Originally Posted by
Step Turn
The data presented in the performance section of the POH is obtained with "average" piloting skill ...
Nope, that only applies to aircraft certified in relatively recent times. My airplane was certified to FAR 23 as of Feb 1965 which only required "must be able to be landed safely and come to a stop without exceptional piloting skill."
Originally Posted by
john_tullamarine
The civil certification standards (eg FAR 23) impose margins above stall to give the operation a reasonable chance of surviving problems .. such as turbulence, engine failure, etc.
Nope, not necessarily. That FAR 23 of 1965 did not require landing distance to be determined nor did it specify the minimum landing approach speed.
Originally Posted by
john_tullamarine
Certainly, the POH approved data can be expected to comply with the nominated standards.
Yep, but one must know the nominated standard. The manual for my airplane states a stall speed of 47 kts and a landing approach speed of 52 kts. Maintenance standards allow my ASI within 2 kts so that would get me to within 3 kts of the stall speed stated. Even 1 kt out reduces approach speed at 50 ft to 1.09 x stated stall speed.
CASA's MOS for a tailwheel endorsement mandates that the trainee demonstrates that he/she do better than the unfactored distance in the manual - what a joke.