Air Tractor AT-802A N807MA

Summary

On 20 August 2009 at about 22:43 local time, a Air Tractor AT-802A registered N807MA, operated by Bureau of Land Managment/DOI, was involved in an accident near Austin, Nevada, 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

20 August 2009 at 22:43

Classification

Accident

Location

Austin, Nevada, United States

Nearest airport

Battle Mountain (BAM)

Coordinates

39.8139, -117.5789

Aircraft

Air Tractor AT-802A

Registration

N807MA

Category

Airplane

Engines

1

Operator

Bureau of Land Managment/DOI

Operating rule

Public Use

Purpose of flight

Fire Fighting

Phase of flight

Not recorded

Route

Battle Mountain → Battle Mountain

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR09GA407

1 person died.

The pilot’s failure to maintain a stabilized approach prior to the retardant drop and his subsequent failure to release the retardant load, resulting in a stall/mush and collision with terrain.

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

Read the full NTSB narrative

The pilot was dropping fire retardant onto a saddle area located between the intersection of two perpendicular ridge lines. One of several witnesses reported that the airplane circled the area and then began a steep descent towards the intended drop point. The pilot did not release the load of retardant over the drop area. The witness observed the nose of the airplane pitch up and “mush through the flare.” The underside of the airplane then made contact with rising terrain within the saddle and continued uphill on its main landing gear toward a crest where the terrain dropped away. It then descended and collided with terrain in the valley below. Postaccident examination did not reveal any anomalies with the airplane, engine, or retardant dispersal system that would have prevented operation. The dispersal system’s operating procedures recommend that it be turned off during flight to prevent inadvertent dumping of the load. According to other pilots it is not uncommon to forget to re-engage the system prior to the drop. The dispersal system included an emergency manual release mechanism that could be used in the event of a primary system failure or an inadvertent oversight by the pilot to turn the system on; however, impact damage prevented an accurate determination of the system's armed status prior to impact. Global Positioning System (GPS) information revealed an excessive rate of descent just prior to the expected drop, which corroborated witness accounts. Analysis of the accident location, with respect to the GPS data, density altitude, airplane load, and witness statements, would indicate that the airplane probably encountered a stall/mush at the drop area. The high density altitude and the airplane's flap settings would have diminished the climb performance considerably in its retardant loaded state. The airplane's continued trajectory after initial impact, as well as propeller witness marks and internal engine damage, indicated that the engine was producing power at the time of the accident.

Quoted verbatim from the NTSB record.