COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Fokker F50 (F27 Mk 50) Series Aeroplanes
AD/F50/33
Amdt 1
Landing Gear - Extension/Retraction Control 7/92
Applicability: F27 Mk 050 aircraft Serial Numbers 20103 to 20197 inclusive.
Requirement: 1. Connect the DOWN solenoid of the landing gear selector valve to the EMERGENCY DC bus No 2 instead of DC bus No 2 as outlined in Fokker Service Bulletin F50-32-013 dated 16 October 1989, or
Note: AD/F50/33 covers Requirement 2 of the RLD Airworthiness Directive, Flight Manual amendment A/ANF 2750/10 has been issued to cover Requirement 1 of the RLD Airworthiness Directive.
2. Replace the Landing Gear Selector Valve P/N 114044002 with a modified Valve P/N 114044003 as outlined in Fokker Service Bulletin F50-32-016 dated 23 December 1991. Compliance with SB F50-32-016 and removal of the Flight Manual amendment A/ANF 2750/10 is an alternative means of compliance with this AD.
Note: RLD Airworthiness Directive BLA 89-138 Issue 3 refers.
Compliance: The Compliance of the original issue of this Directive was prior to 15 March 1990.
This amendment is effective from 25 June 1992.
Background: Fokker have found that an inadvertent UP selection of the landing gear selector valve is possible as a result of a leaking pilot valve at the moment the DOWN solenoid is de-energised. The original issue of this Directive required modification to the system wiring to prevent such an occurrence.
Amendment 1 is issued to advise of an alternative method of compliance and increases the serial number range of aircraft affected.
Overview
The Civil Aviation Regulations 1998, specifically Part 39 - 105 under the Civil Aviation Safety Authority, address the issue of ensuring the airworthiness of Fokker F50 (F27 Mk 50) Series aeroplanes, particularly in relation to the landing gear system. Enacted by the Parliament of Australia, the objective of these regulations is to maintain and enhance the safety standards of civil aviation through specific airworthiness directives. One such directive, AD/F50/33 Amendment 1, focuses on the landing gear extension and retraction control system. This amendment was introduced to address potential safety issues arising from the inadvertent selection of the landing gear valve, a problem identified by Fokker. The amendment mandates modifications to the wiring and replacement of specific components, ensuring compliance with safety standards and providing an alternative method to meet these requirements as outlined in Fokker's service bulletins.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105, outlines the scope and application of the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, with AD/F50/33 Amendment 1 being pertinent to Fokker F50 (F27 Mk 50) series aeroplanes. This directive applies to Fokker F50 aircraft with serial numbers ranging from 20103 to 20197 inclusive. It mandates the modification of the landing gear selector valve's electrical connections and the replacement of the valve to ensure safe operation by mitigating the risk of inadvertent gear selection. The directive is applicable to any entity operating within the Australian jurisdiction that owns or operates the specified Fokker F50 series aircraft. Compliance with these directives is essential for maintaining the airworthiness of these aircraft and ensuring adherence to safety standards set by CASA. The amendment extends the original directive's applicability and offers an alternative compliance method, ensuring operators have flexibility in how they achieve regulatory compliance.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39, Section 105, includes an airworthiness directive (AD/F50/33 Amendment 1) for Fokker F50 (F27 Mk 50) series aeroplanes. This directive applies to F27 Mk 050 aircraft with serial numbers ranging from 20103 to 20197. The primary requirement of this directive is the modification of the landing gear system. Specifically, it mandates that the DOWN solenoid of the landing gear selector valve be connected to the EMERGENCY DC bus No 2 instead of DC bus No 2, as detailed in Fokker Service Bulletin F50-32-013 dated 16 October 1989. Additionally, the directive requires the replacement of the Landing Gear Selector Valve P/N 114044002 with a modified Valve P/N 114044003, as outlined in Fokker Service Bulletin F50-32-016 dated 23 December 1991. Compliance with these modifications is crucial to ensure the safety and airworthiness of the aircraft.
The obligations imposed by this directive are clear and technical, requiring aircraft owners and operators to adhere to the specific modifications detailed in the directive. Owners and operators must ensure that the modifications are implemented by certified personnel, and that the necessary documentation is updated to reflect these changes. This includes updating the flight manual to reflect the changes made to the landing gear system. It is essential that these modifications are carried out before the aircraft is returned to service to ensure compliance with airworthiness standards.
Failure to comply with the provisions of this airworthiness directive can result in serious consequences. Non-compliance may lead to the aircraft being deemed unairworthy, which could result in grounding of the aircraft until the required modifications are made. Furthermore, operators who fail to comply with the directive may face enforcement actions by the Civil Aviation Safety Authority (CASA). Potential penalties can include fines, enforcement notices, or other regulatory actions as deemed necessary by CASA. The exact penalties would depend on the severity and frequency of the non-compliance, but the primary objective is to ensure that all Fokker F50 aircraft within the specified serial number range meet the required safety standards.