Robinson R44 II N449MC

Summary

On 13 November 2015 at about 22:48 local time, a Robinson R44 II registered N449MC, operated by Concho Aviation LLC, was involved in an accident near Alpine, Texas, United States. 4 people were on board and 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

13 November 2015 at 22:48

Classification

Accident

Location

Alpine, Texas, United States

Nearest airport

Private (PVT)

Coordinates

30.1194, -103.6331

Aircraft

Robinson R44 II

Registration

N449MC

Category

Helicopter

Year built

2012

Engines

1

Operator

Concho Aviation LLC

Operating rule

Part 91: General Aviation

Purpose of flight

Aerial Observation

Phase of flight

Not recorded

Route

Alpine → Alpine

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN16LA039

2 people were seriously injured.

The pilot’s failure to maintain adequate rotor speed while maneuvering at low altitude, which resulted in a descent from which he was unable to recover. Contributing to the accident was the pilot's decision to conduct the flight at or near the helicopter's performance limit, which precluded recovery of the rotor speed in sufficient time to avoid the accident.

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

Read the full NTSB narrative

The commercial pilot and crewmembers were conducting wildlife surveys and predator control at the time of the accident. The pilot did not have any recollection of the accident sequence. Crewmember statements and GPS data indicated that the pilot was maneuvering the helicopter about 40 ft above ground level when the low rotor speed warning activated. The pilot attempted to regain rotor speed by descending into a small canyon. However, his efforts were unsuccessful, and the helicopter subsequently impacted trees and terrain. A review of GPS data revealed that the pilot had completed a low-speed, 360-degree turn followed by a gradual descending left turn immediately before the impact. One crewmember reported that the pilot told him that, during the takeoff on the morning flight, the helicopter "wouldn't go" and that the low rotor speed warning came on. A postaccident examination of the helicopter did not reveal any preimpact failures or malfunctions. Postaccident calculations revealed that the helicopter was operated within the gross weight and center-of-gravity limitations. However, the flight was operating at or near the helicopter's out-of-ground effect hover ceiling performance limit. It is likely that the main rotor speed decayed as the pilot maneuvered the helicopter while it was at or near its performance limit and that the pilot decided to conduct the flight knowing the helicopter was near its performance limit. Insufficient altitude was available to allow the pilot to lower the collective and recover the rotor speed before impact with trees and terrain.

Quoted verbatim from the NTSB record.