Cracked, Loose, Failed

During slow-flight maneuvers, the instructor noticed the green, landing gear "safe" light was not illuminated. The student observed the left gear was hanging out-and swinging. The gear was cycled, but the left main remained free and disconnected. The instructor elected to retract the right and nose gears and land gear-up. Maintenance found the left gear pivot had sheared at the spline shaft. The right gear was removed and Zyglo checked. Close inspection found the right pivot was cracked three-quarters of the circumference around the spline shaft, nearing complete failure. Gear pivot p/n: 22411143.

Editorial Staff

Friday, May 22, 2009 at 12:00 AM ET

Verified

Mementos of an early pursuit of flight. Courtesy Gregg Maryniak

Key Takeaways:

Several aircraft experienced critical mechanical failures, including a Cessna R182's sheared main landing gear pivot and a Continental IO-470 piston skirt fracture.
Component failures also affected a Piper PA-31-350's electric fuel pump due to an internal bypass valve issue and a Piper PA32R-301T's main gear down-lock switch wiring due to installation stress.
These incidents underscore issues like structural fatigue, internal component detachment, design-related wiring damage, and potential environmental factors (e.g., cold starts) contributing to part failure.

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Cessna R182

Sheared Main Gear Pivot

During slow-flight maneuvers, the instructor noticed the green, landing gear “safe” light was not illuminated. The student observed the left gear was hanging out-and swinging. The gear was cycled, but the left main remained free and disconnected. The instructor elected to retract the right and nose gears and land gear-up.

Maintenance found the left gear pivot had sheared at the spline shaft. The right gear was removed and Zyglo checked. Close inspection found the right pivot was cracked three-quarters of the circumference around the spline shaft, nearing complete failure. Gear pivot p/n: 22411143.

Part Total Time: 4754.0 hours.

Piper PA-31-350

Failed Electric Fuel Pump

The pilot reported substantial power loss from the left engine just after takeoff, and that the left low-pressure fuel boost pump light was illuminated. A technician could not find any problems with the engine during run-up other than the electric,