Cracked, Loose, Failed

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


Beechcraft E90 King Air

Cracked Wing Spar Caps

The forward outboard, lower wing spar caps were found cracked. The cracks-on both left and righthand assemblies-radiated out from the fourth Huck rivet forward, passing through the wing attach hinge. This aircraft was inspected 15


months /404.2 hours ago by eddy current. No cracks were found at that time. Wing lower spar cap part numbers: l/h: 000-110012-1; r/h: 000-110012-2.

Part Total Time: 8875.6 hours.

Cessna 172R

Tire Tube Failure

The aircraft experienced three landing gear tire tube failures, all of which occurred in the tube sidewalls with no evidence of the tubes having been pinched or otherwise damaged during installation. Failures ranged from small slits to a large -inch split. The tube sidewalls evidence what appears to be some form of “weather checking” normally appearing on old rubber components. All (of these) tubes were of recent manufacture. Tube p/n 302-246-401. The removed tires showed no evidence of defects which may have caused this problem.

Part Total Times: 123, 125 and 112 hours.

Cessna Turbocharged Piston Twins

Exhaust System

Exhaust systems installed on Cessnas turbocharged piston twins have been the subject of numerous ADs and NTSB safety recommendations since the 1970s. In 2000, AD 2000-01-16 was developed to address exhaust system failures and fatal accidents (30 fatals in 30 months).

Nine years after its implementation, there is evidence inspections required by the AD are not being conducted properly, according to the FAA. These exhaust systems have a very good safety record if regularly and properly inspected, but the importance to flight safety of these inspections cannot be overstated.

Cirrus SR22

Loose Turbocharger Oil Lines

During a 100-hour inspection of the turbonormalized Continental IO-550-N installed, a technician found the oil line “B”-nut connecting the manifold pressure controller and the master waste gate broke loose from its torque with very little applied pressure. No anomalies were found. Oil line p/n: AE6682E0200-000-4; reducer fitting p/n: AN919-2

Part Total Time: 796.2 hours.

Piper PA-44-180 Seminole

Cracked Nose Cone Spar

The spar assembly (p/n 86282-010) was found cracked at the left side nosegear support fitting. The crack radiated from the aft lower bolt attachment when viewed from below the nose structure flooring. Only after removing the “A” frame support was the two-inch crack in the spar web visible. By serial number, neither AD 81-10-01 or SB 1143 cover this aircraft.

Part Total Time: (unknown).


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