RCU Forums - View Single Post - J3 cub, crash on take off nearly every time.
Old 10-25-2008, 09:20 PM
Join Date: May 2004
Location: Oklahoma City, OK
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Default RE: J3 cub, crash on take off nearly every time.

ok take my figures as relative to actual airflow over the wings
No, movements that you measure from the ground do not have any intrinsic ties to actual airflow over the wings. If they were, you would not be able to "hover" in a headwind.

cross I am always on the rudder and crabs too, as is expected.
Are you saying that if you did not hold in any rudder, the plane would never stop rotating until it was heading into the wind? I'm not talking about using rudder to hold the plane in a slip in order to maintain a ground track, forget the ground in this case. Think of when your plane is flying straight over the field at altitude, when you're not trying to hold an approach......it might be going straight down the runway, but what do you see when you look up? The plane is pointed into the wind slightly.

Tell ya what, I can't really say anything that I haven't already, and I don't want this turning into a flame war, so I'm done for now. Have you done much organized study on aerodynamics (college aerodynamics course, flight school, etc)? You might want to pick up a book on the subject if you haven't already (Jeppesen's "Private Pilot Training Syllabus" is a good place to start if you just go straight to the chapters dealing with flight), plus the background knowledge will prove useful in interpreting your upcoming flight tests. This isn't a cut-down to you, I think you will find some of the published info out there to be genuinely useful.

We are currently looking into getting sert up with telemetry to fit the cub to give a variety of data including airspeed, gps groundspeed, altitude and attitude variations etc there are set uops that do some for gliders
Sounds fun, keep us posted. This may be of interest to you:
[link=http://baron.flightgear.org/~curt/UAS/Rascal110_1/Instrumentation/]Curtis Olson's wired Rascal[/link]