AD/Do 228/17 Engine Controls Throttle Box Assembly (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.

Dornier 228 Series Aeroplanes

AD/DO 228/17 Engine Controls - Throttle Box Assembly 5/2009

Applicability:

Dornier Luftfahrt GmbH Model 228-100, 228-101, 228-200, 228-201, 228-202 and 228-212 aircraft, all serial numbers.

Requirement:

1.    Do an inspection of the guide pins of the power and condition levers as detailed in paragraphs 2 and 4 of the RUAG Aerospace Dornier 228 Alert Service Bulletin (ASB) ASB-228-279, original issue.

2.    If the wear of the pin exceeds the acceptable wear-limits as defined in paragraph 4.1 of the RUAG ASB-228-279 original issue, replace the pin with a new one.

In the event an operator is unable to establish the accumulated hours Time In Service (TIS) on a given Throttle Box assembly installed on an airplane, the total hours accumulated on the airplane must be used in the determination of the inspection time for the Throttle Box assembly.

3.    Repeat the inspections detailed in Requirement 1 of this AD.

The use of later approved revisions of the referenced document is acceptable for compliance with the requirements of this AD.

Note:  EASA AD 2009-0031 dated 18 February 2009 refers.

Compliance:

For Requirement 1 - By the schedule specified in table 1 of this AD.

Table 1 - Inspection schedule for throttle assemblies

For throttle box assemblies	Do the inspection
With 9,600 hours TIS or less, at the effective date of this AD.	Upon accumulation of 9,600 total hours TIS.
With more than 9,600 and less than 13,200 hours TIS, at the effective date of this AD.	Within 1,200 hours TIS from the effective date of this AD.
With 13,200 hours TIS or more, at the effective date of this AD.	Within 100 hours TIS from the effective date of this AD.

For Requirement 2 - Before further flight.

For Requirement 3 - At intervals not to exceed 9,600 Hours TIS from the last replacement of the pin or not to exceed 1,200 Hours TIS from the last inspection of the pin if it had been found in the acceptable wear-limits, as applicable.
This Airworthiness Directive becomes effective on 7 May 2009.
Background:	Excessive wear on a guide pin of a power lever has been detected during inspections.  The total loss of the pin could cause loss of the flight idle stop and lead to inadvertent activation of the beta mode in flight.  The inadvertent activation of beta mode in flight can result in loss of control of the aeroplane.  This AD requires a repetitive detailed inspection of the guide pins of the power and condition levers and requires the replacement of the pins that exceed the allowable wear-limits.

James Coyne
Delegate of the Civil Aviation Safety Authority

27 March 2009