Bell UH-1H N775AR

Summary

On 16 July 2013 at about 15:55 local time, a Bell UH-1H registered N775AR, operated by Billings Flying Service, was involved in an accident near Dove Creek, Colorado, United States. One person was on board and one died. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

16 July 2013 at 15:55

Classification

Accident

Location

Dove Creek, Colorado, United States

Coordinates

37.7561, -108.7731

Aircraft

Bell UH-1H

Registration

N775AR

Category

Helicopter

Year built

1977

Engines

1

Operator

Billings Flying Service

Operating rule

Part 133: Rotorcraft Ext. Load

Purpose of flight

External Load

Phase of flight

Not recorded

Route

Dove Creek → Dove Creek

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN13FA415

1 person died.

Pilot-induced oscillations caused by the loss of hydraulic assist of the flight controls due to an excessive loss of hydraulic fluid during a critical phase of flight, which resulted in ground impact. Contributing to the accident was an inadequate analysis of the hydraulic fluid leak by the pilot and mechanic.

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

Read the full NTSB narrative

The helicopter pilot flew inbound to a seismic survey location hoisting a basket load with a long-line rope. The pilot overshot the intended drop site, and the basket load and long-line impacted the ground after the pilot likely initiated a load release. The helicopter then entered a right bank, followed by a steep left bank, and subsequently impacted the ground. Postaccident examination of the helicopter revealed evidence consistent with a loss of hydraulic fluid from the flight control system due to a hydraulic leak of a check valve fitting near the tail rotor servo. As the pilot approached the survey location, the loss of hydraulic pressure most likely resulted in very-high collective control forces and pilot-induced oscillations. The director of maintenance stated that the pilot and a mechanic were aware of the hydraulic fluid leak and had ordered replacement parts; however, they had not yet been installed. He stated that they did not expect the leak to cause a significant issue. Thus, it is likely that they did not foresee the leak causing a significant flight hazard.

Quoted verbatim from the NTSB record.