Bell 206B N106TV

Summary

On 30 May 2012 at about 14:10 local time, a Bell 206B registered N106TV, operated by J.R. Helicopters Leasing LLC, was involved in an accident near Burbank, Washington, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

30 May 2012 at 14:10

Classification

Accident

Location

Burbank, Washington, United States

Coordinates

46.2078, -118.9569

Aircraft

Bell 206B

Registration

N106TV

Category

Helicopter

Engines

1

Operator

J.R. Helicopters Leasing LLC

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Zillah → Zillah

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR12CA236

Nobody was injured.

The failure of maintenance personnel to properly torque an air tube fitting, which resulted in a total loss of engine power.

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

Read the full NTSB narrative

During an aerial application flight, the single engine helicopter was flying low over an apple orchard when the engine began to lose power. The pilot decreased his airspeed toward zero and performed a hovering autorotation into the orchard. During the landing, the rotor blades impacted the trees, and the tail boom separated from the main fuselage. An examination of the engine revealed that the compressor discharge pressure (PC) air tube, which connected the PC air filter to the power turbine governor was disconnected. The “B” nut that connected the tube to the PC air filter was present on the tube but not threaded onto the PC air filter boss. The threads on both the PC air filter boss and the “B” nut did not exhibit any damage or abnormalities. Review of the maintenance records showed that, about 6 hours before the accident, the turbine assembly and bleed valve had been replaced. Removal and reinstallation of the PC air tube was conducted as part of the documented maintenance. It is likely that maintenance personnel did not properly torque the “B” nut when reinstalling the tube and the loose “B” nut backed off in-flight. According to the engine manufacturer's technical representative, disconnection of the PC air tube during engine operation would result in a loss of engine power.

Quoted verbatim from the NTSB record.