Bogus Bladders

FAA says Duraflex fuel cells may be suspect


The following information is derived from the FAAs Service Difficulty Reports and Aviation Maintenance Alerts. Click here to view “Airworthiness Directives.”


Fuel bladders in a variety of aircraft may be substandard.

The FAAs Manufacturing Inspection Office in Fort Worth says unapproved fuel bladders were sold and repaired by Duraflex Fuel Cells Corp. and Fuel Cells Maintenance Inc., both of Little Rock, Ark., for use in Twin Commanders, Raytheon Beech 65 and 90 series, Cessna 300 and 400 series, Piper PA-23s and PA-24s, and possibly other aircraft as well.

The FAA says the production and repair of these fuel cells do not meet FAA-approved design requirements, and fuel may leak on aircraft equipped with the suspect parts.

Most of the bladders were sold to A.C. Team (previously known as A. C. Fuel Cells Worldwide) of Memphis, Tenn., and carry a manufacture or repair date between Aug. 1, 1996, and Nov. 24, 1997.

The FAA recommends that owners, mechanics and manufacturers inspect their airplanes or stock for the listed part numbers and serial numbers, verify the FAA approval status of parts purchased from Duraflex Fuel Cells or repaired by Fuel Cells Maintenance, and if any of the parts are installed, take appropriate action.

For more information, including a list of part numbers and serial numbers, contact the Fort Worth MIO, 2601 Meacham Boulevard, Fort Worth, TX 76137-4298.

Beech 58TC Baron
Improper Exhaust System Repair

During an annual inspection, the technician noticed an engine mount on the right engine was practically ground away.A further inspection revealed the turbocharger exhaust stack was improperly repaired and would not fit without grinding on the engine mount. Also, a major portion of the engine truss had been removed. The damage seriously compromised the structural security of the engine and was very costly to properly correct. Neither the aircraft maintenance records nor the aircraft owner could provide a clue concerning the origin of this damage.

Beech E90 King Air
Defective Elevator Trim Actuators

During a phase inspection, both the left and right elevator trim actuators were found out of free play limits allowed by the manufacturer.The technician installed two new actuators using new bushings and bolts. After rigging, another free play check disclosed that the right actuator was within limits by .001-inch. The left actuator exceeded the limits by .009-inch. Another overhauled actuator was installed in the left position, and it exceeded the limits during the free play check.

Cessna 172 Skyhawk
Worn Piston Pin Plugs

During the course of changing the oil and oil filter in a new aircraft, the technician discovered excessive amounts of aluminum in the old oil filter, and the piston pin plugs displayed excessive end wear.The maintenance department sent a piece of the filter to Cessna and the engine manufacturer for analysis. The engine manufacturer replaced the piston pin plugs with the old style piston pin plugs.Part total time – 24 hours.

Cessna 172 Skyhawk
Spinner Bulkhead Cracked

During an inspection of a new aircraft with 50 total hours, the technician found damage to the aft bulkhead of the propeller spinner. The aft propeller spinner bulkhead was broken at the first nut plate adjacent to one of the blade cutouts. A 1-inch piece of the nut plate strip was missing. That broken piece, still attached to the propeller spinner, was bent outward approximately 2 inches.Part total time – 50 hours.

Cessna 172 Skyhawk
Seat Assembly

The pilot seat would not swing forward for access to the rear seats.The technician stated the recline cylinder bolt in the L seat back fitting was loose. This allowed the seat back to remain in a position that was approximately 4 inches toward the reclined position when the full upright position was selected. A closer inspection revealed the L seat back attach fitting was bent 2 inches aft. According to Cessna, the part failure occurred because the part was improperly heat treated.Part total time – 39 hours.

Grumman AA5-B Tiger
Hydraulic Leak

During an avionics installation, the technician noted the aluminum line leading to the right brake was severely corroded and deeply pitted behind the instrument panel and side panel, and the hydraulic fluid was leaking.The defroster duct located directly above and touching the brake line apparently caused the corrosion. This duct was the old scat type design made of cotton material and forming wire. The duct had become moist over time and had began to deteriorate, allowing the rusty iron wire to poke through. When moist iron came in contact with the aluminum, the dissimilar metals electrolytic process contributed to the excessive corrosion.Part total time – 1,258 hours.

Gulfstream G2
Frozen Trim Wheel

While in flight, the pitch trim disengaged prior to descent and the trim froze at the 1 degree nose up attitude position. The crew was unable to move the trim either electrically or manually; however, the pilot was able to make a safe landing.An inspection revealed the roll-pin holes attaching the pilots trim wheel to the crossover torque tube assembly were worn, allowing the indicator inner drive to rub against the bronze inner bushing. The parts fused together and prevented the trim wheel from moving. The area is not covered by any inspection program, and the trim wheel is not opened for inspection. Part total time – 12,029 hours.

Rockwell Commander Grand Turismo
Cracked Rudder Spar

During the annual inspection, the technician discovered the rudder spar was cracked on the edge of the aluminum spacer which is mounted on the underside of the top rudder hinge.The crack apparently originated as a result of flexing in that area. Under normal inspection practices, the area is difficult to see and may continue to go unnoticed if the rudder is not removed during other maintenance procedures.Part total time – 1,427 hours.

Rockwell Commander Grand Turismo
Wiring Problems

The pilot reported the aircraft had a pulsating oil temperature gauge and flickering instrument panel lights. The position light circuit breaker would not reset, and there appeared to be the sound of electrical interference (alternator sound) heard through the headset.An inspection of the electrical system revealed numerous loose heavy gauge wires at the attachment position. There was no evidence that the lock-washers had been crushed. The technician noted that numerous circuit breakers were not securely fastened to the bus bar. Further inspection of other areas within the engine compartment revealed several loose wires associated with switching relays and other components. Additionally, a wet cell battery was installed instead of the proper sealed battery. The aircraft was new.Part total time – 74 hours.

Beech C90 King Air
Main Landing Gear Failure

On the rollout after landing, the aircraft pulled to the right and traveled off of the runway.An inspection revealed that the right main landing gear upper torque knee broke and allowed the lower gear piston assembly to rotate and turn sideways. Beech Service Bulletin 32-3134 addresses this subject and was complied with five months prior to this occurrence. This failure occurred at a different location than that shown in SB 32-3134. The manufacturer may soon issue steel replacement parts for the aluminum torque knee assembly.Part total time – 170 hours.


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