Air Tractor AT-502 N15400

Summary

On 20 July 2007 at about 14:30 local time, a Air Tractor AT-502 registered N15400 was involved in an accident near Slaton, Texas, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

20 July 2007 at 14:30

Classification

Accident

Location

Slaton, Texas, United States

Nearest airport

Slaton Municipal Airport (F49)

Coordinates

33.4842, -101.6564

Aircraft

Air Tractor AT-502

Registration

N15400

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Positioning

Phase of flight

Not recorded

Route

Slaton → Plainview

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

DFW07LA165

Nobody was injured.

An uncontained failure of the turbine engine's power section for undetermined reasons.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot/owner of the single-engine agricultural airplane stated that the gas turbine rotation speed (Ng) was adjusted "one click" prior to departure to increase the engine power from 96 percent to 100 percent (normal range is between 50 and 102 percent). Shortly after takeoff, at an altitude of approximately 150-feet above ground level (agl), the pilot noted that the Ng speed was still at 96 percent, so he turned back toward the airport. As the pilot was turning back to the airport, the engine lost power, and he was unable to maintain altitude. The pilot made a forced landing to a dirt road, impacted a stop sign, and continued over a highway and into an open field. The pilot added that the engine was still producing enough power for him to taxi the airplane out of the field and back onto the highway. External examination of the engine revealed there was a 5-inch-wide hole in the engine's compressor housing. The engine was then disassembled into two sections; the power section module and the gas generator module. Damage of the power section included torn and nicked compressor turbine blades (leading edge), excessive FOD damage to the hot section stator vanes, the power turbine shroud was bent, buckled, and torn with several bolts sheared out of their holes. The containment ring was split in half. The power turbine stator vanes were torn and deformed. The power turbine wheel had 10 sheared blades at or near the blade root, and several other blades were broken in half. The chip detector was removed and was filled with large metal chips. The oil filter was filled with a small amount of fine metallic particles. Examination of the gas generator revealed that the compressor bleed valve, fuel manifolds, compressor turbine stator assembly, accessory gear box assembly, impeller, compressor inlet case and compressor rotor in the gas generator case, and the compressor turbine blades exhibited no anomalies. A review of maintenance records revealed that the last 100-hour inspection performed on the engine was on April 27, 2007, at a Hobbs time of 5,892.9 hours. However, there was no record of the engine's last overhaul, no record of present engine total time/time since overhaul, and no record of engine removal from the aircraft. The reason for the loss of engine power could not be determined.

Quoted verbatim from the NTSB record.