COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Bell Helicopter Textron Canada (BHTC) 407 Series Helicopters
AD/BELL 407/5 Hydraulic Relief Valve Replacement 5/99
Applicability: Bell (BHTC) Model 407 helicopters, serial numbers 53000 through 53266. Requirement: Replace hydraulic relief valves part number 206-076-036-101 with valve part number
206-076-036-105 in accordance with the provisions of BHTC Alert Service Bulletin
(ASB) No. 407-98-20, dated 3 July 1998.
Note: Transport Canada Airworthiness Directive CF-98-28, dated 18 October 1998 refers.
Compliance: Within the next 300 hours flight time after the effective date of this Directive, or by 20 August 1999, whichever occurs first.
This Airworthiness Directive becomes effective on 20 May 1999.
Background: A manufacturing defect has been found on hydraulic relief valve part number 206- 076-036-101 which could lead to an intermittent loss of hydraulic pressure to the flight controls. Replacement of the valve has been made mandatory to correct this safety of flight situation.