Pitot static test mode

[rfazio1951]

Today I had my skyview, pitot static system and transponder checked. It passed with flying colors, but we had one minor problem. The tech wanted to see the transponder output and we had none. It took me a while to figure out that the transponder was in "AUTO" mode and thus thought it was on the ground and off or not transmitting. To get it to transmit I had to go in and set the mode from auto to none. Then turn it on. My suggestion is that when the system is put into the test mode for the pitot static system, the transponder should automatically be put into transmit mode. I know when I go back in two years I'm going to forget all about it again and have to figure out the problem again.

 

[Raymo]

The need to change to NONE is documented in the installation manual but I agree it would be an easy software change to have it do this automatically when in TEST mode.

 

[dynonsupport]

It's a creative idea, but not one the FAA would support.

They are already trying to get shops to put a cage around transponder antennas while testing them. With ADS-B now getting popular, sitting on a ramp with your transponder on while you cycle the altitude up and down creates a false target which ATC and other aircraft can see, and may get alerts for. They really don't want you doing this.

Automating the transponder (which is ADS-B) into ALT mode while knowing the static system is about to be manipulated probably isn't a good idea. There are times you might be in this mode when not testing the transponder.

Remember that a Mode-S transponder also needs to be tested by a Mode-S test set to be a legal test. I believe that this test checks ground interrogations as well, so you actually need to switch modes during the test, not just be in ALT all the time.

I imagine shops will get a lot more used to needing to override a transponder into ALT as many more of them become ADS-B OUT, and thus require auto AIR/GND switching. The need to do this is not unique to the Dynon transponder, it's a TSO requirement of any transponder which is your ADS-B OUT solution.