March 2012 FAA Maintenance Alerts

de Havilland: DHC8103; Corroded Aileron Control Shaft; ATA 2710

An air carrier operation writes, "Roll control was very stiff. (We checked) the tension of the aileron fuselage cables and lubricated the aileron quadrant bearings externally for (initial) troubleshooting." "We replaced the L/H and R/H bearings in the aileron quadrant IAW Mod Kit 8MK0930-001 instructions and the AMM 27-12-31. The control cable tensions (and their safeties) were not disturbed. The L/H aileron control shaft (P/N 82740083-101) was replaced due to corrosion."

Part Total Time: 50,244.0 hours

Piper: PA31-350; Cracked Main Gear Fittings; ATA 3211

(A technician for an air carrier operation provides the following report. His reference can be found at: .)

"(Topic:) Cracks in the Aft Main Gear Side Brace Fitting Assembly (P/N 40294-00). The Aging Aircraft Lab at the National Institute for Aviation Research (NIAR) in Wichita, Kansas recently produced a report titled, 'The Aging Airplane Study: Piper Navajo Chieftain.' Based on their findings, we initiated a dye penetrant inspection program on the forward and aft main gear Side Brace fitting assemblies on our Piper Chieftain Navajo fleet. The inspection of our aircraft revealed several of the aft fitting assemblies on both the left and right landing gear have cracks located in the lower inboard web of the Side Brace (Piper P/N 40294-00). As a result of finding these cracks, we have added a 1,000 hour Special Inspection to our PA31-350 AAIP (Aging Airplane Inspection Program) to monitor and replace any assemblies exhibiting the cracking found in the fitting assemblies. It is interesting to note these cracks have only been found in the aft assemblies on our aircraft."

Continental Magneto: S6RSC-25P; Failed Distributor Gear; ATA 7414

(This report comes to us from Hungary by way of the European Aviation Safety Agency. Both reports reference the same Cirrus SR22 airplane and Continental IO550N engine, but different magnetos.)

A mechanic writes, "The crew reported severe engine vibration and raised EGT (exhaust gas temperature) at the same time in cylinder number three. A quick inspection on the ground revealed the R/H magneto to be inoperative. The operator decided to replace the magneto (P/N 10-500556-101) with a brand new one. After replacement was accomplished, further investigations followed: cylinder differential compression check; spark plug check. During this additional (inspection) we also found the ceramic on the upper spark plug of number three cylinder to be broken. It was replaced, and a test flight conducted. We climbed to 18,000 feet — everything reported normal. During disassembly of the magneto, the distributor gear (was found to have failed). This (defect) might have caused an engine in-flight shut down that could lead to a loss of control. This magneto was replaced...."

Part Total Time: 673.0 hours