Clip-Wing Cessnas

Wing attach fittings can corrode to the point of structural failure


The following information is derived from the FAAs Service Difficulty Reports and Aviation Maintenance Alerts.

The FAA reported that there have been numerous instances of structural corrosion of the wing attachment fitting on virtually all Cessna single-engine airplanes.

The agency recommends an inspection to determine the airworthiness of the parts. Mechanics should remove the top and bottom fairings covering the wing/fuselage attachments and inspect the spar block, the center wing spar and the wing spar assembly for corrosion.

The areas of concern for the Cessnas indicated are the spar block, spar channels and the upper end of the doorposts. Any evidence of corrosion in these areas is cause for removing the wings to determine if more severe corrosion exists in areas that are not otherwise possible to inspect. The inspector should refer to the manufacturers technical data for inspection criteria, corrosion limits and appropriate treatment for corroded areas.

Beech C-23 Sundowner
Defective Door Structure

The pilot reported severe buffet during slow flight, approach and landing.The technician discovered the left cabin doors bottom gasket was missing and the fiberglass door structure was broken adjacent to the last rivet in the diagonal gusset. This defect allowed air to escape from the cabin and disrupt the airflow over the left wing and horizontal stabilator. The right cabin door was broken in a similar manner.

The problem may have been caused by pilots leaving the doors open during ground operation or wind slamming the doors open.Part total time – 8,100 hours.

Beech A-36 Bonanza
Fuel Pump Failure

The pilot reported the engine began losing power unless the electric fuel boost pump was used.

The technician observed fuel stains in the nose gear well and on the skin near the right exhaust stack. Fuel was leaking from the seal drain line for the engine-driven fuel pump.

The problem was addressed by Teledyne Continental in SB 01-1, but the SB is not applicable to the fuel pump installed on this aircraft because it had more than 300 hours time in service. In this case, the fuel pump gave no warning of impending failure.Part total time – 608 hours.

Beech 58P Baron
Throttle Assembly Installation

The pilot reported the right engine throttle was very stiff and difficult to operate.The throttle control assembly had been replaced four months earlier. The throttle cable was chafing very hard against the lower part of the turbocharger compressor-housing clamp. Also, the chafed area of the cable displayed evidence of severe overheating.The throttle cable should have been routed above the exhaust area. The exhaust heat shield would have protected the cable from chafing.Part total time – 242 hours.

Beech 58P Baron
Smoke in the Cockpit

Prior to takeoff, the pilot checked the lights as required on the checklist. During the takeoff run, the cockpit filled with smoke and the pilot aborted the takeoff.A technician found the Pulse Light system, installed via STC, was not properly installed. The circuit breaker supplied with the STC was not installed. An electrical short in a connector adjacent to a light fixture caused the wires to burn. The STC was installed in 1998.

Beech 76 Duchess
Starter Malfunction

The pilot heard an abnormal noise when attempting to start the left engine, then the starter failed. This aircraft is used in a training environment. A technician discovered the forward pivot bushing at the drive end had separated from the casting. The starter had recently been overhauled.Part time since overhaul – 432 hours.

Beech E-90 King Air
Landing Gear Failure

The landing gear stopped approximately one-third of the way to the up position when retracted after takeoff. Also, the landing gear control circuit breakers opened and the gear unsafe light illuminated.The pilot tried to extend the gear using the emergency system, but it failed. While preparing for a gear-up landing, the pilot attempted to retract the gear and reset the circuit breakers, and the gear retracted. He then attempted to extend the gear and got a down and locked indication. The technician discovered the nose gear actuator turned with great difficulty and felt ratchety. Part total time – 330 cycles.

Cessna 172RG Cutlass
Landing Gear Defect

During a scheduled inspection, a technician discovered a landing gear actuator bushing installed in compliance with AD 2001-06-06 was defective. The bushing had worked its way out of the housing and had to be replaced.The mechanic noted two instances of defective bushings after a short time in service.Part total time – 137 hours.

Cessna 208B Caravan
Defective Wing Strut Attachment

During the first scheduled inspection of a new aircraft, the technician found the bolt cotter pin for the left lower lift strut attachment to the fuselage was missing. There was no evidence that the cotter pin had ever been installed. The bolt and nut had rotated, which could allow separation of the nut and loss of the bolt, which could in turn lead to wing separation.Aircraft total time – 193 hours.

Cessna T210L Centurion
Wing Flap Structural Damage

During a scheduled inspection, the technician discovered a crack in a rib on the left wing flap at the bellcrank support bracket rivet hole. The support bracket inboard lower rivet hole is where the crack originated, and it ran approximately 1 inch down and to the left. The problem may have been caused by extending flaps at high airspeed.Part total time – 3,505 hours.

Cirrus SR-22
Induction System Installation

While conducting a ground training class, the instructor removed the top engine cowling. One of the pilot/students, who was also an A&P-IA, noticed that the end of the induction air filter housing was in contact with the engine case. The improper use of an Adel clamp allowed the alternate air induction air filter housing end to rotate within a hose joint, the air filter end to contact the engine case, and an attached section of the duct to chafe against adjacent engine baffling.In addition, the movement of the airbox caused two of the three blind rivets in a support bracket to fail.Part total time – 38 hours.

Piper J3 Cub
Engine Failure

During an accident investigation, the FAA inspector determined the engine failed when both magneto P-lead wires became grounded by chafing against a screw that secured the left inner and outer window trim strips. The wires had chafed against the screw threads until the insulation was penetrated.The window trims original fasteners had been drilled out and longer screws and nuts had been installed. Part total time – 5,586 hours.

Piper PA-23-250 Aztec
Fuel Tank Selector Failure

The pilot reported the fuel tank selector failed.The fuel tank selector cable had broken just below the swivel fitting on the right wing fuel tank selector handle. It appeared the cable failed because of metal fatigue, corrosion, age, and lack of lubrication.AD 80-18-10 requires recurring inspections to detect and correct problems with the fuel tank selector system, as well as lubrication of the components. AD 80-18-10 apparently had not been complied with for some time.

Piper PA-31-350 Chieftain
Heater Fuel Leak

During a scheduled inspection, the Jan Aero cabin heater fuel pressure regulator was found to be leaking.Records showed AD 2001-08-01 and AD 2001-17-13 had been complied with, and the new-type fuel pressure regulator was installed. The fuel pressure regulator was leaking around the housing seal. Part total time – 142 hours.

Piper PA-31T-620 Cheyenne
Nose Wheel Steering Difficulty

After a flight, the pilot complained the nose wheel steering was very stiff, especially to the right. The technician found no defect in the nose landing gear and steering linkage. When he pushed on the pilots right rudder pedal, the tube support block and the tube moved fore and aft. The flange securing the tube support block to the left side of the nose wheel well was cracked. The technician then found the inner and outer torque tubes were binding slightly. There were no provisions to lubricate the torque tubes or the support bearings. Part total time – 5,275 hours.

Piper PA-32R-300 Lance
Uncommanded Nose Gear Extension

The pilot reported the nose landing gear came out of the wheel well without command during flight.The nose gear downlock hook was broken at the attachment to the actuator rod. The technician reported finding this type failure on several occasions, often involving parts with a low number of operating hours. Part total time – 352 hours.

Piper PA-32R-301T Saratoga
Propeller Control Defect

The pilot the propeller control became immobile during cruise flight, but operated normally when speed was reduced for landing.After a lengthy investigation, a technician discovered an engine cylinder baffle interfered with the propeller governor control arm during flight by moving forward during flight. The defect is the subject of Piper SB 1049.Part total time – 197 hours.

Piper PA-46-310P Malibu
Flight Control System Defect

During a scheduled inspection, the technician discovered an elevator push-pull rod in the tail section was severely corroded. Piper SB 962 deals with this subject but does not apply to this particular part.Part total time – 2,321 hours.

Teledyne Continental IO-520
Crankshaft Failure

The pilot reported the engine, installed on a Cessna 207A, would not make full RPM.The technician replaced the propeller governor and an operational test was within normal parameters. On the next flight, the pilot noticed the oil pressure fell below the green arc shortly after takeoff and he shut down the engine. He saw oil on the windscreen, heard a loud bang, and the propeller separated from the aircraft. The engine crankshaft had broken at the crankshaft nose seal location. AD 99-19-01 and AD 2000-23-21 deal with this subject.Time since overhaul – 347 hours.

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