92 2.7.6 Closing Remarks 100 S JUMP TAKEOFF 103 2.8.1 Cierva's Approach.… 104 2.8.2 Pitcairn's Approach 108 2.8.3 Hafner and Kellett's Approach.......... 109 2.8.4 Kellett's Predictions 112 2.8.5 Wheatley's Research 115 2.8.6 Static Thrust and Torque 125 2.8.7 Ground Effect