Pilot Debrief

BELL 407 near DeLand, FL — 2008-01-07

Final reportNYC08LA077
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Date
2008-01-07
Location
DeLand, FL, USA
Aircraft
BELL 407
Registration
N801DS
Category
Helicopter
Highest injury
None
Fatalities
0
Phase of flight
Cruise

Probable cause

A total loss of engine power due to the fatigue failure of a third stage turbine wheel blade.

NTSB narrative

The helicopter was cruising at 120 knots and 700 feet above the ground. About 2 city blocks from the intended destination, the pilot heard a loud "bang," and the helicopter then yawed left about 30 degrees. The pilot initiated an autorotation to a nearby road that was under construction. While attempting to land, the pilot maneuvered the helicopter to avoid construction equipment, and during the landing the main rotor blades contacted the vertical stabilizer. After the helicopter came to rest, the pilot observed a fire in the engine compartment, which he extinguished using the on-board fire extinguisher. Post-accident examination of the engine revealed that one of the blades on the third stage turbine wheel had failed in fatigue, resulting in an over-speed and subsequent burst of the first stage turbine wheel. The root cause of the blade failure could not be determined.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot could have conducted maintenance checks to prevent engine failure.

NTSB coding

Evidence available

  • 5 docket documents
View NTSB final reportView NTSB docket

Docket documents5

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