Avoiding Vne

This has yielded some good food for thought and further
investigation as the season gets going:

1) Look through your flight manual with an eye towards
operating limits, particularly with respect to G-limits
and recommended/allowed use of airbrakes in spins/dives.
I have to admit I've forgotten mine.

2) If you don't have a G-meter in your sailplane get
some stick time in a plane with one pulling 2, 3, 4
Gs to get a good sense for what it feels like by the
seat of your pants.

3) At a safe altitude, pull the spoilers and try some
steep nose down attitudes to get a sense for speed
buildup under different attitudes/configurations (don't
overdo it!). If allowed by the flight manual (and within
your comfort zone/experience), try some spin recoveries
with and without speed brakes deployed. I for one would
love to hear an actual pilot report on maximum speed
achieved, maximum Gs pulled and altitude lost under
each scenario (yes I know there are multiple possible
combinations).

4) Be aware of the likely chain of events that lead
to being sharply nose-down at high speed. A couple
of scenarios come to mind: Open-class ships where it's
just hard to stop the rotation and you end up in a
spiral dive, or late recognition of stall recovery,
resulting in rapid speed buildup. Not much to do about
the first one beyond precise flying technique. The
second one it seems can be prevented with practice
and an eye on the airspeed indicator.

Lastly, I would love to hear factory advice on potential
implications of popping speed brakes near and above
Vne. Assuming you don't exceed the G-limit are there
other issues? It stikes me as a potentially violent
change in configuration, but maybe pilot and plane
can handle the sudden deceleration onset. It seems
like a relatively important decision in a pinch, but
there has been no real resolution of the matter here.

Safe flying,

9B


At 19:12 31 March 2004, Denis wrote:
Todd Pattist wrote:

With flutter, you don't know when it will start, and
you
don't know what will happen if it does. In my experience,
fatal flutter-caused accidents are relatively rare.
G-caused breakage seems to be both more common and
more
predictable. I'll leave my brakes closed, pull to
somewhat
over my max positive G-limit (but nowhere near as
hard as I
can) and let the speed do what it has to do as I bring
the
nose up.

I agree, except for 'I'll leave my brakes closed'...

I think opening the airbrakes would allow you to do
the same without
exceeding placarded airbrakes-out G-limit and with
a lower speed at the
bottom of the recovery...

--
Denis

R. Parce que ça rompt le cours normal de la conversation
!!!
Q. Pourquoi ne faut-il pas répondre au-dessus de la
question ?