AirRabbit wrote:
This is the underlying reason that in an earlier post I pointed out the regulatory requirement that addresses taking off with contaminants posing a safety risk, and attempted to point out why it may be that many (most?) of those pilots who seem to treat wing contamination with less respect than others … do so with confidence that governmental officials are of the opinion that only extreme cases warrant a particular response, and situations not as extreme may be disregarded and a continuation of “ops normal” may proceed. The reference is 14CFR §91.527(a) and it says, “No pilot may take off an airplane that has frost, ice, or snow adhering to any propeller, windshield, stabilizing or control surface; to a powerplant installation; or to an airspeed, altimeter, rate of climb, or flight attitude instrument system or wing…” (my emphasis added). To many, this requirement just may indicate that as long as a contaminant isn’t known to be adhering to the wing, particularly if it’s snow that has just recently fallen on the wing’s surface, it’s perfectly acceptable and certainly legal, to takeoff. The video at the start of this thread would seem to verify that there continues to be those who likely maintain this understanding and act accordingly. I’m not offering excuses … I’m suggesting that we haven’t yet done “all we can” to eliminate potentially confusing signals to those who do this job regularly.
Excellent point AirRabbit, by including the word 'adhering' the regulators are adding a degree of ambiguity to what should be a very simple and clear message here.
It's encouraging to note that the word isn't adopted in the appropriate section of EU-OPS where it states: "..A commander shall not commence take-off unless the external surfaces are clear of any deposit which might adversely affect the performance and/or controllabilty of the aeroplane, except as permitted in the Aeroplane Flight Manual.."
Basically the same requirement but less likely to lead to misinterpretation.