not quite so
1.3 vs is the speed to cross the threshold at 50 feet in normal wind conditions. Common sense should tell you that if you maintain the power setting and change the attitude the speed will reduce further in the descent from 50 ft to the touchdown. if the change to the landing attiude is carried out correctly there will still be enough safe margin above the stall. Speeds are never quoted below 50 ft as there is no point ,you should be looking outside and hoping the stall warner is servicable!
Note some aircraft are already in the landing attitude at 50 ft and only require a power adjustment to settle onto the runway.
Some aircraft do not use 1.3 vs as a threshold speed because of poor aileron response at slow speed, t
not quite so
1.3 vs is the speed to cross the threshold at 50 feet in normal wind conditions. Common sense should tell you that if you maintain the power setting and change the attitude the speed will reduce further in the descent from 50 ft to the touchdown. if the change to the landing attiude is carried out correctly there will still be enough safe margin above the stall. Speeds are never quoted below 50 ft as there is no point ,you should be looking outside and hoping the stall warner is servicable!
Note some aircraft are already in the landing attitude at 50 ft and only require a power adjustment to settle onto the runway.
Some aircraft do not use 1.3 vs as a threshold speed because of poor aileron response at slow speed, the Piper Aztec being an eaxmple.
A performance or short field landing should not have any different threshold speed than any other landing. Its the flap setting and braking tecnique that prodecues the performance or short field landing. Traditionally flying school operations have always added a very generous increment to Vref(threshold speed) to give aproach speed, Vapp, with plenty of margin for error. Short field operations should be conducted to book speeds otherwise book performave cannot be obtained. Approach speed is normally lower becauseof the need to try and maintain constant attitude, and thus speed (1.3VS) earlier out to aid accurate positioning on the runway.
Other points to consider are gusty or strong winds which will need threshold speed increments. Threshold 1.3 i is based on power off stalling speed normally quoted at max landing weight on light a/c. Most short field landing accidents are caused by overspeed at the threshold or deep landings produced by unstable approaches.
not quite so
1.3 vs is the speed to cross the threshold at 50 feet in normal wind conditions. Common sense should tell you that if you maintain the power setting and change the attitude the speed will reduce further in the descent from 50 ft to the touchdown. if the change to the landing attiude is carried out correctly there will still be enough safe margin above the stall. Speeds are never quoted below 50 ft as there is no point ,you should be looking outside and hoping the stall warner is servicable!
Note some aircraft are already in the landing attitude at 50 ft and only require a power adjustment to settle onto the runway.
Some aircraft do not use 1.3 vs as a threshold speed because of poor aileron response at slow speed, the Piper Aztec being an eaxmple.
A performance or short field landing should not have any different threshold speed than any other landing. Its the flap setting and braking tecnique that prodecues the performance or short field landing. Traditionally flying school operations have always added a very generous increment to Vref(threshold speed) to give aproach speed, Vapp, with plenty of margin for error. Short field operations should be conducted to book speeds otherwise book performave cannot be obtained. Approach speed is normally lower becauseof the need to try and maintain constant attitude, and thus speed (1.3VS) earlier out to aid accurate positioning on the runway.
Other points to consider are gusty or strong winds which will need threshold speed increments. Threshold 1.3 i is based on power off stalling speed normally quoted at max landing weight on light a/c. Most short field landing accidents are caused by overspeed at the threshold or deep landings produced by unstable approaches.
i see you also mentioned float.
To prevent float keep the power on for as long as possible past the threshold into the roundout. If you round out as close to the runway as possible and then close the throttle the aircraft should immeadiately sink onto the runway. correct threshold speed and accurate round out are essential
Last edited by whatunion; 10th May 2004 at 14:22.