# NTSB DEN99LA061: Mooney M20K, N12HW, Medicine Bow, WY, March 28, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 28, 1999, 15:15 local (22:15 UTC) - Place: Medicine Bow, WY - Coordinates: 41.890621, -106.199104 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.8906&lon=-106.1991&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 25, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 45988 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN99LA061 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/45988/pdf - Page: https://openairdocs.org/ntsb/DEN99LA061 ## Probable cause A fluctuating turbine inlet temperature and resulting loss of engine power for undetermined reasons. Factors were the rough, unsuitable terrain on which 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(partial) - mech failure/malf, cruise - engine instruments,tit gage - fluctuating (cause) - reason for occurrence undetermined (cause) - Forced landing, emergency descent/landing - Hard landing, emergency landing - terrain condition - open field - terrain condition - rough/uneven (contributing factor) - terrain condition - none suitable (contributing factor) ## Analysis Upon reaching 23,000 feet msl, the pilot leaned the engine's turbine inlet temperature (TIT). About 5 to 10 minutes later, the TIT started rising. He requested and received a clearance to descend to 17,000 feet. The TIT continued to climb, and he requested another descent to 12,000 and reduced power. At that time, the 'engine started to run very rough, popping and spitting and not developing any power.' He requested assistance for vectors to the closest airport. After locating the airport, he observed a tractor positioned in the middle of the runway, and selected a field 1/4 mile east of the airport on which to land. The aircraft landed hard, damaging the right wing and landing gear. Several postaccident examinations of the engine were performed. Fuel was observed in the engine and the fuel tanks and was present in each of the fuel injector nozzles. The fuel boost pump was turned off and the engine surged. The engine driven fuel pump was bench and flow tested, and no discrepancies were observed. A replacement turbocharger was installed on the engine and test run, and the engine continued to run rough and surge. Nothing was found during the investigation to determine what caused the loss of engine power. ## Factual narrative On March 28, 1999, at 1515 mountain standard time, a Mooney M20K, N12HW, was substantially damaged during a forced landing following a loss of engine power while in cruise flight near Medicine Bow, Wyoming. The private pilot, the sole occupant aboard, was not injured. The aircraft was being operated by Blazie Marketing Service of Forest Hill, Maryland, under Title 14 CFR Part 91. The cross-country flight originated from the Salt Lake City International Airport, Salt Lake City, Utah, approximately 1315. A VFR flight plan had been filed; however, an IFR clearance had been activated 50 miles northwest of Medicine Bow for the flight to Omaha, Nebraska. Visual meteorological conditions prevailed at the accident site. According to the pilot, approximately an hour and a half after departing Salt Lake City, he began encountering instrument meteorological conditions. He requested an IFR clearance to climb to 23,000 feet mean sea level (msl). He received a clearance, and upon reaching his requested altitude, he leaned the engine's turbine inlet temperature (TIT) to 1600. The pilot stated that everything appeared normal for the first 5 to 10 minutes, then the TIT started rising. He applied full rich mixture, and the TIT came down. He requested and received a clearance to descend to 17,000 feet. The TIT continued to climb, and he requested another descent to 12,000 and continued to reduce power. At that time, the "engine started to run very rough, popping and spitting and not developing any power." He requested assistance from Denver Center (ARTCC) for vectors to the closest airport. At approximately 2,000 to 3,000 feet above the ground, he broke out of the clouds and located the Medicine Bow Airport. He observed a tractor positioned in the middle of the runway, and he selected a field 1/4 mile east of the airport on which to land. After a hard landing, the aircraft sustained damage to the right wing and the right landing gear. Two postaccident examinations of the engine were performed by FAA maintenance inspectors. Fuel was observed in the fuel tanks, engine, and the fuel injector nozzles. No fuel leaks were detected, and the oil quantity level was normal. The fuel flow divider appeared to be dry. No engine discrepancies were noted. Another engine examination was performed at Western Skyways in Montrose, Colorado. With the fuel boost pump on, the engine ran normally at ranges varying between 1,300 to 1,800 rmp. With the boost pump off, the engine began to surge at those rpm settings. The engine driven fuel pump was bench and flow tested and no discrepancies were found. The entire fuel system, including the fuel injectors and servo controller, was replaced with new parts, and the engine continued to surge. A replacement turbocharger was installed on the engine and test run. The engine continued to run rough and surge with the replacement turbocharger. Nothing was found during the investigation to determine what caused the loss of engine power. ## Aircraft - Registration: [N12HW](https://openairdocs.org/aircraft/N12HW), registered now, S/N 25-0557, built 1981 (OpenAirDocs) - Reported make and model: Mooney M20K - Registry model: [Mooney M20K](https://openairdocs.org/model/mooney-m20k) (registry code 5870220) (OpenAirDocs) - Registry engine: [Continental TSIO-360 series](https://openairdocs.org/engine/continental-tsio-360-series) (registry code 17019, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 25-0557 - Airframe hours: 2486 - Engines: Continental TSIO-520-NB83 305 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Blazie Marketing Service - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 1, 1998 - Departed: SLC, SALT LAKE CITY, UT - Destination: OMA, OMAHA, NE - Flight plan: VFR - Airport: 80V, Medicine Bow Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 30; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 2,500 total, 2,000 in this make and model, 2,500 as pilot in command, 57 in the last 90 days, 38 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: 3,000 ft overcast - Temperature: 30 °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 19990328040339A](https://openairdocs.org/incident/19990328040339A), Mar 28, 1999: Mooney M20K, Medicine Bow, WY, No damage. (-23) Pilot on an IFR flight plan reprted rough running engine wiht a subsequent loss of power. He mead an off airport emergency landing and the aircraft… 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.