SEA03LA128

The pilot reported that the airplane experienced an electrical malfunction 2-3 minutes after takeoff. After multiple unsuccessful attempts to reset the electrical system, the pilot attempted to manually lower the landing gear in preparation for a landing. He reported that he was able to actuate the manual gear extension handle, however, the landing gear would not fully extend and lock. After multiple additional attempts to fully lower the gear, the pilot initiated a landing with the main landing gear in the midrange position. Examination of the landing gear system by representatives from the NTSB and FAA revealed that the landing gear actuator housing fractured, and separated from the gearbox. Damage was also noted to the actuator drive coupling. Representatives from the FAA and the manufacturer of the gear assembly conducted the teardown and examination of the electric landing gear actuator motor. During the examination, 14 volts was applied to the actuator motor in an attempt to functionally test the DC motor. The electric motor did not respond, or draw current. Further examination of the motor revealed that the two brushes in the motor were of dissimilar type and design and showed signs of arcing. Additionally, the motors armature showed signs of severe wear. Logbook records indicated that the electric landing gear motor was serviced on February 1, 2001, approximately 39 flight hours prior to the accident. The log entry indicated that the armature shaft and brushes were replaced and that the gear motor was returned to service.

On July 4, 2003, at 1118 Pacific daylight time, a Mooney M20-J, N201DV, sustained substantial damage following a main landing gear collapse at the Renton Municipal Airport, Renton, Washington. The airplane is owned by a private party and was being operated by the pilot as a visual flight rules (VFR) personal/pleasure flight under the provisions of Title 14, CFR Part 91. The commercial pilot and two passengers aboard the airplane were not injured. Visual meteorological conditions prevailed, and no flight plan had been filed for the local flight.

In a written statement, dated July 21, 2003, the pilot reported that the airplane experienced an electrical malfunction 2-3 minutes after takeoff from the Renton Airport. He reported that "most of the circuit breakers popped" and smoke, originating from instrument and circuit breaker panels, began to fill the cockpit. After multiple unsuccessful attempts to reset the electrical system, the pilot attempted to manually lower the landing gear in preparation for a landing. He reported that he was able to actuate the manual gear extension handle, however, the landing gear would not fully extend and lock. The pilot further reported that he was unable to get the manual gear extension mechanism to engage. After multiple additional attempts to fully lower the gear, the pilot initiated a landing with the main landing gear in the midrange position. He reported that the airplane touched down on runway 33, skidded approximately 100 yards and exited the runway edge. The airplane came to rest in grassy area adjacent to the landing runway.

Examination of the landing gear system by representatives from the NTSB and FAA revealed that the landing gear actuator housing fractured, and separated from the gearbox. Damage was also noted to the actuator drive coupling.

Following the examination, the actuator assembly was shipped to the manufacturer, Dukes, Inc, North Ridge, California, for further testing.

On July 23, 2003, representatives from the FAA Manufacturing Inspection District Office (MIDO) in Van Nuys, California, and Dukes, Inc, conducted the teardown and examination of the electric landing gear actuator motor. During the examination, 14 volts was applied to the actuator motor in an attempt to functionally test the DC motor. The electric motor did not respond, or draw current. Further examination of the motor revealed that the two brushes in the motor were of dissimilar type and design and showed signs of arcing. Additionally, the motors armature showed signs of severe wear.

Logbook records indicated that the electric landing gear motor was serviced on February 1, 2001, approximately 39 flight hours prior to the accident. The log entry indicated that the "armature shaft and brushes" were replaced and that the gear motor was returned to service.