Balance Field Length

[john_tullamarine]

Woomera West

... indeed, good sir ... nothing quite as fine as a good port from a coffee cup in the cantina to protect the guilty from accusations of inappropriate consumption of spirituous and fermented beverages.

Old Smokey and I last spoke about 25-30 years ago before he got into the flying side of the game .. he recalls me quite clearly but I cannot put a face to the memory (clearly my Alzheimers is more advanced than is his ..) .. so far we haven't been able to catch up for a convivial. I have no doubt that a three-way port session would be a delightful way to have three fine chaps converse on matters technical, hysterical, and nautical.

chornedsnorkack

I'm sure there is something subtle in your handle although my lack of imagination causes it to remain elusive in the recesses of my tiny brain ..

V1 most certainly is NOT arbitrary (although one could/can schedule an acceptable V1 range for the day if one so wished and data were available).

WAT has naught to do with it as WAT relates solely to minimum climb performance standards as prescribed in the relevant aircraft Design Standard.

BFL generally and largely is irrelevant as it is only a convenience construct and has no great significance in its own right .. in the same vein as the datum position for weight and balance calculations ...

What you are saying is fine and can be summarised very simply .. certification performance data is artificial in that it establishes lines in the sand for very well defined boundary test conditions. If the line pilot wants to reproduce the data, he needs to have the same boundary conditions and that prerequisite, generally, is unachieveable. It follows that the line pilot probably is going to be able to go close (to a greater or lesser extent) but not quite get to the mark .. and, if achieving the mark is important (rocks at the end of the runway ?), then maybe that difficulty needs to be factored into the operational decision making equation along the way somewhere ... ?