Casualties unknown

2006-04-11: Air Tractor AT-602 (N50669) — Ulysses, KS

Ulysses, KS, US

On April 11, 2006, an Air Tractor AT-602 (registration N50669) was involved in an aviation accident near Ulysses, KS. Investigators recorded the probable cause as: the loss of engine power due to fuel starvation. A contributing factor was the impact with a ditch during the forced landing. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

An aerial application pilot experienced an engine failure after an uneventful flight, leading to a forced landing in a corn field. The aircraft struck a ditch, collapsing the landing gear and buckling the fuselage.

Accident Summary

An aerial application flight ended with an engine failure and forced landing in a hilly corn field. The pilot had departed a private airstrip approximately one hour prior to the event with about 140 gallons of fuel. After spraying two fields, the fuel gauges showed an imbalance, and shortly after departing the area, the engine lost power.

Sequence of Events

The pilot first sprayed one field using a power setting that consumed fuel at a rate of 80 gallons per hour. He then sprayed a second field at a fuel burn rate of 75 gallons per hour. Following the second spraying, the pilot observed the fuel gauges indicating 1/4 fuel remaining in the left tank and 1/8 fuel remaining in the right tank. He activated the fuel boost pump and continued spraying passes on the west end of the field, employing a back-to-back pattern with north-south orientation and right and left turns. The final pass was northward. After pulling up over power lines, the pilot turned right—a downwind turn—toward the local airstrip located three miles away.

Shortly after the turn, the engine lost power. The pilot attempted a restart, and the engine briefly started for about one second before losing power again. With no power available, the pilot executed a straight-ahead, downwind landing in a hilly corn field. During the landing roll, the airplane impacted a ditch at the end of the field, causing the main landing gear to collapse.

Aircraft Examination

Post-event examination of the airframe revealed that the fuselage and firewall were buckled. No other damage details were provided in the source.

Manufacturer Guidance

The airframe manufacturer issued a service letter providing guidance to owners and operators on preventing or minimizing fuel level imbalance between the left and right main fuel tanks. The letter noted that such imbalance could lead to fuel starvation if one tank becomes dry. Possible causes of fuel imbalance include migration of fuel from one tank to the other or uneven fuel flow to the header tank.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20060510X00537. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.