AD/ECUREUIL/108 - Tail Servo-Control

The Directive operates through a combination of applicability filters, prohibitions, mandated compliance with an external technical document, and time‑limited compliance windows. Its principal concepts are applicability, prohibition, inspection to an external technical standard, bench testing, removal and replacement, spare part control, and regulatory referencing.

Applicability. The AD is narrowly targeted. It captures AS 350 B3 helicopters only where the tail servo‑control fitted is a GOODRICH P/N SC5071‑XX or SC5072, but excludes specific SC5072 serial numbers, units overhauled or repaired under a named Service Bulletin, and units never removed since delivery. The precise exception language requires checking serial numbers and maintenance history before the AD’s requirements apply to a particular servo‑control.

Prohibition. The AD establishes a specific operational prohibition: intentional autorotation flight is prohibited until the check of the tail servo‑control is accomplished in accordance with paragraph 2.B.2 of the AT (Requirement 1). That makes an operational restriction conditional on a technical inspection, converting a safety concern into an immediate constraint on flight training and deliberate autorotation manoeuvres.

External normative reference. The substantive inspection, bench check and remedial actions are not set out in the AD itself. Instead the AD mandates compliance with Alert Telex Eurocopter AS 350 No 67.00.30 or later DGAC approved revision, and with specific paragraphs within that AT (for example 2.B.2 and 2.B.6). This means the detailed procedure, acceptance criteria and bench test methods are delegated to the content of the Alert Telex, which the AD incorporates by reference.

Differentiated procedures. Requirement 2 distinguishes helicopters fitted with Automatic Flight Control System from those without, directing compliance with paragraph 2.B.2.a or 2.B.2.b of the AT as appropriate. This recognises that different aircraft configurations require different inspection or operational responses.

Bench testing and removal. The AD requires bench checks of in‑service and spare servo‑controls per paragraph 2.B.6 of the AT, and removal from service where non‑compliance is found, with installation of a compliant unit per paragraph 2.B.2 of the AT. This creates a maintenance workflow: inspect, bench test, remove non‑compliant units, install compliant replacements.

Temporal staging. The AD sets different compliance timeframes: the prohibition (Requirement 1) is effective from the AD’s effective date, the main inspection (Requirement 2) is to be completed within 50 hours time in service from the effective date, removal/replacement (Requirement 3) must be done before further flight after Requirement 2, and spare checks must be done before installation (Requirement 4). The AD thus imposes an immediate operational restriction, a near‑term inspection window, and pre‑installation controls.

Regulatory cross‑reference. The AD refers explicitly to the Direction Générale de l’Aviation Civile (DGAC) form AF UF‑2004‑196 and notes EASA approval 2004‑12557. The document therefore indicates transnational regulatory interaction in both the technical standard and approval record, while the operative instructions remain as stated in the AD and the Alert Telex it references.

The primary affected parties are operators and owners of Eurocopter AS 350 B3 helicopters that have GOODRICH tail servo‑controls with P/N SC5071‑XX or SC5072, maintenance organisations that service those helicopters, and the holders of spare stock of the same servo‑controls. The Directive’s applicability clause defines the universe of hardware and aircraft to which the requirements apply, and the exception categories require operators and maintenance providers to check serial numbers and maintenance history for determination.

Operators and owners. Operators must identify whether their AS 350 B3 helicopters are fitted with the named Goodrich servo‑controls. If so, and if the unit does not fall within the listed exceptions, the operator must enforce the prohibition on intentional autorotation flight, arrange the required inspections and bench checks, and ensure removal of non‑compliant units. The timing requirements mean owners or operators face possible scheduling and operational disruption within a 50 hours time in service window from the effective date.

Maintenance organisations. Maintenance providers responsible for inspections and bench checks must obtain and follow Alert Telex Eurocopter AS 350 No 67.00.30 or its later DGAC approved revision. The AD mandates bench testing in accordance with paragraph 2.B.6 of that AT. Maintenance organisations will need access to the AT, test benches or test procedures, and the capability to identify the exact servo‑control part numbers and serial numbers, and to determine whether units have been overhauled or repaired under the specified Service Bulletin.

Spare parts holders and installers. Requirement 4 requires that spare tail servo‑controls be checked in accordance with paragraph 2.B.6 of the AT before installation on a rotorcraft. Hence entities holding spares, including parts suppliers and maintenance shops, must organise bench checking before fitting a spare unit.

Pilots and training organisations. The prohibition on intentional autorotation flight until the required checks are completed directly affects flight training syllabi, recurrent training and pilot practice that rely on intentional autorotation manoeuvres. Training organisations operating affected helicopters will need to either ground that portion of training on impacted airframes until compliance, or use alternate aircraft not captured by the AD. The AD does not list approved substitutes, it simply prohibits intentional autorotation until the check described in the AT is accomplished.

Regulator and certifying authority. The AD is issued under the Australian Civil Aviation Safety Authority (signature by delegate David Punshon is present). The DGAC and EASA references indicate that the technical material and approval originated overseas, but the operative instrument is a CASA Airworthiness Directive and therefore directly affects Australian operations of the named aircraft types.

Third parties. Less directly, insurers, lessors and air operator certificate holders with affected aircraft will be interested because the AD imposes operational and maintenance obligations that can affect availability of aircraft and potentially risk allocation under lease and insurance arrangements. The AD itself does not address contractual relationships, but parties with responsibilities for aircraft airworthiness must ensure compliance.

The Directive delineates specific duties for operators, maintenance organisations and those installing parts, and it also establishes a limited conditional operational right structure tied to completion of inspections and remedial action. The AD’s operative duties and conditional rights are drawn from the Requirements 1-4 and the applicability exceptions.

Duties

• Prohibition duty: Requirement 1 imposes an immediate duty on operators to prohibit intentional autorotation flight until the check is accomplished in accordance with paragraph 2.B.2 of the Alert Telex. This is a precondition to the right to resume intentional autorotation.

• Inspection duty: Requirement 2 mandates that the specified checks be carried out in accordance with Alert Telex Eurocopter AS 350 No 67.00.30 or later DGAC approved revision. The duty is to follow the AT procedures, and the AD splits the inspection instruction depending on whether the helicopter is fitted with an Automatic Flight Control System. The AD does not set the technical steps itself, it requires compliance with the external AT.

• Removal and replacement duty: Requirement 3 obliges the operator or maintenance provider to remove from service any servo‑control found non‑compliant by the bench check (per paragraph 2.B.6 of the AT) and to install a compliant tail servo‑control according to paragraph 2.B.2 of the AT. The timing is explicit: this replacement must be done before further flight after accomplishing Requirement 2.

• Spare control duty: Requirement 4 requires checking spare tail servo‑controls per paragraph 2.B.6 of the AT before installation on a rotorcraft. This imposes a duty on parts custodians and installers to bench check spares prior to installation.

• Applicability assessment duty: The AD implicitly requires duty bearers to determine applicability. Parties must check the part number and serial number and the service history of servo‑controls against the exception criteria. That obligation is practical: the AD applies only where the servo‑control is of the listed P/N and not within an exception.

Conditional rights

• Right to conduct intentional autorotation: The right to conduct intentional autorotation is conditional. Until the check required by paragraph 2.B.2 of the AT is completed, intentional autorotation flight is prohibited. Completion of the check, and removal/replacement of any non‑compliant unit, restores the right to conduct intentional autorotation, subject to compliance with the AT.

• Right to install spares: The right to install spare servo‑controls on an aircraft is conditional on performing the bench check in paragraph 2.B.6 of the AT prior to installation. No installation is authorised without that check.

Practical consequences of duties and rights

• Technical dependency: The AD delegates technical detail to the AT and to a Goodrich Service Bulletin for exception status, so duties require access to and compliance with those documents. The AD specifies which paragraphs of the AT are relevant, but does not reproduce test thresholds or procedural steps.

• Timing and sequencing: The AD sequences duties with specific time constraints. Requirement 1 is immediate from the AD’s effective date, Requirement 2 must be completed within 50 hours time in service, Requirement 3 must be completed before further flight following Requirement 2 where non‑compliance is found, and Requirement 4 must be done before installation. These time and sequencing constraints define practical maintenance scheduling obligations.

• Record keeping implication: Although not stated verbatim in the AD, application of the exception for units overhauled or repaired in compliance with the specified Goodrich Service Bulletin requires maintenance history verification. The AD therefore requires, in practice, record checks demonstrating compliance with Service Bulletin GOODRICH No. SC507X‑67‑39‑01‑3 to claim the exception.

The AD text itself does not list penalties, fines or a specific enforcement process within its four requirements. The instrument’s enforcement mechanism is primarily the imposition of operational constraints and maintenance obligations which take effect on the stated dates. Two concrete enforcement features appear in the document.

Effective dates and immediate constraints. The AD declares that Requirement 1 is effective as of the effective date of the Directive, and the Directive becomes effective on 7 January 2005. This operationally constrains affected operators from conducting intentional autorotation flights from that date until they complete the required checks. Requirement 2 has a 50 hours time in service compliance window from the effective date, Requirement 3 requires removal/replacement before further flight after Requirement 2, and Requirement 4 requires bench checking before installation. These stated timeframes create enforceable deadlines as of the effective date listed.

Regulatory provenance. The document bears the signature line of David Punshon, Delegate of the Civil Aviation Safety Authority, dated 6 January 2005. The presence of a delegate’s signature indicates issuance by an aviation safety regulator. While the AD does not spell out sanctions, the presence of an AD issued by a national aviation authority implies regulatory expectations of compliance; regulators commonly monitor and enforce compliance with mandatory airworthiness directives through surveillance, audits and conditions attached to certificates. The AD also references DGAC and EASA approvals and a DGAC airworthiness form. However, because the Directive text supplied does not set out the enforcement mechanisms or penalties, no specific statutory penalty provisions or administrative enforcement steps can be cited from this document alone.

Practical enforcement mechanisms that will operate in consequence of the AD, inferred from the document’s structure, are:

• Operational control: Operators must not conduct intentional autorotations on affected airframes until the inspections are done. Breach of that operational prohibition would be observable in flight operations and training records.

• Maintenance control: The AD requires particular bench checks and authorises removal from service of non‑compliant units. A maintenance organisation that fails to perform the AT‑specified bench checks before returning an aircraft to service is in breach of the AD’s obligations.

• Record and traceability: The AD’s reliance on part numbers, serial numbers and compliance with a named Service Bulletin for exceptions means enforcement will involve checking maintenance records and part traceability. Failure to maintain or produce appropriate records will impede claiming exceptions.

Limitations. The AD does not state specific fines, civil penalties, or criminal sanctions, nor does it identify an administrative process for imposing sanctions. The AD likewise does not identify a direct appeals mechanism against the Directive itself. Any formal enforcement action, penalty regime or appeal path would be governed by the broader statutory and regulatory framework under which CASA issues ADs, but that framework is not reproduced in this Directive and therefore cannot be described from this source alone.

The Directive explicitly cross‑references technical documents and approvals issued by other aviation authorities, but it does not itself reproduce or amend external statutory instruments. The interactions stated by the Directive are limited to technical and approval references and to exception criteria that depend on compliance with a named Service Bulletin.

Cross‑jurisdictional technical references. The AD refers to Alert Telex (AT) Eurocopter AS 350 No 67.00.30 or any later DGAC approved revision as the procedural standard for the inspections, bench checks and remedial actions required. It also notes DGAC AF UF‑2004‑196 and EASA approval 2004‑12557. These references indicate that the technical procedures and approvals underlying the AD derive from the Direction Générale de l’Aviation Civile of France and the European Aviation Safety Agency. The AD therefore delegates technical execution to documents that sit outside the AD itself, and that originate in other regulatory regimes.

Service Bulletin exception. One of the exception criteria in the applicability clause exempts tail rotor servo‑controls overhauled or repaired in compliance with Service Bulletin GOODRICH No. SC507X‑67‑39‑01‑3. That links the effect of this Australian AD to compliance with a manufacturer’s service bulletin. The AD treats compliance with the named Service Bulletin as determinative for the exception. Therefore, the AD interacts operationally with manufacturer maintenance standards and with any legal or contractual regimes that recognise service bulletins as part of airworthiness compliance.

Limits on interaction claims. The AD does not reference other Australian statutes, instruments, or civil aviation regulations by section or provision. It does not specify how it modifies any prior ADs, nor does it state that it supersedes or amends any existing Australian instrument. The only cross‑references made in the text are to the Alert Telex, the Goodrich Service Bulletin, DGAC AF UF‑2004‑196 and an EASA approval number. Consequently, any wider legal interaction with Australian aviation law, administrative penalty regimes, or compliance oversight mechanisms lies outside the text of this Directive and cannot be asserted on the basis of the AD text alone.

Practical interaction points for operators. From the content of the AD, practical points of interaction are:

• Maintenance and continuing airworthiness system: Operators will need to integrate the AT procedures into their maintenance control documentation and ensure compliance records reference the AT paragraphs and any Goodrich Service Bulletin compliance that supports an exception.

• International approvals and imports: The note about DGAC and EASA suggests that operators who obtain parts or technical directives from overseas must ensure that the Australian AD’s requirements and effective dates are met, and that reliance on foreign approvals is validated by the AD’s terms.

• Contractual and insurance arrangements: Because the AD imposes operational prohibitions and maintenance obligations, it will intersect with contractual responsibilities under leases and insurance policies, although the AD itself does not address those instruments.

The AD lists one effective date and contains internal references to later revisions of the technical document it mandates, but it does not record any formal amendments to the Directive itself within the supplied text.

Issuance and effective dates. The Directive states that it becomes effective on 7 January 2005. The signature block shows David Punshon as Delegate of the Civil Aviation Safety Authority, dated 6 January 2005. Those dates establish the AD’s issuance and effective timing in the text.

References to later revisions. The AD requires compliance with Alert Telex Eurocopter AS 350 No 67.00.30 or a later DGAC approved revision. That phrase permits incorporation by reference of subsequent DGAC‑approved revisions of the AT, without the AD text itself being formally amended. In other words, the AD’s substantive procedures track updates to the AT so long as those updates are DGAC approved. The AD thus contains a built‑in mechanism for the technical standard to evolve via later DGAC approved AT revisions while leaving the AD wording intact.

Cross‑authority approvals. The AD notes DGAC AF UF‑2004‑196 and records an EASA approval number 2004‑12557. These entries reflect the underlying airworthiness actions taken by foreign authorities and an approval history for the associated AT or technical material. The AD does not state that it has been amended to reflect those approvals; rather it cites them as relevant references.

Absence of listed amendments. The supplied AD text does not include an amendment history section listing prior versions, variations, or supersessions. It contains no statement such as "supersedes AD X", nor does it include an amendment log. Therefore, as far as the document shows, this is the original AD text as issued with the stated effective date and no subsequent amendments are recorded in the text provided.

Practical consequence. Because the AD authorises compliance with future DGAC approved revisions of the AT, operators must monitor both the Alert Telex and DGAC publications for any AT updates. The AD itself does not require an amendment to capture AT revisions, but it does require that operators comply with later DGAC approved revisions of the AT where issued.

The AD text supplies no information about litigation, disputes, appeals, or judicial review arising from its issuance. There are no cases cited, no references to legal proceedings, and no mention of actions challenging the Directive. The document is an administrative airworthiness directive that sets technical and operational requirements; the supplied text contains the directive and background but does not record any subsequent legal contestation.

What can be said from the Directive itself, and without introducing external material, is the following.

• No judicial or administrative challenges are recorded in the AD text. There is no mention of appeals, stay applications, or compliance disputes in this document.

• The AD refers to the DGAC and EASA approvals for the underlying technical material, but it does not state any litigation in those jurisdictions. The EASA approval number is noted, however there is no narrative about disputes or legal proceedings connected to that approval.

• The AD is signed by the CASA delegate, and the text records the effective date and the dates of signature. No annotations indicate that the effective date was stayed, modified, or appealed.

Therefore, based solely on the supplied Directive, there is no litigation history to report. Any litigation, appeal or regulatory challenge that may have occurred after issuance is not reflected in this document and cannot be asserted here.

The Directive’s brevity and reliance on external technical material create a number of practical pitfalls and potential surprises for operators and maintenance organisations. These are concrete items to watch for, grounded in the AD text.

1. Applicability depends on part numbers and serial numbers. The AD applies only to AS 350 B3 helicopters fitted with GOODRICH tail servo‑control P/N SC5071‑XX or SC5072, except for SC5072 serial numbers equal to or above 1372. Operators must verify both the part number and the serial number to determine applicability. A mistake in serial number checking can lead to either unnecessary work or failure to comply where the AD applies.

2. Exception for Service Bulletin compliance requires documentary proof. The applicability exception for units overhauled or repaired in compliance with Service Bulletin GOODRICH No. SC507X‑67‑39‑01‑3 requires verification of overhaul or repair under that exact Service Bulletin. Operators must have maintenance records demonstrating compliance with that Service Bulletin to claim the exception. Absent clear records, the AD will apply.

3. Exception for units never removed since delivery. The AD excludes servo‑controls having never been removed since delivery of a new rotorcraft. That requires knowledge of the unit’s removal history. Aircraft with incomplete records or transfers between operators may face uncertainty about whether an exception applies.

4. The detailed inspection procedures are not in the AD. The AD mandates compliance with Alert Telex No 67.00.30 and cites specific paragraphs (for example 2.B.2 and 2.B.6), but the AT itself is not included in the AD. Operators must obtain the AT and ensure they follow the correct paragraphs. Delays in obtaining the AT can complicate compliance planning.

5. Configuration‑dependent procedures. Requirement 2 distinguishes between helicopters fitted with Automatic Flight Control System and those without, referring to different AT paragraphs (2.B.2.a and 2.B.2.b). Operators must correctly determine aircraft configuration to follow the appropriate AT procedure.

6. Bench check detail. The AD requires bench checks in accordance with paragraph 2.B.6 of the AT. Bench tests require appropriate equipment and expertise. Not all maintenance organisations may have the bench capability immediately available, leading to logistical delays.

7. Timing constraints create scheduling pressure. Requirement 1 is effective immediately; Requirement 2 must be completed within 50 hours time in service from the effective date. For aircraft flying frequently, scheduling inspections within that 50 hour window requires planning. For aircraft flying infrequently, the practical gap between calendar time and flight hours may complicate logistics.

8. Replacement before further flight. If a bench check finds non‑compliance, Requirement 3 requires removal from service and installation of a compliant unit before further flight after accomplishing Requirement 2. That creates potential grounding time if compliant replacement parts are not on hand.

9. Spares must be checked before installation. Requirement 4 requires spare servo‑controls to be checked per paragraph 2.B.6 of the AT before installation. A common operational pitfall is installing a spare from stock without a bench check; the AD prohibits that.

10. Unspecified enforcement and sanctions in the AD. The Directive does not state penalties or enforcement procedures. Operators may mistakenly assume informal remedial action suffices. From the AD’s text, any compliance failure remains an operational breach of the Directive, and enforcement mechanisms are not described in this document.

11. Cross‑reference to foreign approvals. The AD notes DGAC AF UF‑2004‑196 and EASA approval 2004‑12557. Operators might assume equivalence with other jurisdictions, but the AD’s instructions are binding in Australia only as stated. Reliance on foreign documents requires confirming that the AT revision cited is DGAC approved.

12. Ambiguity about "intentional" autorotation. The AD prohibits intentional autorotation flight until the check is accomplished. Determining what constitutes an intentional autorotation in training or emergency practice may require operational definition in an operator’s manual or training syllabus to ensure compliance.

These gotchas arise directly from the AD’s text. They emphasise the need for precise part identification, maintenance history verification, access to the Alert Telex and Service Bulletin, availability of bench test capability, and planning for operational impacts.

Compliance under this Directive follows a short sequence of actions tied to the AD’s Requirements and the referenced Alert Telex. The steps below track the AD’s operative text and timing, citing the relevant Requirement numbers and the AT paragraphs referenced in the Directive. Operators should document each step in maintenance control records.

1. Verify applicability. Immediately determine whether each AS 350 B3 helicopter in the fleet is fitted with GOODRICH tail servo‑control P/N SC5071‑XX or SC5072. If a unit is P/N SC5072, record its serial number; the AD excludes SC5072 units with serial number equal to or above 1372. Check maintenance records to verify whether any unit has been overhauled or repaired in compliance with Service Bulletin GOODRICH No. SC507X‑67‑39‑01‑3, and whether the unit has never been removed since the delivery of a new rotorcraft. These checks establish whether the AD applies to each unit.

2. Implement the operational prohibition. For any aircraft where the AD applies, enforce Requirement 1 immediately: prohibit intentional autorotation flight until the check required by paragraph 2.B.2 of the Alert Telex is accomplished. Amend operational notices, training schedules and briefings to prevent intentional autorotation on affected aircraft. The AD states that Requirement 1 is effective as of the effective date of the Directive.

3. Obtain Alert Telex No 67.00.30. Acquire Alert Telex Eurocopter AS 350 No 67.00.30 or any later DGAC approved revision. The AD mandates compliance with the AT. Identify the paragraphs referenced by the AD, in particular paragraph 2.B.2 (procedures for compliance) and paragraph 2.B.6 (bench check procedures). For helicopters fitted with Automatic Flight Control System, follow paragraph 2.B.2.b of the AT; for helicopters not fitted with AFCS, follow paragraph 2.B.2.a.

4. Conduct the inspections and bench checks within the AD’s timeframe. Complete the checks required by Requirement 2 in accordance with the AT within 50 hours time in service from the AD’s effective date. Organise bench test capability as required by paragraph 2.B.6 of the AT for both in‑service units and spares. If bench testing capability is not available in‑house, arrange for a maintenance organisation that has the required bench test equipment and procedures approved by the appropriate authority.

5. Remove and replace non‑compliant units. If a bench check reveals a servo‑control is non‑compliant per paragraph 2.B.6 of the AT, comply with Requirement 3: remove the unit from service and install a compliant tail servo‑control in accordance with paragraph 2.B.2 of the AT before further flight after accomplishing Requirement 2. Ensure the replacement unit is verified against the AD’s applicability exceptions where relevant.

6. Check spares before installation. For any spare tail servo‑control intended for installation, carry out the bench check required by paragraph 2.B.6 of the AT before installation, per Requirement 4. Record bench test results and retain them with the aircraft maintenance records to evidence compliance should records be audited.

7. Maintain documentary evidence. Document the applicability verification (P/N and serial number checks and SB compliance), the prohibition on intentional autorotation and its lifting once checks are complete, the bench check procedures used and their results, and any removal and replacement work carried out. Because the AD references Service Bulletin compliance and AT paragraphs for exception and procedural criteria, preserve records that demonstrate compliance with those external documents.

8. Plan for operational impacts. Update training syllabi, flight operations manuals and maintenance schedules to reflect the prohibition on intentional autorotation until checks are complete, the 50 hours TIS window for the primary checks, and the need for bench testing of spares prior to installation. Coordinate with parts suppliers and maintenance vendors to ensure availability of compliant servo‑controls and bench test services to avoid extended grounding.

9. Monitor for AT revisions. The AD allows compliance with a later DGAC approved revision of the Alert Telex. Monitor DGAC and Eurocopter communications for any DGAC approved revisions of AT No 67.00.30, and if a later revision is issued, follow the newer revision in place of the cited version, as permitted by the AD.

10. Confirm regulatory records. Although the AD does not specify the enforcement body’s reporting requirements in this text, it is prudent to make the completed maintenance records available to the relevant civil aviation authority or audit process. Given that the AD is issued by CASA (signature by delegate present), operators should ensure records meet the authority’s usual maintenance and airworthiness record requirements.

Following these steps implements the AD’s requirements as written. The operator’s obligations are to identify applicability, implement the immediate prohibition, carry out the AT‑specified checks within the 50 hours TIS window, remove and replace non‑compliant units before further flight, and bench check spares before installation, while documenting all actions and maintaining the chain of evidence of Service Bulletin compliance where exceptions are claimed.