AD/ATR 42/25 - Wire Bundles in the Rear Baggage Zone

The directive deploys several standard airworthiness-regulation mechanisms: limited applicability, incorporation by reference to a manufacturer service bulletin, a two-step inspect-and-correct instruction set, and a time-based compliance window with a before-flight restraint for rectification of any discrepancies. Applicability is narrow: only ATR 42-500 aeroplanes with MSNs 667, 669 and 671 are within scope (Applicability). This focused scope reflects the background statement that certain aircraft produced before 1 April 2008 may have received partial or incorrect implementation of a previously mandated modification (Background).

The AD does not create new technical standards in-text. Instead it requires compliance with the accomplishment instructions of ATR Service Bulletin ATR42-92-0020 dated 17 October 2008, or later revisions approved by EASA (Requirement). That structure makes the Service Bulletin the operative technical source for how to conduct the verification and correction, while the Directive establishes legal compulsion and timing. The AD explicitly connects to prior regulatory instruments: it notes EASA AD 2008-0218 and references AD/ATR 42/23 (EASA AD 2008-0062), which mandated ATR modification 05780 in April 2008 (Background). The AD thus sits in a lineage of regulatory responses to an identified unsafe condition affecting rudder trim, pitch trim and stick pusher control functions.

Two compliance modalities are used. First, a scheduled inspection within 550 hours time in service after the effective date is required for the verification step (Compliance: For Requirement 1). Second, an immediate remedial modality is imposed: if discrepancies are found, the corrective actions must be done before further flight after the verification (Compliance: For Requirement 2). The before-further-flight constraint converts detected non-compliance into a potential grounding until the SB-prescribed fixes are completed. The AD therefore combines forward-looking scheduled compliance with an immediate flight-safety lock on operations where defects are discovered.

The signatory detail is a procedural concept: the AD was issued by a CASA delegate, James Coyne, dated 27 January 2009, and became effective 12 March 2009 (signature; Compliance). The document therefore reflects CASA’s decision to adopt and enforce the EASA-approved Service Bulletin instructions for the three MSNs named.

The document defines its affected population narrowly. Applicable operators are those who operate ATR 42-500 aircraft with Manufacturer Serial Numbers 667, 669 and 671 (Applicability). Owners, operators and maintenance organisations responsible for those three specific aeroplanes are the direct subjects of mandatory action. Because the AD ties required actions to accomplishment instructions in ATR Service Bulletin ATR42-92-0020 (Requirement), maintenance organisations performing the inspection and any corrective actions will be required to use that Bulletin or a later EASA-approved revision as their technical authority for the work.

Indirectly affected parties include the manufacturer to the extent its service bulletin is the prescribed means of compliance, and any parts suppliers that provide protection sleeves, clamps or other hardware specified in the Service Bulletin. The AD does not extend to ATR 42 variants other than the ATR 42-500, nor to other serial numbers; therefore operators of other ATR 42s fall outside its direct scope unless their aircraft are explicitly listed (Applicability).

The AD imposes scheduling obligations on operators. Requirement 1 must be completed within 550 hours time in service after the AD’s effective date, so operators must plan maintenance windows within that flight-hour budget (Compliance). Where discrepancies are found during verification, Requirement 2 requires corrective action before further flight, imposing an operational interruption on the affected aircraft until rectification is complete (Requirement; Compliance). Maintenance providers must be prepared to perform the corrective work to the ATR Service Bulletin standard and to demonstrate compliance.

The document also signals regulatory coordination. It refers to EASA AD 2008-0218 and to an earlier AD, AD/ATR 42/23 (EASA AD 2008-0062), which previously mandated ATR modification 05780 (Background). Operators who have recorded implementation of modification 05780 should nevertheless expect an inspection because the background notes that some aircraft may have received partial or incorrect implementation on the production line (Background). The AD therefore affects record-review practices as well as physical inspection routines for the three listed aeroplanes.

Duties established by this Directive are specific and time-bound. Duty 1: Verify the installation of appropriate protection sleeves and the correct routing and clamping of the wire bundles in the rear baggage zone in accordance with the accomplishment instructions of ATR Service Bulletin ATR42-92-0020 dated 17 October 2008 or later revision approved by EASA (Requirement 1). Duty 2: If any discrepancy is found during Requirement 1, accomplish all corrective actions as instructed in the ATR Service Bulletin ATR42-92-0020 or later revision approved by EASA (Requirement 2). The required standard of work is therefore the Service Bulletin accomplishment instructions, with EASA approval as the touchstone for acceptable revisions (Requirement).

Timing duties are explicit. Duty 1 must be carried out within 550 hours time in service after the effective date of the Directive (Compliance: For Requirement 1). Duty 2 imposes an immediate aviation-safety constraint: corrective actions for any discrepancy must be performed before further flight after the verification (Compliance: For Requirement 2). The Directive’s effective date is 12 March 2009 (Compliance).

The AD does not specify a set of rights in express terms. The document does not describe appeal rights, exemptions, or administrative review routes; it merely prescribes what must be done and when. The Service Bulletin reference means operators have the right to comply using the technical steps set out in ATR42-92-0020 or in a later EASA-approved revision; in practical terms, that creates a right to follow an approved technical method of compliance rather than a locally improvised method (Requirement).

The AD also situates responsibility at operator and maintenance-provider level. The verification step is an operator/maintenance duty; the corrective-action duty is triggered only if discrepancies are found during that verification (Requirement). The background justification shows that the duties respond to an identified loss of fail-safe design criteria for certain control functions following an earlier event and an earlier AD that mandated modification 05780 (Background). That context clarifies the safety premise behind the duties but does not expand the text of the duties themselves.

The text of the Directive supplied does not include a schedule of penalties, specific enforcement procedures, or administrative sanction mechanisms. The document records an effective date (12 March 2009) and prescribes mandatory actions with defined compliance windows (Compliance), but it does not set out penalties for non-compliance within the supplied text. The Directive is signed by James Coyne, Delegate of the Civil Aviation Safety Authority, which indicates the issuing authority (signature). Beyond the signature and effective date, the AD itself does not enumerate enforcement steps (for example, notices to airmen, infringement fines, or suspension mechanisms) within the text provided.

However, the Directive imposes operational constraints with immediate safety effect: if a discrepancy is discovered during the verification required by Requirement 1, corrective action must be accomplished before further flight (Requirement; Compliance). That requirement functionally prevents continued operation of an aircraft with an identified discrepancy until the prescribed corrective actions are taken. In practice, a before-further-flight requirement creates a direct operational enforcement mechanism because an operator who continues to fly an aircraft with a known, uncorrected discrepancy would be operating outside the Instruction set of the AD. The document itself, though, does not describe how such operational non-compliance will be detected, recorded, or sanctioned.

Where the Directive cross-refers to prior EASA ADs and to an ATR Service Bulletin, the enforcement of the technical steps is tied to compliance with those referenced instruments (Requirement; Background). The supplied text does not set out documentary compliance requirements such as mandatory records, nor does it state the evidence an operator must retain to demonstrate compliance. Those matters may be covered elsewhere in regulatory practice or in the referenced Service Bulletin, but they do not appear in the AD text provided.

The Directive explicitly references and incorporates external regulatory and technical instruments. It directs compliance with ATR Service Bulletin ATR42-92-0020 dated 17 October 2008, or with a later revision approved by the European Aviation Safety Agency (EASA). That structure means the technical means of compliance are set by the manufacturer’s Service Bulletin, subject to EASA approval; the AD therefore makes the Service Bulletin an enforceable requirement for the specified aircraft (Requirement).

The AD situates itself in a chain of earlier regulatory action. It notes that AD/ATR 42/23 (which is EASA AD 2008-0062) was released in April 2008 to mandate ATR modification 05780 after a reported event concerning loss of fail-safe design criteria for rudder trim, pitch trim and stick pusher control functions (Background). The current Directive responds to findings that some aircraft manufactured and delivered before 1 April 2008 may have received a partial or incorrect implementation of ATR modification 05780 on the production line (Background). It thus operates as a follow-up to a previously mandated modification and as a verification/completion instrument for aircraft potentially affected by incomplete compliance.

The AD also references EASA AD 2008-0218 (Requirement: Note). That cross-reference shows regulatory coordination between CASA’s Directive and EASA’s rulemaking. Because the Service Bulletin compliance is required only insofar as it is in a later revision approved by EASA, the AD ties the acceptable technical standard to EASA approval. The Directive therefore interacts with EASA’s approval regime for service bulletin revisions.

The supplied text does not explicitly discuss interactions with domestic statutory regimes beyond the CASA signature. It does not, in the text provided, state how the AD interacts with operator certificate conditions, continuing airworthiness obligations under other statutes, dispute-resolution mechanisms, or record-keeping requirements. Those interactions may exist in broader aviation regulatory practice, but they are not detailed in the Directive text supplied here.

The document supplied contains limited explicit amendment history. The AD itself identifies that it refers to prior regulatory action: AD/ATR 42/23 (EASA AD 2008-0062) which was released in April 2008 and which mandated ATR modification 05780 (Background). The AD also references EASA AD 2008-0218 (Requirement: Note). No other amendments, supersessions, or revocations of this AD are stated in the text provided.

The Service Bulletin identified as the technical means of compliance is ATR Service Bulletin ATR42-92-0020 dated 17 October 2008, and the AD permits use of a later revision only if approved by EASA (Requirement). That phrasing implies an amendment path for the technical instructions that is controlled by EASA approval rather than by the issuing authority of this AD. The AD does not itself set out a mechanism for incorporating future revisions of the Service Bulletin other than by specifying that later revisions must be EASA-approved to be acceptable (Requirement).

The Directive was signed by the Delegate of the Civil Aviation Safety Authority, James Coyne, on 27 January 2009, and became effective on 12 March 2009 (signature; Compliance). The AD number and date appear as AD/ATR 42/25 3/2009 at the head of the document. The supplied text does not include any later amendment, reissue, or withdrawal language. Therefore, within the limits of this text, there is no recorded amendment subsequent to its initial issuance.

The text supplied contains no litigation history. It names prior regulatory instruments (EASA AD 2008-0218; AD/ATR 42/23 which is EASA AD 2008-0062) and a manufacturer Service Bulletin (ATR42-92-0020 dated 17 October 2008) but does not reference any judicial or administrative proceedings challenging those instruments or the AD itself. The AD includes background facts regarding a reported event and the potential incomplete implementation of modification 05780 on certain aircraft, but it does not describe any disputes, appeals, or litigation outcomes in respect of the AD, the Service Bulletin, or the prior EASA ADs.

Given the absence of litigation references in the supplied text, readers seeking litigation history or precedent must consult external sources or administrative records not included here. The AD itself simply records regulatory action and technical requirements without annotating any disputes or case law.

Several practical pitfalls are apparent from the Directive as supplied. Limited scope: the AD applies only to three specific ATR 42-500 serial numbers, MSNs 667, 669 and 671 (Applicability). Operators of other ATR 42-500s or ATR variants should not assume they are in scope; conversely, an operator who believes a given aircraft has already been modified must not rely solely on modification records because the background explicitly states that some aircraft manufactured and delivered before 1 April 2008 may have received a partial or incorrect implementation of modification 05780 (Background). That background note creates an inference that a recorded modification may not be conclusive proof of correct implementation.

Reference-to-Service-Bulletin constraint: the Verification and corrective actions must be accomplished in accordance with ATR Service Bulletin ATR42-92-0020 dated 17 October 2008 or a later EASA-approved revision (Requirement). The AD therefore requires obtaining and following the correct version of the Service Bulletin. Operators must confirm that the revision in use is EASA-approved if it is later than the dated bulletin; relying on an unapproved or unpublished revision would not meet the AD’s textual requirement.

Timing measurement: Requirement 1 is to be completed within 550 hours time in service after the effective date of the Directive (Compliance). Operators must compute those hours from the AD’s effective date, which is explicitly 12 March 2009 (Compliance). Miscounting time-in-service hours or mixing calendar days and flight hours could lead to non-compliance.

Operational interruption risk: if a discrepancy is found during verification, corrective actions must be accomplished before further flight (Compliance: For Requirement 2). That creates the risk of unexpected AOG (aircraft on ground) events and potential schedule disruption. Operators should plan for possible corrective work slots and parts availability in advance of the verification date.

Documentation ambiguity: the AD text does not, in the supplied version, state documentary evidence or record-keeping requirements to demonstrate compliance, nor does it include penalties or enforcement details (Penalties and enforcement). Operators should be aware that the AD imposes obligations even though the precise administrative processes for showing compliance are not described in the AD text itself.

Cross-references: the AD notes that EASA AD 2008-0218 refers and that AD/ATR 42/23 mandated modification 05780 (Background; Requirement Note). This creates a chain of documents to check. If an operator or maintenance organisation neglects to reconcile these related instruments and the Service Bulletin, they may fail to apply required steps that are only evident across the instrument set.

The Directive sets a clear, limited compliance pathway. Step 1: Identify whether the aircraft is within scope by confirming the Manufacturer Serial Number. The AD applies only to ATR 42-500 aircraft with MSNs 667, 669 and 671 (Applicability). Step 2: Obtain and use the correct technical instructions. The required verification and any follow-up corrective actions must be accomplished in accordance with the accomplishment instructions of ATR Service Bulletin ATR42-92-0020 dated 17 October 2008 or a later revision approved by EASA (Requirement). Operators should therefore obtain the dated Service Bulletin and confirm whether any later EASA-approved revision is available; compliance may be achieved by following the original dated bulletin or any later EASA-approved revision.

Step 3: Carry out the verification within the stated time window. Requirement 1 must be completed within 550 hours time in service after the effective date of the Directive, which is 12 March 2009 (Compliance). Operators must calculate and schedule the inspection work so that the verification occurs no later than the 550-hour cutoff.

Step 4: If discrepancies are found during the verification, perform corrective actions as specified in the Service Bulletin and accomplish those corrective actions before further flight (Requirement 2; Compliance). The AD makes corrective work a flight-delimiting obligation: the aircraft must not continue to operate until the SB-prescribed fixes are completed.

Step 5: Coordinate with maintenance providers and parts suppliers to ensure the necessary protection sleeves, clamps, routing and any other hardware or labour specified in the Service Bulletin are available at the time of inspection. The AD requires verification of "appropriate protection sleeves" and "correct routing and clamping of the wire bundles" in the rear baggage zone (Requirement), so ensure maintenance personnel are familiar with the Service Bulletin’s specified standards.

Step 6: Cross-reference related documents. The Directive notes EASA AD 2008-0218 and references earlier AD/ATR 42/23 (EASA AD 2008-0062) which mandated modification 05780 (Background; Requirement Note). If records indicate modification 05780 was previously implemented, that fact should not obviate the verification, because the background identifies the risk of partial or incorrect production-line implementation for aircraft manufactured/delivered before 1 April 2008 (Background). The verification mandated by this AD is precisely intended to confirm final and correct implementation where necessary.

Step 7: Record compliance actions. While the AD text supplied does not lay down specific documentary requirements or retention periods (Penalties and enforcement), prudent compliance practice is to record the verification results, describe any discrepancies found, and document the completion of the Service Bulletin corrective actions with dates, personnel and signatures. Retain documentary evidence in maintenance records consistent with usual continuing airworthiness practice so that, if required by the regulator, you can demonstrate that Requirement 1 and, where applicable, Requirement 2 were satisfied within the prescribed windows.

Step 8: Note effective dates and authorities. The Directive became effective on 12 March 2009 and was issued by James Coyne, Delegate of the Civil Aviation Safety Authority (signature; Compliance). Compliance scheduling and demonstration should reflect those dates and the fact that the Service Bulletin must be followed only in the form dated 17 October 2008 or in a later revision that has EASA approval (Requirement).

Following these steps implements the AD as written: verify the specified wiring protections and routing in accordance with the prescribed Service Bulletin within 550 hours TIS, and correct any discrepancies before further flight in accordance with the same Service Bulletin.