October 2012 FAA Maintenance Alerts

Pilatus:  PC1247; Failed Brake Disk; ATA 3242

"This aircraft was undergoing a 100 hour inspection," says this submitter. "(The mechanics) removed the L/H and R/H main landing gear wheel assemblies to complete NDT (non-destructive testing) — and upon wheel removal one of the wheel's brake disk assemblies fell onto the floor in two separate pieces. Both L/H and R/H brake assemblies (presented) separated brake disks. These brake disk assemblies were not the original (units). They were installed at an earlier date and (had been tagged) as removed from another aircraft. The operator did not notice any abnormal sounds or conditions during aircraft operations. The technician did not notice any abnormal sounds or conditions during operational run up, and the wear guide pins (indicating) 'normal system' functioned properly."

Part Total Time: 1,043.0 hours

Champion Spark Plug:  RHB32S, Cracked Insulators; 7421

(A pilot/mechanic provides this defect report referencing a Cirrus SR22 aircraft with a Continental IO550N engine.) "The engine (ran) rough during climb to 14,000 feet. (I) could not set 17.5 GPH (fuel consumption) for cruise. CHT (cylinder head temperature) for number one cylinder increased from 340 degrees to 480 degrees and beyond. I had normal EGT (exhaust gas temperature), high and rising TIT (turbo inlet temperature) on turbocharger number two — from 1,600 to 1,750 degrees. When the oil pressure dropped I diverted (for landing).  Inspection revealed no differential pressure on cylinder number two, the oil filter was full of metal, the waste gate controller was missing parts, and the spark plugs had cracked insulators and pre-ignition (indications) on the cylinders. There was metal contamination throughout the engine. An annual inspection (... had been accomplished 30 hours prior to the flight)."

Part Total Time: 30.0 hours

Sky-tec Starter:  C24SF3; Shorted Commutator, ATA 2434

(This report references Cirrus SR20 aircraft with a Continental IO360ES engine.)

"After start up, the crew noted the R/H IFD (instrument flight display) went blank," says this repair station mechanic. "The maintenance crew suspected a bad battery (low voltage), so they installed a new battery.  When the negative wire was installed, a large spark (was generated). The 'Battery No. 1' relay was found to be stuck. After replacing the relay and the battery, the engine would not start. The starter was replaced, and during run up all conditions were normal. IFD data was downloaded and reviewed, and the starter disassembled. The maintenance crew determined a dead short-to-ground caused by a section of the commutator coming loose had caused Battery No. 1 to rapidly discharge, causing the relay to stick in the closed position. (My) recommendation to flight crews is to monitor the systems page on the IFD (after start up) to determine proper battery discharge/charge rate and bus voltages."

Part Total Time: 850.0 hours