One of the most difficult things to teach a student pilot are the failures that can occur in an aircraft. Oh sure we talk about them, and what to do when they occur, but without being able to simulate them in the plane it’s just an exercise in the procedures. So when a failure happens it’s a good teaching moment as they don’t always just fail instantly. The failure can be gradual and may present itself as a series of failures.
This was the case recently while we were in the pattern practicing landings. The first indication was the intercoms and radio started sounding a little scratchy. Then at one point the tower repeated an instruction 3 times as they never heard the first two read backs. I thought that was odd as the student did a good job and I saw the “T” on the radio indicating he was transmitting.
A few minutes later tower reported they no longer were receiving our mode c from the transponder and asked us to recycle. We did that and still they weren’t getting our altitude readout. This was now the third odd thing of the flight. Even for me it snuck up on me as I have experienced an electrical failure twice so far. It’s a gradual failure of multiple systems that really makes one think.
It was time to get this on the ground. However with everything going on we were high on final and the student decided to go-around. I advised tower that we had an electrical failure and asked to get our landing clearance early in case the battery totally failed. They asked if we required assistance which is always an attention getter for me. I declined as mechanically we were fine as there was no smoke or evidence of something serious. After telling us we were number 2 to land if we needed priority to land just advise. I acknowledge and we flew a good pattern and landed normally.
On the taxi back we discussed what would happen if the battery failed before we got our clearance to land. He responded with the appropriate light gun signals the tower would use. Good answer. Next trip out to the airport I think I’ll have the tower shine a light gun at him so he can see what they are. It’s good to be familiar with these things.
We put the plane away and then debriefed the flight and discussed more scenarios that could have played out if it happened away from the airport and what would you do then? It was a good discussion and valuable lesson in another failure for him to file away in his experience.