Air Tractor AT-400 N501JS

Summary

On 2 July 1996 at about 15:30 local time, a Air Tractor AT-400 registered N501JS was involved in an accident near Huffman, Texas, United States. One person was on board and one died. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

2 July 1996 at 15:30

Classification

Accident

Location

Huffman, Texas, United States

Coordinates

30.0593, -95.0905

Aircraft

Air Tractor AT-400

Registration

N501JS

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

FTW96FA288

1 person died.

corroded flight control components, due to the operator's inadequate maintenance and inspection of the airplane; the pilot's failure to follow procedures and directives, by flying the airplane without proper maintenance and annual inspection; and subsequent failure of a corroded flight control component.

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

Read the full NTSB narrative

After completing aerial application, the pilot entered a right base turn to final approach for landing at a private dirt airstrip. During the turn, a witness observed the 'the left wing' go down and 'also the nose.' The airplane crashed in a left wing low (descending) attitude. The pilot/mechanic had performed maintenance on the aircraft and had certified on March 1, 1995, that the 'aircraft has been inspected in accordance with an annual inspection and was determined to be in an airworthy condition.' Postaccident examination revealed that the empennage flight controls exhibited severe corrosion. The left elevator bellcrank assembly elevator horn was found separated from the control rod elevator torque tube. The left stabilizer strut lower attachment was separated where the tube of the strut was welded to the 'U' shaped attachment bracket. Examination of the 'U' bracket only revealed corroded remnants of the forward bracket and no evidence of the edge welds that joined the bracket pieces together. Fracture surfaces on the elevator horn were consistent with overstress separation. Manufacturing specifications required a 0.080 inch steel sheet for the elevator horn. Over the majority of the horn and near the control rod attachment fracture, the thickness was as low as 0.059 inches.

Quoted verbatim from the NTSB record.