Today I finished the last step to get the Cessna back in the air. My friend Dan from across the airport is certified to do transponder checks. I was nervous about this one. There are lots of things that can go wrong, especially with my "vintage" transponder system. As you can see in the picture, there is a lot of stuff needed to do the check. On the wing is a device that reads the transponder squawk and altitude transmissions. On the chair is a device that you hook up to the static system to simulate flight at altitude. The yellow box is a vacuum pump to hold the static system device to the side of the airplane. Anyway, the good news was that after a tweak to the altitude encoder, everything was working just fine. I have a lot of documentation to do and have to check ADs. Then it is break in time for the engine. That means fly it.