AD/F100/84 Fuel Crossfeed Valve and Fire Shut-Off Actuators (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.

Fokker F28 Series Aeroplanes

AD/F100/84 Fuel Crossfeed Valve and
Fire Shut-Off Actuators 7/2007

Applicability:

F28 Mark 0070 and Mark 0100 aircraft, serial numbers 11244 through 11585 inclusive, if equipped with fuel crossfeed valve- and fuel fire shut-off valve actuators, Part Number (P/N) 9409122.

Requirement:

1.    Perform an operational check of, and application of grease on, the LH and RH fuel crossfeed valve actuators and fuel fire shut off valve actuators as defined in Part 1 of SBF-100-28-049 or later NAA approved revision.

2.    a.    Perform a visual inspection of the applied grease layer on the LH and RH fuel crossfeed valve actuators and fuel fire shut off valve actuators as defined in Part 2 of SBF-100-28-049 or later NAA approved revision; and

b.    Perform an operational check and visual inspection of the LH and RH fuel crossfeed valve actuators and fuel fire shut off valve actuators as defined in Part 3 of SBF-100-28-049 or later NAA approved revision.

3.    When, during any of the inspections as required by Requirement 2a of this AD, the layer of grease on any valve actuator is found to be insufficient (less than approx. 2 - 3 mm), repeat the application of grease as defined in Part 1 of
SBF-100-28-049 or later NAA approved revision.

4.    When a fuel fire shut-off valve actuator fails the operational check as required by Requirements 1 or 2b of this AD, replace the valve actuator with a serviceable part in accordance with the Aircraft Maintenance Manual.

5.    When a fuel crossfeed valve actuator fails the operational check as required by Requirements 1 or 2b of this AD, replace the valve actuator with a serviceable part in accordance with the Aircraft Maintenance Manual or operate the aircraft in accordance with (the conditions and remarks in) MMEL item 28-23-1.

Note:  EASA AD 2007-0122 dated 3 May 2007 refers.

Compliance:

1.    Within 30 days after the effective date of this AD, unless previously accomplished.

2.    After compliance with paragraph 1 of this directive:

a.     At intervals not to exceed 7 days.

b.    At intervals not to exceed 28 days.

3.    Before further flight after the effective date of this AD.

4.    Before further flight after the effective date of this AD.

5.    Before further flight after the effective date of this AD.

This Airworthiness Directive becomes effective on 5 July 2007.

Background:

In-service experience revealed that, due to their position on the aircraft, ice may form on actuators P/N 9409122 installed on fuel crossfeed valves and fuel fire shut-off valves.  Tests revealed that the ice can prevent the actuator and thus the valve from operating in flight (frozen stuck).  A new actuator is being developed by Fokker Services; However, an airworthiness assessment revealed that interim actions are required for actuators P/N 9409122 installed on fuel crossfeed valves and fuel fire shut-off valves until the new actuators are installed.  Fokker Services has issued SB SBF100-28-049 to introduce interim actions that will reduce the probability that fuel crossfeed and fuel fire shut-off valves equipped with actuators P/N 9409122 do not operate due to ice.  The interim actions consist of an operational check of the actuators and the application of a grease layer on the actuators, followed by a weekly visual check of the applied grease layer and a 4-weekly operational check of the actuators.

Charles Lenarcic
Delegate of the Civil Aviation Safety Authority

14 May 2007