Squawk Box

June 2018 Issue




Nuts And Bolts

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

nut and bolt

Beechcraft Model A36 Bonanza
Loose crankshaft bolts

While changing an IO-520-BB’s oil during an annual inspection, steel and red rubbery pieces were found in the filter. Metal determined to be coming from crankshaft gear driving alternator. Rubber was coming from alternator drive coupler. Four bolts holding crankshaft gear to crank were loose, allowing gear to slop around and cause wear of gears and coupler. Locking plates securing the four bolts were missing.

Part total time: Unknown


Cessna Model 150
Wing spar corrosion
Corrosion found on forward and aft wing spars under fuel tank spacer blocks, in fuel tank mounting bay. Problem discovered when fuel tanks were removed for repair. No visual corrosion indications noted around spacers when mounted. Spacers were removed on a “hunch” that underlying corrosion may exist. Condition existed in both wings.

Part total time: Unknown


Cessna Model 177RG Cardinal RG
Cracked Wheel Hub

Left brake reported soft. Inspection revealed a large crack on the inside of the wheel hub. Wheel disassembled and cracks were discovered in the area of four of the six mounting bolts. The cracks were parallel to the bolt hole centerline axis and continued into the wheel web structure.

Part total time: Unknown


Cessna Model 421C Golden Eagle
Failed gear extension cable

Landing gear would not retract after takeoff or extend when gear down was selected. The emergency gear extension handle was pulled, and it broke off in the pilot’s hand. The aircraft was landed gear-up. Troubleshooting revealed that the emergency gear extension cable broke at the handle base.

Part total time: Unknown


Cirrus SR20
Defective starter

After engine start, instrumentation became inoperative. Inspection revealed the wire/loom assembly was charred and burned. The hot spot was attributed to a defective starter (p/n C24ST3) that showed evidence of an internal electrical arc that had burned a hole entirely through the starter housing.

Part total time: Unknown


Cirrus SR22
Failed starter adapter bearing

Noticed clunking and ticking noise from engine when pulled through to set magneto timing. Noise traced to the starter adapter. Removed adapter and found the drive shaft bearing very rough and jerky. This is the second occurrence of this issue on two different aircraft, both with very low time on the starter adapters.

Part total time: Unknown