# NTSB DEN99TA013: Air Tractor AT-400, N73080, Aztec, NM, October 19, 1998 - Type: NTSB accident investigation - Classification: Accident · No injuries · Final report - Date: October 19, 1998, 13:00 local (19:00 UTC) - Place: Aztec, NM - Coordinates: 36.81916, -108.000526 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=36.8192&lon=-108.0005&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report May 19, 1999 - Report: Approved by Office Director - NTSB case key (mKey): 45133 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN99TA013 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/45133/pdf - Page: https://openairdocs.org/ntsb/DEN99TA013 ## Probable cause The pilot's inadequate preflight inspection of the airplane. Factors were the unsecured oil dipstick, the loss of engine oil pressure necessitating a precautionary landing on unsuitable terrain, and the collision with the tree. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Miscellaneous/other, maneuvering - lubricating system,oil filler cap - not secured (contributing factor) - aircraft preflight - inadequate, pilot in command (cause) - fluid,oil - low pressure (contributing factor) - On ground/water encounter with terrain/water, landing - roll - precautionary landing - performed, pilot in command - terrain condition - none suitable (contributing factor) - object - tree(s) (contributing factor) ## Analysis The pilot had flown the aerial application flight for 12 minutes when he began to 'get oil on [the] windshield, and [began] losing oil pressure'. A precautionary landing ensued. During the landing roll, the right wing struck a tree. The airplane spun around and slid aideways, collapsing the left landing gear. The left wing was also 'wrinkled.' The pilot said he found the oil dipstick had not been secured. ## Factual narrative On October 19, 1998, approximately 1300 mountain daylight time, an Air Tractor AT-400, N73080, operated by J.R. Davis Flying Service under contract to the U.S. Bureau of Land Management, was substantially damaged during a forced landing near Aztec, New Mexico. The airline transport pilot, the sole occupant aboard, was not injured. Visual meteorological conditions prevailed, and no flight plan had been filed for the aerial application flight being conducted under Title 14 CFR Part 137. The flight originated at Aztec, New Mexico, approximately 1230. According to the pilot's accident report, he had flown the aerial application flight for 12 minutes when he began to "get oil on [the] windshield, and [began] losing oil pressure." A precautionary landing ensued. During the landing roll, the right wing struck a tree. The airplane spun around and slid sideways, collapsing the left landing gear. The left wing was also "wrinkled." The pilot said he found the oil dipstick had not been secured. ## Aircraft - Registration: [N73080](https://openairdocs.org/aircraft/N73080), registered now, S/N 400-0639, built 1985 (OpenAirDocs) - Reported make and model: Air Tractor AT-400 - Registry model: [Air Tractor AT-400](https://openairdocs.org/model/air-tractor-at-400) (registry code 0390202) (OpenAirDocs) - Registry engine: [Pratt & Whitney PT6A series](https://openairdocs.org/engine/pratt-whitney-pt6a-series) (registry code 52034, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 400-0639 - Airframe hours: 4171 - Engines: P&W PT6-11 600 horsepower turbo prop - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: James R. Davis - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, July 5, 1998, 666 hours before - Departed: Q19, NM ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 60; airline transport; airplane ratings: single-engine land, multi-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 24,200 total, 3,000 in this make and model, 24,200 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 100° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 66 °F, dew point 34 °F - Altimeter: 30.00 inHg - Observed at: FMN ## 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 19981019029799A](https://openairdocs.org/incident/19981019029799A), Oct 19, 1998: Airtrc AT400, Azetc, NM, Substantial damage. Acft was involved in aerial application when the engine ran out of oil due to the pilot not securing the dipstick.(.19) on October 19, 1998, approximately 1300… ## Other investigations on N73080 (1) 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. - [NTSB MIA97LA012](https://openairdocs.org/ntsb/MIA97LA012), Oct 21, 1996: Air Tractor 400 (N73080), Sylvester, GA, substantial damage. Probable cause: Was the pilots intentional disregard for operating the engine contrary to the flight manuals for intentionally exceeding the maximum engine temperature, resulting in creep failure of one of the… 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.