Greetings, Friend of Pegasus,
(a) I was actually referring to producing the original load sheet ....
Next time I will try to read/interpret the post correctly.
(b) The palmtop wins hands down ....
So long as a given system is well tested, acceptably accurate, repeatable, and reasonably idiot proof, it matters little which approach we individually prefer. I was a bit antipathetic to the system I described until I saw it working real well in practice and became a very rapid convert.
As you infer, the aim is to do a similar task in two different ways with the reasonable expectation that the same mistake is not likely to be made twice - not strictly independent, but approximately so - if the end answer agrees, then the confidence is high.
There are many ways to achieve a quasi-independent procedure - none is perfect and, indeed, perfection is not the aim - rather an acceptably high level of accuracy, reliability and repeatability - perfect is too expensive in most cases, one way or another.
(b) However the ability ....
Fine, if the takeoff is runway limited. In the case of an obstacle limited situation, the flightdeck use of a computed solution (whether electronic or manual) will be flawed unless the obstruction data are programmed in as well in some appropriate manner - which is what I presume you have done. If the usual RTOW schedule (OAT by WV) and a suitable Hp correction is there, then the problem goes away.
(c) No, we never derate. It is prohibited (there are reasons) ...
I figured that there was an underlying discussion there. If you are willing to do so, I would very much appreciate some details on this one by email for my own benefit.
And, good fun ? .... indeed. Well do I remember takeoffs very late at night in sub-zero ambient with negligible payload in the Electra .. did someone say "rocket powered" ?
regards ....