# NTSB DEN02LA005: Irwin Thorp T-18, N2819L, Longmont, CO, October 26, 2001 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 26, 2001, 12:25 local (18:25 UTC) - Place: Longmont, CO - Coordinates: 40.169738, -105.109725 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.1697&lon=-105.1097&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report July 25, 2002 - Report: Approved by Office Director - Parties: FAA FSDO - NTSB case key (mKey): 53698 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN02LA005 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/53698/pdf - Page: https://openairdocs.org/ntsb/DEN02LA005 ## Probable cause The loss of engine power for undetermined reasons, which resulted in a forced landing. A contributing factor was the lack of suitable terrain for the forced landing ## Analysis The pilot was conducting a test flight to do a further "run-in" on the engine, which had 3.0 hours since major overhaul. He stated that the engine ran smoothly and that all pressures and temperatures were normal prior to a point on the return flight where at approximately 5 miles northeast of the airport, the engine temporarily faltered. At that point, the pilot was able to reestablish power by manipulating the mixture control lever. He was concerned about his position over a densely populated area and modified his approach by circling south of the airport. At approximately 4 miles south of the airport, the engine began to run rough and quit, "similar to a fuel starvation failure." The pilot was unable to regain engine power and he landed the airplane in a field. During the landing roll, he applied the brakes, and the airplane tipped nose down. Fuel samples taken prior to the flight and after the recovery of the airplane revealed no evidence of fuel contamination. ## Factual narrative On October 26, 2001, at approximately 1225 mountain daylight time, an Irwin Thorp T-18, N2819L, was substantially damaged when it impacted terrain during a forced landing near Longmont, Colorado. The airline transport pilot, the sole occupant on board, was not injured. Visual meteorological conditions prevailed and no flight plan was filed for this local test flight being conducted under Title 14 CFR Part 91. The flight originated at Vance Brand Airport, Longmont, Colorado, at approximately 1100. According to the pilot, he was conducting a test flight to do a further "run-in" on the engine, which had 3.0 hours since major overhaul. He stated that the engine ran smoothly and that all pressures and temperatures were normal. When the airplane was approximately 5 miles northeast of the airport, the engine "temporarily faltered." At that point, the pilot was able to reestablish power by manipulating the mixture control lever. He was concerned about his position over a densely populated area and modified his approach by circling south of the airport. At approximately 4 miles south of the airport, the engine began to run rough and quit, "similar to a fuel starvation failure." The pilot was unable to regain engine power and he landed the airplane in a field. During the landing roll, he applied the brakes, and the airplane tipped nose down. The airplane sustained damage to the propeller, left flap assembly, left main landing gear and substantial damage to the rear spar of the left wing. The pilot stated, "the problem was definitely fuel related," but the fuel samples taken prior to the flight and after the recovery of the airplane revealed no evidence of fuel contamination. Weather conditions at the time of the accident, obtained from Jeffco Airport, Broomfield, Colorado, located approximately 14 statute miles to the southwest, were: airfield elevation, 5,670 feet mean sea level; temperature, 12 degrees Celsius; dew point, minus 8 degrees Celsius; altimeter setting, 30.51. The calculated density altitude was 6,102 feet above mean sea level. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, maneuvering - reason for occurrence undetermined (cause) - Forced landing, emergency descent/landing - Nose down, landing - roll - terrain condition - rough/uneven - terrain condition - none suitable (contributing factor) ## Aircraft - Registration: [N2819L](https://openairdocs.org/aircraft/N2819L), registered now, S/N 1116 (OpenAirDocs) - Reported make and model: Irwin Thorp T-18 - Registry model: [Irwin Wayne R THORP T-18](https://openairdocs.org/model/irwin-wayne-r-thorp-t-18) (registry code 89510JJ) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 1116 - Airframe hours: 5 - Engines: Lycoming O-320 160 horsepower reciprocating - Damage: Substantial damage - Flight: Flight test, Part 91 - Registered owner: Thomas T. Melsheimer - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, October 8, 2001, 4 hours before - Departed: 2V2, Longmont, CO - Destination: 2V2, Longmont, CO ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 65; injuries: none; flight instructor, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; last flight review November 3, 2000; seat: left; flight hours: 11,414 total, 9,390 as pilot in command, 43 in the last 90 days, 9 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 160° at 8 knots - Visibility: 60 statute miles - Lowest ceiling: none - Temperature: 54 °F, dew point 18 °F - Altimeter: 30.51 inHg - Observed at: KBJC, 14 nm away ## 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 20011026030929A](https://openairdocs.org/incident/20011026030929A), Oct 26, 2001: Amtr THORPT18, Longmont, CO, No damage. (-23) Aircraft was being test flown. Engine started to run rough, pilot adjusted mixture control, engine seemed to run fine, then it quit running. Pilot was… 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.