# NTSB WPR09CA064: Air Tractor AT-502, N1035F, Dinuba, CA, December 16, 2008 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: December 16, 2008, 10:08 local (18:08 UTC) - Place: Dinuba, CA - Coordinates: 36.458332, -119.385276 - Nearby events: https://openairdocs.org/map.md?lat=36.4583&lon=-119.3853&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report January 29, 2009 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 73131 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR09CA064 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/73131/pdf - Page: https://openairdocs.org/ntsb/WPR09CA064 ## Probable cause The failure of maintenance personnel to properly install the engine's Py line correctly, which resulted in the total loss of engine power and subsequent force landing. Contributing to the accident was the lack of suitable terrain. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (turbine/turboprop)](https://openairdocs.org/ntsb-findings/01057200): Aircraft › Aircraft power plant · Incorrect service/maintenance (probable cause); cases with it: [Air Tractor AT-502, 2 cases](https://openairdocs.org/ntsb-findings/01057200/cases.md?model=0390303), [All aircraft, 67 cases](https://openairdocs.org/ntsb-findings/01057200/cases.md) - [Maintenance: installation](https://openairdocs.org/ntsb-findings/02062035): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Air Tractor AT-502, 3 cases](https://openairdocs.org/ntsb-findings/02062035/cases.md?model=0390303), [All aircraft, 371 cases](https://openairdocs.org/ntsb-findings/02062035/cases.md) - [Terrain: rough terrain](https://openairdocs.org/ntsb-findings/03021015): Environmental issues › Physical environment · Ability to respond/compensate (probable cause); cases with it: [Air Tractor AT-502, 2 cases](https://openairdocs.org/ntsb-findings/03021015/cases.md?model=0390303), [All aircraft, 442 cases](https://openairdocs.org/ntsb-findings/03021015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Prior to flight: Aircraft maintenance event](https://openairdocs.org/ntsb-events/040); cases with it: [Air Tractor AT-502, 1 case](https://openairdocs.org/ntsb-events/040/sequence.md?model=0390303), [All aircraft, 484 cases](https://openairdocs.org/ntsb-events/040/sequence.md) - [Maneuvering-low-alt flying: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Air Tractor AT-502, 4 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=0390303), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Air Tractor AT-502, 7 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=0390303), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-flare/touchdown: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Air Tractor AT-502, 1 case](https://openairdocs.org/ntsb-events/096/sequence.md?model=0390303), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot reported that about halfway through the first spray pass he experienced a complete loss of engine power. The pilot stated that he pulled up out of the field, dumped the load, and chose to land straight ahead in an adjoining field. The pilot reported that after touching down and holding the stick back the tail started lifting. Before it stopped, the airplane nosed over and came to rest inverted. A Federal Aviation Administration (FAA) airworthiness aviation safety inspector conducted a post accident examination of the airplane. The airplane's most recent annual inspection had been completed the day prior to the accident. The FAA inspector found the engine's Py line had not been secured properly, which would have prevented proper fuel scheduling to the engine's fuel control unit. The inspector also reported that the outboard leading edge of the left wing tip had sustained substantial damage, which would have adversely affected the flight characteristics of the airplane. ## Factual narrative The pilot reported that about halfway through the first spray pass he experienced a complete loss of engine power. The pilot stated that he pulled up out of the field, dumped the load, and chose to land straight ahead in an adjoining field. The pilot reported that after touching down and holding the stick back the tail started lifting. Before it stopped, the airplane nosed over and came to rest inverted. A Federal Aviation Administration (FAA) airworthiness aviation safety inspector conducted a post accident examination of the airplane. The airplane's most recent annual inspection had been completed the day prior to the accident. The FAA inspector found the engine's Py line had not been secured properly, which would have prevented proper fuel scheduling to the engine's fuel control unit. The inspector also reported that the outboard leading edge of the left wing tip had sustained substantial damage, which would have adversely affected the flight characteristics of the airplane. ## Aircraft - Registration: [N1035F](https://openairdocs.org/deregistered/N1035F-2020-04-08), registration cancelled 2020-04-08, S/N 502-0081, built 1990 (OpenAirDocs) - Reported make and model: AIR TRACTOR AT-502 - Registry model: [Air Tractor AT-502](https://openairdocs.org/model/air-tractor-at-502) (registry code 0390303) (OpenAirDocs) - Registry engine: [Pratt & Whitney PT6A series](https://openairdocs.org/engine/pratt-whitney-pt6a-series) (registry code 52032, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 502-0081 - Airframe hours: 9990.2 - Engines: Pratt & Whitney PT6A-34 750 horsepower turbo prop - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Gilbert Aviation Industries INC - Registered owner: Gilbert Aviation Industries INC - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, December 15, 2008, 0.3 hours before - Departed: D86, Visalia, CA - Destination: D86, Visalia, CA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; injuries: none; commercial; airplane ratings: single-engine land; medical: class 2, without waivers/limitations; last flight review November 21, 2008; seat: single; flight hours: 1,752 total, 434 in this make and model, 1,642 as pilot in command, 66 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 90° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 41 °F, dew point 36 °F - Altimeter: 30.01 inHg - Observed at: VIS ## 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 20081216852519A](https://openairdocs.org/incident/20081216852519A), Dec 16, 2008: Airtrc AT502, Dinuba, CA, Substantial damage. During aerial application, the pilot stated that he lost power. The pilot did not have enough altitude to prepare for this landing. He dumped his load and… 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.