Air Tractor AT 602 N604RH

Summary

On 28 April 2017 at about 18:00 local time, a Air Tractor AT 602 registered N604RH, operated by Gray Ag Air, was involved in an accident near Hollis, Oklahoma, 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

28 April 2017 at 18:00

Classification

Accident

Location

Hollis, Oklahoma, United States

Nearest airport

Hollis Municipal (O35)

Coordinates

34.7003, -99.9086

Aircraft

Air Tractor AT 602

Registration

N604RH

Category

Airplane

Year built

2011

Engines

1

Operator

Gray Ag Air

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Hollis → Hollis

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN17FA170

1 person died.

An impact with terrain during final approach for reasons that could not be determined because no evidence of an in-flight failure or malfunction was observed.

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

Read the full NTSB narrative

The pilot was returning from an application flight at the time of the accident. A witness observed the airplane approaching the airport. He noted that an unusual noise came from the airplane but was unsure of the exact nature. Shortly afterward, he heard a loud explosion. Ground-based video footage depicted the airplane entering a rapid descent while on final approach until it went behind an intervening tree line. A plume of smoke rose from that location few seconds later. A postaccident examination of the airframe, engine and propeller did not reveal any anomalies consistent with a preimpact failure or malfunction. However, an examination of some components was limited due to the extent of the impact damage. Toxicology testing revealed that the pilot had used three sedating drugs: cetirizine, oxycodone, and oxazepam. However, only oxycodone was still present at a level that could have been impairing. Because patients using opioids may develop significant tolerance to the sedating side effects, there is no accepted relationship between blood levels and impairment from these medications. Therefore, the extent of impairment, if any, could not be determined. The reason for the abrupt descent and impact with terrain while on final approach could not be determined because the postaccident examination did not reveal any preimpact anomalies.

Quoted verbatim from the NTSB record.