The following information is derived from the FAAs Service Difficulty Reports and Aviation Maintenance Alerts.
Lycoming IO-540 Engines
Crankshaft Gear Bolts
A new AD supercedes AD 2002-23-06 regarding certain zinc plated crankshaft gear retaining bolts installe d in Lycoming AEIO-540, IO-540, LTIO-540, and TIO-540 series engines. The AD retains the original requirement but expands the population of affected engines by 161. In addition, it AD adds five additional kits (alternative method of complia nce) for replacing the crankshaft gear retaining bolts.
Fuel Pressure Transducer
AD 2004-06-09, Fuel Pressure Transducer Inspection, is effective May 3, 2004, and affects Lancair models LC40-550FG and LC42-550FG airplanes. It requires a repetitive inspection of the fuel pressure transducer for evidence of chafing and for measurement of the cross section diameter.The AD also requires installing a compliance kit at a time dependent upon the outcomes of the inspection and measurement. The installation of the kit is the terminating action for the repetitive inspection requirements. Compliance is within 100 hours TIS or within five hours TIS after May 3, whichever occurs later. Repeat at 25 hour intervals. Follow Lancair MSB-04-002B, March 2004.
Engine Components Inc. (ECi) Cylinders
Cylinder Cracks, Separation
AD 2004-08-10 is directed at Teledyne Continental Motors (TCM) model 520 and 550 series engines with certain ECi (Engine Components, Inc.) cylinders installed. This AD requires results from reports of 34 failures of cylinder heads marketed by ECi. Cylinder heads, P/N AEC65385, manufactured between September 1, 2002, and May 12, 2003, s/ns 1044 through 7708, are susceptible to an over-hardened condition, which reduces the fatigue strength of the cylinder and increases risk of cracking. Effective May 5, 2004, the AD requires performing a check to identify cylinders, ECi p/n AEC631397, s/n 1044 through 7708, within 50 hours time-in-service after the effective date of this AD. If a cylinder has an affected p/n and s/n and was not inspected at ECi, it must be replaced before further flight.
Cessna Model T-210J Centurion II
Alternate Air Door
The submitter reported the original alternate air door hinge pin (P/N 1250839-12) was made of aluminum. The pin had worn and dropped pieces into the intake system causing damage to the turbocharger. According to the submitter, the new hinge pin is made of stainless steel and secured in the hinge by crimping. He recommended routine inspections and changing the aluminum pins to stainless steel pins. Part total time: 2,230 hours.
Piper Model PA-28R-201; Arrow III
MLG Down-Lock System
During a preflight walk-around, the pilot noticed the main landing gear down-lock spring (p/n 67203-00) was hanging down by one end. Further investigation revealed the spring attach bracket (P/N 67753-000) had broken and the main gear down-lock spring was not attached to the trunnion. The spring attach bracket is mounted to the trunnion underneath the squat switch and is attached by two bolts. The bracket failed at the attach point for the down-lock spring. According to the submitter, the spring is the emergency-extension system backup if the hydraulic system fails.A search of the FAA Service Difficulty Reporting Program database revealed two additional reports citing failure of the main landing gear down-lock spring attach bracket. Part total time: 11,129 hours.
Beech Model A36
Heater Muffler Assembly
The heater muffler assembly (P/N 701-21) failed the 500-hour pressure test performed in accordance with the Beech A36 maintenance manual. Upon disassembly, the technician found large bulges in the exterior of the main barrel of the muffler, which is located near one end. The submitter stated it was possible that overheating caused this failure. He recommends adhering to Beechs recommended inspection schedule in order to remove the failing unit before it causes carbon monoxide in the cabin or engine compartment fires. Part total time: 598 hours.
Cessna Model 172S
Improperly Routed Duct
During a routine inspection, the technician discovered the plastic glove box (P/N 0513552-15) was melted at the forward end on the right side. The technician also found that the heater ducting was routed against the glove box. He rerouted the heat duct to prevent future occurrences. The submitter stated finding the same problem on a like aircraft. Part total time: 1,346 hours.