Originally Posted by
shdw
I have answered all of this, some of it multiple times through my posts on this thread. If you have a specific question about something that was said I would be glad to try and answer it, but I am not going to retype what I have already typed, sorry.
No matter how much we discuss it though, 5 minutes in a sim will explain it better than any book will do. Apply more thrust to the downwind engine, use the rudder to keep the ball centered (which will put the aircraft in a side slip) and leave the crab angle as is, watch the aircraft drift upwind. You will immediately recognize what has been discussed here, heck you can do it on flight sim right now on your computer if you have a way to use rudders.
Aircraft type is irrelevant in this case as we are talking nothing more of how forces apply to off centerline thrust. We could have the exact same discussion about boats and the result would be the same, unfortunately difficult to see as a boats engine arm off centerline is a matter of a couple feet.
PS The repeated mockery on each of your responses is getting a little old, and frankly is a bit childish.
Shdw, don't take this personal. Now that I finally fully understand your technique (before it wasn't clear), here is an explaination as to why I do not like it.
In multi-engine prop aircraft, you learn day one that you don't fly them with asymmetric thrust and in a coordinated (ball centered) side-slip. You should be banking 2-3 degrees into the good engine with about 1/2 ball displacement into the good engine.
Here's why ...
1. You increase drag because the deflection of the fuselage and rudder with respect to the relative wind increases.
2. Unfortunately, because of the greater yawing moment due to the asymmetric thrust, you must deflect the rudder more so than if you were flying with symmetric thrust. Due to the sideslip, rudder deflection is parallel to the relative wind now and that makes it is less effective. The net result is that you need to use more rudder than otherwise necessary. You must counteract the yawing moment from asymmetric thrust and the natural weather vaning into the wind.
3. Since rudder authority is reduced (due to he relative wind being parallel to the rudder deflection), VMCA is going to increase. Depending on the type of aircraft, this could be very significant.
4. The relative wind striking the fuselage/tail on the reduced engine side, increases the yawing moment. This adds to the rudder problem. (see #2)
5. Extra drag is produced because of the rudder deflection and fuselage being deflected into the wind. (drag is increasing, but you are reducing power on an engine???)
6. Stall tendencies can be masked or changed because the airflow over the wing (on the side with the engine that has been increased) is partially blocked by the fuselage.
7. But the biggest reason I don't like this technique is this. If you suddenly lose the higher thrusted engine, you are going to instinctively push up the power on the remaining engine. When you do, and you have that rudder deflected into the once high powered engine, the increased yawing moment and associated roll is going to prove dangerous.
In a normal crab to forward-slip landing, you aren't as susceptible to an engine failure. In my current aircraft, the manufacturer recommends the crab to forward-slip procedure. Even the autopilot uses this method when flying autoland approaches. Even if you lose an engine at 50 feet or below, the autopilot can still autoland.
If flying your technique, I don't think you would have similar results if the unfortanate happened close to the ground.