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Old 14th Jan 2012, 07:47
  #21 (permalink)  
BackPacker
 
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(Note to the reader - this was originally posted in a different thread which was subsequently deleted by the OP. The mods were kind enough to retrieve it from the bit bucket and post it here, since it has some relevance here too. I later tweaked it a bit to better fit in here. The original context was a post where the author believed that with a bank angle of 45 degrees, the load factor automagically increases to 1.41, and thus the stall speed automagically by 20%.)

In a stable turn (non accelerating, non descending etc) the theory says that the load factor in a 45 degree turn is 1.4. But in the engine off scenario you are by definition not in a stable turn. You will be losing altitude for sure, and possibly bleeding speed as well, intended or not. Furthermore, the load vector angle is getting more and more horizontal, and this only increases when you go beyond the 45 degrees.

The result of that is that you can increase and decrease your load factor (by pulling more or less on the stick) a significant amount, but you will only increase or decrease the vertical component of lift by a tiny amount. With an increased load factor comes a higher stall speed, higher induced drag, but also a tighter turning radius. So pulling to the stall gives you the tightest turn, but also the least amount of time to "get it right". (And pull to the stall when the speed is too high/bank angle is too low will cause the aircraft to climb and thus bleed speed even more quickly.)

Making matters worse, without a lot of aerobatics experience (and the subsequent "feel" for the aircraft near the stall), without a G meter and with your head mostly outside the cockpit (which is a very good idea in those circumstances, don't get me wrong) how are you going to judge the load on your aircraft exactly? So how sure are you that your stall speed is indeed 61 knots? It probably could have been anywhere between 50 and 75.

I have not read that Rogers document intimately, but here's what I would do: Throw the aircraft in a 45-60 degree bank and then pull until the stall warner. Then play the stall warner and bank angle against each other so that I know I'm at the maximum turning rate while inevitably bleeding off the airspeed and the altitude. (In fact bleeding the altitude off in a controlled manner is the way to keep the airspeed up.)

But hey, I've got a lot of experience doing 75-degree banked turns (stable, thus 4G) at a mere 80 knots (sometimes even slower), with the stall warner blaring continuously, and playing the buffet. So playing bank angle against the stall buffet is not all that unusual for me.

Anyway, kudos for actually trying this, learning what your aircraft is capable of and how you actually achieve that performance. You now know you can do it from 500' up. If the EFATO ever happens for real, stick to what you've learned so far. Don't try it below 500' because some anonymous bloke on the internet told you it could possibly be done if you altered your technique. Land straight ahead.

Last edited by BackPacker; 14th Jan 2012 at 14:22.
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