High-lift devices in T-45 provide excellent slow flight characteristics

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

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

(1) On a leading edge of large radius, the flow

is smooth

(2) On an airfoil with a small radius leading

Sg 1, fr 5

Fig 1: Leading Edge

edge (T-45), the air flow tends to "jump"

Vortexing (3 overlays)

around the leading edge due to the

discontinuity

Overlay 1

(a) An area of low pressure forms on the

leading upper surface of the small

radius leading edge

Overlay 2

(b) High pressure air from under the wing

comes around the leading edge

creating a leading edge vortex

Overlay 3

stall

Sg 1, fr 7

Fig 2: Tip Stall

As tip stalls

(3 overlays)

(1) Ailerons become ineffective

Overlay 1

(2) A loss of lateral stability occurs as center of

pressure of each wing moves inboard

(3) No stall warning occurs

Overlay 2

As centers of pressure move inboard on each

wing, they also move forward, shifting the

aerodynamic center of the aircraft forward

Overlay 3

(1) If aerodynamic center shifts forward of

center of gravity, aircraft will have negative

longitudinal stability, and nose will pitch up

C. High-lift devices in T-45 provide excellent slow flight

characteristics 1.7.1.4.1.2

Sg 1, fr 10

Geometric twist (3-1/2 degrees)

Fig 3: Effect of

Geometric Twist,

Reduces angle of attack of tip compared to root

Flaps, and Slats

(2 overlays)

Accomplished by reducing angle of incidence

used at tip compared to root

(9-99) Original

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