Air Tractor AT 802A N70LA

Summary

On 31 July 2017 at about 18:40 local time, a Air Tractor AT 802A registered N70LA was involved in an accident near Wells, Nevada, 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

31 July 2017 at 18:40

Classification

Accident

Location

Wells, Nevada, United States

Nearest airport

Wells Muni/Harriet Field (LWL)

Coordinates

41.1169, -114.9197

Aircraft

Air Tractor AT 802A

Registration

N70LA

Category

Airplane

Year built

2000

Engines

1

Operator

Not recorded

Operating rule

Public Use

Purpose of flight

Fire Fighting

Phase of flight

Not recorded

Route

Battle Mountain → Wells

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR17LA177

Nobody was injured.

The pilot's failure to maintain directional control during a period of thermal activity, which led to a runway excursion and impact with terrain.

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

Read the full NTSB narrative

The commercial pilot reported that at the conclusion of the flight, he entered the left downwind leg of the airport traffic pattern, and observed about 10 knot winds from the north. He subsequently configured the airplane for a wheel landing to runway 26. The tailwheel had been in the "locked" position from the time he departed on the accident flight. Shortly after the main landing gear touched down, the airplane began to veer to the right. As the tailwheel came down, the airplane suddenly departed the right side of the runway in a hard right turn. The left main landing gear impacted an imperfection in the runway, the airplane then rotated spinning 180 degrees to the right before it came to rest. The pilot, experienced in the accident airplane make and model, reported no mechanical anomalies with the control system before the accident. Postaccident examination of the control system revealed no abnormalities with the rudder and aileron. The pilot further stated that he departed with the tailwheel in the "locked" position, and only disengaged the locking mechanism during the landing roll to regain control of the airplane. The manufacturer reported that landing with the tailwheel in the "unlocked" position will typically result in a tailwheel shimmy, and may not have led to a further loss of directional control. A weather study indicated an absence of fronts and weather systems and a presence of variable winds consistent with local circulations and thermals at the time of the accident. Additionally, the airport manager reported that thermal activity is prevalent at her airport, and that multiple runway excursions occur each year due to variable wind conditions and other phenomena. With the presence of variable winds in the morning and subsequent thermal activity at the time of the accident, it is likely that a sudden wind shift or thermal activity overwhelmed the pilot, which resulted in a loss of directional control and the airplane's subsequent excursion from the runway.

Quoted verbatim from the NTSB record.