Region of reverse command

[NoahWerka]

Those of us who are old enough remember getting "behind the power curve". Now we get in the "region of reverse command". From the Airplane Flying Handbook. "If the airspeed is too slow an increase of pitch and the application of full power may only results in an increased sink rate. This occurs when the angle of attack is so great and creating so much drag that the maximum available power cannot overcome it. Generally referred to the region of reverse command, or operating on the back side of the power curve."
:beer:

 

[TRGFlyer2006]

Those of us who are old enough remember getting "behind the power curve". Now we get in the "region of reverse command". From the Airplane Flying Handbook.

I'm Not that old, and have read the AFH, and still have been taught being "behind the power curve".

 

[Alltheway]

Talk about something your flying in denver on a hot day in a fully loaded C-150 comming to land with full flaps and you find yourself sinking abit much on app, so you add some power to adjust but you find you have full power just trying to make a normal decent, can't take the flaps out b/c we all know what happens then so the only thing to do is get ride of that induced drag so you have to lower the nose and now whats there the ground so you crash. the end

 

[Amish RakeFight]

Not worth saying.

 

[midlifeflyer]

I'm Not that old, and have read the AFH, and still have been taught being "behind the power curve".

And it fits much better with the L/D/power graph where the "region of reverse command" is =literally= "behind the power curve."

 

[Stby One]

Well, while it is generally true that the region of reverse command falls below L/D max, the technical definition is when the speed drops below the best endurance speed. The best endurnace speed is actually a little slower than the speed found at L/D max. So theoretically, a small range of speed below L/D max actually occurs within the region of normal command.

You're absolutely right. Its the power/required power curve(s) that's interesting when you talk about pistons (or propeller aircraft)

For a Jet though its also max endurance, however since the Jet engines "power" output is mesured as a force (thrust) it's the lowest point on the drag curve that's interesting (max L/D)

 

[Goose Egg]

I think it's important to remember that the Power [Required] Curve is not a drag curve, and that the two do not neccessarily correspond, even though drag itself has a large influence on the actual power required. For example, while L/Dmax is the low point on a drag curve, it is the tangent point on the power curve with a line drawn from the origin. (The low point on a PR curve is max endurance, or min sink for you glider guys.)

Therefore, being "behind the power curve" or in the "region of reversed command" pertains to when power required begins to increase with a decrease in airspeed, and not necessarily to L/D max or Min Sink per se.

Source: Flight Theory for Pilots, Charles E. Dole, page 108

-Goose