Static Blockage at 4000' - VSI and ALT inop, followed by A/S

[Seanhoya]

Gents,

 

I had a static-system blockage at 4000' today that also played havoc with my airspeed indication on descent.  It was -10 Degrees Celsius at altitude, and I think that I probably have water in my static system, and the alternate static port is probably broken.

 

Has anyone ever traded out their "automatic" alternate static-air for a manual type?  Also, has anyone else had problems with the static drain in the belly of the aircraft?  I can't seem to get the drain to pass the static check, even after having re-packed it.  So my mechanics bypassed the drain.  Maybe this wasn't a big deal in California, but it had serious consequences in the North East.  I plan to have the drain re-packed and re-connected, but I don't know if that will solve the problem - I think that I am going to get another static leak.  Any recommendations?  I have had two pitot-statics in the last 18 months, and I am confident that the instruments are good, it is simply an issue with the drain and now water in the lines in -10 Degree Celcius weather.

 

Appreciate any and all advice.

 

Sean

[Marauder]

Sean - I have failed a couple of pitot static tests over the years because of leaks in the drains for each system. The culprit in these cases were just a bad O rings. If this seats get corroded enough, replacing the O-rings sometimes just doesn't work.

When you said an automatic alternate air, are you talking about alternate air for your pitot static system or an automatic alternate air for your engine intake? I have never seen an automatic alternate air source for the static system. Maybe this is something that is a feature on the new Mooneys. My Mooney has a manual valve under the instrument panel left of the yoke for the pilot.

[Seanhoya]

Thanks for the info on the o-ring, I may have to replace the valve entirely - the re-packing didn't work.

 

Yes - I meant an automatic alternate source.  I had never seen it either until I bought the plane.  I am glad to hear that you have a manual alternate static - I will be going that direction.      

 

Sean

[carusoam]

Welcome back north...

Check the battery for proper acid strength while you are at it...(just thinking out loud)

Best regards,

-a-

[adrian]

I put a manual valve in under the panel in my '66 E.  If you have an Aspen PFD, it is absolutely essential, as a blocked static causes the attitude indicator to fail within a few seconds - as well as all the other problems that you would expect.

[MARZ]

My alternate static is the VSI glass - was that the norm for the 67 vintage birds?

[carusoam]

That was the PP training from back in the 90s using C152 intending to only fly in VMC...

Best regards,

-a-

[Seanhoya]

- a - ,

 

Thanks for the advice on the battery - I actually traded it out while in Dallas, TX - couldn't get the engine to turn over in the cold weather.

 

I have ordered an alternate static valve kit from Mooney - hope this does the trick.  There is also a Service Instruction from 1979 that discusses the very problem that I had (m20-43).

 

Cheers,

 

Sean