Pilot Debrief

BELL 230 near Peoria, IL — 2009-07-01

Final reportCEN09IA618
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Date
2009-07-01
Location
Peoria, IL, USA
Airport
PIA
Aircraft
BELL 230
Registration
N880SF
Category
Helicopter
Highest injury
None
Fatalities
0
Phase of flight
Cruise

Probable cause

The loss of the number one hydraulic system fluid and hydraulic pressure during cruise due to the failure of the bolts that secure the hydraulic pump's cover.

NTSB narrative

The helicopter pilot observed a caution light for the number one hydraulic system and a corresponding complete loss of hydraulic system pressure for that system. The pilot declared an emergency and performed a run-on landing. A postincident examination of the system's hydraulic pump revealed that two of its cover attachment bolts had separated. The bolt heads fractured in tension from their shanks via intergranular cracks which initiated at the filet radius between the bead and the shank. The bolt fractures exhibited intergranular fracture features over 90 percent of the surface. The operator’s incident report safety recommendation stated that the pump's cover bolts should be replaced at overhaul; however, it is not required. The helicopter had accumulated 269 hours since overhaul.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Replace hydraulic pump cover bolts at overhaul to prevent failure.

NTSB coding

  • Sys/Comp malf/fail (non-power) · Enroute

Evidence available

  • 5 docket documents
View NTSB final reportView NTSB docket

Docket documents5

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