AD/Bell 430/13 Removal of Air Temperature Restriction (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Bell Helicopter Textron Canada (BHTC) 430 Series Helicopters

AD/BELL 430/13 Removal of Air Temperature Restriction 6/2008

Applicability:

Model 430 helicopters, serial numbers 49001 through 49098.

Requirement:

Action in accordance with the requirements of Transport Canada AD CF-1997-23R3.

Note:  BHTC Alert Service Bulletins 430-01-22 original issue, and 430-03-28 original issue, refer.

Compliance:

Unless already accomplished, as specified in the Requirement document.

This Airworthiness Directive becomes effective on 5 June 2008.

Background:

A main rotor path plane separation on a Model 430 helicopter was found to have been caused by the limited damping characteristics of the elastomeric lead-lag dampers.  BHTC introduced as an interim measure a fluid-elastic (fluidlastic) lead-lag damper set, which has increased damping.  Additionally, the operation of the aircraft was temporarily restricted to a minimum ambient temperature of -20 degrees C
(-4 degrees F).  BHTC ASB 430-01-22 reinstated the original temperature operation of the aircraft down to -40 degrees C (-40 degrees F) and introduced installation of new decals with the revised airspeed limitations.  The latest revision of the Requirement document introduces an increased Vne airspeed at low temperatures.

David Villiers
Delegate of the Civil Aviation Safety Authority

21 April 2008