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Safety Action

Summary

Local safety action

Immediately following the incident, the helicopter operator changed the tail rotor pitch change shaft bearings in all of the AS332L helicopters in its fleet. Subsequently, the operator issued Alert Message AM/332/03/008 to all of its local and international facilities, instructing maintenance personnel to immediately change the pitch change shaft bearings should they have been contaminated by hydraulic fluid, or should any doubt exist as to the bearing's condition.

On 5 November 2003, the aircraft manufacturer issued Information Telex 00000151, alerting all operators of AS332, AS330 and AS532 aircraft of the subject incident and instructing maintenance personnel to check the tail rotor pitch change bearing if any fluid leak is discovered at the tail rotor servo actuator. Subsequently, Alert Telex 00000158 was issued on 8 December 2003 requiring 10-hourly inspections for hydraulic leaks at the tail rotor boot and detailing a new mandatory maintenance procedure to be applied should a leak be discovered. Due to an error in the original Alert Telex, an erratum document (Alert Telex 00000166) was issued on 19 December 2003.

On 26 February 2004, the Direction Gnrale de l'Aviation Civile France ( DGAC) issued airworthiness directive (AD) No. F-2004-031, mandating the 10-hourly inspection of the AS332 tail rotor hub boot for evidence of hydraulic fluid leakage. If fluid leakage is discovered, replacement of the pitch-change shaft bearing is required. The Australian Civil Aviation Safety Authority subsequently issued AD/S-PUMA/51 on 26 February 2004, mirroring the requirements of AD F-2004-031 for aircraft in the Australian fleet.

 


1 Right-hand thread, clockwise rotation to tighten.
2 Counter-clockwise to tighten.
3 The aircraft manufacturer identified the bearing grease as Aeroshell-33 universal airframe grease (MIL-PRF-23827C Type 1).
4 Specified as Aeroshell fluid 41 (MIL-PRF-5606H).
5 Anexus Laboratories, Bulleen Victoria. Report No. C1110 "Assessment of Bearing Grease for Possible Contamination".

 
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