Aerospatiale AS350B N729DP

Summary

On 30 June 2012 at about 19:07 local time, a Aerospatiale AS350B registered N729DP, operated by Chopper II LLC, was involved in an accident near Camp Verde, Arizona, United States. 4 people were on board and 4 died. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

30 June 2012 at 19:07

Classification

Accident

Location

Camp Verde, Arizona, United States

Nearest airport

Scottsdale (KSDL)

Coordinates

34.4444, -111.7894

Aircraft

Aerospatiale AS350B

Registration

N729DP

Category

Helicopter

Year built

1990

Engines

1

Operator

Chopper II LLC

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Scottsdale → Scottsdale

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR12FA282

4 people died.

The pilot's improper decision to fly at a low altitude through a river canyon, contrary to voluntary guidance within the Special Conservation Area, which led to collision with a cable. Contributing to the pilot’s decision were his cognitive and psychomotor impairment from his use of an antihistamine medication.

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

Read the full NTSB narrative

The helicopter was reported missing by family members, and the wreckage was found the next day in a deep river canyon abutted by 200-foot vertical cliffs. Before the accident, a U.S. Geological Survey (USGS) cableway system had spanned the river about 300 feet north of the wreckage and had been elevated about 39 feet above the river's center. Examination of the cable, its landing platforms, the helicopter, and the wreckage location revealed evidence consistent with the helicopter impacting the cable while traveling in level-forward flight. A photo of the cableway taken by the USGS before the accident showed that the cable suspended over the river was not visible against the terrain background; however, the cableway did not meet the Federal Aviation Administration (FAA) aerial marker requirement criteria. The USGS has replaced the cableway with aerial markers. In addition, the accident occurred within a designated Special Conservation Area, which the FAA recommends avoiding, if practical, or if flown through, it recommends that pilots should make every effort to fly not less than 2,000 feet above ground level. The pilot's postaccident ethanol levels were indicative of the ethanol being produced postmortem; if any of the ethanol was due to ingestion, it was well below the FAA regulatory limit, and it is unlikely to have contributed to the accident. The pilot's postaccident diphenhydramine level suggests that he had taken it within an hour of taking off. Diphenhydramine causes marked sedation, is a central nervous system depressant, and it has been observed to alter mood and impair cognitive and psychomotor performance. It is likely that diphenhydramine led to cognitive and psychomotor impairment to the pilot and contributed to his decision to fly at an insufficient altitude in a river canyon.

Quoted verbatim from the NTSB record.