Derek,

you're mixing up things. Speed limits for positive flap settings have
nothing to do with g-load; they are to limit the forces on the flap.

With a constant speed, a wing produces always the same lift - disregarding
speed or deployed/undeployed airbrakes. If you pull the airbreaks at any
given speed, the load factor of the wing will momentarily be less than 1 g
(you just destroyed a part of the lift and are vertically accelerating), and
then return to 1 g, but now with a different load distribution accross the
wing. Pulling the airbrakes alone will _never_ get you more than 1 g load
factor.

Only when you start to pull up, you have to think about max load factor with
airbrakes deployed.

--
Bert Willing

ASW20 "TW"


"Derek Copeland" a écrit dans le
message de news: ...
At 21:48 10 July 2005, Denis posted the message ' Nimbus 4 Accident'
I don't understand your choice ! if there is a risk at high speeds, the
best choice to avoid it is to avoid these speeds, and that's what the
airbrakes are for, aren't it ? Pulling g's after loosing control is the
best way to break any aircraft...
------------------------------------------
Denis
The point that I was trying to make was that exceeding the positive flap
limiting speed and then opening the airbrakes is also likely to cause
damage
to the wing structure. Gliders are certified to withstand +5.3g with the
brakes shut, but only +3.5g with them open.

Derek Copeland



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