j_t, you're helping turn the alphabet into workable training curriculum! q) r) s) are done, only 7 to go; of course we may want to re-sort the topics later on.
There's one other thing for which I have answer am not happy with.
On my type, EO ACC ALT is defaulted at 1500 AFE and if obstacle data require, will be raised in the computation result to comply with MNM EO ACC value.
Here's the problem:
For certain types of RWY contaminant, manufacturer specifies that WET (equivalent) figures shall be used. The certified wet envelope ends at -5 deg C which is logical. Hence if the OAT is lower, the software (and paper RTOW tables as well) will require the pilot to enter the calculation with -5. As far as TORA, TODA, ASDA, and gradient are concerned the result will be more conservative than actual achieved performance. So far so good.
Normally MNM EO ACC ALT derived form the calculation is corrected for altimeter density error, so the chosen EO ACC ALT makes sure to lift you over obstacles by (35?) feet even at ISA -20 i.e. OAT-5. However, when true OAT is -25 and we use wet equivalent figures for frosty runway take-off, the displayed value is not corrected by 20 deg K, which invalidates MNM EO ACC ALT by quite a large margin. Solution would be to manually correct EO ACC ALT by delta (-5) minus OAT. That is a major training problem/cost. Exactly opposed to what computerised tkof performance aim to achieve.
Any thougts?
Sincerely,
FD (the un-real)