# NTSB DEN06CA060: Air Tractor AT-602, N50669, Ulysses, KS, April 11, 2006 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Data collection · Final report - Date: April 11, 2006, 11:00 local (16:00 UTC) - Place: Ulysses, KS - Coordinates: 37.603889, -101.373336 - Nearby events: https://openairdocs.org/map.md?lat=37.6039&lon=-101.3733&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report July 31, 2006 - Report: Approved by Office Director - NTSB case key (mKey): 63478 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN06CA060 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/63478/pdf - Page: https://openairdocs.org/ntsb/DEN06CA060 ## Probable cause the loss of engine power due to fuel starvation. A contributing factor was the impact with a ditch during the forced landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, maneuvering - aerial application - fuel system - starvation (cause) - Forced landing, descent - emergency - On ground/water encounter with terrain/water, landing - flare/touchdown - terrain condition - ditch (contributing factor) ## Analysis The pilot departed a private airstrip approximately 1 hour prior to the accident with approximately 140 gallons of fuel. He sprayed one field with a power setting of 80 gallons per hour fuel burn, then sprayed a second field with a power setting of 75 gallons per hour fuel burn. After spraying the second field, the pilot noted the fuel gauges indicated 1/4 fuel in the left tank, and 1/8 fuel in the right tank. He turned on the fuel boost pump and sprayed passes on the west end of the field using a back to back pattern, running north and south with right and left turns. The last pass was to the north. He pulled up over power lines and turned right (downwind) for the local airstrip located 3 miles away. The engine lost power, and the pilot attempted a restart. The engine started "for a second" and then lost power again. The pilot then landed straight ahead, downwind, in a hilly corn field. The airplane impacted a ditch at the end of the field collapsing the main landing gear. Examination of the airframe revealed the fuselage and firewall were buckled. An airframe manufacturer's service letter provided guidance to the Owner/Operator in preventing and/or minimizing the imbalance of the fuel level between the left and right main fuel tanks, which could lead to fuel starvation if one tank goes dry. The fuel imbalance can result from migration of fuel from one tank to the other, or uneven fuel flow to the header tank. ## Factual narrative The pilot departed a private airstrip approximately 1 hour prior to the accident with approximately 140 gallons of fuel. He sprayed one field with a power setting of 80 gallons per hour fuel burn, then sprayed a second field with a power setting of 75 gallons per hour fuel burn. After spraying the second field, the pilot noted the fuel gauges indicated 1/4 fuel in the left tank, and 1/8 fuel in the right tank. He turned on the fuel boost pump and sprayed passes on the west end of the field using a back to back pattern, running north and south with right and left turns. The last pass was to the north. He pulled up over power lines and turned right (downwind) for the local airstrip located 3 miles away. The engine lost power, and the pilot attempted a restart. The engine started "for a second" and then lost power again. The pilot then landed straight ahead, downwind, in a hilly corn field. The airplane impacted a ditch at the end of the field collapsing the main landing gear. Examination of the airframe revealed the fuselage and firewall were buckled. The pilot sustained minor injuries. According to the pilot's statement, he listed the following recommendations: "A. Most of all I think Air Tractor has a problem with their fuel delivery system. No way should an aircraft starve for fuel with 10 gallons of fuel on board let alone 30-40 gallons. They may need a larger header tank, fuel pumps located differently, fuel tank pickups redesigned, or a way of venting air; I don't know. I have heard from other operators that this is not an uncommon problem. B. I should have, in retrospect, carried more fuel. C. I should have made myself aware of all service letters concerning this aircraft." According to the airframe manufacturer's service letter #178, "Imbalance of Fuel in Fuel Tanks", "This Service Letter is to provide guidance to the Owner/Operator in preventing and/or minimizing the imbalance of the fuel level between the left and right main fuel tanks, which could lead to fuel starvation if one tank goes dry. The fuel imbalance can result from migration of fuel from one tank to the other, or uneven fuel flow to the header tank." ## Aircraft - Registration: [N50669](https://openairdocs.org/aircraft/N50669), registered now, S/N 602-0447, built 1997 (OpenAirDocs) - Reported make and model: Air Tractor AT-602 - Registry model: [Air Tractor AT-602](https://openairdocs.org/model/air-tractor-at-602) (registry code 0390309) (OpenAirDocs) - Registry engine: [Pratt & Whitney Canada PT6A-66 series](https://openairdocs.org/engine/pratt-whitney-canada-pt6a-66-series) (registry code 52118, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 602-0447 - Engines: Pratt & Whitney PT6A-45-3R turbo prop - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Tri Rotor Spray and Chemical - Airworthiness certificate: Special, Restricted (Special) - Departed: Ulysses, KS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 51; commercial, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2; flight hours: 3,351 total, 206 in this make and model, 117 in the last 90 days, 54 in the last 30 days ## Weather - Conditions: Visual (VMC), Day ## 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 20060411013569A](https://openairdocs.org/incident/20060411013569A), Apr 11, 2006: Airtrc AT602, Ulysses, KS, Substantial damage. (-23) The aerial applicator was finishing his last trim pass in the pasture to the north three miles from his home base. With the fuel boost pump on the pilot… 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.