Bell 206 N61PH

Summary

On 16 April 2019 at about 14:06 local time, a Bell 206 registered N61PH, operated by Van Horn Aviation, was involved in an accident near Fort McDowell, Arizona, United States. 2 people were on board and 2 died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

16 April 2019 at 14:06

Classification

Accident

Location

Fort McDowell, Arizona, United States

Coordinates

33.6236, -111.6756

Aircraft

Bell 206

Registration

N61PH

Category

Helicopter

Year built

1981

Engines

1

Operator

Van Horn Aviation

Operating rule

Part 91: General Aviation

Purpose of flight

Flight Test

Phase of flight

Not recorded

Route

Mesa → Mesa

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

WPR19FA109

2 people died.

The separation of the main rotor head from the mast as a result of a sudden displacement of the cyclic stick during a low-G maneuver, leading to mast bumping. Contributing to the accident were the unsecure positioning of the flight test engineer’s laptop computer and the deviation from standard operating procedures to leave the left seat cyclic control installed during the test flight.

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

Read the full NTSB narrative

The pilot and flight engineer were conducting a flight test to evaluate developmental main rotor blades that had been installed on the helicopter. The flight consisted of multiple autorotations at maximum gross weight, entered following a 1-second delay after a simulated loss of engine power. A witness saw the helicopter falling from the sky and saw several other objects descending to the ground before losing sight of it behind trees. Examination of the wreckage revealed damage to the main rotor mast, consistent with a mast bumping event. Cyclic controls were installed in both the pilot’s seat and the left seat, where the flight test engineer sat with equipment used for recording flight parameters, including an 8-lb laptop computer. In order for the engineer to operate the computer or take notes on the clipboard, he would have to hold the computer with one hand while using the other to enter commands or take notes. The installation of the cyclic in the engineer’s position represented a deviation from company procedures by both the pilot and the flight test engineer. Examination revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation of the helicopter prior to the mast bumping. The flight engineer’s fatigue of holding the 8-lb computer over his lap, the awkwardness of entering commands with one hand, or taking notes single-handedly may have allowed the computer to suddenly shift and strike or block the cyclic during the simulated loss of power test at the critical low-G flight condition.

Quoted verbatim from the NTSB record.