Given the deep teardown that’s often associated with avionics retrofits, the first few flights after a project can bring sizable risks. In a previous life as an avionics tech, I’ve experienced more dicey shakedown flights than I care to remember. This included an engine failure with an off-field landing, numerous electrical failures, smoke in the cabin and plenty of equipment failures the result of infant mortality. Whether your shop hands you the aircraft to test-fly the new systems by yourself or with them riding shotgun, approach the task with a healthy level of caution and start with a focused preflight inspection. Remember, avionics installs often include a lot of airframe teardown and in many cases, some engine and fuel system work, depending on the system interfacing.
The first thing to remember is that the project isn’t complete until it’s been fully flight tested to verify that everything works. Many STC installation manuals outline the items to check both on the ground and in flight. I’ve seen far too many owners schedule passenger-carrying trips on the first flight. Bad idea. I’ve also seen owners launch into low IMC on the first flight. Worse idea. It’s not a bad idea to limit the aircraft to VFR for the first few hours while you make close observations of the equipment and interface, while also getting comfortable with the new feature set and layout. I’ll never forget the hair-raising story from a turboprop owner who made the mistake of launching into low IMC with a new EFIS/autopilot interface. He was seconds away from losing control of the aircraft because the autopilot was doing something he didn’t expect it to do (it turned to the opposite heading than what was bugged) while he was busy doing other things. If you don’t know the new system cold—and that includes potential failure modes—take the time to get some training. We covered avionics training in the June 2021 issue of Aviation Consumer and found there are plenty of good options.