Tip: Static leak test

[RVG8tor]

Reading up on this site I read where a fells used a syringe to create the vacuum for the static system leak check. The idea is you can check you system, find and correct leaks before you get the official check. I did not want to crawl into the tail to tap into the line there. What I came up with was this;



I drilled a hole in the center of the suction cup to take the 1/4" hose, I put it over the static port with the opposite one taped over. You have to hold the cup while pulling the plunger, once there is a good amount of suction the cup will stay in place. I taped the hose to the side then slowly set the altitude. I used a snake camera with a removable monitor to give me a view of the altitude window back by the static port.

Set the altitude to 1000 feet or nearly so and then left it for 5 minutes, no change in altitude. Now I have a new tool for my tool box.

Start of test: You can see the snake camera pointed toward the EFIS



After 5 minutes:



BTW The SafeAir kit is awesome, the connectors are kind of large but easy to use.

[Walt]

Not sure what your field elevation is but the static system test per 23.1325 requires the leak rate be tested at 1000 ft above field elevation, limit is 100 ft/min.

[AltonD]

100 per minute or 100 per hour? I had the 100 per minute leak and pounded my head many times to fix it to pass a 100/ hr perceived requirement.
Either way, I now have zero leaks. It did cost me a heated pitot tube ($400 off ebay). I go for the offical IFR cert Monday in Columbus, Ga.

The Gretz I had, leaked where the copper tube was bonded to the body. Gretz is going to replace it, but I needed one now and did not want to wait for shipping to Austrailia. When I get the new one back, I will offer it up on VAF. BTW, the pitot tube off of ebay is certified and chrome. Chrome all by itself makes anything look faster while standing still.

[Walt]

From 23.1325:

(i) Unpressurized airplanes. Evacuate the static pressure system to a pressure differential of approximately 1 inch of mercury or to a reading on the altimeter, 1,000 feet above the aircraft elevation at the time of the test. Without additional pumping for a period of 1 minute, the loss of indicated altitude must not exceed 100 feet on the altimeter.

[RVG8tor]

I did not realize the official test was 1000' AFE but I was just interested in confirming I did not have a leak in the static lines since I just installed them. I don't think I can self certify the pitot static check so I will have to get an avionics shop to do the official one.

My garage elevation is 208' so I guess I needed to go to a higher altitude, easy to do with the little set up I made.

If anyone knows, can you do your own IFR pitot static check?

[Walt]

Originally Posted by RVG8tor

I did not realize the official test was 1000' AFE but I was just interested in confirming I did not have a leak in the static lines since I just installed them. I don't think I can self certify the pitot static check so I will have to get an avionics shop to do the official one.

My garage elevation is 208' so I guess I needed to go to a higher altitude, easy to do with the little set up I made.

If anyone knows, can you do your own IFR pitot static check?

This question comes up from time to time:
"Can the builder with a repairman certificate for the aircraft he built perform his own static system/altimeter check or transponder certification?"

Answer:
No. Although the CFR's do authorize the "manufacturer" of the aircraft to conduct the tests, the builder of an amateur-built aircraft does not meet the FAA's definition of a "manufacturer".

[s24789]

Walt, quick question if all instruments Were vented to the cabin why do a leak check ? Also I used a druck air data test set I had access to and conducted the test myself. Why do I not qualify as a manufacturer ? Not trying to be a pain but I would like to fly the aircraft to the avionics shop after the first series of flights. Is this not allowed per FARs ?
Thanks
I am new to this
Phelps

[scard]

I figured I would just tack onto another useful thread:

It is that time again for us to do (have done) the static and transponder check. I figured I would setup to test the static for leaks before standing there at the avionics shop with a leaky system. This is mostly for those that might follow.

First, don't paint the edge of a stripe within 1.5" of the static ports. Geez, how silly of me to allow that to happen. It just makes the suction cup impossible to seal against the side of the airplane. I had to wet sand the edge of that paint way down in order to get things to seal up reliably. Second, all of the source of any/all of my static leaks have been at NPT threads of fittings. As far as I'm concerned, lots of teflon tape is required here. Sometimes more than you would think. Third, electrical tape over the other static port doesn't work for me in the 100deg hangar. The sure thing is aluminum tape.

Ok, so the suction cups are from Home Depot "5lb picture hangar". Drill a hole, press fit some tubing. I used some 1/8" barb fittings that I clipped off as an expansion insert into the tubing. I rigged up a tiedown strap with a hole in it to maintain a secure press of the suction cup on the side of the airplane. I also used fuel lube as a positive sealing agent to overcome the remainder of the paint line. It doesn't take much movement of the syringe to do the trick. Much care is in order.

I have this really fun digital differential pressure instrument (manometer and more) that has a high precision that is perfect for this stuff. I used it for some plenum testing years ago and just had to drag it out for this project for the fun of it. It is nice having a second direct source leak down test instrument for diving into individual components. The syringe obviously has its own leak as the plunger is pulled back down, so crimping the tubing is critical for real results.

I'll say it again. Teflon Tape! Good times. Build on.

[Mike S]

Scott, good info and photo spread.

One tip for your tip------when you do a hole in something like this strap, burn through it with a heated metal rod, the edges of the hole will not fray.

[scard]

Originally Posted by Mike S

Scott, good info and photo spread.

One tip for your tip------when you do a hole in something like this strap, burn through it with a heated metal rod, the edges of the hole will not fray.

Well, of course, but I gnawed that hole with my teeth as there seemed not to be another sharp or hot tool in sight at the time. I think I did pretty good, don't you . I did think about heating up a phillips head screwdriver with the airplane battery... Ok, so I wasn't on a desert island after all.