It is interesting to read all the responses to the Impossible Turn. The post of the SIM video on the Cirrus/COPA forum produced a discussion on the relationship bank angle in the turn and stall risk and thus the discussion goes there about the AOA, G-forces in a 45 or 60 degrees turn and stalling. So there is this table posted there with the bank angle and the increased stall speed. Then others are saying that the bank angle by itself will not necessarily increase the stall speed but that it is the pulling of the yoke to keep flying level in the turn that increases the angle-of-attack. Can someone here clarify as it seems to be something discussed here before (reading the reaction on the AOA device).
About the spin recovery training ... I have done this including some aerobatics training in an Avia F22 aircraft and had it from the number 1 instructor here in Holland, but that stopped when they man got involved (after flying more than 30 years without one incident) in a deadly accident with another of his planes that killed 2 and heavily injured another.
the bank angle by itself will not necessarily increase the stall speed but that it is the pulling of the yoke to keep flying level in the turn that increases the angle-of-attack.
A wing does not stall at a "speed" but at an angle of attack. The angle of attack which is required to provide the required lift at any given speed, will have to be increased as the required lift increases. Double the G loading (like a 60 degree banked turn) and you are doubling the required lift, so the speed required to enable the wing to sustain that higher load without exceeding the critical AoA increases greatly.
Or, you can choose to not increase the G, which means not demand the lift of the wing, which certainly means trading off altitude - if you have it to trade. If you are flying in this manner, you are already outside the scope of "normal" flying, and probably doing near aerobatic maneuvers, but it can be done in any GA aircraft.
However, as the "impossible turn" your choice to trade off altitude, particularly at low speed, will require you to recover that now high rate of descent, and resume one G flight. The G's you have to use to do this are directly related to the altitude you have to play with to do it. This is where the "secondary stall" comes in.
During a stall recovery, you unload the wing, recover the stall, and get going down. But you have not really accelerated yet. The ground rushes up at you, you pull, and stall again. I assure you, that if you have let things get this bad, an AoA indicator is not going to help you at all, you'll be much too busy looking everywhere else to just try to regain control. An AoA indicator should be considered useful for stabilized maneuvers only.
Can someone here clarify as it seems to be something discussed here before (reading the reaction on the AOA device).
There have been at least ten threads so far regarding AoA indicators in light aircraft in the short time this forum is online... I don't read any printed aviation magazines any more but have the strong impression that this topic is currently on the "hot list", probably driven by manufacturers who hope to establish a new market.
Or, you can choose to not increase the G, which means not demand the lift of the wing, which certainly means trading off altitude - if you have it to trade. If you are flying in this manner, you are already outside the scope of "normal" flying, and probably doing near aerobatic maneuvers, but it can be done in any GA aircraft.
I routinely do that on the downwind to final turn. Starting at 1000ft AGL one can do a really nice tight turn, starting in the full landing config, at about 90kt, and ending up on very short final still doing 80-90kt.
It's probably not "aerobatic" given that the bank is below 30 degrees, although I am sure any "turnback" version would have to be well beyond 30 degrees. That is certain what Prof Rodgers reckons.
One has to make sure the circuit is empty before doing this, though it is fairly safe if the only known traffic on final approach is either in French airspace or north of Gatwick, which is often the case at Shoreham 
As you say, having height to trade is the absolute key. But that could be the case in the turnback situation, if you took off into enough headwind and/or the runway is long enough.
A couple of years ago I saw someone do a turnback at Shoreham. Nothing was heard; he just appeared on the runway. It was some sort of aerobatic type.
There's also the matter of judging the low, steep, descending turn with the ground filling the windscreen. Another first, (as well as the prop drag of a dead engine), for most pilots.
1000ft by glider is a no-brainer, even with an old, wooden one.
200ft by glider isn't all that challenging, even in an old wooden one. On the FAA glider training syllabus, you do just that. When I did mine, it was in a Schweizer 2-33 which is about as terrible as you get in terms of gliders. I actually managed to make an abbreviated circuit and landed into wind.
However the big difference with a glider is that if the rope breaks, it flies just the same as it always does when gliding because it's doing just what it's designed to do. There is no windmilling prop robbing you of energy and making the glide steeper than it usually is when you're out practising forced landings. Also gliders fly slowly, so things just don't happen fast, and even an old wooden glider often has a much, MUCH better glide ratio than even the best power plane. For instance our club's wooden Berkfalke 4 has a glide ratio of 28:1 and it does that at the sedate speed of just 43 knots. So in a glider you have three things you won't have in a power plane with the engine out: you can go relatively slowly, you have good glide performance, and the glider flies exactly the same as when you're making just a normal flight.
In an emergency you'll fly like crap. I've had the winch cable break on a winch launch, and I can confirm this. One instructor said to me while doing simulated cable breaks - fly a bit fast, you'll fly like crap and the extra speed will keep you from stalling, but it won't rob you of much performance. However, flying a "bit fast" in a glider is maybe doing 60 knots, which is slower than best glide in a Cessna 172, and all the while - even in a wooden glider - your glide ratio is going to be very much better than any power plane.
Having said that if you're at 1000 feet in a power plane and there's a strong wind, you can probably make an abbreviated circuit and land - so long as you're used to making tight circuits and aren't flying something with a high best glide speed. In the Auster, from 1000 feet, I wouldn't think twice - I'd just fly an abbreviated circuit and land - but the Auster has an excellent climb angle (we have a larger engine than originally fitted), and on a day even with moderate wind I've been at 1000 feet before crossing the departure end of the runway. I habitually fly a close circuit at our home airfield to keep noise as confined to the airfield as possible, and also to be able to observe the runway environment. The Auster also flies very slowly - I've got a wheel landing out of a 45 mph approach speed. But at 600 feet, I'd still prefer to put it in a field rather than trying to turn back. With a good headwind the plane will land very short with a low ground speed and it has large main wheels so putting it in cow pasture is just not an issue - and by far the safest option should things go quiet that low - especially considering the propeller drag on an already draggy airframe (which at least has a very low stall speed and big wings, so you can arrest the sink at surprisingly low airspeeds).
Or, you can choose to not increase the G, which means not demand the lift of the wing, which certainly means trading off altitude - if you have it to trade. If you are flying in this manner, you are already outside the scope of "normal" flying, and probably doing near aerobatic maneuvers, but it can be done in any GA aircraft.
I used to do this off an overhead join in the Chippy to quickly get from 1,500' overhead to 800' circuit height once on the dead side; roll on a lot of bank but don't pull, let the aeroplane lose height, then roll erect to cross the field at 800'.
I also used it to 'throw away' an aerobatic entry if not happy. In the Chippy these nearly all start with a dive to entry speed, brief level section, then pull up for the manouvre. If, after pulling up, I'm not happy I simply roll the wings vertical without pulling, and 'fall out' of the climb.
The legendary Alan Bramson in his 1980 book "Be A Better Pilot" dedicates half a chapter to this and lays claim to the phrase. Alan looks at the science and suggests only attempting this if >600ft AGL and confronted with nothing but trees, buildings or crocs in water.
Alan says in a light 4 seater, if you respond immediately, are in current practise and complete a coordinated rate 3 turn in the direction of known crosswind and without delay through the 225 degrees necessary to realign with the runway, with accurate speed control throughout to compensate for the greatly increased stall speed and any turbulence, then somehow re-establish on centreline and stabilise the approach in a matter of seconds remaining - then you have a 'fair' chance... Although Aeroplus makes it look commendably easy:)
Well we have all these great sims now, so hopefully someone can report having tried this with a 10KT crosswind and say a little turbulence having just called "gear up" at 700 ft...
I have tried it out as well for real, but not below 700 feet but 1000 feet and now waiting 4 seconds to count for the confusion that would normally occur. There was a crosswind, but I am not sure how much and I had an instructor sitting next to me, just to be sure we have more eyes to watch/feel the airspeed, loads on the aircraft, etc.
The only time I would try this is I had briefed this and had no alternatives with a possible better outcome than this (like pulling the chute).
Impressiv research. I tryed it with a C150 with MTOW, 500 FT AGL no problem to get back. The same with a "ligt" (one Person no load) C210! No chance from 500 FT AGL to get back to the runway. I didnt´t wait 4 seconds, I immediately turn and reduce speed from 90 to 75 KIAS (best glide). Half the turn I lost more than 300 FT an added power. In a real configuration with Pax and load even at 1.000 FT AGL (further away from the runway) to go ahad on a "field" would be a better solution than hit the threes before reaching the runway!
