McDonnell Douglas Heli 369FF N530RL

Summary

On 31 January 2011 at about 18:15 local time, a McDonnell Douglas Heli 369FF registered N530RL, operated by Pima County Sheriff's Department, was involved in an accident near Marana, Arizona, United States. 4 people were on board and one died, 2 were seriously injured, one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

31 January 2011 at 18:15

Classification

Accident

Location

Marana, Arizona, United States

Coordinates

32.3514, -111.4761

Aircraft

McDonnell Douglas Heli 369FF

Registration

N530RL

Category

Helicopter

Engines

1

Operator

Pima County Sheriff's Department

Operating rule

Public Use

Phase of flight

Not recorded

Route

Tucson → Marana

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR11GA115

1 person died.

An inadvertent tail rotor strike during an attempted pinnacle landing, which resulted in the pilot's loss of control of the helicopter. Inhospitable terrain/topography contributed to the severity of the accident.

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

Read the full NTSB narrative

The four-place, turbine-powered helicopter was being operated by the county sheriff's department in support of a county emergency communications system development and construction project. The accident flight was intended to enable technical personnel to conduct a site survey for the planned installation of a communications repeater tower near the top of a mountain. The sheriff's department pilot had satisfactorily completed training for and had demonstrated confined area, slope, and pinnacle landings. None of the three passengers were helicopter pilots, and no anti-torque pedals were installed at the front passenger's station. The mountain's remote location and its topography prevented postaccident availability of specific meteorological conditions at the time of the accident, but analysis of available data indicated that mostly overcast skies, intermittent rain, and a generally westerly wind at 10 to 15 knots were present. Those conditions were within the helicopter's and pilot's performance capabilities. The helicopter orbited the peak for general reconnoitering before the pilot attempted a landing. The pilot's selected landing zone was on a relatively level area of a pinnacle on the northeast side of the mountain, and the approach was from the southeast. The passengers reported that during the landing attempt, they felt a bump, and the helicopter rose a few feet, then the nose pitched down, and the helicopter began to spin to the right. The main rotor blades struck a rock outcrop, and the helicopter tumbled and slid about 120 feet down a shallow canyon on the northeast face of the peak before it was halted by rocks and scrub vegetation. The wreckage was examined in situ, recovered, and examined in detail. All components were accounted for. All damage patterns were consistent with the helicopter's low-speed impact with terrain in the horizontal and vertical planes, and its subsequent tumble down the canyon. The engine successfully met specification power settings during an operational run in a test fixture. No evidence of any preexisting mechanical defect or malfunction was noted during the examination or testing of the airframe and engine. Main and tail rotor damage patterns and debris distribution were consistent with rotor strikes under power. The witness and passenger descriptions of the helicopter's motions are consistent with a tail rotor ground strike and a subsequent loss of directional control. Although no reliable ground scars indicative of a tail rotor strike were found, that was likely precluded by the rocky, hard surface of the landing zone.

Quoted verbatim from the NTSB record.