Air Tractor AT-502 N1528T

Summary

On 18 September 2003 at about 13:05 local time, a Air Tractor AT-502 registered N1528T was involved in an accident near Fort Pierce, Florida, United States. One person was on board and nobody was injured. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

18 September 2003 at 13:05

Classification

Accident

Location

Fort Pierce, Florida, United States

Nearest airport

Southeastern Airport (FD30)

Coordinates

27.4114, -80.5261

Aircraft

Air Tractor AT-502

Registration

N1528T

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Fort Pierce → Unknown

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

MIA03LA183

Nobody was injured.

Failure of one blade in the engine compressor turbine disk due to fatigue which was caused by loss of gap between the blade platforms as a result of corrosion due to a foreign element (phosphate). This resulted in loss of engine power during takeoff and overrun of the runway and collision with trees during the subsequent aborted takeoff.

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

Read the full NTSB narrative

The pilot aborted the takeoff when heard a loud explosion shortly after lift off. The airplane overran the runway, and collided with trees. The examination of the aircraft revealed the compressor turbine disk exhibited two blades fractured near the platform, the remaining blades exhibiting severe impact damage. Fatigue was observed on the fracture surfaces of the two blades which had fractured near the platform. Corrosion was observed on the side of the compressor turbine blade platforms from these two fractured blades.. The corroded platform area of the compressor turbine blades contained foreign elements mostly composed of phosphate and lead oxide. The corrosion observed had caused a volume change which closed the required gap between blade platforms. According to Pratt and Whitney personnel this would have an adverse effect on the blade airfoils by altering the natural vibration frequency of the blades. Pratt and Whitney personnel concluded that the distress of the compressor turbine disk was initiated by the fracture of one blade in fatigue from multiple origins. The fatigue fracture of the compressor turbine blades likely resulted from a loss of gap between the blade and platforms as a result of the observed corrosion.

Quoted verbatim from the NTSB record.