SEA04LA108

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, however the braking action had no affect and the airplane continued off the side of the runway. The nose gear subsequently collapsed. Inspection of the left side landing gear and brake assembly found that the caliper side pressure plate was cocked and signs of metal to metal gouging on the brake disc was present, and that two of the pads (on the caliper side pressure plate) were missing. Maintenance records indicated that the aircraft had been signed-off for an annual inspection and that the description of work performed indicated that the brakes and tires had been serviced. The aircraft had flown a one hour flight since the annual inspection. During that flight, one takeoff and one landing was accomplished without incident. The accident flight was the second flight after the inspection. 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 that 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.

On June 16, 2004, at 0930 Pacific daylight time, a Cessna 421B, N332CC, registered to and operated by Jeriko Development LLC, as a 14 CFR Part 91 personal flight, veered off the side of the runway during the takeoff roll at Bend Municipal Airport, Bend, Oregon, subsequently collapsing the nose gear. Visual meteorological conditions prevailed at the time and no flight plan was filed for the local flight. The aircraft was substantially damaged. The airline transport pilot/flight instructor seated in the right seat, the airline transport pilot receiving recurrency training and seated in the left seat, and the passenger seated in the second row were not injured.

The purpose of the flight was for a check-out flight for the airline transport pilot in the left seat to satisfy insurance requirements.

The flight instructor seated in the right seat reported that the left seat pilot was at the controls for the takeoff on runway 34. Shortly after the left seat pilot applied power to begin the take off roll, the aircraft pulled to the right. Power was reduced to idle and correction to regain directional control (left brake application) was unsuccessful. The left seat pilot requested that the right seat pilot help with braking, however, there was no reaction to the application of the brakes. The aircraft traveled to the side of the runway where the nose wheel and right main landing gear entered the gravel along the side of the runway. The nose wheel subsequently collapsed.

The pilot seated in the left seat reported during a telephone interview and subsequent written statement that she checked the brakes during the preflight and before taxiing from the hangar. The aircraft was then taxied to the run-up area where the aircraft's parking brake was set. After the run-up checks, the pilot taxied to the displaced threshold and lined up on runway centerline. The pilot held the brakes as she powered up the engines to check that the engine gages were even and in the appropriate green arcs. The pilot then released the brakes and added full power when the airplane made a hard right turn. The pilot applied left brake and rudder action and reduced power to idle. The airplane did not straighten out and she asked the right seat pilot to "get on the brakes." The braking action was ineffective and the airplane continued to roll off to the side of the runway with the right main landing gear and the nose gear traveling off the runway edge. The aircraft traveled approximately 170 feet from the start of the roll to final resting point.

Maintenance records indicated that the aircraft had been signed-off for an annual inspection on April 7, 2004. The description of work performed indicated that the brakes and tires had been serviced. The aircraft had flown a 1.5 hour flight the day before with the same flight crew since the annual inspection. During that flight, one takeoff and one landing was accomplished without incident. The accident flight was the second flight after the inspection.

An Airframe and Powerplant mechanic with an Inspection Authorization inspected the landing gear and damage to the aircraft. The mechanic reported that the steering bellcrank and cables were inspected and found normal. Brake fluid was at normal levels. The right side landing gear and brake assembly was normal. Inspection of the left side gear and brake assembly found that, "The caliper side pressure plate was cocked and signs of metal to metal gouging on the brake disc. Upon closer inspection I found that two of the pads (on the caliper side pressure plate) were missing."

Inspection of the nose gear assembly found that the gear had collapsed and was torn out of the nose gear well. The right side trunnion had separated from the upper gear assembly, and the trunnion bearing assembly was torn out of the box structure of the nose well.

The nose gear trunnion and retainer were removed from the aircraft and sent to the National Transportation Safety Board Materials Laboratory, Washington D.C. for inspection. The Materials Engineer conducting the inspection reported that the trunnion right side lug fractured off from the main body in two separate pieces at the lug transition radius. The Engineer reported that a visual inspection of the fracture surface found multiple origins consistent with fatigue cracking. The Engineer stated that, "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. See attached Material Laboratory Factual Report.