It doesn't suck

I went up today for two reasons:

• Flying is better than not flying
• I wanted to get one more flight in before Harvey Field's asphalt runway gets torn up and replaced over the next month.

The weather this morning was MVFR, but the skies cleared and, by about noon, it was lovely. I went out to the airport and started my pre-flight inspection.

Right away, I noticed a problem. The starboard fuel sump drain valve was leaking fuel, albeit very slowly. There was still plenty of fuel in the tank. I don't know when this started, but it must have been in the last few days because I went flying this past Thursday and it wasn't leaking then. It may have started when I checked the fuel before that flight. Perhaps it didn't seal up fully after that.

I worked it a few times with the fuel testing cup. It was still leaking. I worked it a few more times. It was still leaking. I worked it a few more times and it looked like it had stopped. I walked over to the FBO to use the facilities, figuring I'd give it some time before I checked it again. On the way back I stopped and chatted with one of the other Musketeer owners at Harvey. I told him about the fuel leak and he said that he'd had the same issue for a while but it was an easy fix. When I got back, it appeared that it really had stopped leaking, so I went ahead and pulled the plane out.

I started the engine and then taxied over to get fuel. After I was done fueling, I walked into the FBO again to wash my hands. When I got back out, I didn't see any evidence that it was leaking so it definitely appears that I was able to get it to seal tightly again. I started up the engine, went over to the runup area for my runup, then I taxied out to the runway and took off.

I headed north and climbed to my cruising altitude. All was going well and I was passing Arlington airport when I looked down and noticed that my attitude indicator was not working properly. It was showing me in a steep climb when I was flying level. I looked down at my suction gauge and it was reading a big, fat zero. I had experienced a failure of my vacuum system. I did a 180 and headed straight back to the airport. My heading indicator was still working as the gyro hadn't spun down yet, but it did eventually stopped working as well. I made a decent landing and put the plane away.

I just now checked the POH and, as it turns out, it says that the attitude indicator and heading indicator (aka the directional gyro) are not actually required for VFR flight, even at night. They are only required for IFR. So I could have continued my flight while still being within requirements. But I'm glad I decided to head back. I wasn't sure, so I decided not to take the risk.

I've already called up the shop and asked them to check the sump drain valve and the vacuum system when they next take it in to check the oil for any additional metal. Best case scenario, one of the lines came loose and just has to be reattached. Worst case scenario, the vacuum pump needs to be repaired or replaced. Fortunately, a vacuum pump isn't terribly expensive, at least as far as airplane parts go. The shop technician I spoke to said a new one was $333 plus tax. With labor, I'd probably be looking at about $500 or so. Not cheap, but still well under a thousand bucks, which is what I figured it would be.

If it was going to be rather more expensive, I'd consider using it as an excuse to go ahead and replace the AI and DG with electronic instruments, and do away with the vacuum pump altogether. However, I think I'll wait to do that until sometime later.