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larryj

Well Known Member
One simple way to provide for an Alternate Static source is to run the primary static line to a pnuematic 3-port switch; have the primary port (primary switch position) feeding the instruments and the secondary port (secondary switch position) open to the cockpit. The common valves I've seen are brass, and I just didn't want the weight and look of brass; so I went looking. I found an all-aluminum-body 3-port toggle switch perfect for the above stated application and thought I'd pass it along: ARO valve #M251LS - G1130. I ordered mine from WW Grainger and their p/n is 3NB16. I received it yesterday and it is just what I was after.
 
Hi Larry,

I have one of those on my desk and while it's a fine valve, here are the reasons we decided not to stock it:

While it is aluminum, it actually weighs more than the little brass one we do stock, it's about 3 times the size (larger) and about double the price. While you'll still see a tiny little bit of brass sticking through the panel, the toggle is still chrome...a sharpie does wonders if you want to make the brass part black. :)

Anyway, it's not a bad valve that you have and will work fine (we've used them before) so it's not meant as a flame, just as a data point.

My 2 cents as usual.

Cheers,
Stein
 
Two inexpensive ways to go. Both work well, a save some money and you will probably never need it.

1- use a small tee fitting with a cap on the tee which can be taken off.

2- cut the line with a pair of side cutters. A union can always be used for repair.
 
Darn Stein, I just should have talked with you first !! And I really like Norman's idea of just cutting the line - now that is "git-er-done" !!! Thanks guys.
 
Another thing I like about the static switch, is that you can try it when ever you want (without something so drastic as cutting a line) and get a feel for the difference (error) it will cause. Adds some understanding to how sensitive the pitot static system is.

Bevan
 
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This is the way mine is setup.

Norman CYYJ said:
Two inexpensive ways to go. Both work well, a save some money and you will probably never need it.

1- use a small tee fitting with a cap on the tee which can be taken off.
Click to expand...

The added benefit is to allow you to easily hook into the T for static check. I added the T to my pitot line also for testing.

Kent
 
Years ago we were taught to smash the VSI if the static line got frozen over. But that is kinda hard to do with today's glass cockpits.
 
kentb said:
The added benefit is to allow you to easily hook into the T for static check. I added the T to my pitot line also for testing.

Kent
Click to expand...

Exactly! And with the QD fittings (like Stein sells, among others) you can just put a plug in it - very easy to release if required, and a service point for those two-year checks.
 
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