# NTSB FTW00LA068: Mooney M20K, N1157G, Tyler, TX, January 19, 2000 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: January 19, 2000, 12:30 local (18:30 UTC) - Place: Tyler, TX - Coordinates: 32.320652, -95.299049 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=32.3207&lon=-95.2990&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report March 2, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 48491 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW00LA068 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/48491/pdf - Page: https://openairdocs.org/ntsb/FTW00LA068 ## Probable cause The failure of the crankshaft drive gear as a result of fatigue, which resulted in a forced landing. A factor was the lack of suitable terrain for the 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 - normal - engine assembly,gear - fatigue (cause) - engine assembly,gear - failure (cause) - Forced landing, emergency descent/landing - On ground/water collision with object, emergency landing - object - fence post - terrain condition - none suitable (contributing factor) ## Analysis The pilot reported that the engine lost total power while in cruise flight between 1,500 feet and 2,000 feet agl. He executed a forced landing, during which the airplane contacted a fence post. During the postaccident examination of the engine, the crankshaft drive gear was observed fractured. Three consecutive gear teeth of the crankshaft drive gear separated, of which two were recovered. The crankshaft drive gear and gear teeth were examined at the NTSB Materials Laboratory and three areas of fatigue were observed. Each fatigue area originated at the relief radius at the root of one of the three separated teeth. No tooling marks or gouge marks were observed near the fracture surface or on the remainder of the crankshaft gear's teeth. The outermost nitrided layer of the crankshaft drive gear appeared smooth and no cracks were noted. Additionally, machining marks through the entire crankshaft drive gear appeared consistent. ## Factual narrative On January 19, 2000, at 1230 central standard time, a Mooney M20K, N1157G, was substantially damaged during a forced landing following a loss of engine power near Tyler, Texas. The private pilot, who was the registered owner and sole occupant of the airplane, was not injured. Visual meteorological conditions prevailed for the 14 Code of Federal Regulations Part 91 personal flight and a flight plan was not filed. The cross-country flight departed from the Addison Airport, Addison, Texas, approximately 1155, and was destined for the Tyler Pounds Field, Tyler, Texas. According to the pilot, he was flying between 1,500 and 2,000 feet agl and was 10 miles from the Tyler Pounds Airport when the "engine rpm gradually decreased," and the engine lost total power. He switched the fuel selector from the left tank to the right tank and attempted to re-start the engine, but was unsuccessful. He then initiated a forced landing to a field. During the landing roll, the left wing contacted a 6"X6" wood fence post, damaging the wing spar, and the airplane came to a stop upright 6.5 miles from the Tyler Pounds Airport. The 210-horsepower Continental TSIO-360-LB1 engine was examined by an FAA inspector and a representative from Teledyne Continental Motors. During the examination they removed the rear accessory case cover and observed that the crankshaft drive gear was fractured. Three consecutive teeth of the crankshaft drive gear separated. Two of the three teeth were recovered. The NTSB Investigator-In-Charge and an NTSB Metallurgist examined the fractured crankshaft drive gear and gear teeth at the NTSB Materials Laboratory in Washington D.C. Three areas of fatigue were observed. Each fatigue area originated at the relief radius at the root of one of the three consecutive teeth of the crankshaft drive gear that separated. No tooling marks or gouge marks were observed near the fracture surfaces or on the remainder of the crankshaft gear teeth. The outermost nitrided layer of the crankshaft drive gear appeared smooth and no cracks were noted. Additionally, machining marks through the entire crankshaft drive gear appeared consistent. ## Aircraft - Registration: [N1157G](https://openairdocs.org/aircraft/N1157G), registered now, S/N 25-0729, built 1982 (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: 20-0729 - Airframe hours: 2231 - Engines: Continental TSIO-360-LB1 210 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: David Saloman - Airworthiness certificate: Standard, Normal - Last inspection: Annual, November 19, 1998, 156 hours before - Departed: ADS, ADDISON, TX - Destination: TYR, TYLER, TX ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 47; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 2,600 total, 1,500 in this make and model, 2,450 as pilot in command, 44 in the last 90 days, 2 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 7 knots - Visibility: 7 statute miles - Lowest ceiling: none - Temperature: 55 °F, dew point 52 °F - Altimeter: 29.00 inHg - Observed at: TYR ## 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 20000119043949A](https://openairdocs.org/incident/20000119043949A), Jan 19, 2000: Mooney M20K, Tyler, TX, Substantial damage. (-23) Pilot reported the engine quit and he could not restart. Pilot landed in a pasture, going through a barb wire fence and a large post. In checking… 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.