# NTSB NYC94LA170: Eagle DW-1, N8810Z, Houlton, ME, September 7, 1994 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 7, 1994, 06:00 local (10:00 UTC) - Place: Houlton, ME - Location: 46.1214° N, 67.8322° W: Placed by OpenAirDocs: center of Houlton, ME, within about 6 miles (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=46.1214&lon=-67.8322&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report October 13, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 38825 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC94LA170 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/38825/pdf - Page: https://openairdocs.org/ntsb/NYC94LA170 ## Probable cause Inadequate maintenance inspection which failed to detect internal corrosion of the magneto, resulting in ignition arcing and the loss of engine power. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, maneuvering - aerial application - ignition system,magneto - corroded (contributing factor) - maintenance - inadequate (cause) - ignition system,magneto - arcing (contributing factor) - Forced landing, descent - emergency - On ground/water collision with object, landing - flare/touchdown - object - tree(s) - Nose over, landing ## Analysis THE PILOT HAD STARTED THE INITIAL PASS OVER A FIELD, AND WAS ABOUT TO START AERIAL APPLICATION, WHEN THE ENGINE LOST POWER. ACCORDING TO THE PILOT'S STATEMENT, THE 'PLANE STARTED TO SHAKE, SPUTTER AND BACKFIRE.' THE PILOT TRIED TO LAND AT THE AIRPORT, BUT WAS UNABLE TO REACH THE RUNWAY. THE PILOT ELECTED TO LAND ON INTERSTATE HIGHWAY 95. DURING THE LANDING THE RIGHT WING STRUCK A TREE AND THE AIRPLANE THEN HIT A GUARD RAIL AND FLIPPED OVER. AN ENGINE TEST RUN REVEALED THAT THE ENGINE COULD NOT SUSTAIN A CONTINUOUS RUN. BLACK SMOKE WAS OBSERVED COMING FROM THE EXHAUST PIPES AND THE ENGINE WAS 'KICKING BACKWARDS.' MAGNETO TIMING WAS CHECKED, AND FOUND TO BE 'APPROXIMATELY 27 DEGREES BEFORE TOP DEAD CENTER.' THE MAGNETO TIMING WAS ADJUSTED, AND AGAIN THE ENGINE COULD NOT SUSTAIN A RUN. THE MAGNETO WAS REPLACED AND THE ENGINE RAN SUCCESSFULLY. FURTHER EXAMINATION OF THE MAGNETO (BENDIX D6LN-3000, P/N 10-682560-13), REVEALED CORROSION WAS PRESENT INSIDE THE HOUSING, AND ON THE ROTATING MAGNET (RIGHT SIDE) AND THE POINTS WERE ARCING. ## Factual narrative On September 7, 1994, at 0600 eastern daylight time, an Eagle DW-1 (crop duster), N8810Z, registered to and piloted by Duane E. Mahue, sustained substantial damage during a forced landing near, Houlton, Maine . The pilot was not injured. Visual meteorological conditions prevailed, and no flight plan was filed. The departure point was Houlton. The local flight was operated under 14 CFR Part 133. The pilot had started the initial pass over a field, and was about to start aerial application, when the engine lost power. According to the pilot's statement, the "plane started to shake, sputter and backfire." The pilot tried to land at the airport, but was unable to reach the runway. The pilot elected to land on Interstate Highway 95, the right wing struck a tree, the airplane hit a guard rail, and flipped over. The engine was removed from the airframe, and shipped to Williamsport, Pennsylvania, at the request of the NTSB. An engine test run was conducted under the supervision of the FAA, at Lycoming's facilities, Williamsport, Pennsylvania, on November 15, 1994. The engine was mounted on a test stand and a start was attempted. According to the test run report submitted by Lycoming, the engine tried to start, but "would not continue to run." Black smoke was observed coming from the exhaust pipes and the engine was "kicking backwards." Magneto timing was checked, and found to be "approximately 27 degrees before top dead center." The magneto timing was adjusted, and again the engine could not sustain a run. The magneto was replaced, and the engine ran successfully. Disassemble of the Bendix (dual) magneto, Model D6LN-3000, P/N 10-682560-13, S/N-6197, revealed that a piece of metal was found logged under the impulse spring cover. The piece of metal was removed, the impulse coupling was reassembled. After reassembly the investigation revealed that the, "impulse was still very hard to turn." Detailed examination of the magneto revealed that corrosion was present in the magneto housing, and on the rotating magnet (right side). The points were arcing, and the arcing was sufficient enough to cause a partial power loss. ## Aircraft - Registration: [N8810Z](https://openairdocs.org/deregistered/N8810Z-2013-08-29), registration cancelled 2013-08-29, S/N DW-1-0066-82 (OpenAirDocs) - Reported make and model: Eagle Aircraft Co. DW-1 - Registry model: [Eagle EAGLE DW-1](https://openairdocs.org/model/eagle-eagle-dw-1) (registry code 3230203) (OpenAirDocs) - Category: Airplane - Serial number: DW1-006682 - Airframe hours: 2264 - Engines: Lycoming IO-540-M1B5 300 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Duane Maheu - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, May 12, 1994, 232 hours before - Departed: HUL, HOULTON, ME ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 54; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: center; flight hours: 10,000 total, 2,200 in this make and model, 10,000 as pilot in command, 150 in the last 90 days, 50 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Dawn - Wind: calm - Visibility: 25 statute miles - Temperature: 45 °F ## 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 19940907048409A](https://openairdocs.org/incident/19940907048409A), Sep 7, 1994: Eagle DW1, Houlton, ME, Substantial damage. Lost power after pass over a field. Landed on highway, wing hit tree. Flipped. Mag corroded and arcing. 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.