Bell 212 CFHDY

Summary

On 3 June 2000 at about 22:10 local time, a Bell 212 registered CFHDY was involved in an accident near Eugene, Oregon, United States. 2 people were 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

3 June 2000 at 22:10

Classification

Accident

Location

Eugene, Oregon, United States

Nearest airport

Hahlon Sweet Field (EUG)

Coordinates

44.0401, -123.2205

Aircraft

Bell 212

Registration

CFHDY

Category

Helicopter

Engines

2

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Unknown

Phase of flight

Not recorded

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

SEA00LA097

Nobody was injured.

Inadequate quality control by the manufacturer during the manufacturing process, which led to the total failure of a fastener, and the separation of the tail rotor blade balance weight. An adhesive debond between the adhesive and the surface was a factor.

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

Read the full NTSB narrative

During a practice power recovery autorotation to a hover, at about 600 feet AGL, the two pilots heard a loud bang, followed by a severe vibration. The PIC lowered the collective and rolled both throttles off to continue the autorotation to the ground, which landed without further incident. Inspection of the helicopter revealed that the 90-degree gearbox with tail rotors attached had separated from the tail boom. Inspection of the tail rotors revealed that the tip weight in one of the blades was missing. Examination of the blade revealed evidence of adhesive debonding between the adhesive and the spar surface. As a secondary securing method, four countersunk screws are in line chordwise and offset in pairs on each side of the blade. All four screw holes showed no significant evidence of deformation. It was determined that the four countersunk screws were ineffective due to the limited amount of clamping provided by the machining, at the manufacturer, of too large a diameter in the countersunk hole relative to the diameter of the screw head, thus allowing the four secondary load path screws to slip behind the spar, resulting in the tip block separating from the blade. The manufacturer reported that although the bonding adhesive is identified as the primary securing method for the tip block, and the four countersunk screws as the secondary, either method independent of the other is capable of carrying the load.

Quoted verbatim from the NTSB record.