From the logbook...maintenance

Back a few years ago as I was working as a mechanic in training, I knew all the hard days were going to be worth something... someday. Today was a classic example of why MAF requires that their pilots are also mechanics. Although I haven't done a lot of maintenance since arriving in Ecuador, I have used my mechanical knowledge and problem solving a lot.

During my pre-flight today (I was really excited to go flying after a week of coordinating) I noticed a funny sound as I turned the propeller backwards. We do this 6 times to check for compression in all 6 of the cylinders. I felt compression in all 6 cylinders, but one of them was letting out air, with a shwooshing type sound. After taking off the engine cowling and a few pieces of baffling, I turned the prop again, this time having squirted the cylinder with soapy water. Sure enough, bubbles started foaming out like crazy indicating a crack, and I knew my hopes for flying today were dashed.

So, we pushed Alas 13 to the maintenance end of the hangar and begin pulling the jug to get another one on. Tomorrow is a big day of flying, and the goal was to get 13 back on line today. By 2:00pm with the help of one of our mechanics, I had the engine ready to start back up. It was gratifying to do something more extensive than the usual little fixes that I do. The fact that it all came back to me, and I could do it with efficiency and speed were also pluses.

We all went and had lunch together before I started the engine. We wanted to take a break and come back to the engine and see what we had missed after our brains were nourished. After a positive ground runup, I took 13 flying for a while and still everything worked fine. Tomorrow, 13 will be back on the flight line and working hard.

This is what the inside of a typical airplane cylinder looks like. The two empty holes are where the spark plugs go. The smaller circle on the left is the exhaust valve, and the larger one on the right is the intake valve. You can easily see the crack between the two black lines I made. Thankfully, this was caught on the ground. I think this jug was about to split in half.