AD/FSM/31 Precision Airmotive Fuel Injection Servo Plugs (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.

Fuel Supply and Metering Equipment

AD/FSM/31 Precision Airmotive Fuel Injection Servo Plugs 5/2008 TX

Applicability:

This AD applies to the following reciprocating engines with an installed Precision Airmotive LLC, RSA-5 or RSA-10 series fuel injection servo, having a servo plug gasket, part number (P/N) 365533, installed under the fuel injection servo plug,
P/N 383493:

 - Lycoming Engines IO, (L)IO, TIO, (L)TIO, AEIO, AIO, IGO, IVO, and HIO series reciprocating engines, regardless of displacement, either new, rebuilt, overhauled, or repaired since 22 August 2006, and/or with an affected fuel injection servo installed either new, rebuilt, overhauled, or repaired since
22 August 2006.

 - Teledyne Continental TSIO-360-RB reciprocating engines, either new, rebuilt, overhauled, or repaired since 22 August 2006, and/or with an affected fuel injection servo installed either new, rebuilt, overhauled, or repaired since
22 August 2006.

 - Superior Air Parts, Inc. IO-360 series reciprocating engines, either new, rebuilt, overhauled, or repaired since 22 August, 2006, and/or with an affected fuel injection servo installed either new, rebuilt, overhauled, or repaired since
22 August 2006.

 - This AD also applies to any other Precision Airmotive LLC fuel injection servos received since 22 August 2006, or any fuel injection servos that have had the fuel injection servo plug, P/N 383493, removed during maintenance since
22 August 2006.

Requirement:

1.    Inspect the fuel injection servo plug, P/N 383493, for looseness, by attempting to turn it by hand, while being careful not to damage the safety wire or seal.  If the plug moves, it is loose.

a.     If the plug is not loose, proceed to Requirement 2 of this AD.

b.    If the plug is loose, do the following:

i.     Carefully cut and remove the safety wire that spans between the servo plug and regulator cover only.

ii.     Remove the servo plug while ensuring that the gasket, P/N 365533, that is behind the plug, is not lost.  The gasket may be slightly stuck to the regulator cover.

iii.    Examine the threads on the servo plug and regulator cover for damage. Threads should be smooth and consistent, with no burrs or chips.  The servo plug outer diameter threads should also measure within
0.7419-0.7500-inch.

iv.    If the threads on either the servo plug or the regulator cover are damaged, or do not measure within the limits in Requirement 1.b.iii. of this AD, the servo is not eligible for any installation and must be replaced before further flight.

v.    Inspect the gasket, P/N 365533, for tears and other damage.  We are allowing the re-use of undamaged gaskets.  Replace damaged gaskets with a new gasket, P/N 365533.

vi.    When reassembling, do not install any servo plug or regulator cover that is not eligible for installation.  Install the gasket onto the servo plug and reassemble the servo plug to the regulator cover.

vii.   Torque the servo plug to a new, higher torque of 90-100 in-lbs, to help maintain the proper clamp-up force against the plug and cover.

viii.  Safety-wire the servo plug with 0.025-inch diameter wire to the regulator cover. Information on properly safety wiring the plug can be found in Precision Airmotive LLC Mandatory Service Bulletin No. PRS-107, Revision 1, dated 6 March 2008.

ix.    Inspect all other safety wire on the servo. Replace any that are damaged.

2.    Repeat the inspection and remedial steps specified in Requirement 1 of this AD.

Aircraft are not to be repositioned until compliance with airworthiness directive has been accomplished.

Note 1:  No Special flight permits will be issued to reposition aircraft not in compliance with this directive.

Note 2:  FAA Emergency AD 2008-06-51 dated 12 March 2008 refers.

Compliance:

1.    Before further flight after the effective date of this AD, unless previously accomplished.

2.    At every engine oil change or within every 50 hours of engine run time, whichever occurs first.

This Airworthiness Directive becomes effective on 14 March 2008.

Background:

The FAA have received eighteen reports of fuel injection servo plugs, P/N 383493, that had loosened or completely backed out of the threaded plug hole on the regulator cover of the fuel injection servo.  The issuing of this AD is intended to prevent a lean running engine, which could result in a substantial loss of engine power and subsequent loss of control of the aeroplane.

David Punshon
Delegate of the Civil Aviation Safety Authority

13 March 2008