# NTSB SEA03LA128: Mooney M20-J, N201DV, Renton, WA, July 4, 2003 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 4, 2003, 11:18 local (18:18 UTC) - Place: Renton, WA - Coordinates: 47.491664, -122.214996 - Nearby events: https://openairdocs.org/map.md?lat=47.4917&lon=-122.2150&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report March 30, 2004 - Report: Approved by Office Director - Parties: FAA-MIDO, FAA-FSDO - NTSB case key (mKey): 57415 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA03LA128 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/57415/pdf - Page: https://openairdocs.org/ntsb/SEA03LA128 ## Probable cause In-flight failure of the electric landing gear motor during the initial takeoff climb. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, takeoff - initial climb - landing gear,normal retraction/extension assembly - failure (cause) - electrical system,electric motor - failure (cause) - electrical system - worn - Main gear collapsed, landing ## Analysis 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. ## Factual narrative 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. ## Aircraft - Registration: [N201DV](https://openairdocs.org/aircraft/N201DV), registered now, S/N 24-0088, built 1977 (OpenAirDocs) - Reported make and model: Mooney M20-J - Registry model: [Mooney M20J](https://openairdocs.org/model/mooney-m20j) (registry code 5870219) (OpenAirDocs) - Registry engine: [Lycoming I0360 series](https://openairdocs.org/engine/lycoming-i0360-series) (registry code 41515, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 24-0088 - Airframe hours: 2263 - Engines: Lycoming IO-360 200 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Mark W. Hawk - Registered owner: Roy Hawk - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 7, 2002, 15 hours before - Departed: RNT, Renton, WA - Destination: RNT, Renton, WA - Airport: RNT, Renton Muni, runway 33, 5,382 × 200 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 46; injuries: none; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2; last flight review September 7, 2001; seat: left; flight hours: 985 total, 700 in this make and model, 780 as pilot in command, 4 in the last 90 days, 1 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 350° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 70 °F, dew point 52 °F - Altimeter: 30.14 inHg - Observed at: KRNT ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20030704013729A](https://openairdocs.org/incident/20030704013729A), Jul 4, 2003: Mooney M20J, Renton, WA, Substantial damage. (-23) On July 4, 2003, the aircraft departed Renton airport. During the flight, the aircraft experienced smoke in the cockpit, accompanied by the tripping of… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.