Casualties unknown

2004-06-16: Cessna 421B (N332CC) — Bend, OR

Bend, OR, US

On June 16, 2004, a Cessna 421B (registration N332CC) was involved in an aviation accident near Bend, OR. Investigators recorded the probable cause as: On ground encounter with terrain during the takeoff roll as a result of the left side brake not operating. Inadequate maintenance inspection, overload of the nose landing gear and soft terrain were factors. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

After applying takeoff power, an airplane veered right. Brake application had no effect, and the aircraft departed the runway, causing the nose gear to collapse. Inspection revealed a malfunctioning left brake and a pre-existing fatigue crack in the nose gear trunnion that failed under overload.

Takeoff Excursion

Shortly after applying power for the takeoff roll, the airplane pulled to the right. The pilot reduced power and applied corrective action to the left side brake, but the braking action had no effect, and the airplane continued off the side of the runway. Subsequently, the nose gear collapsed.

Left Brake Inspection

Inspection of the left side landing gear and brake assembly revealed that the caliper side pressure plate was cocked, and there were signs of metal-to-metal gouging on the brake disc. Additionally, two of the pads on the caliper side pressure plate were missing.

Maintenance History

Maintenance records indicated that the aircraft had been signed off for an annual inspection, and the description of work performed stated that the brakes and tires had been serviced. The aircraft had flown a one-hour flight since the annual inspection, during which one takeoff and one landing were accomplished without incident. The accident flight was the second flight after the inspection.

Nose Gear Failure

Inspection of the nose gear found that the right side of the nose gear trunnion fractured off from the main body in two separate pieces at the lug transition radius. A visual inspection of the fracture surface found multiple origins consistent with fatigue cracking. The fatigue region initiated at the lug radius on the lower side of the lug and propagated toward the interior, consuming approximately 5% of the cross-sectional area, with the remaining region being overstress. The Materials Engineer who inspected the trunnion reported that, even though the lug contained pre-existing cracking, it appeared that the failure of the component was the result of a single large overload event.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20040621X00842. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.