It can be done with just aileron input in some planes where the adverse yaw is sufficient to spin it, but I doubt there are many of those. It can also happen in a bent plane, but we probably should limit the discussion to ones that are airworthy.
It's just that in the aerobatic airplanes (and all others) I've flown, you cannot produce an actual spin in this manner...and acro planes are designed to stall/spin easily. But I have not flown them all.Out of curiosity, how far did you let it develop? How many rotations did you do? I've done something similar in a C-150 where it snapped over the top during an accelerated stall in a turn. But it was more of a sharp roll (wing drop) than an actual spin entry. It was immediately recovered with opposite rudder and relaxation of the elevator. A developed spin does not immediately stop, but takes about a quarter turn after anti-spin inputs have been made.
Not holding right rudder (and it would be slight rudder) in the situation you describe would produce a slight slip, which is much more spin resistant than a skid. With no rudder and neutral aileron (as is the case during a turn), I just find it hard to believe an actual developed spin resulted...and that it would actually stay in a spin (not a spiral) with neutral rudder and no strong yawing forces at work (no adverse yaw either). But I guess I need to find a 150/152 and try this again.
It could be as you describe, but I do know that many folks equate a sharp roll during a stall as a spin entry, which it may not necessarily be, and in most cases is not.
How do you figure that? Twisting the ailerons opposite the rudder creates adverse yaw in the same direction as the rudder deflection, which increases the yaw, making a spin more likely.
Not holding right rudder (and it would be slight rudder) in the situation you describe would produce a slight slip, which is much more spin resistant than a skid. With no rudder and neutral aileron (as is the case during a turn), I just find it hard to believe an actual developed spin resulted...and that it would actually stay in a spin (not a spiral) with neutral rudder and no strong yawing forces at work (no adverse yaw either). But I guess I need to find a 150/152 and try this again.
It could be as you describe, but I do know that many folks equate a sharp roll during a stall with a spin entry, which it may not necessarily be, and in most cases is not.
Actually, the more crossed the controls, the more spin-inducing yaw you're creating. Yes, the airplane will roll over against the ailerons before it actually enters the spin, but it will indeed do that with the controls crossed enough if you get the AoA high enough. That's probably why "Crossed-Control Stalls" are a required demonstration maneuver on the CFI-A practical test. In that demo, if you use aileron to try to fight the roll once it starts instead of reversing rudder, you can indeed induce a spin.
Exactly my point. While it's hard to do in a C-152/172, it remains possible, and it's easier to do in other aerodynamically less-forgiving airplanes.
Both the FAA and I are with Dan on this one. The FAA dropped spin recovery from the PP requirements many decades ago after they found that nearly all the fatal stall/spin accidents occurred in the pattern from altitudes too low to recover. That's when they made spin prevention rather than spin recovery the principal goal, and the stall/spin fatality rate dropped dramatically.
If the rudder is kept "coordinated" (i.e., centered ball), you cannot spin unless the plane is bent. You'd have to fail to correct the developing yaw to get into a spin in this situation, and that would mean the ball coming out of center, i.e., uncoordinated flight.
I think what Henning is saying is that if a student has seen a spin before he or she will already be familiar with that wing-dropping sensation. Of course you don't even need to get into a spin to demonstrate that sensation. Since recovery in a trainer is basically just letting go and not fighting the wing drop it might be something valuable to learn. I was shown a spin pre-solo and could spin and recover before the private checkride but that was quite a while ago and pretty much the philosophy at the place where I learned. I don't think spins should be a requirement for pre-solo or private but going at least as far as the wing drop might be something to think about. However, I think many students get to the wing drop themselves especially during power on stalls. I did.
Exactly, and in the crossed control stall (e.g., left bank, left aileron, right rudder), you have full rudder in the direction in which the airplane yaws/rolls as it stalls. If you don't remove that rudder input and/or the opposite aileron input which aggravates that yaw, you may spin.
Cessna is well known for its excessively stallophobic recommended pattern speeds. The FAA recommends 1.4 Vs until final, and then 1.3 Vs0. In a typical 172 (flaps up stall speed about 52 knots CAS and full flap stall speed about 46 knots CAS) that would be 73 knots (KCAS and KIAS being about the same at that speed) at the abeam position and 60 knots on final -- at max gross. For short field, I like 1.2 Vs0 on short final, which would be about 55 knots at max gross. Drop each of those about a knot for each 100 lb under max and you'll be close enough for government work on the "square root of gross weight" correction.
YMMV.
Actually, my experience is the opposite. When I got my CFI in 1973, the Cherokee 140 in which I was training would not enter or stay in a spin without fully-crossed controls. It needed the extra adverse yaw of the opposite aileron to have enough yawing moment to spin. Any release of the aileron off the stop opposite direction of spin resulted in the airplane recovering itself, especially in spins to the right (where you were fighting torque, P-factor, and the spiraling slipstream even at idle). It was rather hard to get the thing to stay in a spin for the required three full turns, again, especially to the right.
That'll do it -- Piper's book recommendations are more in line with the FAA's.
Me, neither, as far as a 172 goes.
Something tells me you haven't tried to do many spins from steep turning slipping stalls. I sure the haven't flown a light ga aircraft that will go into a spin from a slipping turning stall.
Can you explain that further? The local airspeed is somewhat different, but wouldn't the angle of attack still be pretty much equal? If anything, I would think that the outer wing would have a lower angle of attack - My reasoning for that is that if the bank angle isn't changing, the lift from each wing must be roughly equal, thus if the outer wing had a higher airspeed (which it clearly does) AND a higher angle of attack, the airplane would always roll itself into a steeper and steeper bank, which doesn't start happening until the bank angles are fairly high (which, in turn, leads to a greater airspeed differential between the wings).