Air Tractor AT-502A N6126U

Summary

On 10 January 2024 at about 18:10 local time, a Air Tractor AT-502A registered N6126U, operated by Blair Ground Services, was involved in an accident near Stratford, California, 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

10 January 2024 at 18:10

Classification

Accident

Location

Stratford, California, United States

Nearest airport

Blair Air (Priv)

Coordinates

36.2048, -119.7941

Aircraft

Air Tractor AT-502A

Registration

N6126U

Category

Airplane

Year built

1995

Engines

1

Operator

Blair Ground Services

Operating rule

Part 91: General Aviation

Purpose of flight

Positioning

Phase of flight

Not recorded

Route

Lemoore → Visalia

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR24LA070

Nobody was injured.

A partial loss of engine power due to the malfunction of the engine compressor bleed-off valve.

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

Read the full NTSB narrative

The pilot was repositioning an empty agricultural airplane for fertilizer application. During takeoff, the airplane failed to develop full power. At about 200 feet above ground level (agl) the engine rolled back to near idle. The pilot’s attempt to vary the power lever inputs did not affect engine power output, and he initiated a forced landing into a grove of small pistachio trees and soft dirt. Postaccident examination of the engine and follow-up bench testing of the engine compressor bleed-off valve (BOV) revealed an abnormal amount of air leaking around the piston. Disassembly of the BOV revealed a piston ring set was stuck within the piston groove, consistent with an abnormal air leak and irregular function. Abrasive and adhesive wear was observed on the piston rings and piston groove. The wear was likely due to environmental contaminants or twisting in the BOV’s metal piston ring profile. Based on the condition of the BOV’s rings, the BOV likely did not fully close during the accident flight, which resulted in a partial loss engine power during takeoff.

Quoted verbatim from the NTSB record.