An issue or so back, Ask Paul responded to a question about a TCM O-470 (Did additive cause engine problems? Aug. 10 issue). He suggested replacing all the oil cooler hoses. Unless 470s, 520s and 550s have an add-on remote cooler, they don’t use hoses. The coolers mount directly to the engine. Supposedly, after World War II, Continental saw hoses as being prone to failure, so they mounted the coolers directly to the cases. However, I’ve seen more TCM OCs or mounting plates fail than I have hoses on Lycomings.
In the latest issue a guy asked about max RPM (When should I achieve highest RPM? Aug. 24 issue). One thing you didn’t mention, along with the prop diameter, is the pitch. While there is a specific prop to go on the aircraft, most aircraft also have optional pitch settings for cruise or climb pitches. Most standard props are mid-range. The aircraft could be fitted with a cruise pitch prop, either legally or illegally, in which case it would hardly ever come close to redline. On the other hand, a climb pitch can allow it to reach or even exceed redline quite readily.
As an A&P/IA, I always enjoy the information in Ask Paul — and sometimes it’s something I can use right then!
FRANK MAY
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