No fatalities

25 Sep 2014: BELL 206B — CHEM AIR INC — Nashoba, OK

Nashoba, OK, United States

On 25 Sep 2014, a BELL 206B operated by CHEM AIR INC was involved in an aviation accident near Nashoba, OK. No fatalities were reported. Investigators recorded the probable cause as: Loss of tail rotor effectiveness and directional control. This summary draws on records from NTSB; 12 related events involving the same aircraft type or operator are linked below.

SourcesNTSBPrimary reportUpdated 1778583330Data APIEditorial standards

A helicopter experienced loss of directional control during takeoff after refueling for an aerial application flight. The pilot landed hard on uneven terrain, and the tail rotor struck debris, causing substantial damage. The helicopter was estimated 66 pounds over maximum gross weight.

Accident Overview

A helicopter involved in aerial application operations sustained substantial damage after a loss of directional control during takeoff. The incident occurred shortly after the helicopter was refueled and departed for its flight.

Sequence of Events

As the helicopter lifted off, the pilot lost directional control, and the nose began to turn to the right. The pilot verified that the throttle was open. After the helicopter had turned through 180 degrees, the pilot reduced engine power to idle, maintained a level attitude, and touched down hard on uneven terrain. During the landing, the tail rotor contacted a pile of debris, resulting in substantial damage to the tail rotor.

Contributing Factors

No malfunctions or failures were reported that contributed to the accident. However, the helicopter was estimated to be approximately 66 pounds over its maximum gross weight. Additionally, the accident occurred in rugged terrain, which likely caused an unexpected wind shift during the takeoff.

Analysis

The circumstances of the accident are consistent with a loss of tail rotor effectiveness and subsequent loss of directional control. The combination of being over maximum gross weight and the likely wind shift may have exacerbated the situation, leading to the pilot's inability to maintain directional control during the initial climb.

Probable cause

Loss of tail rotor effectiveness and directional control

Contributing factors

Causes

Directional control — Not attained/maintained

Other contributing factors

Ability to respond/compensateSloped/uneven