Cessna: 172; Primer Line Fuel Leak; ATA 2820
Fuel was noted spraying from the number three cylinder when fuel priming prior to engine start. A mechanic describes finding the primer line (P/N LW12098-1-116) cracked at the welded tip where it attaches to the cylinder. “This is a ball-type end on this line. I suggest more security (for these) primer lines at more places to minimize vibrations.” (Good advice, Lucas! Any such fuel leaks in the engine compartment represent a horrible safety scenario. Next time please throw in some part times so others can develop a “relative expectancy” for their own units. Thanks—Ed.)

Cessna: 172, 180, 182,185, 188; Elev. Torque Tube Corrosion; ATA 2730
Specific applications are: all 172’s, 180/182’s through 1961, and all 185/188’s. This safety article is published as received from the Wichita Aircraft Certification Office.  The Australian Civil Airworthiness Safety Authority (CASA) has issued an airworthiness bulletin (AWB 53-006) recommending inspections for corrosion damage on the elevator torque tubes (P/N 0532001-31) in Cessna model 172 airplanes. This part has been installed on Cessna model 172’s since it was introduced in 1956, and it continues to be installed on new Cessna model 172 production airplanes. The part is an aluminum tube exposed to wheel spray during landings, or spray from floats during water landings. The tube is oriented horizontally, so it tends to retain water. Exposure to moisture (particularly in coastal regions) over many years leads to corrosion damage. CASA reports similar problems with the P/N 0734110-7 torque tubes used on the Cessna model 188 airplanes. This part is also used on the Cessna model 180’s, the early model 182’s (through 1961), and the model 185 airplanes. Two SDRs in 1992 and 1994 were found in the FAA database on P/N 0532001-31 where corrosion was an issue. One submitter suspected the corrosion was due to coastal weather conditions. No SDRs were found for P/N 07341100-7 where corrosion was an issue. However, two SDRs for the same airplane (one SDR for each side) were found for a Cessna model 170 in 1995 where the torque tubes were found rusted and pitted. The new parts had to be locally fabricated from a drawing. The submitter recommended the tubes be inspected on the airplane. The P/Ns were identified as 0334106 and 0334206. AC 43-16A October 2007