CAPFlyer wrote:
I agree that you play by the rules when you can, but at the same time, if you are in a situation where you need to deviate, then you need to be prepared to do it and not let fear of repricussions keep you from doing it (and result in a mishap).
Precisely, but one ought
not to plan for deviating from the rules. Sometimes the final planned figures show
zero remaining (unused) allowable margins, and commercial aviation included, it is an okay situation. One only needs to recognize that now one's doing what one has been training for,
if excrement hit the fan.
CAPFlyer wrote:
Again, I agree that the aerodrome operator can pretty much do whatever they want ("it's their place, if you don't like it - go elsewhere" and all that), but at the same time, when a pilot sits there and says on one end that his performance calculations said that without flaps the runway was barely enough and thus he used flaps to ensure sufficient performance; then starts his takeoff roll before the threshold and tells everyone that he was wrong (full stop) plus the other things discussed above, it shows a lack of proper risk management training for this pilot and puts out a contradictory statement to the public. What I mean by contradictory is that on one hand he's saying that he's doing the proper safety checks (performance calculations) however he's saying that not considering using the whole available pavement to ensure he can operate safely without introducing other safety issues around him is right as well. Again - it's not like he's always departing this runway from the "taxiway". He did so this time when it may have been actually prudent as to ensure all other safety requirements were met (including the noise abatement procedure), even if it wasn't a conscious decision. To then say that was a mistake (full stop) without couching that statement with the discussion of why it might be a good idea to use it in certain circumstances, is where the lack of proper risk management training comes in, and where I have my problem. This is the kind of narrow thinking that has gotten many pilots killed and is a big part of the high GA accident rate in the United States (that being runway excursions where other options were available to ensure safe operation).
And I agree as well. But the pilot must be comfortable with his performance calculations. One must not expect to be allowed to disobey instructions for his own comfort, but must apply his own personal comfort margins to the given, official runway distance available.
There have been several serious incidents where, in cases, widebody airlines having hundreds of people onboard have smacked down some runway end lights for the crew having mistaken their performance figures by inputting a typo worth of
100 tons in one instance (Emirates in Melbourne, if I recall). Should we prohibit reduced power takeoffs for airliners as well? What about intersection takeoffs? Both of these knowingly reduce the safety margins. But given the benefits, they only bring in
an acceptable risk, that can and should be treated via channels of training and awareness. I don't see how GA planning decision should be any different. One shouldn't see these occasional added pavement areas much higher than a 737 captain should see the RESA.
The use of reduced power or an intersection for takeoff are legitimate choices, in the end. Using non-ASDA RESA for added climb performance (by increasing V1, if ASDA-critical) is not.
-Esa