Two days before the Taylor 125 air race my Attitude Indicator rolled over and died. It had been shakey at start up and slow to erect (OK, OK, it's not funny) for sometime before this final failure. I drove down to Rudy, Arkansas and turned it in for overhaul. Yesterday they called to say it was fixed and I asked what they found. Mike told me the rotor was loaded with debries which had destroyed the bearings. He asked if I had a vacuum pump failure and I reported that I did have one last year. He said this sequence is common and to prevent the carbon dust from the vacuum pump failure from destroying the Gyro instruments you need an inline filter between the pump and the instruments with the flow arrow pointing to the pump. When I built my plane I installed a Rapco Vacuum System Kit (p.383 in the 2007-2008 catalog) which does not include an inline filter (p.385 in the same catalog). He suggested cleaning the hoses with mineral spirits (blowing then out will not work) or replacing them and replace the filters. He also said it is a good idea to replace the filters at the time of the annual condition inspection. Finally, he said to use the black woven shroud hoses instead of the soft rubber hoses which will collapse. Anyway, I thought I would pass this along. The maintenance procedure sounds conservative but I am changing my checklist to cover it.
Bob Axsom
Bob Axsom