An older style of graphical presentation in the AFM - common UK format and less so for the US. Doubt that you would find any references outside the dusty archives of various aerodynamics offices among the various manufacturers ...
Long time since I have looked at a sample and none in the office at present.
Never really worried about what the D/X represented specifically but I will dig a couple of AFMs out of the dust and have a think about it for you.
Recollection in the back of the mind is that we are looking at OEI V1/VR (or V1 unbalanced/balanced) ratios and corrected TODR against corrected ASDR .. often referred to as a "web" carpet or similar presentation.
Either way the presentation made it fairly easy to do unbalanced length calculations and run a V1/VR optimisation exercise.
A fairly typical Brit presentation was to have separate AEO/BFL/OEI charts ... a bit of a pile of paper but, once the regressions had been done and the data plugged into the computer, gave the potential for a very accurate (judged against the paper AFM) RTOW calculation.
Give me a day or two .. assuming I can find an old manual somewhere in the filing cabinets ? HS/BAe manuals used this presentation a lot as I recall ...
Last edited by john_tullamarine; 27th Jun 2005 at 22:11.