Old 28th Dec 2018, 15:05
  #37 (permalink)  
Join Date: Jun 2009
Location: florida
Age: 76
Posts: 1,079

Thanks, Cpt McHale. Guess those puppies move about a lot, although the right vane seems to be more highly dampened.

I had noticed a change in the left AoA a minute or two before T/O roll and figured it was some kinda configuration change. Upon looking at the heading trace, the vane prolly changed when the jet "jinked" on the taxiway or ramp when heading to the rwy. Then the thing apparently moves again as the plane lines up. From there we see a near constant bias from the other AoA vane. And so...

@ 'bird and others with lots more maintenance experience that I ------ If we assume that the FDR does not get the raw analog signals from the AoA vanes that we see on the data, but from a "box" or module in a "box", then I wonder if there is a dip switch change or "plug" that must be inserted/removed when the AoA vane is replaced. This would tell the "box" using the raw analog signals to bias the digital data according to "right" AoA or "left" AoA mounting.. In other words, the "universal" vanes can be placed on either side without having different mounting hole spacing. I like that idea for $$$, standardization of parts, and so forth. But it is a procedure that must be followed and then verified
Jez wondering...

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