|Posted by RICH OLESZCZUK on March 14, 2012 at 12:35 AM|
Saturday morning, March 3rd, had about a dozen people in Mike Carzoli’s hangar at Lake in the Hills airport. We were gathered near the tail of a 1967 Piper Cherokee 180, held up on jacks, in the beginning stages of its annual inspection. I am one of five co-owners of N9741J which is based at The Landings Airport in Huntley. Mike was hosting a clinic on the nuts-and-bolts of an annual, using our plane as a case-study.
Ole Sindberg started things off by discussing the unique design and construction of the stabilator w/anti-servo tab that is common to all Cherokees; the tab also functions as the trim device for pitch. Ole emphasized that the integrity of the tail assembly in airplanes is of equal importance as the main wing; a fact often overlooked.
Mike answered questions regarding Airworthiness Directives (AD’s) and the responsibilities of aircraft owners and the mechanics doing their inspections and/or maintenance. He noted that just because an Airframe & Powerplant (A&P) mechanic with or without an Inspection Authorization (IA) might be hired to do a specified inspection or repair, they are not allowed to ignore any airworthiness issues that they might come upon incidental to the original work.
Next, we all moved to the front of 41J where Mike explained and demonstrated a differential compression check on one of the cylinders. He noted that it is really a cylinder leak-down test in automotive terms. He cautioned against careless prop control during the test as the propeller can get away from you and do harm.
Mike showed us his optical bore scope and allowed everyone a chance to use the device. We saw first-hand how to inspect the condition of the piston top, cylinder walls, valves and combustion chamber as viewed from inside the cylinder.
Other items were discussed including the benefits (or not) of oil analysis, the use of engine pre-oilers and various techniques to prevent corrosion in our aircraft engines.