Originally Posted by PJ2
AirRabbit;
Not disputing your numbers but just curious as to the source, (aside from the FSF). They differ slightly (some more conservative, some less), from the Airbus numbers but I think for most of us the reasons for the differences are understandable in terms of specific test results vs general rules where actual distances and factors are not provided for the crew in the FCOM or QRH. Nevertheless I think they're appropriate.
I thought someone would ask that question ... as my often failing memory works, I think these numbers were developed over a number of years when I was on active duty with the military. There were always some serious calculations that one was supposed to use - and no one ever wanted to take the time ... so some pared them down to a "rule of thumb." I've seen similar "rules of thumb" provided to various organizations throughout my career, and I would imagine that I've incorporated (and adjusted accordingly) some that might be easier to remember. Over the years this is what developed. I haven't yet checked the FSF website, but I presume, if there, those numbers would be at least somewhat similar.
Originally Posted by PEI_3721
AirRabbit, #510, you perhaps unintentionally imply that the crew ‘deliberately’ overflew the first 4000ft. Deliberation would suggest awareness of the situation which might not have been the case.
Consider how a normal flare and landing is judged with respect to distance. This is probably by a sense of time - threshold to touchdown, time during the flare, particularly where ground markings are poor / night-time.
Distance, depends on ground speed, thus any tailwind might double the speed/distance difference for a given time, therefore for the perception of ‘normal timing’, the aircraft could have flown much further.
Add to this distance an increment due to a high approach – poor vis in heavy rain, poor lighting, and a tailwind.
Also, I wonder what effect a HUD flare profile has (see WhatsaLizad # 511). The difference between a manual landing and an auto land could be a 1400ft increase according to advisory landing data. If the HUD flare follows a similar profile as an autoland then a longer landing may result.
Of course, you are most certainly correct. I wasn't necessarily pointing an accusing finger of guilt at that particular flight crew. My comment was intended to be one of "generality" to include all the facets you named as well as those of inattention, insufficient planning, lack of awareness, sloppiness, etc. to wind up with the position that however one gets to a point halfway (or almost halfway) down almost any runway and then attempts to land, the results can, and often will, be less than desirable. I've seen such circumstances develop from average to very good pilots when they have been used to the "a-typical," Orlando-type runway lengths - where you
can land halfway down a wet runway, with a tail wind, and still have to add power to taxi if you wanted to turn off at the end.
It's been a long time since I've been into the Kingston airport in any capacity other than as a passenger, so I'm not aware of any marking anomaly or lighting or reflection deficiency that may currently exist; although I fully acknowledge the problems such circumstances could present. Be that as it may, however ... there are issues that remain puzzling.