Rotorcraft

AEROSPATIALE, AS 350B2
SDR # 20080722005
Main Rotor Head Ring Cracked

SDR submitted:

On a routine mast reconditioning and inspection, which have a 6-year inspection requirement, the ring was sent for non-destructive testing (NDT) along with the rest of the parts from the assembly (no NDT requirement for the ring at any point, or for any part of the assembly at the 6 year inspection). There was a stress crack during the Magnetic Particle Inspection (MPI) check, which was cause for rejection of the part.

The ring is located at the top of the main rotor shaft, where the rotor head attaches, and rotates with the main rotor shaft/head.

The customer was notified of the defect, and the part was replaced.

Transport Canada Comments:
A heads up to operators that this inspection should be implemented in their maintenance program.Hammer and wrench in X formation indicating end of article

Crique dans le joint torique de la tête du rotor principal

BELL TEXTRON - Canada, 206B
SDR # 20081125005
Vertical Fin Washers Cracked

SDR submitted:

The vertical fin was removed to facilitate seal replacement of the pitch change mechanism. The radius washers that are used on the vertical fin attachment were inspected, and it was noted that 3 of the 4 washers had cracks on the outside perimeter of the washer. The washers, part number 140-019-1, were replaced and the fin re-installed.

Transport Canada Comments:
It is not known if this condition is due to over tightening of the fastener, or the increase in torque value following issuance of Alert Service Bulletin 206-06-107.Hammer and wrench in X formation indicating end of article

Rondelles de dérive fissurées

SIKORSKY, S76A
SDR # 20090901001
Pitch Change Horn Cracked

SDR submitted:

A routine inspection revealed an apparent crack in the tail rotor pitch change beam. After removal of the protective paint coating, the existence of a crack was confirmed both visually and by the Liquid-Phase Infiltration (LPI) method.

The crack extended from the outside diameter of the bushing outward to the outer edge of the horn.

Due to the critical location of the discovered crack, the pitch change beam was replaced and the aircraft was returned to service.

Transport Canada Comments:
The operator added that they will implement a one-time inspection and have increased the inspection guidelines for repetitive inspection. Hammer and wrench in X formation indicating end of article

Crique sur le guignol de pas

Crique sur le guignol de pas

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