Originally Posted by
thomasfo
Any reason the pitot tube covers are not made with a weak spot and with a 'parachute' so they would just rip off at takeof speed? Sounds like a $1 solution to a repeating problem.
A number of reasons, one of the simplest is so that they don't get blown off in a storm.
Another is that it will make people skip the checks, statistically only slightly more often than with "non-parachute" covers, knowing (maybe unconsciously) that they'll blow off anyway. And then maybe the "little $1 parachute" fails ...
Lack of total air pressure data is noticeable on the takeoff roll long before V1, and should be an immediate criterion to reject the takeoff. There are numerous speed call-outs on aircraft with multiple pilots, things like "airspeed alive", "80 knots" (and/or "100 knots"), "Vee One" and "Rotate", all based on indicated airspeed. Some of these calls need to be acknowledged by the other pilot after cross-checking the speed indication on the instrument on his side, usually with something like "(80 knots,) checked". A discrepancy will cause a reject.
This is a matter of a safety culture, that procedures and safety awareness are in place and pervasive (although this is not something that can be created overnight). An airline where it can happen that multiple checks for pitot covers fail has a deeper problem with its organisational culture.
Small ad-hoc technical fixes may seem to be the solution to a specific problem, but they may also distract from a deeper problem. If it can happen that pitot covers remain undetected, what else will be regularly overlooked on pre-takeoff checks? A takeoff with pitot covers, while rare, is not only a serious issue in itself, but also a symptom of much deeper problem.
Bernd