No fatalities

24 Aug 2014: AIR TRACTOR INC AT-401 (N91968) — RED RIVER DUSTING INC — Natchez, LA

Natchez, LA, United States

On 24 Aug 2014, an AIR TRACTOR INC AT-401 (registration N91968) operated by RED RIVER DUSTING INC was involved in an aviation accident near Natchez, LA. No fatalities were reported. Investigators recorded the probable cause as: The loss of power due to the failure of the No. 2 exhaust valve and rocker boss during takeoff. This summary draws on records from NTSB; 12 related events involving the same aircraft type or operator are linked below.

SourcesNTSBPrimary reportUpdated 1778583330Data APIEditorial standards

On August 24, 2014, an Air Tractor AT-401 (N91968) was destroyed by post-impact fire after a forced landing due to engine power loss near Natchez, Louisiana. The pilot was uninjured.

Accident Details

On August 24, 2014, at approximately 1730 central daylight time, an Air Tractor AT-401, registration N91968, was destroyed by a post-impact ground fire. The accident occurred following a forced landing resulting from a loss of engine power near Natchez, Louisiana. The airplane was operated by Red River Dusting Inc. under 14 Code of Federal Regulations Part 137 as an aerial application flight. Visual meteorological conditions prevailed, and no flight plan was filed. The flight was departing from a private grass airstrip near Natchez.

Pilot Report

The pilot reported that during climbout, about 75 feet above the runway, he heard a loud “pop” and the engine began losing power. He dumped 250 gallons of chemical, weighing approximately 2,000 pounds. The airplane continued to lose altitude, and he executed a forced landing to a cotton field. During the landing roll, the airplane struck a ditch, causing it to spin. A post-impact engine fire ensued, and the airplane was consumed by fire. The pilot was not injured.

Engine Examination

The pilot reported that the No. 2 cylinder “swallowed the exhaust valve” and broke the top of the jug. Examination of the engine revealed a crack in the No. 2 cylinder exhaust rocker boss. The 600-horsepower radial engine had accumulated a total of 11,534 hours of operation. Time since the last inspection was 229 hours, and time since the last overhaul was 1,314 hours.

Contributing factors

Recip eng cyl section — FailureDamaged/degraded