The following information is derived from the FAAs Service Difficulty Reports and Aviation Maintenance Alerts. Click here to view “Cessna Gear Fatigue.”
The FAA has recently been advised that engine fuel strainers are failing at an increasing rate in new-production Cessna singles.
The manufacturer recommends maintenance personnel exhibit care when reassembling the threaded gascolator/fuel strainer standpipe into the fuel strainer housing after internal inspections of these components. The standpipe should be replaced if the standpipe threads are damaged or there is an insufficient number of threads. The current configurations of fuel strainer standpipe have an increased number of threads.
The prior configuration standpipes, which are currently installed, may be acceptable. Satisfactory thread condition with acceptable thread engagement is required for the standpipe to be acceptable when reassembled. It is also necessary that the bottom nut be secured as shown in all of the maintenance manuals with safety wire at the base of the fuel strainer.
Aviat A1-B Husky
Exhaust System Defects
The owner reported the engine was making an unusually loud sound.The technician removed the muffler and engine exhaust system duct assembly and discovered the internal muffler baffles were missing and the lower slip joint for the number 4 cylinder was leaking severely.Part total time – 589 hours.
Poor Engine Operation
After returning from a flight, the pilot reported a loss of engine power on the left engine. He had believed the problem to be carburetor ice, but heat did not fix the problem.A technician found the carburetor airbox was worn excessively, especially around one of the weld assemblies. Part time since overhaul – 1,357 hours.
Beech F33A Bonanza
Instrument Air System Failure
After returning from a flight, the pilot reported the instrument air pressure went to zero just after takeoff.A technician discovered the Rapco vacuum pump drive shaft was sheared. The FAA Service Difficulty Program database contains six additional reports of drive shaft failure on this vacuum air pump in the last two years. The lowest operating time before failure in the seven reports was 50 hours and the highest was 574 hours. Part total time – 574 hours.
Beech E35 Bonanza
Defective Air/Oil Separator
After performing an engine-operational test to locate an oil leak, the technician noticed oil coming from the air/oil separator.The oil was leaking from the lower outboard corner of the Beryl D-Shannon air/oil separator. Oil was leaking through corrosion pits and into the exhaust port. The technician disassembled the unit and found severe corrosion inside the unit.Part total time – 1,291 hours.
Cessna T210N Centurion
During a landing rollout, the left main gear collapsed.A technician discovered the landing gear powerpack was inoperative. The electrical wiring for the powerpack and nose gear down lock switch were misrouted. Apparently the powerpack wire was cut by being in the wrong location during the gear-retraction cycle.
Flight Control Cable Damage
During a scheduled inspection, a technician discovered the aileron control cables were severely damaged.All four cables had broken strands and had to be replaced. The left forward carry-through cable had approximately 70 percent of the cable strands broken where they contacted the pulley guard, which was incorrectly installed. Also, the cables were rubbing against the Phenolic blocks where the cables exited the fuselage. Part total time – 1,950 hours.
Cessna T337F Turbo Skymaster
Landing Gear System Failure
The pilot stated all of his efforts to extend the nose landing gear failed. Inspection revealed the nose landing gear hydraulic hoses were replaced with newly fabricated hoses approximately 8 operating hours prior to this event. Rubber particles, apparently from the new hydraulic line, were found blocking flow throughout the system.Part total time – 8 hours.
Engine-Mount Frame Tube Damage
During a scheduled inspection, a technician discovered that an engine-mount frame tube was damaged.An Adel clamp, used to support a fuel line, chafed the engine-mount tube. The rubber cushion on the Adel clamp had worn through and allowed the metal band to contact the lower aft section of the engine mount frame. The submitter reported finding this discrepancy on two other like aircraft. The aircraft manufacturer issued Service Bulletin (SB) 22-28-01, dated December 17, 2001, which offers a new clamp-support bracket and reroutes the fuel line to alleviate this problem.Part total time – 101 hours.
Defective Landing Gear Component
The landing gear collapsed on landing, and investigation determined the landing gear actuator had failed.The electric Dukes landing gear actuator was evaluated by an FAA Airworthiness Inspector and repair station personnel. The actuator worm shaft gear teeth were worn far beyond acceptable limits. The worm shaft was subjected to a Rockwell hardness test that revealed the shaft material was not hardened to the proper specifications. This landing gear collapse incident occurred shortly after the worm gear assembly was replaced in accordance with AD 75-23-04. Part total time – 168 hours.
Piper PA-28-161 Warrior
Main Gear Strut Defect
During a scheduled inspection, a technician discovered that one ear of the left main gear upper torque link was broken.There are two ears attached to the main landing gear upper strut housing that are used to attach the upper half of the torque link. After finding this defect, he inspected the right main gear and discovered one of the upper attachment ears was cracked. Due to this finding, he inspected the remainder of his fleet of aircraft and found one other strut with a cracked torque link attachment ear.The FAA Service Difficulty Program database contains 26 additional reports concerning cracks and separation of the torque link attachment ears. These additional reports involved the PA-28-140, PA-28-151, PA-28-180, and PA-28-181, all of which use the same strut. Part total time – 11,438 hours.
Piper PA-28R-201 Arrow
Takeoff Engine Failure
The pilot/owner stated that during takeoff, he experienced a loss of engine power just after liftoff.The technician discovered the alternate air door had separated and was lodged inside the fuel control servo throttle body. This effectively blocked air induction into the engine and caused the loss of power.This induction air system uses an adapter assembly to attach the alternate air door hinge. Three rivets are used to attach the hinge. In this case, the three rivets sheared, allowing the door to separate.Part total time – 273 hours.
Piper PA-34-220T Seneca
Binding Flight Controls
After returning from a flight, the pilot stated the flight control column locked up and could not be moved forward or aft. With a sudden jerk, the pilot was able to regain control of the aircraft and landed safely.When the flight controls were freed, the pilot noticed the control column bushing was frozen to the shaft of the control yoke. Part total time – 2,031 hours.
Piper PA 46-500TP Meridian
Cabin-Entry Door Defect
In the process of a scheduled inspection, a technician discovered a defect on the cabin-entry door.The forward door support cable was severely frayed adjacent to the upper swaged fitting where the T handle is attached. The damage required replacement of the support cable assembly.Part total time – 79 hours.
Textron Lycoming O-320
Defective Crankshaft Timing Mark
This engine was installed in a Piper PA-28-140 aircraft. After installing a new engine, a technician performed an operational test and found it would not develop full power.The technician discovered the crankshaft gear timing mark was lined up; however, the timing was not actuated. The crankshaft gear timing mark was off by one tooth.Part total time – 0 hours.
Twin Commander 690A
Wing Flap System Defect
During a scheduled inspection, a technician discovered a structural component of the flap system was cracked.The wing flap master pulley upper support bracket was cracked at the forward lower inboard corner. The location of this defect is somewhat hidden behind cables and linkage and could be easily overlooked during inspections. The crack may have resulted from mis-rigged flaps or from extending the flaps at an excessive airspeed.Part total time – 5,883 hours.
Rudder Control Defect
While inspecting the aircraft, a technician discovered the rudder control rod was broken at the fourth thread of the shank from the bearing end.The technician discovered the rudder was out of alignment and placed a preload stress on the lower rudder rod end bearing attachment.Part total time – 172 hours.