Nimbus 4 Accident

Derek Copeland a écrit :

2) With large span gliders, opening the airbrakes causes the wingtips to
bend up. We fitted a second paddle to our Nimbus 2 airbrakes and I did the
test flight in which I was supposed to fly up to Vne (135 knots) with the
brakes extended. By 95 knots the wings were bending up so much that I
started to fear for the structure and didn't go any faster! I resolved that
should I ever lose control of the speed, I would slow it down by pulling g
rather than opening the airbrakes.

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

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

Denis a Nimbus 4 does not have airbrakes. It has spoilers. These are
two different animals alltogether

Earlier, wrote:

Denis a Nimbus 4 does not have airbrakes. It has spoilers. These are
two different animals alltogether

I'm not one to be a sticker about such things, but I generally observe
this system: If the boards hinge out of the wing surface like on a
Schweizer, I call them spoilers. If they slide out of slots in the wing
like on most European ships, I call them airbrakes.

Anyhow, the factory calls them airbrakes, specifically "Schempp-Hirth
type airbrakes." From the Schempp-Hirth Web site:

The wing (six pices for easier rigging)
has full span camber-changing flaps and
double-panel Schempp-Hirth type airbrakes
on the upper surface of the inboard panels.

The standard text on sailplane design, _Fundamentals of Sailplane
Design_ by Fred Thomas (translated by Judah Milgram), generally applies
the term "dive brake" to any flat nasty that comes out of a glider
wing. It does mention in passing that hinged panels are often referred
to as "spoilers," but that is the only use of the term.

Thanks, and best regards to all

Bob K.
http://www.hpaircraft.com

A Nimbus 4 has airbrakes.
And as for different animals: A glider certified under JAR22 needs to have
means which limit a dive to 45 deg at vne. Whatever you call them, you can
use them to limit your speed and deploy at any speed up to vne.

--
Bert Willing

ASW20 "TW"


a écrit dans le message de news:
...
Denis a Nimbus 4 does not have airbrakes. It has spoilers. These are
two different animals alltogether

Bert Willing wrote:

A Nimbus 4 has airbrakes.
And as for different animals: A glider certified under JAR22 needs to have
means which limit a dive to 45 deg at vne.

Just nitpicking: JAR22 asks for a dive angle of 30 degrees. 45 degrees
are only needed to be certificated for cloud flying or aerobatics.

Stefan

So it seems to be right that Scotch affects the memory...

--
Bert Willing

ASW20 "TW"


"Stefan" a écrit dans le message de news:
...
Bert Willing wrote:

A Nimbus 4 has airbrakes.
And as for different animals: A glider certified under JAR22 needs to
have means which limit a dive to 45 deg at vne.

Just nitpicking: JAR22 asks for a dive angle of 30 degrees. 45 degrees are
only needed to be certificated for cloud flying or aerobatics.

Stefan