Bell 206L-1 N613

Summary

On 30 October 2000 at about 17:30 local time, a Bell 206L-1 registered N613, operated by U.s. Bureau of Reclamation, was involved in an accident near Mesa Verde, Colorado, 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 October 2000 at 17:30

Classification

Accident

Location

Mesa Verde, Colorado, United States

Coordinates

37.1797, -108.4904

Aircraft

Bell 206L-1

Registration

N613

Category

Helicopter

Engines

1

Operator

U.s. Bureau of Reclamation

Operating rule

Part 91: General Aviation

Purpose of flight

Public Use

Phase of flight

Not recorded

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

DEN01LA012

Nobody was injured.

The manufacturer's use of improper materials, and inadequate quality control of the tail rotor blades during the manufacturing process, which resulted in fatigue failure of the blade.

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

Read the full NTSB narrative

During approach to land on a helipad at the completion of a seeding flight, the helicopter began, what the pilot described as, an unusual vibration. The pilot conducted a normal landing and during inspection following shutdown, the pilot found that one tail rotor blade had shed the trailing edge counterweight and trailing edge skin. He also found that three of the four mounting points for the tail rotor gearbox had fractured. Both tail rotor blades, which had accumulated approximately 30.8 hours since new, were sent to the NTSB Materials Laboratory for examination. The helicopter was repaired and when the shipping container containing new tail rotor blades was opened and the blades unpacked, the repair station rejected one blade for visual abnormalities in the area of the trailing edge counterweight. The rejected blade was also sent to the laboratory for examination. The laboratory examination provided evidence the tail rotor blade failed due to fatigue in the inboard and outboard skins initiating at the root near the trailing edge counterweights. The fatigue initiated due to buckling deformation of the inboard skin, which was found to be thinner than that specified in the manufacturer's drawings. The rejected tail rotor blade examination provided evidence of uneven bonding of the inboard counterweight and deformation due to the riveting process. Deformation was also noted on the outboard counterweight. Composite Structures, LLC, Monrovia, California, manufactured all the tail rotor blades.

Quoted verbatim from the NTSB record.