teryn1
Posts: 282
Joined: 12/31/2001
From: Green Valley, AZ, USA
Status: offline
|
Let me clarify: rudder is necessary for coordinated turns (as I mentioned), for steering on the ground, cross wind landings, etc. But if we are off the ground in normal speed, straight and level flight not doing anything unusal (like flying at the stall or doing unusal aerobatics), then any conventional, inherently stable airplane can be flown safely, controllably without the use of the rudder. A rudder merely enhances and makes the flight cleaner, in normal flight. The important fact that some people are missing in my last post here is that the rudder, fundamentally, does not turn the airplane. There is nothing in the physics that suggests otherwise....
The magnitude of adverse yaw is dependent on a lot of factors. In general, I do not see adverse yaw effects as dramatic on RC because of the low Reynolds number and inertia effects compared with full-scale planes. A big factor on how much adverse yaw you get is the wing length. Longer wings suffer more because the moment arm is longer. However, all airplanes that have ailerons suffer from adverse yaw in varying degrees. Next time, take your airplane up in trimmed level flight and make a turn with the ailerons only and watch how the airplane yaws. You will get more of an effect by rolling quickly at lower airspeeds and higher angles-of-attack and with planes with longer wings (Piper Cubs have dramatic adverse yaw tendencies).
A coordinated turn means that the tail is tracking the nose, and that the fuselage is always aligned with the direction of flight (which way the plane is going). In other words, there is no yaw angle-of-attack. Adverse yaw comes about because of a difference in induced drag created on each side of the wing when the ailerons are deflected - assuming that each is deflected the same amount. This causes the airplane to yaw in the opposite direction to the bank (that was created by the ailerons in the first place). Rudder is used to yaw the airplane back in the same direction as the roll. This is called "coordinating" your turn....Coordinating your turn is not a necessary thing to do in order to fly SAFELY on 99% of conventional airplanes. But it's not an elegant or practiced way of flying....
If you want to learn some more basics about airplanes, look at this hour long video documentary with Real Player:
http://www.grc.nasa.gov/WWW/K-12/ArchiveOOC.ram
< Message edited by teryn1-RCU -- 10/6/2004 2:54:27 PM >
|
Printable Version
All Forums >> RC Airplanes >> Crash & Rebuild >> RE: video: 20 ft wingspan B-24 crash on maiden flight.... 
RE: video: 20 ft wingspan B-24 crash on maiden flight.... - 
RE: video: 20 ft wingspan B-24 crash on maiden flight.... - 
RE: video: 20 ft wingspan B-24 crash on maiden flight.... - 