Bent, Corroded, Cracked

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


Beech 65-B80

Cracked Bellcrank Support Arm

A crack was found on the r/h bellcrank support arm assembly (p/n 50-524414) during a mandatory five-year inspection per Service Bulletin 2231, Revision 1.

Bent Nose Gear Torque Link Bolt


Part Total Time: Unknown

Cessna 500

Corroded Hydraulic Brake Lines

While investigating a soft-brake condition, Skydrol was noted leaking from around the belly beacon-its lens was full of fluid. After removing the interior and center-aisle floor panels, hydraulic fluid was noted dripping from the rigid right brake line (p/n 90E5517010-64 at fuselage station FS248.1).

The Cessna-installed Keith Air Conditioning cold-air duct is Ty-wrapped to the brake fluid lines. The belly beacon is directly below the corrosion and the Skydrol leakage. The aircraft is not equipped with belly drains.

The submitter speculates water condenses in the belly of the aircraft and the beacon creates heat-(in turn generating) humidity, causing corrosion on component parts in the underfloor area.

Part Total Time: 8348.8 hours.

Diamond DA42

Bent Nose Gear Torque Link Bolts

A technician at a flight training school submitted a worn and bent nose landing gear torque link attach bolt (p/n LN9037-M5 x 22), noting, “The nose landing gear torque links were removed to facilitate other maintenance. The four bolts used to secure the torque links were found to be bent and joggled; presumably, from shear loads.”

Part Total Time: 616.0 hours.

Piper PA28-161

Corroded Main Gear Attach Bolt

While washing the aircraft, the scrub brush knocked off the nut from one of the AN4-11A bolts securing the right main landing gear assembly (p/n 35644-05) to the right wing. The bolt was corroded all the way across its cross section.

The submitter suggests 1) periodically checking torque on these bolts to ensure it is not corroded through like this one and, 2) replacing these bolts periodically to preclude corrosion failure.

Part Total Time: 8236.1 hours.

Piper PA46

Cracked Fuel Pressure Tube

The pilot described a loss of power over California but continued the flight to Texas. Fuel was discovered dripping from the belly, which was traced to a cracked fuel tube at the fuel control unit (Pratt & Whitney p/n 3033981). The crack was found on the end B-nut taper at the fuel control. The reason for the crack is unknown. Fuel streamed the full length of the fuselage.

Part Total Time: (unknown).


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