View Full Version : Jet aircraft rudder stall?
asiancanucks
18th Feb 2005, 22:35
Will the rudder stall on a jet aircarft?
Ac
Mostly it will be the fin/rudder combination which stalls.
If the designer gets it wrong and they are too small then they will stall too soon.
If the designer gets it wrong the other way and they are too big than he has wasted metal and introduced directional stability problems.
18-Wheeler
19th Feb 2005, 02:14
If the designer gets it wrong the other way and they are too big than he has wasted metal and introduced directional stability problems.
How can too-large a fin reduce directional stability?
Wheeler
Who said anything about reducing directional stability.
With a too large fin/rudder the aircraft will have too much stability and thus be less manoeuvreable.
one dot right
19th Feb 2005, 06:36
how can too large a fin reduce directional stability? Well,in my understanding it can cause spiral instability,which I believe is the opposite of dutch roll.
CAUTION: The above may be complete B*!!*ck$
High Wing Drifter
19th Feb 2005, 09:02
Well,in my understanding it can cause spiral instability,which I believe is the opposite of dutch roll.
I think spiral instability is just being unstable in the logitudinal axis (roll). Where as dutch roll is likely because of being too logitudinally stable when compared to "normal" (directional) stability...
...I fink :\
Maverick
19th Feb 2005, 09:13
Too much of Rudder plane surface leads to Directional Stability.
We must appreciate that improving stability in one aspect invariably leads to compromise on some other aspect.
Too much of Lateral Stability leads to dutch roll as in a bank the aircraft wants to come back to its neutral point.
Too much of Directional Stability leads to spiral instability.
As a rudder is an aileron in itself, it Will suffer Stall (seperation of airflow) just as a wing would. So if you exceed the rudder's crical angle of attack, your rudder Will stall.
The stall can be delayed by adding dorsal and ventral fins to it.