Angle of attack (AOA) system

T-45A/C TS, E2-C2, ADV & IUT Aero-03

Slow-Speed Flight, Stall and Spin, and AOA System

III. Angle of attack (AOA) system 1.7.1.4.1.3

Sg 3, fr 2

Lesson Organization

A. Provides the pilot with information necessary to obtain

optimum aircraft performance, particularly at low

SLOW-SPEED FLIGHT,

airspeeds and high AOAs

STALL AND SPIN,

AND AOA SYSTEM

B. Used primarily during the approach and landing phases

* Slow-speed flight

* Stall and spin

of flight

* Angle of attack

(AOA) system

NOTE: Aerodynamically, AOA is indicated airspeed

(IAS). By controlling the AOA, the pilot controls IAS.

C. Indicates for each AOA a percentage of the maximum lift

Sg 3, fr 3

Fig 13: AOA System

coefficient available for the flap configuration being used

Theory

During flight at a constant AOA (approach and

landings), a constant coefficient of lift is maintained

NOTE: Recall that as aircraft weight decreases, so

must lift (basic lift formula). This is accomplished in

the T-45 by holding AOA constant and reducing IAS

as weight is reduced.

Flying correct AOA and maintaining proper

glideslope (using power) will obtain optimum landing

speed, landing attitude, and sink rate

Reduces possibility of in-flight engagements

Reduces overstressing of the aircraft

Use during landings is more desirable than use of the

pitot-static system

AOA more accurately measures aircraft

performance than pitot-static system at low speeds;

as speed decreases, position error increases

Optimum landing AOA is not affected by weight,

bank angle, g load, or density altitude; IAS is

affected

(9-99) Original

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