American Eurocopter AS350B3 N3948A

Summary

On 10 January 2014 at about 14:15 local time, a American Eurocopter AS350B3 registered N3948A, operated by US Customs and Border Protection, was involved in an accident near Encino, Texas, United States. 3 people were on board and one was seriously injured, 2 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

10 January 2014 at 14:15

Classification

Accident

Location

Encino, Texas, United States

Coordinates

27.0369, -98.1686

Aircraft

American Eurocopter AS350B3

Registration

N3948A

Category

Helicopter

Year built

2010

Engines

1

Operator

US Customs and Border Protection

Operating rule

Public Use

Phase of flight

Not recorded

Route

McAllen → McAllen

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN14GA109

1 person was seriously injured.

The pilot’s failure to maintain directional control while maneuvering, which resulted in a loss of tail rotor effectiveness. Contributing to the accident were the pilot’s limited experience in the operating environment and lack of formal mission training.

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

Read the full NTSB narrative

The pilot reported that he descended the helicopter from 800 to 150 feet above ground level and then hovered on a southerly heading. The helicopter began to drift to the southeast, so the pilot repositioned the helicopter by making a left climbing turn. The wind was from the southeast with gusts estimated by the flight crewmembers to be 15 to 20 knots. As the helicopter turned left, it experienced a change from a right quartering tailwind to a left quartering tailwind, a flight environment associated with the onset of loss of tail rotor effectiveness. According to the pilot, the helicopter shuddered and spun rapidly left. The pilot applied full right pedal and attempted to accelerate because he believed that he had regained control. However, the helicopter then continued to spin left and subsequently impacted trees and terrain. The helicopter sustained substantial damage to the fuselage, main rotor blades, and tail rotor. The pilot stated that he heard a sound similar to the low rotor rpm horn before impact. The pilot reported no preimpact anomalies with the helicopter. A postaccident examination of the helicopter and engine revealed no mechanical malfunctions or failures that would have precluded normal operation. The vehicle engine monitoring display (VEMD) recorded an overtorque event and a free turbine overspeed event consistent with the main rotor blades striking the trees and ground and the main gear box coupling separating on impact. The VEMD also recorded a gas generator overspeed event consistent with the engine producing power at the time of impact. The VEMD did not record any preimpact events that would have precluded normal engine operation. On the basis of the evidence, it is likely that the pilot failed to maintain directional control while maneuvering, which resulted in a loss of tail rotor effectiveness.

Quoted verbatim from the NTSB record.