Factorisation

[Wacked]

I've just left a big smelly airline to fly a Citation II which is great. I can't seem though to get my head around the performance figures.
For example , the AFM says that the landing distance required for a dry runway at Max Landing weight of 12700lbs at sea level, 0 deg C and 0 headwind is 4250feet. This according to the manual is factored by 1.92. Does this have to be re-factored for JAA air transport or does it have to be de-factored and the factored by 1.67 for JAA. My other question is what factoring do Cessna use for the manual?

[His dudeness]

AFAIK, under JAROPS you factor an UNFACTORED distance by 1,67 for dry runways and by 1,92 for wet if no other data for contaminated runways exist.

So if they are already factored by 1,92, unfactor them and use the appropiate factors then.

[CL300]

did not Cessna get into a kind of parametric figures ? Instead of unfactored ?
On the performance manual of mine with the same conditions stated above the Landing distance from 50 ft is 2190 ft Vref 108 Kias. This is a 1992 speed booklet.

YOu are flying a sn below 627 then ?
edited for the ld Value and comment

[Wacked]

Yes its SN is in the low 400's . It says the figures are factored by 1.92, it doesn't say the criteria used in the factorisation or that its from 50ft, but i am assuming its from 50ft because it says "speed Vref at 50ft".

Is the 50ft part of the factored figures or unfactored figure?

[Red Goose]

1.92=1.67 (dry)x 1.15 (wet)

Cheers,

Red