And we (me and tgrayson) have both pointed out that this is wrong. One technique is entirely based on physical law.
I don't think you understand what I mean when I use the word "technique". As I said much earlier in this thread, in a given situation, both techniques result in the application of the same control inputs. The difference is only in why you decided to make them.
You cannot use pitch for glide slope (altitude) in the region of reverse command.
You can. I can fly Slow Flight to PTS standards using either technique. As I said, you end up with the same control inputs regardless of technique.
It has nothing to do with one technique being deemed safer than another?
That depends on the situation. Many techniques are implemented just for standardization because it's safer if everyone, on every crew, does it the same way. There are often more than one safe way to do the same thing. Other procedures are established for their specific safety benefits.
In light pistons, pitch = AS | power = alt, will not fail if applied in any situation ever.
That's not true. AoA = A/S, not pitch. Pitch effects AoA as does the power setting.
Why in the heck would the student decrease power.
He decreased power because we were too high and his primary instructor had drilled into him that pitch=A/S, power=Altitude, was a law of physics. He applied it by rote without understanding the context in which he was operating.
The same student, a low-time Private Pilot who earned his license in 1979 and hadn't flown since 1980, made the other pitch/power mistake that has been mentioned. He initiated a go-around by increasing to full power while holding the nose down as he make his radio report on CTAF or Tower (yes, he made this mistake more than once). The result was that we accelerated toward the runway at an impressive rate.
It eventually took about 8 hours to get this guy proficient again after his nearly 30-year absence from flying. I did it by teaching him the alternate technique, and the proper way to apply the pitch=A/S technique. Once he understood, and could fly, using either technique he had a more complete understanding of the effects of the primary controls and could consistently maneuver the airplane safely in every situation that I presented.
If you always use pitch when you are sinking to control altitude, ...
If you always use power to control altitude you will similarly fail in the two real life situations that I described above. You can't say that a technique fails because it doesn't work when it's improperly applied. Both techniques fail when they are improperly applied.
The power reduction is the wrong move (unless the plane is very high), but the reduction in AoA is the right move.
Agreed. People are teaching "Pitch=A/S", not "AoA=A/S". I agree that AoA=A/S. Pitch=A/S is just one part of a larger overall technique which, when correctly applied, works well. The alternate technique also works well.
The throttle needs to be adjusted to control the flight path that results from the AoA change. This is always the case.
Those control inputs are always the case but the reasoning for making those inputs does not have to be as you stated. The situation can also be flown safely and precisely by adding power to maintain/increase A/S while the pitch is adjusted to control the flight path. In the end, you make the exact same control inputs.
Remember that the balloon is caused by...
Doesn't really matter how he ended up high and slow. There are other ways in which a pilot might arrive in that situation other than a too-rapid increase in pitch. In this case he simply flared (way) too high. The rate of pitch and AoA increase was not rapid, it was quite normal. It just happened about 50' too high.
You've identified the real problem here which is people saying "Pitch" when they mean "AoA". When I say that pitch can be used to control flight path they are thinking that pitch and AoA are the same. They are not. You seem to be saying, however, that pitch controls AoA which is not correct. Pitch affects AoA, power affects AoA. To achieve a desired AoA, i.e. a desired airspeed, you must apply both controls in a coordinated manner.
I agree with all of the equations that have been posted. They describe mathematically what is occurring. What they do not do is tell you how you MUST operate the controls. The two competing techniques give pilots two ways to break down a complex situation and decide what control inputs to make to achieve the desired performance. As I've said, in a set situation, both techniques, properly applied, will result in the exact same control inputs. That will keep all of your formulas happy.
I'd like to wire a 12-volt battery to someone's tongue and each time I hear "pitch", ZAP!
It wouldn't surprise me if you had one lying around that agreed with mine.
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