Squawk Box

July 2017 Issue




Wheels

The following information is derived from the FAA’s Service Difficulty Reports and Aviation Maintenance Alerts.

Cessna Model 170
Poorly Maintained Tailwheel

The tailwheel could not be steered during an annual inspection. The tailwheel had been painted; its grease fitting had been completely covered. The owner stated a technician told him not to grease the tailwheel and to tighten the nut on the bottom of the steering pivot bolt as tight as possible. Disassembly revealed all parts inside the tailwheel unit were extremely worn. Additionally, the axle for the tailwheel had been damaged, preventing proper cotter pin installation. The entire assembly was beyond repair and was replaced.

Part total time: Unknown

Cessna Model 172N Skyhawk
Cracked Through Bolt Hole

While visually inspecting a wheel half assembly (p/n 16204700, of p/n 40113 wheel assembly), a crack was discovered in one of the wheel bolt feed-throughs on the inside of the wheel half. This was most likely caused by improper torque of the wheel half bolts. The wheel half had to be scrapped.

Part total time: Unknown

Cessna Model 172 Hawk SP Seaplane
Dual Nose Wheel Strut Failure

During takeoff from a grass strip, as the aircraft approached 30 to 40 knots, both nose wheel assemblies on the floats failed, causing the aircraft to flip onto its back. Upon examination, the failure occurred at the weld joint of both left and right wheel struts. It appears the welds did not have adequate penetration.

Part total time: 120.0 hours

Cessna Model 208B Grand Caravan
Corroded Nose Wheel

Excessive corrosion in the center of both halves of the nose wheel assembly (p/n C1630010901) was discovered while performing a phase inspection. Disassembly of the nose wheel assembly revealed corrosion beyond acceptable limits. Both nose wheel halves were replaced with new parts and the aircraft was returned to service.

Part total time: 215.0 hours

Parker Main Wheel

Flight Design CTLS
Failed Main Wheel

During takeoff, the left main wheel outer rim half separated 75 percent from the wheel, allowing the tire to come loose. The added rolling drag of the loose tire caused the aircraft to swerve off the left side of the runway.

Part total time: 550.0 hours

Pilatus PC-12/45
Loose Wheel Bolts

During landing and taxi, crew noticed an intermittent noise coming from right main landing gear area and tire appeared to be low. When the hub cap was removed, wheel assembly nuts and washers were found loose with some missing. Several wheel half-bolts were found to have contacted the brake assembly as the wheel rotated.

Part total time: 10.1 hours