Pilot Debrief

BELL 427 near Indiantown, FL — 2012-06-04

Final reportERA12LA379
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Date
2012-06-04
Location
Indiantown, FL, USA
Aircraft
BELL 427
Registration
N427AL
Category
Helicopter
Highest injury
Minor
Fatalities
0
Phase of flight
Maneuvering

Probable cause

The inflight collision with birds, resulting in damage to the rotor head assembly and a subsequent forced landing and rollover.

NTSB narrative

The pilot reported that, about 25 minutes into the flight, he maneuvered the helicopter to avoid large birds. The pilot felt something impact the upper right side of the helicopter near the main rotor mast area. The helicopter began shaking violently and became difficult to control. He immediately decided to abort the flight. During the landing attempt, helicopter control was lost; the helicopter entered a left spin, impacted the ground, and rolled over. The main and tail rotor systems and the fuselage sustained substantial damage. The immediate decision to abort the flight after impact with the birds most likely aided the pilot in executing an emergency landing. Evidence of bird remains were present on components of the rotor head, two of the four pitch change rods, and the tail rotor. Both pitch change rods with bird remains were separated from one of their attach points. The bird remains were removed and sent to the Smithsonian Institute for identification. According to the report, male and female Black Vulture DNA was found on the pitch control rods, pitch control linkages, and the tail rotor. Examination of the rotor head parts found two pitch change links failed in tensile overstress; one of these exhibited an inward bending that could have been caused by a bird strike. The damage to the other pitch change link was most likely caused by the dynamic rollover as the rotor blades impacted the ground or other helicopter components. The accident sequence most likely initiated when the birds struck the pitch change rods.

Analysis

Primary failure mode
Environmental
First missed decision gate
Pilot could have chosen a different route to avoid bird strike.

NTSB coding

Evidence available

  • FDR / data
  • Photos
  • 16 docket documents
View NTSB final reportView NTSB docket

Docket documents16

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