AD/AS 355/64 Amdt 1 - Main Servocontrol Rods

The Directive operates on a small set of aviation-safety mechanisms: component identification, mandatory inspection, mandatory removal/replacement, and a prohibition on future installation of identified parts. The principal objects are "main servocontrols" and also tail servocontrols; the safety concern is a "manufacturing defect" in a batch of main servocontrol rods, the failure of which "will lead to loss of control of the helicopter" (Background). The AD therefore treats the identified servocontrols as an immediate airworthiness risk.

Key definitional and operational concepts in the text are these.

• Applicability by aircraft and parts. The AD is explicitly limited to AS 355 helicopters of specified versions and to servocontrols listed in Table 1 and Table 2. The two tables set out affected TRW-SAMM part numbers and detailed serial number lists and ranges. Table 1 highlights P/N SC 5083 and SC 5084 with particular serial-number ranges; Table 2 expands the list to include SC5081-1, SC5082-1, SC5083, SC5084, SC5071-1 and SC5072 with enumerated serial numbers. The tables include single serial numbers, numbers with letter suffixes such as "M", leading-zero serial formats like "045", and ranges (for example "1150 to 1155"). The tables also explicitly exclude part numbers containing a "V" suffix from the listed entries (see Note 1).

• Identification plate and suffix "V". Note 1 states: "Servocontrols that have been checked or reconditioned by TRW-SAMM and are identified by a letter 'V' engraved to the right of the part number on the identification plate." The tables, as structured, list only part numbers without the "V" suffix, which means reconditioned items carrying the "V" should not appear in the tabulated lists. The AD does not itself say that a "V" suffix restores airworthiness or that a "V" part is automatically compliant; it only defines the marking and distinguishes the tabulated entries as those "without the suffix 'V.'"

• Differentiated compliance timing. The AD splits actions into immediacy tiers. Requirements 1 and 2 are paired with Compliance items 1 and 2 requiring action "before further flight." Those provisions apply respectively to the initial check (Requirement 1) and to replacement of servocontrols listed in Table 1 (Requirement 2). Requirement 3, dealing with parts listed in Table 2, carries a longer compliance window of 550 flight hours or 24 months after the directive's effective date (Compliance 3). Requirement 4 prohibits installation of listed servocontrols from the effective date (Compliance 4). The three-tier timing approach is the AD's mechanism for prioritising higher immediate risk and giving a measured phase-out for additional affected parts.

• Replacement standard. The replacement requirement is framed by exclusion rather than prescription. Requirements 2 and 3 require that affected servocontrols be "replaced with servocontrols not listed in Table 1 or Table 2." The AD therefore prohibits re-installation of any part matching the table entries but does not specify an approved replacement P/N or supplier within the text. Compliance thus requires operators to procure and install parts whose P/N and serial numbers are not in the tables.

• Administrative provenance and reference. The AD is issued under subregulation 39.1(1) of CASR 1998 and references a foreign airworthiness authority AD, DGAC AD 2003-100(A), in Note 2. The Background paragraph explains the factual basis as a detected manufacturing defect and an expanded discovery prompting the amendment. The AD records dates for original issue and for this amendment and bears the signature of the CASA delegate.

These concepts combine identification precision with mandatory remedial action and a clear prohibition on use of the specified parts. The directive leverages serial-number-level specificity to limit the set of affected components, and it distinguishes between immediate replacements and those that may be scheduled within a specified flight-hours/time window.

The primary legal and operational targets of this AD are operators and owners of Eurocopter AS 355 series helicopters, versions E, F, F1, F2 and N, when those helicopters are fitted with the servocontrols listed in Table 1 or Table 2. The Applicability clause reads: "All AS 355 helicopters, versions E, F, F1, F2 and N, fitted with main and tail servocontrols listed in Table 1 and Table 2 of this Directive." That identifies both the airframes and the installed parts that bring an aircraft within scope.

From an organisational standpoint the AD affects several actor groups:

• Aircraft operators and owners. They must check their fleet (Requirement 1) and, when applicable, perform the required replacements within the specified timeframes (Requirements 2 and 3). The actions required "before further flight" for Table 1 items create immediate operational consequences for affected aircraft.

• Maintenance organisations and certifying engineers. Those who inspect, remove, and replace servocontrols will be responsible for identifying the P/N and serial numbers on the identification plates, confirming whether a "V" suffix is present, and ensuring replacements are not from the listed parts. Maintenance providers will carry out the physical work and must track compliance times (for example counting flight hours toward the 550-hour limit for Table 2 parts).

• Parts suppliers and manufacturers. The mention of TRW-SAMM as the maker of the listed servocontrols and the identification of a reconditioning mark "V" on parts implies that TRW-SAMM and its authorised reconditioners are directly implicated. Suppliers of replacement servocontrols will experience demand from operators needing "servocontrols not listed in Table 1 or Table 2." Those suppliers must ensure their part numbers and serial ranges are not in the prohibited lists.

• Regulatory administrators. CASA's delegate issued the Directive under subregulation 39.1(1) of CASR 1998 and is the administrative decision maker recorded in the text. The AD was notified in the Commonwealth of Australia Gazette, which is the public administrative record. The directive also cross-references DGAC AD 2003-100(A), signalling that foreign-certification issues and international coordination may be relevant.

Who pays. The AD text does not quantify costs, but the prescriptive requirements impose direct costs on aircraft operators and owners for inspection, parts replacement, and maintenance labour. Replacement parts must be "servocontrols not listed in Table 1 or Table 2," which ordinarily implies procurement of alternative (and presumably compliant) components. Maintenance organisations will perform labour and manage scheduling; parts suppliers who can provide acceptable replacements will capture sales. The AD does not specify funding or compensation mechanisms.

Who decides. The AD itself is the decision instrument: the CASA delegate revokes the prior AD and issues the amendment under the cited regulation. Practically, operators decide when and how to schedule the required work within the compliance windows, subject to the mandatory timeline constraints in the AD. Maintenance organisations and parts suppliers decide on sourcing and verification procedures to ensure replacements are not among the listed parts. CASA maintains administrative authority by issuing the AD; however the text does not spell out enforcement processes or penalties within its four corners.

Behavioural change. Operators must alter procurement, maintenance, and installation behaviour to avoid installing any servocontrols listed in the tables from the effective date. They must also prioritise replacement for Table 1 items before further flight, and plan removal of Table 2 items within the 550 flight hours or 24 month window. Maintenance providers must verify identification plates and record the relevant P/N and serial number information to demonstrate compliance.

The Directive frames explicit duties for affected parties and contains implicit rights by omission. The text organises mandates under "Requirement" and "Compliance" headings; those form the primary legal duties.

Key duties

• Inspect for listed servocontrols: Requirement 1 requires checking "whether any of the servocontrols listed in Table 1 and Table 2 of this Directive are installed on the aeroplane." Compliance 1 ties this check to an immediacy requirement "Before further flight." The duty to inspect is immediate.

• Replace Table 1 servocontrols: Requirement 2 requires replacement of any servocontrols listed in Table 1 "with servocontrols not listed in Table 1 or Table 2." Compliance 2 demands that replacement occur "Before further flight." This duty is both absolute and urgent for any aircraft found to have Table 1 items installed.

• Replace Table 2 servocontrols: Requirement 3 requires replacement of any servocontrols listed in Table 2 with servocontrols not listed in Table 1 or Table 2. Compliance 3 provides the replacement window: "Within 550 flight hours or 24 months, whichever occurs first, after the effective date of this Directive." This creates a scheduled phase-out for Table 2 parts.

• Prohibition on installation: Requirement 4 states "Do not install any servocontrols listed in Table 1 or Table 2 of this Directive." Compliance 4 reiterates: the prohibition applies "From the effective date of this directive." This duty constrains future procurement and maintenance choices.

• Identification checking duty: Implicit in the replacement duties is the need to verify part numbers and serial numbers on the component identification plate and to note any "V" suffixes because the tables are stated to list part numbers "without the suffix 'V'" (Note 1). Practically, an installer has a duty to verify the exact plate marking.

Rights and procedural scope

• Choice of replacement part: The AD prescribes replacements only by exclusion. It does not specify a particular approved part number or supplier. The duty is to replace with servocontrols not listed in the tables. Thus, within the AD's text, operators have the right to choose replacement parts so long as those parts are not in Table 1 or Table 2.

• Reconditioned parts identification: Note 1 defines the "V" suffix marking for parts "checked or reconditioned by TRW-SAMM." The AD does not explicitly state that a "V" part is compliant, nor does it mandate that a "V" part is unacceptable. It only defines what the "V" marking means and distinguishes listed entries as "without the suffix 'V.'" The practical implication is that a reconditioned part bearing a "V" will not match a table entry that lists the same part number but without "V." The AD therefore leaves operators the ability to consider and use parts with the "V" suffix, subject to their airworthiness and any other regulatory constraints external to the AD.

• No procedural notification required in text: The AD sets inspection and replacement duties and timing but does not, within its own text, require operators to notify CASA upon completion. The absence of a notification requirement in the AD means that, as drafted, compliance is about completing the listed acts rather than reporting them to CASA in a prescribed manner. This does not preclude other regulatory requirements under CASR or operator continuing airworthiness obligations that may require recordkeeping, but such requirements are not contained in the AD text itself.

Verification and proof

• Operators and maintenance organisations will need to keep records to demonstrate compliance in practice because the AD mandates actions tied to flight-readiness and flight hours. The AD binds actions to the aircraft's ability to fly: two of the Requirements are linked with "Before further flight." Those words functionally convert the replacement duty into a pre-flight prerequisite that operators must demonstrate is satisfied before resuming flights.

Limits of duties in the AD

• The AD does not itself quantify penalties, nor does it prescribe which alternative part numbers are acceptable. It also does not describe an administrative appeal or objection process within the text. It does, however, operate under the regulatory authority of subregulation 39.1(1) of CASR 1998, which is the statutory channel the delegate used to issue the Directive.

In sum, the Directive imposes immediate inspection and replacement duties for a subset of identified servocontrols, forbids further installations of listed components, and leaves parties able to choose non-prohibited replacement parts.

The AD text itself does not set out fines, criminal penalties, or specific enforcement procedures. Its legal force is evident in its issuance under subregulation 39.1(1) of the Civil Aviation Safety Regulations 1998, which is cited at the front of the document as the statutory authority for CASA's issuance of the Directive. The AD records administrative steps: revocation of the earlier AD (AD/AS 355/64), issuance of this Amendment, signature by the CASA delegate and publication notification in the Commonwealth of Australia Gazette on 9 May 2003.

What the AD states

• Authority. The AD is issued "under subregulation 39.1 (1) of CASR 1998," which provides the administrative legal basis for the delegate's action. The AD identifies the delegate and includes a signature block (Jim Coyne, Delegate of the Civil Aviation Safety Authority 6 May 2003).

• Mandatory nature. The Requirement and Compliance sections use imperative language: "check", "replace", and "Do not install." The Compliance deadlines are explicit, including "Before further flight" for immediate items and "Within 550 flight hours or 24 months" for others. Those features combine to create mandatory obligations for affected parties.

What the AD does not state

• The AD does not specify penalties or direct enforcement mechanisms such as infringement notices or criminal sanctions in the text. It does not prescribe how CASA will audit or validate compliance, nor does it describe a reporting obligation back to CASA upon completion.

Consequences implicit from the AD’s form

• Operational consequence. For items covered by Requirements 1 and 2, the Compliance schedule "Before further flight" creates an operational constraint. Failure to perform the mandated inspection and, if necessary, replacement would mean that an aircraft remains in a non-compliant state relative to the AD; the AD frames required actions as prerequisites to further flight for certain parts.

• Administrative enforcement rests with the issuing regulator. The AD is an instrument of CASA and recorded in the Commonwealth Gazette; enforcement and any penalties for non-compliance would, as a matter of administrative practice and statutory regime, be addressed under the broader CASR enforcement framework and CASA's compliance processes rather than within the AD's four corners. The AD provides the normative mandate; the statutory and regulatory enforcement apparatus outside the AD is the mechanism by which CASA would act.

Cross-reference to other instruments

• The AD refers to DGAC AD 2003-100(A) in Note 2. The mention suggests cross-jurisdictional coordination with the French Directorate General for Civil Aviation, but the AD text does not convert that reference into an enforcement mechanism within Australia. It remains an informational cross-reference.

Practical enforcement implication for operators

• Operators must treat the AD's Requirements and Compliance times as mandatory tasks because the AD is an official CASA instrument, published and dated, and tied to airworthiness and flight safety. The immediate "Before further flight" requirements create a need to ground an aircraft for inspection and possible replacement until the AD's conditions are met. While penalties are not spelled out in the AD, the combined effect of the directive and the statutory authority under which it is issued is that failure to comply will place an aircraft and its operator outside the AD's mandated state of airworthiness.

In short, the AD sets clear mandatory duties but leaves the specifics of enforcement responses and sanctions to the statutory enforcement regime of CASR and CASA practices, which are not detailed in the AD text.

The AD expressly situates itself within the Civil Aviation regulatory framework and references an overseas airworthiness authority. The interaction points are limited to what the AD records.

Statutory authority and administrative family

• The AD is issued under subregulation 39.1(1) of the Civil Aviation Safety Regulations 1998. That citation situates the AD within the statutory and regulatory framework that gives CASA authority to issue airworthiness directives. The AD’s text records that it "revokes Airworthiness Directive (AD) AD/AS 355/64 and issues the following AD under subregulation 39.1 (1) of CASR 1998." That revocation and reissuance operation is an administrative instrument action within the CASR framework.

Interaction with previous ADs

• The Directive explicitly revokes the prior AD/AS 355/64 and replaces it with the amendment (Amdt 1). The AD records that "This Amendment becomes effective on 9 May 2003" and that "This original issue of this Directive became effective 3 December 2001." The revocation and replacement mechanism is directly part of how the AD interacts with existing regulatory instruments affecting the same airframe and components.

Cross-jurisdictional reference

• Note 2 states "DGAC AD 2003-100(A) refers." That reference ties the Australian action to a DGAC (French Directorate General for Civil Aviation) AD. The AD does not enact DGAC law in Australia; it records a cross-reference and, by including the foreign AD in the note, signals that the Australian regulator is aware of and responding to the foreign authority’s directive or findings. The AD text does not elaborate mechanisms of mutual recognition, nor does it specify that compliance with the DGAC AD satisfies the Australian directive.

Airworthiness and certification regimes

• The AD requires replacement with servocontrols "not listed" in the tables but does not specify approved replacement parts, nor does it state how replacement parts must be certificated or approved. The AD thus interacts in practice with suppliers, parts certification processes, and continuing airworthiness obligations, but those processes are not set out in the AD itself.

Recordkeeping, maintenance and operational law

• While the AD contains mandatory tasks and timing, it does not specify recordkeeping or administrative filings. Those tasks will interact with operators’ general continuing airworthiness responsibilities and maintenance-release obligations under the broader CASR regime. The AD does not itself impose a separate reporting requirement within its text.

Limit of interaction statements within the AD

• The AD does not reference other Australian legislative instruments, criminal penalties, or administrative enforcement steps. It does not specify appeals, variation procedures, or exemptions. Any interaction with other legal rules,such as inspection, maintenance, procurement, import/export control of parts, or enforcement,must be inferred as engagement with the broader CASR regulatory regime and usual aviation regulatory practice, but the AD's text limits itself to stating the mandatory airworthiness actions and their timing.

In sum, the AD is a CASA airworthiness instrument that operates under CASR subregulation 39.1(1), replaces an earlier AD, and cross-references a DGAC AD. The document itself does not set out the broader procedural or enforcement machinery, but it integrates into the larger web of airworthiness regulation by imposing specific compliance duties on operators and maintainers within the statutory framework.

This AD document contains its own minimal amendment history within the text. The following items are explicit in the source:

• Original AD effective date. The AD states "This original issue of this Directive became effective 3 December 2001." That records the initial issuance of AD/AS 355/64.

• Reason for amendment. The Background paragraph explains the original directive was prompted by detection of "a manufacturing defect... in a batch of rods of the main servocontrol," and that the failure of the rod "will lead to loss of control of the helicopter." The present amendment (Amdt 1) was prompted by "additional defects being discovered in servocontrols with additional part numbers and serial numbers." The amendment therefore expands the set of affected parts beyond the original list.

• This amendment effective date. The text states "This Amendment becomes effective on 9 May 2003." It also records the delegate's signature dated 6 May 2003 and notification in the Gazette on 9 May 2003.

• Revocation of prior AD. The front matter declares that the CASA delegate "revokes Airworthiness Directive (AD) AD/AS 355/64 and issues the following AD under subregulation 39.1 (1) of CASR 1998." The revocation and reissuance indicate that this instrument replaces and supersedes the prior Directive, rather than simply amending it in place.

• Amendment scope. The amendment expands Table 1 and Table 2 entries to include additional part numbers and serial numbers. Table 1 lists P/N SC 5083 and SC 5084 with specific serial-number ranges. Table 2 carries a much larger enumeration, covering SC5081-1, SC5082-1, SC5083, SC5084, SC5071-1 and SC5072 with individual serial numbers and ranges. Note 1 clarifies that the tables list parts "without the suffix 'V'."

• Administrative formalities. The AD records the delegate's signature: "Jim Coyne, Delegate of the Civil Aviation Safety Authority 6 May 2003." It also records that "The above AD is notified in the Commonwealth of Australia Gazette on 9 May 2003." Those entries are the formal administrative milestones for amendment issuance and notification.

What is not in the AD’s amendment history

• The AD does not include a detailed change log showing exactly which serial numbers or part numbers were added or removed relative to the original AD issued in December 2001. It does not reproduce the prior AD text or highlight the delta between the original and amended tables in a side-by-side fashion. The AD's narrative simply states that this amendment is prompted by discovery of "additional defects being discovered in servocontrols with additional part numbers and serial numbers."

• The AD does not provide a timeline of follow-on amendments beyond Amdt 1. The document ends with the effective date of the amendment and the notification statement.

Practical relevance of the amendment history

• Operators and maintainers must treat this AD as a statutory update replacing the pre-existing Directive. The replacement means that compliance must be gauged against the amended tables and requirements that are effective from 9 May 2003 rather than the earlier December 2001 version. Where an operator relied upon the earlier AD's content, they must now check the amended tables and the updated compliance timing (notably the immediate "before further flight" requirement for Table 1 parts and the 550-hour/24-month window for Table 2).

In short, the AD records a straightforward amendment history: original AD effective 3 December 2001; discovery of more defects led to the issuance of Amdt 1 effective 9 May 2003; the amendment revokes the prior AD and expands the set of affected servocontrols. The AD contains the delegate's signature and Gazette notification as formal closure of the amendment process.

The AD document itself contains no litigation history, court decisions, appeals, or references to judicial proceedings. The only legal-administrative citations contained within the text are the statutory authority under which the AD is issued, subregulation 39.1(1) of CASR 1998, and a foreign airworthiness directive reference, DGAC AD 2003-100(A). There are no case names, court orders, or litigation narratives in the AD.

What the AD records

• Administrative issuance record. The AD bears the signature of the CASA delegate and a notification date in the Commonwealth of Australia Gazette. These entries are administrative steps that create an official public record. Those steps may form the basis for any later administrative or judicial review, but the AD does not reveal whether any such reviews occurred.

• Revocation of prior AD. The AD revokes the previous AD/AS 355/64 and replaces it. The text does not indicate whether the prior AD was the subject of any challenge or whether the revocation was in response to compliance difficulties. There is no discussion of disputes, compliance disputes, or enforcement proceedings.

Implication for researchers and litigators

• Absence of litigation indicators. Because the AD contains no litigation references, one cannot, from the AD text alone, identify any specific legal challenges, precedential rulings, or court interpretations related to this Directive. Any litigation history would need to be located in external records such as court databases, administrative law reviews, CASA enforcement records, or industry publications that record legal challenges. The AD does not provide those materials or refer to them.

• Administrative record as evidence. The AD’s publication in the Commonwealth Gazette and the delegate's signature create a formal record that could be used in any subsequent administrative or judicial proceedings. If a party were to challenge the AD's validity or its application, the Gazette notice and the AD text would be primary documentary evidence of the regulator's action and the directive's content and effective date.

Limitations on what can be inferred

• The AD does not describe any enforcement action taken against an operator or any remedial action beyond the replacement mandate. It does not describe settlements, prosecutions, or civil claims arising from the defective servocontrols. Any mention of legal liability, damages, negligence, or product liability is absent from the text and would be outside the AD's scope.

In short, the AD includes no litigation history. Researchers seeking to determine whether the AD prompted or was the subject of disputes must consult external legal records or CASA enforcement archives; the AD itself contains only the administrative instrument and its formal issuance details.

Operators, maintenance organisations and parts suppliers need to pay attention to precise drafting and practical traps that can cause non-compliance or operational disruption. The AD’s specificity is helpful for targeting, but it also creates several practical "gotchas" that require attention to detail.

1. Exact matching of part numbers and serial numbers

• The tables list P/Ns and serial numbers with mixed formats: leading zeros (for example "045"), letter suffixes (for example "43M", "347M", "289M"), and ranges (for example "1150 to 1155" or "682 to 721"). Failure to match the component plate exactly against the table entries risks mistaken inclusion or exclusion. The AD’s Requirement 1 obliges a check "whether any of the servocontrols listed in Table 1 and Table 2 of this Directive are installed." That is an exact-match task. Practically, maintenance staff must read identification plates carefully and reconcile formatting differences.

2. The "V" suffix distinction

• Note 1 clarifies that the tables list part numbers "without the suffix 'V'" and defines "V" as an engraving indicating the unit "have been checked or reconditioned by TRW-SAMM." A servocontrol bearing the same base part number but with a "V" engraved will not match the tabulated entries as written. This creates two possible traps. First, staff might mistakenly assume any appearance of a listed part number renders the unit immediately prohibited; they must verify whether a "V" is present. Second, the AD does not state that a "V" part is automatically acceptable airworthiness-wise; the Directive simply distinguishes the marking. Operators should verify reconditioned items meet airworthiness requirements through standard continuing airworthiness processes outside the AD text.

3. Immediate grounding potential

• Requirements 1 and 2 must be complied with "Before further flight." If an operator finds a servocontrol listed in Table 1 installed, the AD requires replacement before continuing flight. That effectively grounds the aircraft until a suitable replacement is fitted. Operators must plan for parts availability and logistics because a lack of immediately available replacement parts can cause operational disruption.

4. Replacement constraint is by exclusion, not by prescription

• The AD requires replacement "with servocontrols not listed in Table 1 or Table 2." It does not identify approved replacement P/Ns or vendors inside the AD. That leaves operators to source replacement parts and to ensure their documentation proves the replacement is not among the prohibited items. Without a specified approved part, operators must exercise procurement diligence to avoid installing a part that unknowingly appears on the lists.

5. Tail servocontrols included in Table 2

• Table 2 heading includes "Main and tail servocontrols" and enumerates serials for multiple part numbers. Some operators might focus only on main servocontrols and miss tail units listed in Table 2. The Requirement 1 inspection must therefore include both main and tail servocontrols that match the part numbers and serial numbers.

6. Flight-hour counting and the 550 FH/24-month window

• For Table 2 items, replacements must occur "Within 550 flight hours or 24 months, whichever occurs first, after the effective date of this Directive." Operators must accurately track flight hours from the effective date, not from discovery or installation date, and be able to demonstrate compliance. Miscounting hours or misapplying the "whichever occurs first" rule can lead to late replacement.

7. Prohibition on installation from the effective date

• Requirement 4 states "Do not install any servocontrols listed in Table 1 or Table 2 of this Directive," with Compliance 4 reading "From the effective date of this directive." That requires changes to procurement and stock-control procedures immediately as of 9 May 2003. Parts held in inventory that match the listed items cannot be installed after that date.

8. Serial numbers may include letter suffixes and ranges that overlap

• The tables include lettered suffixes like "M" and have ranges that could overlap with serials in operator inventories. Interpreting ranges and suffixes requires careful reading of the tables to avoid either overinclusive removals or overlooking affected items.

9. Cross-reference to DGAC AD

• Note 2 says "DGAC AD 2003-100(A) refers." That suggests a parallel foreign directive exists. Operators should check that DGAC item as a cross-check but must not assume compliance with DGAC AD automatically satisfies Australian obligations because the AD itself is the governing instrument for Australian-registered aircraft.

10. Recordkeeping and proof of compliance

• The AD does not itself prescribe a notification process to CASA on completion. Nevertheless, inspectors or auditors may request evidence of the checks and replacements. Operators should prepare contemporaneous documentation: identification plate photos, maintenance release entries, part-number and serial-number documentation for replacements, and flight-hour logs for timing compliance.

In short, the combination of exact serial-number lists, the "V" suffix nuance, immediate pre-flight replacement mandates for Table 1 items, and a non-prescriptive replacement requirement create several potential operational pitfalls that must be managed through disciplined parts identification, procurement control, and maintenance recordkeeping.

The Directive sets out a clear, limited set of actions and timings. Below is a practical compliance checklist that stays within the AD's instructions and aligns with the specific language in the Requirement and Compliance sections.

Step 1 , Identify affected airframes

• Confirm whether the aircraft is an AS 355 helicopter of version E, F, F1, F2 or N. The AD's Applicability clause identifies those models as the scope. If the airframe is outside that set, the AD's requirements do not apply as written.

Step 2 , Inspect installed servocontrols immediately

• Perform the inspection mandated by Requirement 1 "whether any of the servocontrols listed in Table 1 and Table 2 of this Directive are installed on the aeroplane." Compliance 1 requires that check "Before further flight." Under this step:
  • Physically examine the identification plate on each main and tail servocontrol and note the exact part number and serial number as engraved.
  • Pay attention to formatted serial entries: leading zeros, letter suffixes such as "M," and ranges in the tables.
  • Check for a "V" suffix engraved to the right of the part number, which Note 1 defines as indicating the unit "have been checked or reconditioned by TRW-SAMM." Remember that the tables list P/Ns without the "V" suffix.

Step 3 , Act on findings for Table 1 items (immediate)

• If any servocontrol matching Table 1 is installed, Requirement 2 mandates replacement "with servocontrols not listed in Table 1 or Table 2." Compliance 2 requires this "Before further flight." That implies:
  • Do not operate the aircraft until the replacement is installed and the aircraft is released as airworthy by the certifying maintenance organisation.
  • Source a replacement part whose part number and serial number are not among Table 1 or Table 2 entries. Confirm the replacement's identification plate to ensure it is not on either list.
  • Document the replacement in the aircraft maintenance log and retain photographic evidence of the old and new identification plates where practical.

Step 4 , Schedule and complete replacements for Table 2 items

• If any servocontrol matching Table 2 is installed, Requirement 3 requires replacement "with servocontrols not listed in Table 1 or Table 2" within 550 flight hours or 24 months, whichever occurs first, after the AD’s effective date. To comply:
  • Start counting flight hours for the affected aircraft from the effective date of the Directive, which the AD records as 9 May 2003.
  • Plan maintenance windows to complete replacement well before the 550 flight hour or 24 month trigger. Avoid last-minute scheduling that risks non-compliance.
  • Verify replacement parts against Table 1 and Table 2 to ensure they are not listed.
  • Keep maintenance records, invoices, and identification-plate photos to evidence timely replacement.

Step 5 , Do not install listed servocontrols

• Requirement 4 and Compliance 4 prohibit installing any servocontrols listed in Table 1 or Table 2 "From the effective date of this directive." To operationalise that:
  • Update procurement and stock-control processes to flag and quarantine any inventory matching the listed part numbers and serial numbers.
  • Brief maintenance teams that installation of any listed servocontrols is prohibited from the effective date.
  • Ensure contractors and third-party MRO providers are aware of the prohibition.

Step 6 , Manage parts with a "V" suffix carefully

• Note 1 distinguishes reconditioned parts with a "V" suffix from the tabulated entries. Practically:
  • If a part has the same base part number as a tabulated entry but shows a "V" suffix, it will not match the table entries verbatim because the tables list P/Ns "without the suffix 'V'." Record and verify the reconditioned part’s plate and any supporting TRW-SAMM reconditioning documentation.
  • Confirm via standard continuing airworthiness checks that any reconditioned unit meets airworthiness requirements before installation. The AD does not declare a "V" part automatically compliant; it merely identifies the marking.

Step 7 , Documentation and audit trail

• The AD does not prescribe reporting back to CASA, but good practice and likely regulatory expectation is to maintain an audit trail. For each affected aircraft, retain:
  • The inspection record verifying P/Ns and serial numbers.
  • Photographic evidence of identification plates before and after replacement.
  • Maintenance release forms and invoices for replacement parts.
  • Flight logs that substantiate hours counted toward the 550-hour limit for Table 2 items.

Step 8 , Cross-check DGAC AD

• Note 2 says "DGAC AD 2003-100(A) refers." It is prudent to consult the referenced DGAC AD for technical detail or additional recommendations, but compliance with the Australian AD is governed by this instrument. Use the DGAC reference as ancillary technical information rather than as a substitute for meeting Australian compliance dates.

Step 9 , Update continuing airworthiness and procurement controls

• Amend parts procurement specifications and stock records to prevent inadvertent installation of prohibited parts. Ensure MRO contracts and work orders require confirmation that replacement parts are not among the Table 1 or Table 2 lists.

Step 10 , Plan for operational disruption and costs

• For Table 1 replacements, expect immediate aircraft downtime until a compliant replacement is fitted. For Table 2 parts, schedule replacements at maintenance intervals consistent with the 550 FH/24 month limit. Budget for parts acquisition and labour; the AD does not allocate funding or compensation.

Following these steps implements the AD's Requirements and Compliance provisions as written. The AD gives operators latitude in choosing replacement parts so long as those parts are not in Table 1 or Table 2; accordingly, source verification and documentation are critical to demonstrate that replacements satisfy the AD’s exclusionary criterion.