# NTSB SEA95LA108: Air Tractor AT-301A, N31580, Terreton, ID, May 29, 1995 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: May 28, 1995, 18:10 local (May 29, 1995, 00:10 UTC) - Place: Terreton, ID - Coordinates: 43.829593, -112.410354 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=43.8296&lon=-112.4104&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report January 19, 1996 - Report: Approved by Office Director - NTSB case key (mKey): 42156 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA95LA108 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42156/pdf - Page: https://openairdocs.org/ntsb/SEA95LA108 ## Probable cause THE PILOT'S FAILURE TO MAINTAIN AN ADEQUATE ALTITUDE TO OVERCOME THE DOWNDRAFT. THE DOWNDRAFT WAS A FACTOR. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, maneuvering - aerial application - weather condition - downdraft (contributing factor) - In flight collision with terrain/water, maneuvering - aerial application - altitude - inadequate, pilot in command (cause) ## Analysis THE PILOT STATED THAT AFTER MAKING THREE AERIAL APPLICATION PASSES, HE ENCOUNTERED A VERY STRONG DOWNDRAFT FROM AN APPROACHING THUNDER CELL. HE TRIED TO CORRECT THE LOSS OF ALTITUDE AND AIRSPEED BY DUMPING THE LOAD AND TURNING TO LOWER TERRAIN. HE WAS UNABLE TO GAIN AIRSPEED AND ALTITUDE AND STRUCK THE GROUND. ## Factual narrative On May 28, 1995, about 1810 mountain daylight time, N31580, an Air Tractor AT-301A airplane, operated by Desert Air Ag, Terreton, Idaho, collided with terrain while maneuvering during an aerial application and was substantially damaged in Terreton. The commercial pilot, the sole occupant, received minor injuries. Visual meteorological conditions prevailed and no flight plan had been filed. The flight departed from Mud Lake, Idaho, and was conducted under 14 CFR 137. According to an FAA aviation safety inspector from Salt Lake City, Utah, witnesses in the area reported gusting winds and thunderstorms in the vicinity of the accident site at the time the airplane was maneuvering over a field to spray herbicide. The pilot stated that after making three passes on the field, he encountered a very strong downdraft from an approaching thunder cell. He attempted to correct the loss of altitude and airspeed by dumping the load and turning to lower terrain. He was not successful in these attempts and the airplane could not gain enough airspeed to keep from striking the ground. The airplane sustained substantial damage at impact with rocky terrain. ## Aircraft - Registration: [N31580](https://openairdocs.org/deregistered/N31580-2022-11-05), registration cancelled 2022-11-05, S/N 301-0484, built 1983 (OpenAirDocs) - Reported make and model: AIR TRACTOR AT-301A - Registry model: [Air Tractor AT-301](https://openairdocs.org/model/air-tractor-at-301) (registry code 0390103) (OpenAirDocs) - Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 301-0484 - Engines: P&W R-1340 600 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Desert Air Ag - Airworthiness certificate: Special, Restricted (Special) - Departed: MUD LAKE, ID ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 29; commercial; airplane ratings: single-engine land; medical: unknown, valid medical--no waivers/lim.; seat: front; flight hours: 1,940 total, 700 in this make and model, 1,854 as pilot in command, 150 in the last 90 days, 75 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 100° at 12 knots - Visibility: 60 statute miles - Lowest ceiling: 8,000 ft broken - Temperature: 63 °F, dew point 30 °F - Altimeter: 30.00 inHg - Observed at: IDA ## 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 19950528017769A](https://openairdocs.org/incident/19950528017769A), May 28, 1995: Airtrc AT301, Terreton, ID, Substantial damage. Encountered downdraft from nearby thunderstorm on a spray run. Dumped load but unable recover. Impacted ground. ## Other investigations on N31580 (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 ERA22LA224](https://openairdocs.org/ntsb/ERA22LA224), May 11, 2022: Air Tractor AT-301 (N31580), Somerville, TN, substantial damage. Probable cause: The inadequate inspection and maintenance of the engine exhaust system, which resulted in an in-flight fire. 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.