# NTSB SEA95LA028: Piper PA-28-236, N4300V, Medicine Bow, WY, December 10, 1994 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: December 10, 1994, 11:30 local (18:30 UTC) - Place: Medicine Bow, WY - Coordinates: 41.889572, -106.200599 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.8896&lon=-106.2006&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report July 31, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 42093 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA95LA028 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42093/pdf - Page: https://openairdocs.org/ntsb/SEA95LA028 ## Probable cause THE FAILURE OF THE MAGNETO SYSTEM DUE TO SHORTING OF BOTH MAGNETO COILS TO THE MAGNETO HOUSING AND THE LACK OF SUITABLE TERRAIN TO MAKE A FORCED LANDING. ## 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, cruise - ignition system,ignition coil - shorted (cause) - Forced landing, emergency descent/landing - Gear collapsed, emergency descent/landing - terrain condition - none suitable (cause) ## Analysis WHILE CRUISING AT 11,500 FEET MSL, THE AIRCRAFT EXPERIENCED A COMPLETE LOSS OF ENGINE POWER. BEING UNABLE TO REGAIN POWER, THE PILOT ELECTED TO ATTEMPTED A FORCED LANDING NEAR MEDICINE BOW, WYOMING. THE TOUCHDOWN WAS SUCCESSFUL, BUT THE NOSE GEAR AND RIGHT MAIN GEAR COLLAPSED DURING THE LANDING ROLL ON THE ROUGH/UNEVEN TERRAIN. LATER INVESTIGATION REVEALED THAT BOTH MAGNETO COILS HAD SHORTED TO THE MAGNETO HOUSING. ONE COIL HAD BURNED THROUGH ITS INSULATION, AND THE OTHER SHOWED SIGNS OF ARCING THROUGH A NUMBER OF CRACKS IN ITS INSULATION. ## Factual narrative On December 10, 1994, approximately 1130 mountain standard time (MST), a Piper PA-28-236, N4300V, experienced a gear collapse during a forced landing near Medicine Bow, Wyoming. The commercial pilot and his two passengers were not injured, but the aircraft sustained substantial damage. The personal pleasure flight, which departed Sheridan County Airport, Sheridan, Wyoming at 1000 MST, was being operated in visual meteorological conditions. The aircraft was on a VFR flight plan en route to Broomfield, Colorado at the time of the accident. Although the ELT was not activated by the accident sequence, the pilot turned it on after the accident in order to assist searchers in finding the aircraft. According to the pilot, the flight was cruising at 11,500 feet MSL when the engine suddenly lost power. Being unable to regain power, the pilot attempted a forced landing in an open field about 12 miles southeast of Medicine Bow. The touchdown was successful, but the nose gear and right main gear collapsed during the landing roll on the rough/uneven terrain. An FAA monitored teardown inspection was performed at Teledyne Continental's Atlanta facility, and it was determined that both magneto coils showed evidence of shorting to the magneto housing. The right coil had burned through its insulation, and evidence of electrical arcing was found on the adjacent surface of the housing. A number of cracks, with attendant electrical distress marks, were found in the insulation of the left coil, and evidence of electrical arcing was found on the housing adjacent to these cracks. ## Aircraft - Registration: [N4300V](https://openairdocs.org/aircraft/N4300V), registered now, S/N 28-8311016, built 1983 (OpenAirDocs) - Reported make and model: PIPER PA-28-236 - Registry model: [Piper PA-28-236](https://openairdocs.org/model/piper-pa-28-236) (registry code 7102815) (OpenAirDocs) - Registry engine: [Lycoming O-540-J3A5D](https://openairdocs.org/engine/lycoming-o-540-j3a5d) (registry code 42358, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 28-8311016 - Engines: LYCOMING O-540-J3A5D 235 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Air West Flying - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 19, 1994 - Departed: SHR, SHERIDAN, WY - Destination: BJC, BROOMFIELD, CO - Flight plan: VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 362 total, 14 in this make and model, 265 as pilot in command, 12 in the last 90 days, 6 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 330° at 30 knots - Visibility: 70 statute miles - Lowest ceiling: none - Temperature: 19 °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 19941210041299A](https://openairdocs.org/incident/19941210041299A), Dec 10, 1994: Piper PA28236, Medicine Bow, WY, Substantial damage. Lost power en route. Collapsed nose gear landing in field. Both magneto coils were arcing and shorting. 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.