Raising stall speed?
12-19-2012, 06:22 PM
#51
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RE: Raising stall speed?
I've played with trainers a bit over the years. Took an Eagle 63 and mounted the wing from an Ace Super Pacer on it (only 400 squares, fully symetrical) to make a little rocket ship demo. Also removed the covering from the bottom side of an Eagle 63 and added material to each rib to make the airfoil semi-symetrical so it was a more advanced trainer. Cut down the span of a Kadet LT-40 by one bay to increase the wing loading after the 10 year old pilot got bored with it. Even ezperimented with flying a standard trainer with only the rudder and throttle, very intertaining for all you instructors out there. Works best while still balanced nose heavy. Play around with these things, they are good teaching tools, especially if you move the CG (the "of" is silent) around.
12-19-2012, 07:05 PM
#52
RE: Raising stall speed?
I'm not sure everyone is on the same page with the term reflex ailerons. I think it means to adjust them up and doing that simulates wash out if barn door.
I'm not acquainted with the Nexstar systems so won't speak to them but will offer a general comment about trainers with fairly powerful engines. They tend to get trimmed for full or considerable power, which often requires some down trim due to flat bottom foils that doesn't satisfy good off power trim and the glide slope is too steep and they gain too much speed when descending without power.
I cut my RC teeth back in the day when most old salts had a good bit of freeflight experience. They preached trim a plane for off power and then adjust the engine thrust to control powered trim. The good news is that most modern transmitters eliminate many things we used to have to do to the airplane and so it is with matching power on/off trim.
Trim the plane for a proper glide slope with the nose a little higher and use a mix to trim it for full throttle. In practice, I do it the other way around but wanted to illustrate the point. I sometimes mix some up trim that kicks in as the throttle is reduced.
I'm not acquainted with the Nexstar systems so won't speak to them but will offer a general comment about trainers with fairly powerful engines. They tend to get trimmed for full or considerable power, which often requires some down trim due to flat bottom foils that doesn't satisfy good off power trim and the glide slope is too steep and they gain too much speed when descending without power.
I cut my RC teeth back in the day when most old salts had a good bit of freeflight experience. They preached trim a plane for off power and then adjust the engine thrust to control powered trim. The good news is that most modern transmitters eliminate many things we used to have to do to the airplane and so it is with matching power on/off trim.
Trim the plane for a proper glide slope with the nose a little higher and use a mix to trim it for full throttle. In practice, I do it the other way around but wanted to illustrate the point. I sometimes mix some up trim that kicks in as the throttle is reduced.
12-21-2012, 04:56 PM
#57
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RE: Raising stall speed?
Lots of good tips on this thread. I think using elevator throw to 'induce' a stall is the least desirable fix, as now you have an aircraft that's out of control, and close to the ground.
The stall strips on full size, depending on what aircraft, either help maintain lift by enhancing laminar flow or, acts as turbulators that cause a burble over the elevator. Later Bonanzas have 2 near the wing root; the outboard strip sends turbulent air over the elevator tip, giving the pilot a mild buffet, and the inboard becomes effective at higher angles-of-attack, giving a stronger shake through the elevator to the pilot as a warning that bad things may soon happen. [X(]
Odd that this plane flies 'too slow' - I always thought that was a good thing. Changing to a lower-pitch prop may be the easiest fix and, I hate to say it, but flying the airplane the way it dictates - lower altitude on downwind, very low power setting, etc., - means more consistent results. Excessive floating on final means the approach was too high and/or too fast.
Well if you want the wing to stall at a higher speed add stall strips to the leading edge, basically these are triangle stock on the leading edge of the wing to promote seperation. They use them on full size aircraft to taylor stall characteristics, and are generally found at the root of the wing.
Odd that this plane flies 'too slow' - I always thought that was a good thing. Changing to a lower-pitch prop may be the easiest fix and, I hate to say it, but flying the airplane the way it dictates - lower altitude on downwind, very low power setting, etc., - means more consistent results. Excessive floating on final means the approach was too high and/or too fast.
