AD/ECUREUIL/133 Amdt 1 - Collective Pitch Lever Locking Stud

An airworthiness directive (AD) is a legally enforceable notice issued by CASA requiring inspection, modification, or operational restriction on aircraft within a defined scope to correct an unsafe condition. This particular AD concerns the collective pitch lever locking system on helicopters. The collective pitch lever is the control that simultaneously changes the pitch angle of all main rotor blades; if it unlocks or locks unexpectedly during flight, control can be lost. The locking stud is a component on the lever, and the locking strip is a fixed part against which the stud bears when the lever is at the low pitch stop. The critical parameter is the clearance between the end of the locking stud and the locking strip; the AD specifies a minimum threshold of 3 mm. If clearance is less than 3 mm, corrective actions differ depending on whether the helicopter has embodied modification 073175 or 073237. Modification 073237 introduced a longer locking stud to prevent wear that could cause unintentional unlocking during engine start; modification 073175 appears to be a further or alternative modification (the AD does not describe it but uses it as a branching condition). Helicopters that have not embodied modification 073237 are also covered, as a precaution because the pre-modification configuration also presents a risk of insufficient clearance. Service Bulletin (SB) No. 67.00.37 corresponds to modification 073237. The AD references Eurocopter Emergency Alert Service Bulletin No. 05.00.58 as the procedural document for measuring clearance and performing repairs. A ferry flight is a one-time flight to a maintenance location; the AD allows it only with no passengers. Compliance intervals are defined as: for requirements 1 and 2 the original effective date applied (after the last flight of the day from 5 December 2008); for requirement 3 (repeat inspections) the interval is each time certain components are replaced or the setting is readjusted, and in any case not more than 660 flight hours or 2 years, whichever occurs first. The AD also notes that the Aircraft Individual Inspection Record (RIC), Log Cards (FM), or aircraft logbook should be used to identify the actual helicopter configuration. The AD itself is a one-page instrument, but it incorporates external documents by reference, making those documents effectively mandatory. This incorporation by reference is a common feature of ADs and imposes costs on operators to obtain and follow the referenced material.

The directive directly affects owners, operators, and maintenance providers of the listed Eurocopter AS350 series helicopters. The applicability section defines the population: helicopters delivered before modification 073175 was embodied, helicopters with reworked or modified locking studs, levers, or strips (meaning in-service changes or repairs), helicopters that have accomplished earlier revisions of Eurocopter SB No. 67.00.37 (the modification 073237 service bulletin), and a specific set of 37 serial numbers (3972 to 4671). This captures a large proportion of the worldwide AS350 fleet, but in Australia the affected population is limited to helicopters registered with CASA. The AD imposes obligations on the registered operator: they must ensure the inspection is performed and any corrective actions are taken, and they must maintain records. Maintenance organisations (approved maintenance providers under Part 145 or similar) will be engaged to perform the work. Pilots are indirectly affected because the AD permits a ferry flight only with no passengers; if a helicopter is found non-compliant, pilots cannot fly passengers. The manufacturer, Eurocopter (now Airbus Helicopters), is affected because the AD requires contacting them for instructions in certain circumstances (helicopters that have embodied modification 073175 but not 073237, and where clearance is below 3 mm - those must suspend flights and contact Eurocopter for corrective actions). That requirement places a contingent duty on Eurocopter to provide instructions. The AD also affects suppliers of locking stud kits and locking strip parts because demand for replacements will increase. From a regulatory perspective, CASA itself is affected because it must process conformity inspections and follow-up. The compliance burden falls most heavily on private and commercial operators of these helicopters, particularly those with older models or those that have had rework. The cost includes technician labour (measuring clearance, possibly adjusting or replacing parts), parts procurement (locking studs, locking strips, or modification kits), and aircraft downtime. The ferry flight provision slightly reduces the cost of being caught away from a maintenance base, but still required grounding for the inspection. No exemption is provided for smaller operators or those with low utilisation, nor is a risk-based alternative described.

The primary duty is to measure the clearance between the end of the locking stud and the locking strip in accordance with Eurocopter Emergency Alert Service Bulletin No. 05.00.58, paragraph 2.B.2.a or 2.B.3.a depending on whether modification 073237 has been embodied. If the clearance is equal to or more than 3 mm, the helicopter may be returned to flight configuration. If clearance is less than 3 mm, the operator must follow one of three corrective action pathways: (a) for helicopters with modification 073237 but not 073175, accomplish the instructions in paragraph 2.B.2.b; (b) for helicopters with both modifications, accomplish paragraph 2.B.2.c; (c) for helicopters without modification 073237 and without 073175, follow paragraph 2.B.3.b; and (d) for helicopters without 073237 but with 073175, suspend flights and contact Eurocopter for instructions. The duty to repeat the inspection arises: each time the collective pitch lever, locking stud, or locking strip is replaced, each time the locking strip setting is readjusted, and at intervals not exceeding 660 flight hours or 2 years, whichever occurs first. That is a periodic re-inspection obligation that continues for the life of the helicopter unless the AD is superseded or terminated by further regulatory action. The AD grants a right to use later approved revisions of the service bulletin; if Eurocopter issues revision 2 or later, the operator may comply with that instead of revision 1, provided CASA has not objected. The AD also grants a right to perform a ferry flight to a repair station or place where compliance can be achieved, subject to the condition that no passenger is on board. That right is valuable because it avoids the need for mobile maintenance teams in remote areas. The AD does not grant any right to deviate from the prescribed intervals or methods; no alternative means of compliance are mentioned. Operators have the right to rely on the aircraft’s configuration records (RIC, log cards, aircraft logbook) to determine applicability. They also have the right to contact CASA for interpretation questions, though that is implicit. The AD does not create any private right of action for third parties (e.g., passengers); its duties flow to the regulator.

The AD itself does not list specific penalties, but non-compliance with an airworthiness directive issued under the Civil Aviation Act 1988 is a regulatory offence. The Civil Aviation Safety Regulations 1998 (CASR) provide that operation of an aircraft not in compliance with an applicable AD is prohibited. Specifically, CASR 42.050 (as it then stood) and now 42.015 make it an offence to operate an aircraft unless it is airworthy and all ADs have been complied with. Penalties can include: fines up to 200 penalty units for an individual (currently $31,300 per offence) and higher for bodies corporate, suspension or cancellation of the aircraft’s certificate of airworthiness, grounding directions, and disciplinary action against licensed maintenance personnel or pilots. CASA can issue a direction to ground the aircraft until compliance is demonstrated. In practice, enforcement is usually achieved through pre-flight checks and audits; if a non-compliance is found during a ramp check or maintenance review, CASA may issue a notice of proposed suspension or vary the airworthiness certificate. The AD itself is a mandatory continuing airworthiness requirement; failure to comply may also affect insurance coverage and liability in the event of an accident. Because the AD requires repeat inspections, the enforcement risk persists; an operator who complies once but fails to track the next interval faces renewed liability. There is no explicit defence of reasonable mistake in the regulation, though an operator may argue they acted on incorrect information about the helicopter’s configuration. The ferry flight provision is a limited exemption from the grounding requirement; if an operator ferries with passengers, that itself is a breach. The background section of the AD identifies the risk as potential loss of control, which elevates the seriousness of non-compliance. CASA’s delegate signs the AD; enforcement is handled by CASA’s compliance and enforcement branch.

This AD operates within the hierarchy of Australian aviation law. The Civil Aviation Act 1988 is the enabling statute; ADs are issued under regulation 37 of the Civil Aviation Regulations 1988 (CAR) or under CASR 39.003, depending on the date. The effect is that an AD imposes a mandatory condition on the aircraft’s certificate of airworthiness. The AD explicitly states it supersedes EASA AD 2008-0205-E and references EASA AD 2009-0019. This means that for helicopters that are also subject to EASA jurisdiction (e.g., if the aircraft is imported from Europe), the Australian AD takes precedence, but compliance with the later European AD may be accepted as equivalent if identical. The AD also references Eurocopter Service Bulletin No. 67.00.37 and Eurocopter Emergency Alert Service Bulletin No. 05.00.58. Those documents are incorporated by reference; they become part of the regulatory requirement. If a later revision of the SB is approved, the operator may use it without further amendment to the AD. The AD interacts with maintenance regulations: the work must be performed by an authorised maintenance organisation (Part 145 or equivalent) and the results must be recorded in the aircraft’s maintenance records. The AD may also affect other ADs that apply to the same helicopter model; operators must ensure they are complying with all applicable ADs, as they are cumulative. The ferry flight provision interacts with airspace and flight rules: a ferry flight with no passengers is a controlled flight under the operator’s AOC or private operations; it is not exempt from other regulatory requirements (e.g., VFR/IFR minima). The AD does not interact with privacy or competition law. It is a safety regulation, so it does not conflict with trade practices law unless it creates an unjustified barrier to trade; here it applies equally to all operators regardless of origin. The reference to contacting Eurocopter for instructions in one specific situation means that the manufacturer becomes a quasi-regulatory body for that step. If Eurocopter does not respond, the aircraft remains grounded; that creates a dependency on a foreign company.

The original issue of AD/ECUREUIL/133 became effective on 5 December 2008. That version required a one-time clearance measurement and, if clearance was less than 3 mm, corrective actions as described. It did not contain any repeat inspection requirement. Amendment 1 was signed by James Coyne, Delegate of CASA, on 27 March 2009, and became effective on 7 May 2009. The sole change introduced by Amendment 1 is the addition of a third requirement: repeat the clearance measurement at intervals not exceeding 660 flight hours or 2 years, whichever occurs first, and also each time the collective pitch lever, locking stud, or locking strip is replaced, or the locking strip setting is readjusted. The compliance section for Requirements 1 and 2 was left unchanged from the original (after the last flight of the day from 5 December 2008). The text of the AD table was updated to include the new requirement 3 and the corresponding compliance table entries. The background section was also updated to note that Amendment 1 required repeat inspections. The AD number remained AD/ECUREUIL/133 Amdt 1; there is no evidence of a second amendment. The AD supersedes EASA AD 2008-0205-E, which was presumably the European equivalent that this AD replaced for Australian purposes. The amendment history is brief but significant: it transformed a one-off check into an ongoing recurring obligation, increasing compliance costs and administrative burden for operators. No further amendments are present in the source. The timing is notable: the repeat inspection requirement was added only about five months after the original, suggesting that CASA or EASA concluded the risk was not eliminated by a single check. The amendment was signed by a delegate, indicating it was an administrative action rather than a review by the full CASA board.

The source document contains no reference to any litigation concerning AD/ECUREUIL/133 Amdt 1. No court cases, tribunal decisions, or other proceedings are mentioned. The AD itself is a routine safety directive; such instruments are rarely litigated in Australia because they are based on technical findings and the regulation affords limited grounds for judicial review (except on procedural grounds or jurisdictional error). It is possible that an operator could challenge an AD if it were argued to be ultra vires or irrational, but that would be exceptional. The absence of litigation in the source does not prove no litigation exists; but as a matter of disclosure, the source is silent. Given the nature of the instrument, it is likely that compliance has been uncontroversial. The AD incorporates manufacturer service bulletins, which are commercial documents; any dispute about the adequacy of the instructions in those bulletins would be between the operator and Eurocopter, not a matter of public record under CASA’s AD. If CASA took enforcement action against an operator for non-compliance, that could lead to a proceeding in the Administrative Appeals Tribunal or Federal Court, but such cases are rare and the source does not mention any. The background notes that the original AD was triggered by an in-flight autorotation test; there is no indication that this test was part of any accident investigation or litigation. The AD itself was issued, so any potential tort claims if an accident had occurred would be mitigated by the directive. In summary, there is no litigation history evident from the source.

Several aspects of the AD could trap unwary operators. First, applicability depends on configuration, not just model. Operators must check the aircraft records (RIC, log cards, logbook) to determine whether modifications 073175 and 073237 have been embodied, and whether any locking stud, lever, or strip has been reworked or modified in service. A helicopter that left the factory with both modifications might still be captured if a later in-service repair used non-standard parts. Second, the clearance measurement threshold is 3 mm, but the AD does not specify how to measure it; it refers to the Eurocopter bulletin, which the operator must obtain separately. If the operator relies on memory or a different method, compliance may be invalid. Third, the corrective actions for helicopters that have modification 073237 but not 073175 and have clearance less than 3 mm are not fully described in the AD - they are in paragraph 2.B.2.b of the bulletin. Similarly, for helicopters with both modifications and clearance less than 3 mm, see paragraph 2.B.2.c. The AD does not summarise what those actions entail; operators must have the bulletin. Fourth, for helicopters without modification 073237 but with modification 073175 and clearance less than 3 mm, the AD requires suspending flights and contacting Eurocopter for instructions. This creates risk: if Eurocopter does not respond quickly, the aircraft remains grounded. There is no specified timeframe for Eurocopter’s response, and no fallback if Eurocopter offers an unsatisfactory answer. Fifth, the repeat inspection interval is tied to component replacement and setting readjustment, as well as the 660 hour/2 year cap. If an operator replaces the locking stud at 500 hours, the next inspection is due not at 1160 hours total but at the time of that replacement (the clock resets). However, if the operator replaces the lever at 500 hours but not the stud, the AD says “each time the collective pitch lever, the locking stud or the locking pitch are replaced” - unclear if that means any one replacement triggers a check, or only if the specific component that is replaced affects the clearance. The word “or” suggests any of them. Sixth, the ferry flight provision is limited: it is allowed only to get to a place where the maintenance can be performed, and only after the helicopter has been found non-compliant (or before compliance). But it says “if a flight is necessary to ferry the helicopter to a repair station or a place where the maintenance can be performed in order to comply with Requirements 1 or 2 of this AD”. It does not explicitly permit a ferry flight to comply with Requirement 3 (repeat inspections). However, since Requirement 3 is the same measurement action, arguably it applies. The safest interpretation is that it applies for any non-compliance discovered at any inspection. The note says “no passenger on board” - crew only. Seventh, the AD becomes effective on 7 May 2009, but compliance for Requirements 1 and 2 remains unchanged from the original AD - meaning they were to be complied with from 5 December 2008. An operator who purchased the helicopter after that date inherits compliance; the new repeat requirement applies prospectively. Eighth, the AD does not address what happens if the clearance is exactly 3 mm - presumably it is “equal to or more than 3 mm” so it passes. Ninth, the AD references “later approved revisions” of the service bulletin; but approval by whom? The context suggests Eurocopter, but CASA could also have an approval process. If an operator uses an unapproved revision, compliance may be invalid. Tenth, the AD is short and appears simple, but the incorporation of external documents by reference means the full requirements are not on the page. An operator who reads only this AD may miss critical steps.

Compliance with AD/ECUREUIL/133 Amdt 1 requires a systematic approach. First, determine whether the helicopter falls within the applicability: check the aircraft model (AS350 B, BA, BB, B1, B2, B3, or D), the delivery status (before embodiment of mod 073175), the service history (has SB 67.00.37 Revision 0 or 1 been accomplished, or have locking studs/levers/strips been reworked or modified in service), and the serial number if on the list. Consult the Aircraft Individual Inspection Record (RIC), Log Cards (FM), or aircraft logbook. If the helicopter is captured, obtain a current copy of Eurocopter Emergency Alert Service Bulletin No. 05.00.58; use the latest approved revision. For the initial compliance (Requirements 1 and 2, which were due after the last flight of the day from 5 December 2008), if the helicopter has already complied, record that fact. For ongoing compliance, implement a programme that triggers a clearance measurement at each replacement of the collective pitch lever, locking stud, or locking strip; each readjustment of the locking strip setting; and at intervals not exceeding 660 flight hours or 2 years, whichever comes first. The measurement procedure is described in the bulletin: for helicopters with modification 073237, follow paragraph 2.B.2.a; for those without, follow 2.B.3.a. If clearance is 3 mm or more, no further action is needed beyond recording the result and proceeding to flight. If clearance is less than 3 mm, identify the configuration: (i) if the helicopter has modification 073237 and not 073175, accomplish paragraph 2.B.2.b; (ii) if it has both modifications, accomplish paragraph 2.B.2.c; (iii) if it has neither modification, accomplish paragraph 2.B.3.b; (iv) if it has modification 073175 but not 073237, suspend flights and contact Eurocopter for instructions; do not fly until corrective action is provided and completed. Record all measurements and actions in the aircraft maintenance records. For any ferry flight required to reach a maintenance base, ensure no passengers are carried. Ensure that maintenance is carried out by an appropriately authorised organisation (e.g., CAR 30 or Part 145 certified). If a later revision of the service bulletin is published and approved, you may use it instead. Keep records to demonstrate compliance to CASA auditors. Because the repeat inspection is life-of-type, add a reminder system in the aircraft’s maintenance tracking (e.g., computer system or logbook placard) to ensure the interval is not exceeded. Note that if the aircraft is operated under an AOC, the operator’s continuing airworthiness management system should already track ADs. Failure to comply is an offence; therefore, treat this AD as a mandatory step before any flight after the due date.