Originally Posted by
JamesNoBrakes
Well, you can do a steep spiral and come down very fast without being uncoordinated at 60 degrees of bank, not to mention that I think most people assume coordinated flight unless specified otherwise. The FAA recently put out some stuff on using more than one control surface to input full deflections and Va, although I'd assume this is done slow enough where it's no problem. It's more than just pilot technique, it's knowledge and sometimes misunderstandings as to what the aircraft was really rated/intended for. I just don't see any major reason to do this uncoordinated. I've done plenty of high bank angle "knife edge" slips, but if I was taking people up flight after flight, I'd think equal fuel is a more important consideration.
While this knife edge steep spiral is very hard on a 182 if not done correctly, many limit of the performance envelope maneuvers are done for many reasons in training and operations, and it is not a valid argument in itself that simply because it is risky we do not do it. Where the advantages outweigh the disadvantages, like in student training, air shows, and in skydiving ops we do high risk maneuvers. And do them carefully. Like any high risk action, we manage the risk carefully to reduce it and control it.
Knife edge steep spiral is only done in smooth air. You need to knock it off and quickly slow to Va if not, and in this case you would never speed past Va if you knew there was rough air around. We are talking about a drop zone where you fly the same profile 20-30 times a day. You know what the winds are.
However, the fastest way down in this airplane is this maneuver, which explains why it is used. If you do not believe me then call some drop zone who use it and ask why. They do not do other types of rapid descents because they simply take longer and time is money. It's a question of rate of wasted of potential energy in physical terms. The uncoordinated steep turn wastes a large amount of energy height.
Like said, I have done thousands of turns of this maneuver, never a single fuel issue. This is due to my careful risk management- I carry enough fuel not to unport anything.
... It's more than just pilot technique, it's knowledge and sometimes misunderstandings as to what the aircraft was really rated/intended for.
I actually agree with this statement. Drop zones will not allow their pilots to do serious steep turns or other edge of flight envelope tasks if they cannot train them well enough to do it safely. If there is a high pilot turnover and/or poor pilot training they will stick to easier maneuvers. That's why we see the other kinds of descents being used.