Alternative Static Air Source

[plythall]

I read in an EAA article that for an IFR equipped aircraft there should be a valve installed on the panel that allows the static air system to utilize the cabins atmosphere as the static source in the event of a static system failure. Granted that the cabin is not a reliable source, it is better than no instruments.

My question is where do I locate one of these valves, I remember seeing it in a 69 C172 but I can't locate the valve on Aircraft spruce or anywhere for that matter.

Thanks in advance for your assistance.

[kevinh]

Originally Posted by plythall

I read in an EAA article that for an IFR equipped aircraft there should be a valve installed on the panel that allows the static air system to utilize the cabins atmosphere as the static source in the event of a static system failure. Granted that the cabin is not a reliable source, it is better than no instruments.

My question is where do I locate one of these valves, I remember seeing it in a 69 C172 but I can't locate the valve on Aircraft spruce or anywhere for that matter.

I'm going to install one of these on my panel before I fly IFR (mostly because I want an excuse to work on the plane ). I want to use one of the NPT style fittings that plug into the bottom of an air compressor - anyone know of a good source?

[vlittle]

I tee'd off my static line, dropped a length of tubing down about 12" to a bracket riveted to the fuselage longeron.

I then used an NPT nipple and a locking fuel drain. Since this is the low point of the static system it doubles as both a drain and an alternate static source.

I like the idea of a petcock instead of the fuel drain, because it might be a bit easier to open in flight.

Vern

[AlexPeterson]

I used silicone tubing to plumb my instruments behind the panel, so for an alternate source I simply put a straight connector in the line, flush with the bottom of the panel, and easily accessible in flight. For alternate static, I simply pull one of the tubes off from the barbed connector.

[George in Langley BC]

Hi Peter

I use a Curtis CCA 1550 quick drain valve. "T" into static line and mount on a bracket under the left arm rest 6A & 7A.

George
(worked as holiday relief controller in YXJ tower, summer 1965)

[sadams]

I wanted a nice looking switch mounted in the panel, so I used a miniature 3 way routing valve that accepts fittings for the static lines. Hook up the input to your instruments, one output to the static port, and leave the other output open. It works great and looks nice. I got mine from a friend, but it is similar to the first one shown on this link.

http://www.specialtymfg.com/miniatur...s1/default.asp

[Rick6a]

Originally Posted by plythall

.........My question is where do I locate one of these valves, I remember seeing it in a 69 C172 but I can't locate the valve..........

A few years ago, I picked up a used one for $20 out of a wrecked Cessna at the salvage/scrap yard in Staunton, Il. http://www.cent-air.com/ For a real eye opener, visit one of these places sometime! This particular one has a grass runway, but you must call first because there might be a few wrecks parked on it. In any event...give em a call.

I don't know if it is true or not but someone once told me a simple aquarium valve would work just as well.

[RV7ator]

I installed a branch T in the 1/4 hose between instruments. The branch is a 1/8 pipe thread with a cap on it barely visible below the panel. Just unscrew it. I'd be wary of installations pulling a line off a barb. It's either too easy with failure potential, or you're struggling to work it off in flight, needing both hands.

John Siebold
Boise
-7 (180 hrs), -7 finished airframe