2005 09:17:17 -0700, Eric Greenwell
wrote:

Any glider can suffer partial control failure from connection problems,
freezing, stick or linkage blockage, undetected damage, mechanical
failures, or improper repairs. I think giving pilots some experience in
these situations with an experienced instructor would be an asset.

Hmm... it depends on the type of glider, type of damage, pilot skill,
and luck. I think an airbrake failure is survivable, but any other
kind of primary flight control failure needs a lot of luck to be
survivable.

For example, the seemingly not-so-important rudder:
I once saw a halfways safe no-damage landing of a Twin 2 with a jammed
rudder - but a jammed rudder killed two very experienced pilots in a
DG-500M when they were unable to touchdown in a controlled manner out
of a sideslip.


Basically I think it's not a good solution to find myself slowly
losing control of your glider while on final at 150 ft although I
could have bailed out safely 2.000 ft higher. At least I can blame
myself for trying to be a hero till impact.

My decision for myself is clear: As soon as I'm not absolutely sure
anymore to have the glider under control, I bail out. I have no need
for control experiments at low altitudes where the slightest mistake
is definitely going to kill me - especially if the alternative is a
relatively safe bail-out out of a halfways controlled glider.




Bye
Andreas

Andreas Maurer wrote:


My decision for myself is clear: As soon as I'm not absolutely sure
anymore to have the glider under control, I bail out. I have no need
for control experiments at low altitudes where the slightest mistake
is definitely going to kill me - especially if the alternative is a
relatively safe bail-out out of a halfways controlled glider.


Yes, but deciding when that happens is the hard part, well was for me
anyway. I have had 2 partial primary control failures (in 4 years of
gliding), landed safely each time, but I still wonder if I made the
right decision. The first was in LS4, at about 7000 feet and at that
time I had about 120 hrs in about two years of gliding. It was a rented
ship away from my own club. The ship just had its manual, was test
flown by its owner and I have flown it for 4 days prior to this
incident. I do a pcc before each flight and did it then. The aileron
movement was not the smoothest but I was assured it was OK. Anyway at
about 7000 I needed a large aileron deflection to the right and about
half way there was a definite stop. Stupidly (if automatically) I
applied a fair force and powered through the obstruction. I remember
thinking at the same time something like "you idiot, what if it does not
come back". Well it did come back, I did some testing, the event did
not repeat in a pattern that I could discern, but as the obstruction
only occurred at about half travel so I have decided to land. I have
increased speed to about 70 kts, where only small deflections were
needed and landed normally. I have only recently found out that there
was a serious problem that was rectified.
The second incident happened in my club ship, a Hornet. Once again a
DI, including a PCC was done. I have flown for about 2 hours without an
incident when I went to pull up quite sharply into a thermal when the
elevator come to a full stop with what felt like a soft clunk. Anyway
once again I did some testing and found that with what was a full
elevator I could fly no slower then 55 kts and a bit more with
airbrakes. The controls felt perfectly normal in the remaining range.
Anyway, once again I decided to land. When I descended to about 2000 ft
AGL I put away the air brakes to set up a landing pattern. At stage I
found that I could not fly slower then about 65kts. Anyway, a bit of
adrenalin must have manifested itself at this point and a sharper tug on
the elevator freed the control. I have landed normally. When we
removed the elevator we have discovered a piece of lead ballast in the
tail. It was put in upside down and moved in flight wedging under a
flange on the elevator pushrod (hence the soft clunk).
Clearly a few safety issues here - the use of the ballast was not
universally known by club members, checking for it was not part of the
DI and apart from the control locking there could have been a C of G
problem for lighter pilots. Anyway, these issues have been addressed.

The second incident came about 3 month after the first one and I am sure
both had a significant impact on my flying confidence.

In any case, to this day I am not sure that I have done the right thing
by remaining with the glider. In both cases I had a stable platform to
depart and I have some 100 jumps to my name, admittedly some 30 years
earlier, so I think I would have been relatively comfortable jumping.


Paul

Paul wrote:

In any case, to this day I am not sure that I have done the right thing
by remaining with the glider. In both cases I had a stable platform to
depart and I have some 100 jumps to my name, admittedly some 30 years
earlier, so I think I would have been relatively comfortable jumping.

This is interesting, because some people recommend all gliders making at
least one practice jump, partly on the theory they won't be so reluctant
to jump when they need to. Maybe it's more wishful thinking than good
advice, but I don't know of any "post jump" interviews to see if the
jumpee agreed with the theory.


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Eric Greenwell
Washington State
USA

Eric Greenwell wrote:


This is interesting, because some people recommend all gliders making at
least one practice jump,

Make that "glider pilots".



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Eric Greenwell
Washington State
USA

Well, I've been making spoilerless landings for years. Of course, the
ships I've flown most don't have them... but I had my smart@$$ hat on
and just couldn't help myself...

Jack Womack

Jack wrote:

Well, I've been making spoilerless landings for years. Of course, the
ships I've flown most don't have them... but I had my smart@$$ hat on
and just couldn't help myself...

Well, then, how about landing with just one flap?


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Eric Greenwell
Washington State
USA

The Slingsby Kestrel 19 is one glider which needs care if sideslipping close
to the ground. The rudder overbalances, and it needs a considerable force
on the rudder to take the sideslip off.

If you have no rudder, how do you get it out of the sideslip once you have
rudder overbalance? I can't think of a way to do it.

One friend of mine had his Kestrel 19 go out of control in yaw shortly after
releasing from aerotow at about 2,000ft. QFE. In fact the rudder had
fallen off, though sitting in the cockpit he did not know this. He baled
out while the glider was flying level though not under full control; I and
everyone else at the time thought he was sensible to do this.

The rudder drive had broken, all Kestrels were modified as a result.

W.J. (Bill) Dean (U.K.).

"Andreas Maurer" wrote in message
...
On Thu, 29 Sep 2005 09:17:17 -0700, Eric Greenwell
wrote:

Any glider can suffer partial control failure from connection problems,
freezing, stick or linkage blockage, undetected damage, mechanical
failures, or improper repairs. I think giving pilots some experience in
these situations with an experienced instructor would be an asset.

Hmm... it depends on the type of glider, type of damage, pilot skill,
and luck. I think an airbrake failure is survivable, but any other
kind of primary flight control failure needs a lot of luck to be
survivable.

For example, the seemingly not-so-important rudder:
I once saw a halfways safe no-damage landing of a Twin 2 with a jammed
rudder - but a jammed rudder killed two very experienced pilots in a
DG-500M when they were unable to touchdown in a controlled manner out
of a sideslip.


Basically I think it's not a good solution to find myself slowly
losing control of your glider while on final at 150 ft although I
could have bailed out safely 2.000 ft higher. At least I can blame
myself for trying to be a hero till impact.

My decision for myself is clear: As soon as I'm not absolutely sure
anymore to have the glider under control, I bail out. I have no need
for control experiments at low altitudes where the slightest mistake
is definitely going to kill me - especially if the alternative is a
relatively safe bail-out out of a halfways controlled glider.




Bye
Andreas