GAP-26 altimeter Test (part 43.appendix E) - Expert Question

HI

GAP-26 altimeter Test (part 43.appendix E)

I read in the g3x touch installation manual that the GAP-26 [5.5.5] must completely cover the pitot, aoa and the drain ports for the pitot test. Can the drain port simply be blocked with some mastic during the test? Removed afterward of course.

I want to test this myself before hiring an expensive technician.

Thanks.

When I had mine done (same GAP-26) the tech had to disconnect the union between the aluminum tubes and my nylon tubing just inside the access panel where the pitot mast is mounted. He said it was due to the AOA portion of the pitot tube.

I use vinyl tape to cover drain ports, no issues.

Walt said:

I use vinyl tape to cover drain ports, no issues.

Click to expand...

Thanks, Walt, I thought that would work, just wanted to be sure. I am researching how to make an adapter with a fat internal o-ring to do the test, but it would not reach the aft-most drain. The store bought units look pretty pricey.

Jasonm said:

When I had mine done (same GAP-26) the tech had to disconnect the union between the aluminum tubes and my nylon tubing just inside the access panel where the pitot mast is mounted. He said it was due to the AOA portion of the pitot tube.

Click to expand...

Thanks Jason for the heads up on that - I wanted to avoid removal and to include the pitot/AOA connections in the test. Is that test method acceptable for IFR sign-off?

No pitot test required for an IFR cert on an unpressurized aircraft.

Be sure that the static, pitot and AOA are all connected together for the altimeter test, failure to drive all sensors together can damage the sensors.