MAXIMUM DECELERATION

At speeds near hover, the deceleration capability is equal and opposite to the acceleration capability but in high speed flight, the capability may be limited by

Speed, knots

FIGURE 5.14 Maximum Longitudinal Acceleration Capability

rotor autorotation at some overspeed limit usually specified by structural design to be 10-20% over normal rotor speed. The procedure for calculating the deceleration capability under this limitation using the rotor charts of Chapter 3 are, as follow:

• Assume that CT/o = Cr/o.

• For even values of tip speed ratio, find 0O at Cq/o = 0.

• Find СЦ-рр from charts.

Calculate

COS ttTpp

• Find new 0O at Cq/o = 0.

• Convert CT/o to T at applicable tip speed.

• Convert Cj/a to H at applicable tip speed.

• Convert tip speed ratio into speed and dynamic pressure, q.

• Calculate the deceleration capability from the equation: