A chain is only as strong as its weakest link, and that cliché applies more in aviation than just about any other field — with the possible exception of training attack dogs. Old Bonanzas like mine have Continental E-series engines, similar to later O-470s, but with enough differences to make operating one a constant source of education. One important class involves the Thompson TF1900 engine-driven fuel pump. Experience may be the best ‘professor’ but when it comes to E-series Continental engines, Lew Gage is right up there on the podium alongside the school of hard knocks. From his book, E-Series Bonanzas concerning the Thompson pump:
“The pump part of this unit is very well designed and manufactured to close tolerances with high quality. However, the drive end is of marginal design and poorly manufactured. Due to this condition, the [FAA-mandated] 300-hour inspection is a very necessary maintenance procedure.”
