Rusty Pilot Posted February 4, 2023 Report Posted February 4, 2023 I am not sure if I am able to get all of the water out of my static lines with the drain on the bottom. Today I had ice in the system and lost altimeter and airspeed indicator. I found it during takeoff when airspeed didn't go live and aborted takeoff. Any simple tricks to get the moisture out of the system once it thaws? Also, how accurate is alternate static source under the panel? TIA
N201MKTurbo Posted February 4, 2023 Report Posted February 4, 2023 You will be off about 5% using the alternate static source. Depending on airspeed. The best way to clear it out is to remove the fitting from the first place it goes behind the panel and blow back into the system. Towards the static port never towards the instruments. If you are a stickler for the regs, you should have the static system re-certed after that, but I won't tell if you don't Just don't tell me about it while im doing your annual or I'll make you get a cert. 3
PeteMc Posted February 4, 2023 Report Posted February 4, 2023 I had no issues with mine for years, then over the years I'd see an occasional flicker in the gauges, but nothing ever came out of the drains. The once doing night currency the lines froze up. Mechanic went through and double checked everything making sure there were no dips in any of the lines preventing the water from draining. There were no big bends, but he found a few little ones from over years with various work being done. Theory is that if I flew right after heavy rains with strong winds I'd get just a little water stuck in in the lines that never made it to the drain. Usually it evaporated relatively quickly, but that one cold night doing night currency it froze before it evaporated. 1
carusoam Posted February 6, 2023 Report Posted February 6, 2023 Things to consider… 1) The M20C May use a dead leg instead of a drain… static system. 2) If you don’t have a drain… visually inspect your dead leg inside the tail cone… 3) The right conditions…. A driving rain storm can put a cup of water into the static system…. 201er video taped draining a bunch of water out of his one day… 4) Water in the system can give all kinds of weird results… ice would be worse… 5) Most modern Mooneys have an alt static system valve in the cockpit… 6) The M20C didn’t even get a decal to remind us…. In case of emergency, break glass, on this instrument…. (VSI?) 7) If desired… it is really easy to add an alt static valve on the panel…. Because it is really hard to know when you want to use an alt static source… 8) Nobody I know has ever broken the glass of an instrument to see if the static system is behaving improperly… 9) Everybody that has an alt static valve tests it every pre-flight… PP thoughts only, not a CFI… Best regards, -a- 1
Rusty Pilot Posted February 7, 2023 Author Report Posted February 7, 2023 On 2/6/2023 at 11:09 AM, carusoam said: Things to consider… 1) The M20C May use a dead leg instead of a drain… static system. 2) If you don’t have a drain… visually inspect your dead leg inside the tail cone… 3) The right conditions…. A driving rain storm can put a cup of water into the static system…. 201er video taped draining a bunch of water out of his one day… 4) Water in the system can give all kinds of weird results… ice would be worse… 5) Most modern Mooneys have an alt static system valve in the cockpit… 6) The M20C didn’t even get a decal to remind us…. In case of emergency, break glass, on this instrument…. (VSI?) 7) If desired… it is really easy to add an alt static valve on the panel…. Because it is really hard to know when you want to use an alt static source… 8) Nobody I know has ever broken the glass of an instrument to see if the static system is behaving improperly… 9) Everybody that has an alt static valve tests it very pre-flight… PP thoughts only, not a CFI… Best regards, -a- Thanks, I do have the alternate static valve under panel 1
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