AD/F100/91 Amdt 1 Fuel System Crossfeed Valve Actuator (Cth)
AIRWORTHINESS DIRECTIVE
On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/F100/91 and issues the following 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.
Fokker F100 (F28 Mk 100) Series Aeroplanes
| AD/F100/91 Amdt 1 | Fuel System - Crossfeed Valve Actuator | 8/2009 |
Applicability: | Fokker Aircraft B.V. F28 Mark 0070 and Mark 0100 aircraft, all serial numbers, if an actuator Part Number (P/N) 9409122 or P/N 53-0013 is installed on one or both fuel crossfeed valves. |
Requirement: | 1. For aeroplanes in pre-SBF100-28-046 configuration - Accomplish either Requirement 1a or 1b below: a. Remove each fuel crossfeed valve actuator with P/N 9409122 from the aeroplane and replace it with a fuel crossfeed valve actuator P/N 53-0013 and accomplish the associated modifications in accordance with the Accomplishment Instructions of Fokker Services SBF100-28-046 dated b. Remove each fuel crossfeed valve actuator with P/N 9409122 from the aeroplane and replace it with a fuel crossfeed valve actuator P/N 53-0027 and accomplish the associated modifications in accordance with Part 1A or 1B, as applicable, of the Accomplishment Instructions of Fokker Services SBF100-28-061 dated 20 April 2009. 2. For aeroplanes in post-SBF100-28-046 configuration, which includes aeroplanes that have complied with Requirement 1a of this AD: Remove each fuel crossfeed valve actuator with P/N 53-0013 from the aeroplane and replace it with a fuel crossfeed valve actuator P/N 53-0027 in accordance with Part 2 of the Accomplishment Instructions of Fokker Services 3. Do not install a P/N 53-0013 fuel crossfeed valve actuator on any aeroplane. The use of later approved revisions of these documents is acceptable for compliance with the requirements of this AD. Note 1: After installation of P/N 53-0013 or P/N 53-0027 fuel crossfeed valve actuators on an aeroplane, the requirements of CASA AD/F100/84 no longer apply to the fuel crossfeed valve actuators installed on that aeroplane. |
| Note 2: EASA AD 2009-0116 dated 29 May 2009 refers. | |
Compliance: | For Requirement 1 - Remains unchanged as detailed in the original issue of this AD as within 12 months from 28 August 2008 (The effective date of the original issue of this AD), unless previously accomplished. For Requirement 2 - Within the next 18 months after the effective date of this AD. For Requirement 3 - After 12 December 2010. |
| This Amendment becomes effective on 30 July 2009. | |
Background: | Due to their position on the aeroplane, fuel crossfeed valve actuators P/N 9409122 are susceptible to freezing, which has an adverse effect on the operation of the valve. This condition, if not corrected, may generate fuel asymmetry alerts when a valve remains in the open position after being selected closed. It may also prevent the flight crew from correcting a fuel asymmetry when a valve remains in the closed position after being selected open. One event was reported where, due to such problems, the flight crew shut down an engine in-flight and diverted the aircraft. Aeroplanes with serial numbers 11244 through 11441 were delivered from the production line with actuators P/N 9401037 (“chimney type”) installed. However, on some aeroplanes, these actuators have subsequently been replaced in service with actuators P/N 9409122 (using mounting blocks P/N 7923505) on one or both fuel crossfeed valves. As a result, those aeroplanes are also affected by this unsafe condition. To address and correct this unsafe condition, EASA issued AD 2008-0126 that required the replacement of all P/N 9409122 fuel crossfeed valve actuators in accordance with Fokker Services SBF100-28-046 with new actuators developed by the manufacturer Eaton Aerospace, P/N 53-0013, which have improved reliability and are less susceptible to freezing. Following the introduction of actuator P/N 53-0013 in service, Eaton Aerospace reported manufacturing and design errors on actuators with P/N 53-0013. As a result of these errors, the top-cap of the actuator may become loose, possibly leading to actuator failure. Eaton Aerospace has eliminated these problems by introducing a new actuator P/N 53-0027 and Fokker Services have published SBF100-28-061 to introduce these improved actuators on aeroplanes. This AD also allows direct installation of P/N 53-0027 on aeroplanes that are still in pre-SBF100-28-046 configuration. |
| The original issue of this AD became effective on 28 August 2008. |
James Coyne
Delegate of the Civil Aviation Safety Authority
16 June 2009
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