"Cripps, David" wrote:
>
> As part of my annual permit renewal, my new UK PFA inspector has asked me to
> carry out a check of the pitot static system and instruments. I have located
> somewhere to get the ASI and altimeter checked and calibrated as separate
> instruments, but what is the best way to check out the plumbing of the pitot
> static system? Also, do other people test their pitot static instruments
> 'in situ', by adding pressure/vacuum directly to the pitot head? This would
> appear to test the whole system - but how would you know whether any errors
> lay in the instruments or in the plumbing.
The static system test is to place a vacuum on the static port so
altimeter reads +1,000 feet; altimeter should not show greater than
100 feet leakage in 1 minute. Can be done with fluid in flexible
tubing; about -14" of water for +1,000'. One can isolate error to an
instrument by connecting test plumbing directly to it.
Careful in applying vacuum to the static port, as the ASI can be
damaged, but it doesn't check the pitot line or ASI. That test can
similarly be done with fluid in flexible tubing; 100k requires only 6+
inches of water. Leakage tolerance is effectively zero, but more
easily achieved.
That requirement is strict! Only needed here for IFR flight, every 2
years.
Best,
Fred F.
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