AD/AS 355/66 Amdt 2 - Sliding Door

Primary responsibility falls on operators of Eurocopter AS 355 helicopters in versions E, F, F1, F2 and N that are equipped with sliding doors and that have not incorporated the specific modifications or service bulletin named (MOD 073287, MOD 073290 or Eurocopter Service Bulletin No. 52.00.22). The text of the directive identifies "Applicability" in those precise terms; that determines the direct scope. For such operators the duties include carrying out the specified measurement check in accordance with Eurocopter AS 355 Alert Service Bulletin No. 05.00.39 Revision 2.2 and then following the action in paragraph 2.B.2 (permit or prohibit door operation in flight and, if prohibition applies, affix a placard to the instrument panel). Pilots and crew of affected helicopters are indirectly affected because the directive can alter allowable in-flight procedures: in some aircraft door operation in flight will be prohibited. Maintenance organisations and licensed engineers who perform inspections and measurements are affected because the Requirement directs them to apply the specific paragraphs of the Service Bulletin to determine C1 and C2 and to document the outcome. Aircraft owners and managers are affected because implementing the directive could require immediate inspection "before further flight after 3 July 2002", and then recurrent inspections at intervals not exceeding 100 flight hours, which impose workload and potential out-of-service time for maintenance. Regulators and their delegates are affected insofar as the directive forms part of the airworthiness measures they oversee: the document is signed by the "Delegate of the Civil Aviation Safety Authority" (David Villiers) and cross-references EASA AD 2006-0249, showing a chain of regulatory inputs (DGAC report, EASA AD, CASA amendment). The applicability exclusion for modified aircraft imposes a need for operators and maintainers to validate modification status against MOD 073287, MOD 073290 and Eurocopter Service Bulletin No. 52.00.22 before applying the directive's measurements and restrictions. Finally, passengers and charter clients are indirectly affected where the prohibition of in-flight door operation alters available services or operations that previously relied on opening sliding doors in flight.

The directive sets out discrete duties and the operational consequence options anchored to measured values. The primary duties are:

• To perform the inspection and measurements specified "in accordance with paragraph 2.B.1 of Eurocopter AS 355 Alert Service Bulletin No. 05.00.39 Revision 2.2", namely to "check the diameter of the sliding door roller and the dimension of the front end opening of the middle rail" (Requirement). This is mandatory for applicable aircraft and must be done "before further flight after 3 July 2002".
• To act on the measurement results as required by paragraph 2.B.2 of that document: apply the thresholds C1 and C2. The decision rule is explicit: if C1 ≥ 5 mm and C2 ≥ 1.5 mm, then door operation in flight is allowed; if C1 < 5 mm and/or C2 < 1.5 mm, then door operation in flight is prohibited (Requirement).
• To install a placard on the instrument panel "specifying this restriction" where door operation in flight is prohibited (Requirement).

The directive also imposes a duty on operators to re-check at intervals "not to exceed 100 flight hours" once the initial compliance has been satisfied. The directive emphasises that "the initial compliance time remains unchanged by this issue of the Directive", indicating that operators must comply with any earlier-stated initial compliance obligations in prior iterations.

Rights are implicit and limited by the operational decision rule: an operator whose measurements meet the threshold criteria has the right to continue door operation in flight, subject to continuing inspections every ≤100 flight hours. Conversely, the directive grants no discretionary relaxation: the measurement thresholds determine the right to operate the door in flight. The directive does not specify any alternative mitigations or remediation steps beyond the measurement-based prohibition; the Service Bulletin is the referent for the precise remedial measures if wear is found. The document also limits who must comply by excluding aircraft with MOD 073287 and/or MOD 073290 or Eurocopter Service Bulletin No. 52.00.22 incorporated, so an operator who has incorporated those mods or the SB is outside the directive’s applicability and therefore has the right not to apply these particular Requirement checks as far as this directive is concerned. The directive does not, within its text, articulate enforcement mechanisms, penalties, or appeals processes; it requires measurement, operational restriction where thresholds are not met, placarding, and recurrent inspections, and becomes effective on the stated date. (Applicability; Requirement; Compliance; "This Amendment becomes effective on 26 October 2006".)

The AD text itself does not specify monetary penalties, administrative sanctions, or criminal consequences. The document records prescriptive obligations , inspection steps, decision thresholds, placarding and a repeat inspection interval , and states these obligations in mandatory terms (for example, "Requirement:" and "Compliance: Before further flight after 3 July 2002; and thereafter at intervals not to exceed 100 flight hours"). The AD is issued and signed by a CASA delegate (David Villiers), and the text identifies it as an amendment to AD/AS 355/66; the presence of this signature indicates this instrument is a regulatory airworthiness directive. The AD does not in its text set out the enforcement mechanisms, who enforces compliance day-to-day, or the penalties for non-compliance. It also does not specify procedures for notification of compliance, record-keeping requirements, or an appeals or rectification process.

From the instrument’s structure, the immediate enforcement-related facts one can draw from the source are: (1) the AD sets mandatory requirements that become effective on a stated date ("This Amendment becomes effective on 26 October 2006."); (2) it identifies a clear compliance schedule (initial check before further flight after 3 July 2002 and thereafter at intervals not to exceed 100 flight hours); and (3) it limits applicability by modification status, which creates an objective criterion for whether an aircraft is within scope. The text does not record the means by which an operator must certify compliance to the regulator, nor any penalty schedule. Any question about penalties, administrative enforcement or remedial steps beyond the technical measurement and placarding instructions is not addressed in this document and would need to be resolved by reference to the wider regulatory framework or to CASA guidance and enforcement policy, which are not part of this text. (Requirement; Compliance; "This Amendment becomes effective on 26 October 2006".)

The AD explicitly cross-references other regulatory and manufacturer documents and changes applicability based on incorporated modifications or service bulletins. It refers to Eurocopter AS 355 Alert Service Bulletin No. 05.00.39 Revision 2.2 as the prescriptive technical procedure that operators must follow (Requirement). It notes that EASA AD 2006-0249 "refers" and that Amendment 2 was "issued in response to a new EASA AD, which introduces a revision of the Requirement document, and limits applicability to unmodified aircraft" (Background). It also excludes aircraft that have incorporated MOD 073287 and/or MOD 073290 or Eurocopter Service Bulletin No. 52.00.22 from applicability (Applicability). These references show that the directive is not a stand-alone measure but part of a chain of manufacturer guidance and foreign regulatory action: the EASA AD is explicitly acknowledged as informing Amendment 2, and the Eurocopter service bulletin is the technical implementer of the measurement and decision steps.

The directive therefore operates in the following interactions, as stated in the text: it imports manufacturer-prescribed measurement procedures (the Alert Service Bulletin), it aligns with or follows an EASA airworthiness directive (EASA AD 2006-0249), and it conditions applicability on whether earlier modifications or service bulletins have been incorporated. The AD does not, in its text, explicitly state how it interfaces with other statutory provisions or with certificate-holder obligations outside of these specific cross-references, nor does it set out interactions with operational rules or operating limitations beyond the door-operation prohibition that may result from the measurements. The directive’s exclusionary language for aircraft with certain modifications or SBs means that operators must reconcile their maintenance/airworthiness records (to determine whether the MODs or SB were incorporated) with the AD’s applicability test before implementing the measurement requirement.

Because the AD references a foreign regulator’s AD (EASA) and a manufacturer service bulletin, it creates a compliance chain: follow the service bulletin’s measurement method, apply the thresholds set out in the AD, and respect the AD’s timing and placarding requirements. The AD does not itself amend any operating certificate conditions stated here, nor does it reproduce detailed remediation procedures; those are to be found in the referenced Service Bulletin and in the EASA AD. The directive also documents the national regulatory action in response to a DGAC safety report, showing a feed of safety information between regulators and manufacturer guidance. (Applicability; Requirement; Background.)

The AD text itself records a short amendment history and the reasons for each change. The chronology and changes recorded in the document are:

• An earlier notice or Alert Telex existed addressing the sliding door issue; Amendment 1 "converted the previous Alert Telex to an Alert Service Bulletin, with no change in technical content; but introduced an additional check criterion in order to prevent the risk of the aft guide roller coming out of the middle rail when the door is opened in flight." This records both a change in form (Telex to Service Bulletin) and a substantive technical addition (an additional check criterion), but clarifies that the technical content otherwise remained unchanged at that stage.
• Amendment 2 is the current issuance recorded in the document. It is "issued in response to a new EASA AD, which introduces a revision of the Requirement document, and limits applicability to unmodified aircraft." The document states that this Amendment becomes effective on 26 October 2006.
• The AD records an operational compliance deadline that predates the Amendment 2 effective date for initial compliance: the compliance section requires the checks "Before further flight after 3 July 2002; and thereafter at intervals not to exceed 100 flight hours." The AD states that "The initial compliance time remains unchanged by this issue of the Directive." That indicates earlier editions of the AD or predecessor instruments set the original initial compliance time; Amendment 2 does not alter that initial deadline but does alter the Requirement document and applicability.
• Administrative details: the directive bears a signature block indicating "David Villiers, Delegate of the Civil Aviation Safety Authority" and a date of signature of 13 September 2006. The directive text also includes the line "This Amendment becomes effective on 26 October 2006." The document includes a "Note: EASA AD 2006-0249 refers." and attaches the tabular header "AD/AS 355/66 Amdt 2" indicating this is the second amendment to AD/AS 355/66.

From the text, the amendments therefore comprise a sequence from an initial alert mechanism (Alert Telex) to a Service Bulletin (with an added check criterion), then a further amendment in response to an EASA AD that revises the Requirement and restricts applicability to unmodified aircraft. The AD does not include the earlier Alert Telex text or the prior amendment wording in full; it states only that Amendment 1 converted the Telex and introduced the additional check criterion, and that Amendment 2 revises the Requirement document and limits applicability. The AD also contains the practical compliance timeline that remains anchored to 3 July 2002 for first compliance and to a 100 flight-hour repeat interval thereafter. (Background; Applicability; Compliance; "This Amendment becomes effective on 26 October 2006".)

The AD text contains no information about judicial proceedings, administrative appeals, challenges to the directive, or litigation outcomes. The document records a safety report from the DGAC, the issuance of an Alert Service Bulletin and the chain of amendments, and the effective date of the current amendment, but it makes no reference to legal challenges or litigation. Consequently, within the scope of this source there is no recorded litigation history to summarise or to cite. Any commentary on disputes, court decisions, or enforcement litigation arising from this AD would require reference to external material not provided in this document. For users seeking to understand whether non-compliance with this AD has been the subject of legal proceedings, or whether enforcement actions or penalties have been litigated, the necessary information is not present in the AD itself and must be sought in regulator enforcement records or judicial databases. The AD makes clear that the issue arose from a safety report of roller dislodgement and that the regulatory response included conversion of advisories into Service Bulletins and successive amendments, but it does not record any subsequent or contemporaneous litigation. (Background; Requirement; Compliance.)

This AD contains several concrete operational and administrative pitfalls that operators and maintainers should be alert to, as detailed in the text.

• Applicability nuance: The AD applies only to AS 355 versions E, F, F1, F2 and N equipped with sliding doors, and only to those aircraft that do not have "MOD 073287 and/or MOD 073290 or Eurocopter Service Bulletin No. 52.00.22 incorporated." That exclusion is a strict applicability gate; failing to confirm whether a given airframe has incorporated those mods or the service bulletin can lead to inappropriate application or non-application of the Requirement. The AD therefore forces a records-check as a threshold step.
• Document versioning: The Requirement refers specifically to "Eurocopter AS 355 Alert Service Bulletin No. 05.00.39 Revision 2.2", and the decision steps rely on paragraphs 2.B.1 and 2.B.2 of that Revision. Using an incorrect revision of the Service Bulletin risks inconsistent measurements or thresholds because Amendment 2 was issued "in response to a new EASA AD, which introduces a revision of the Requirement document." Operators must therefore ensure they use Revision 2.2 when performing the check required by this AD.
• Thresholds and measurement accuracy: The AD gives numeric thresholds (C1 ≥ 5 mm; C2 ≥ 1.5 mm) but does not include detailed measurement tolerances, measurement technique, or acceptable measuring instruments in the AD text itself; those details are in the referenced service bulletin (paragraph 2.B.1). Failure to follow the exact measurement method in the Service Bulletin may produce contested results affecting whether door operation is permitted. The AD does not define C1 and C2 in its text beyond referring to the Service Bulletin; misinterpretation of what constitutes C1 and C2 is therefore a practical risk.
• Timing oddity: The AD requires checks "Before further flight after 3 July 2002" though Amendment 2 is effective on 26 October 2006 and the signature date is 13 September 2006. Operators who did not act at the earlier date may have continued to operate without the check; the AD’s restatement of this initial compliance deadline means that the initial deadline remains binding even though the amendment itself is dated later. That temporal layering can confuse compliance audits or inspections that rely on the AD effective date alone.
• Placard specification gap: The AD requires "A placard specifying this restriction is to be affixed to the instrument panel of the helicopter." The AD does not prescribe the exact wording, formatting, size, location or language of the placard beyond these words. Operators must interpret what suffices as a compliant placard, or refer to the Service Bulletin or other regulatory guidance for placard standards. Absent clear instruction in the AD text, different operators might apply different placard conventions and face questions in audits.
• Operational and service impacts: If C1 or C2 fail to meet thresholds, door operation in flight is prohibited; the AD does not specify how to manage activities previously dependent on in-flight door operation (for example, certain aerial work tasks). That absence forces operators to devise alternative operational procedures or seek modifications or repairs consistent with airworthiness practices, and may create immediate service interruptions or route reductions.
• Recordkeeping, recurrency and tracking: The AD prescribes repeat inspections "thereafter at intervals not to exceed 100 flight hours." The AD itself does not specify the record-keeping method for demonstrating compliance with the 100 FH interval; operators must ensure their maintenance records and scheduling systems track this interval precisely. Failing to track flight hours accurately risks non-compliance.
• Limitation of remedial detail: The AD does not list explicit remedial actions beyond the placard and prohibition. For guidance on corrective maintenance, operators must consult the referenced Eurocopter Service Bulletin. If the Service Bulletin’s remedial measures are lengthy or require substantial parts/engineering work, operators face additional out-of-service time and costs that are not quantified in this directive.
• Cross-jurisdictional triggers: The AD explicitly notes EASA AD 2006-0249 and DGAC reporting as part of the chain of events prompting the AD. Operators that operate internationally must ensure their records reconcile the EASA AD, the manufacturer Service Bulletin and this national AD to avoid inconsistent actions between jurisdictions.

Operators and maintainers should therefore treat the AD as a rule plus an instruction to consult the specified Revision of the manufacturer Service Bulletin for all technical specifics and remedial steps, and must pay attention to modification status, Service Bulletin revision, measurement method, placard implementation, accurate flight-hour tracking, and potential operational substitutions if door operation is prohibited. (Applicability; Requirement; Compliance; Background.)

The AD prescribes a clear, stepwise compliance pathway when followed exactly as stated in the text:

1. Confirm applicability. Determine whether the airframe is an AS 355 version E, F, F1, F2 or N fitted with sliding doors, and verify whether MOD 073287, MOD 073290 or Eurocopter Service Bulletin No. 52.00.22 have been incorporated. If any of those modifications or that service bulletin have been incorporated, the aircraft is outside the AD’s stated applicability and this particular AD’s Requirement does not apply (Applicability).

2. Obtain and use the exact Service Bulletin revision. The AD mandates the checks "in accordance with paragraph 2.B.1 of Eurocopter AS 355 Alert Service Bulletin No. 05.00.39 Revision 2.2." Before performing measurements, obtain Revision 2.2 and review paragraphs 2.B.1 and 2.B.2 so that the measurement technique and definitions of C1 and C2 are applied exactly as intended (Requirement).

3. Perform the initial inspection before further flight after 3 July 2002 if the aircraft remained subject to the AD. The AD requires the check "Before further flight after 3 July 2002; and thereafter at intervals not to exceed 100 flight hours." Operators must have satisfied any outstanding initial checks required by earlier versions; the AD states that "The initial compliance time remains unchanged by this issue of the Directive." If the aircraft has already been inspected in accordance with the earlier requirement, document that compliance in maintenance records.

4. Measure C1 and C2 per paragraph 2.B.1. Using the measurement procedure in paragraph 2.B.1 of the specified Service Bulletin, measure the diameter of the sliding door roller and the dimension of the front end opening of the middle rail to derive values for criterion C1 and criterion C2. The AD’s Requirement identifies the two measures to be checked but delegates the precise measurement process to the Service Bulletin (Requirement).

5. Apply the decision rule in paragraph 2.B.2. If C1 ≥ 5 mm and C2 ≥ 1.5 mm, the AD permits door operation in flight. If C1 < 5 mm and/or C2 < 1.5 mm, the AD prohibits door operation in flight (Requirement). Where door operation is prohibited, proceed to step 6.

6. Affix the required placard if prohibition applies. The AD requires that "A placard specifying this restriction is to be affixed to the instrument panel of the helicopter." Affix the placard in a visible location on the instrument panel; ensure maintenance records document the placard installation and content. Because the AD does not prescribe exact placard wording, size or location beyond "instrument panel," operators should consult the Service Bulletin or applicable local guidance if they require specifics for audit compliance (Requirement).

7. Establish recurrent inspection scheduling. Once the initial compliance is satisfied, schedule and perform repeat checks at intervals not to exceed 100 flight hours. Maintain accurate flight-hour records to ensure inspections occur within the mandated interval. The AD explicitly states "and thereafter at intervals not to exceed 100 flight hours" (Compliance).

8. Document all actions and outcomes. Record the measurement values, the date of inspection, the identity and licence of the person performing the measurement, the action taken under paragraph 2.B.2 (permit/prohibit), the installation of any placard, and the scheduling of the next inspection within 100 flight hours. The AD itself does not specify the exact content of records, but those records will be the primary evidence of compliance in maintenance audits.

9. If remediation is needed, follow the Service Bulletin. If the measurements require door operation prohibition, or if the measurements indicate wear, consult the Eurocopter Service Bulletin (and any associated instructions or corrective actions) for repair or replacement procedures to restore the dimensions to acceptable criteria. The AD does not specify the repair steps; it requires measurement-based decisions and references the Service Bulletin for technical content (Requirement).

10. Monitor for further regulatory action. The AD notes alignment with EASA AD 2006-0249 and the issuance of amendments. Operators should monitor for any further amendments, revisions of the Service Bulletin or related EASA/CASA directives that could change measurement methods, thresholds, remediation options, or applicability.

In short, compliance requires verification of applicability, use of the exact Service Bulletin Revision 2.2 measurement method, strict application of the two numerical thresholds (C1 and C2), placarding where prohibited, and re-inspection at intervals not to exceed 100 flight hours. The AD does not itself specify placard text, measurement tolerances beyond the thresholds, or remedial steps beyond the Service Bulletin; operators must therefore rely on the Service Bulletin for technical details and on their own maintenance and record-keeping systems to evidence compliance. (Applicability; Requirement; Compliance; Background.)