Understanding The Elevator – An Element of Airmanship

This is the pilot’s view of a forward slip on approach to landing. The airplane is slipping forward on flight path to runway; control inputs are engine at idle, aileron sets bank with “forward” wing down, opposite or “cross control” rudder to maintain runway alignment and elevator pressure to control airspeed.
This is the pilot’s view of a forward slip on approach to landing. The airplane is slipping forward on flight path to runway; control inputs are engine at idle, aileron sets bank with “forward” wing down, opposite or “cross control” rudder to maintain runway alignment and elevator pressure to control airspeed.
What does the elevator do? Most pilots when asked would probably say the elevator controls pitch. A more concise definition is “elevator controls rotation on lateral axis”: but, having said that what does the elevator do? What is it good for? Elevator is not a descriptive term. Perhaps we should refer to the elevator as the Angle of Attack Control because that is what it does. The elevator controls the wing’s angle of attack; therefore,
• The elevator controls airspeed
• The elevator make the airplane turn
• The elevator makes the airplane stall

The concept of energy management offers an easy explanation of how the elevator controls airspeed. For this discussion, we could define stable flight as the situation when some power setting maintains constant altitude at some constant airspeed. If the pilot increases angle of attack with increased up elevator deflection, the wing will produce more lift and climb; total energy (lift plus speed) must remain constant, so airspeed will decrease. Should the pilot decrease angle of attack with increased down elevator pressure, the wing produces less lift and the airplane will descend. Total energy (lift plus speed) will be constant, so airspeed must increase. The angle of attack control, the elevator, controls airspeed.

When an airplane is banked, the horizontal component of lift pushes the airplane through a change of direction (a turn). If during a turn, the pilot increases “up elevator” the angle of attack increases and creates more lift (including the horizontal component of lift) thereby increasing the turning force. The rate of turn increases, the turn tightens. If during that same turn, a pilot unloads the elevator (neutral stick) to decrease angle of attack the airplane will continue on heading – the turn stops. Angle of attack control, the elevator, makes airplane turn.

A stall is when the airplane exceeds its critical angle of attack, but certified airplanes are inherently stable and do not stall! Pilots cause airplanes to stall by exceeding the critical angle of attack. That is circular logic, and not very instructive. Factually, a pilot will cause an airplane to stall with excessive deflection of the elevator. The angle of attack control, the elevator, makes airplane stall.

Key Point: Airplanes do not stall at slow airspeed! When an airplane “gets slow” there is less lift, so the nose will drop and airplane will descend. The airplane will not stall unless the pilot attempts to defy the laws of physics and “holds the nose up” with elevator deflection.

This month’s featured video is The Fabulous Chandelle. The Chandelle is a climbing, 180 degree turn. The challenge is energy management. With proper use of the elevator, the pilot trades airspeed for altitude. It is difficult to do well, but when mastered, the Chandelle demonstrates real airmanship and is a point of justified prime for accomplished pilots. click to view

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