AD/EC 225/3 - Main Rotor Blade De-Icing System Harness Connectors

Airworthiness directive (AD): A mandatory regulatory instrument issued under the Civil Aviation Act 1988 and Civil Aviation Safety Regulations 1998 (CASR) requiring an owner, operator, or maintainer to inspect, modify, or repair an aircraft, engine, propeller, or appliance to correct an unsafe condition. ADs are published by CASA and have the force of law; non-compliance can result in enforcement action including grounding and penalties.

Eurocopter EC 225 LP: A long-range, twin-engine helicopter designed for offshore transport and search and rescue. The AD applies to all serial numbers of this model, making it a fleet-wide directive rather than a subset defined by production block.

Main rotor blade de-icing harness: An electrical system that prevents ice accretion on the main rotor blades by heating them. The harness runs from the slip-ring assembly (the rotating electrical interface at the rotor head) along the blade. The directive specifically targets the connectors joining the harness to the slip-ring assembly. The part number 42994 is the critical identifier: helicopters not equipped with that harness are outside scope.

Slip-ring assembly: An electromechanical device that transmits electrical power and signals from the stationary fuselage to the rotating main rotor system. The de-icing harness connectors attach to this assembly. The directive focuses exclusively on the slip-ring side, not the blade side, because both reported failures occurred there.

Locking system: The self-locking mechanism inside the screwed-type connector, consisting of a spring ring that prevents the connector from loosening due to vibration. The background explains that failure of this spring ring (or an assembly anomaly of the retaining ring) leads to loss of the locking function, allowing the connector to disengage.

Heat-shrinkable sleeve: A piece of tubing that shrinks when heated, providing a secure fit over the connector after it is tightened. The sleeve acts as a secondary retention device, preventing the connector from backing off even if the primary locking mechanism fails. The AD requires sleeves to be installed initially and then each time a connector is disconnected and reconnected.

Time in service (TIS): Flight hours accumulated by the aircraft, measured from the moment it leaves the ground until it lands. Compliance intervals in the AD are expressed in TIS, plus a calendar-month alternative for Requirement 2: 50 hours TIS or three months, whichever occurs first. Requirement 3 uses only TIS (85 hours). This distinction matters for operators that fly infrequently, because the calendar limit may bind first.

EASA EAD 2007-0012-E: The European emergency airworthiness directive that originally addressed this issue. The Australian AD incorporates it by reference: helicopters that already complied with that EAD’s paragraph 2 (the locking-system check and sleeve installation) do not need to repeat Requirement 2. However, Requirement 1 (pre-flight tightness check) still applies until compliance with that paragraph is achieved, and Requirement 3 (repetitive 85-hour checks) references the EAD for determining the initial compliance point.

ASB 05A006: Eurocopter Alert Service Bulletin 05A006 dated 21 December 2006, which contains the detailed accomplishment instructions for the required checks and sleeve installation. The AD permits use of later revisions approved by EASA, which gives operators flexibility if the manufacturer updates the procedure.

The AD does not define “correct tightness” or specify a torque value; it relies on the ASB for those engineering details. This is standard practice: the AD sets the legal obligation, while the service bulletin provides the technical method. Operators must obtain and follow the current approved version of the ASB.

The primary duty bearers are operators and owners of EC 225 LP helicopters equipped with main rotor blade de-icing harnesses part number 42994. In practice, this covers a small fleet: the EC 225 is a niche heavy helicopter used mainly by offshore oil and gas transport operators, search and rescue organisations, and government agencies (e.g., police, coast guard). The directive applies to all serial numbers of the model, so any EC 225 in Australia with that harness is affected.

Maintenance organisations (both CASA-approved and self-administering operators) must perform the inspection and modification tasks in accordance with the ASB. They bear the direct labour cost and the cost of sourcing heat-shrinkable sleeves. For organisations with multiple EC 225s, the repetitive 85-hour inspection (Requirement 3) becomes a recurring compliance burden that must be tracked and scheduled.

Engineers and maintenance personnel are the individuals who physically perform the checks and installations. They must be familiar with the ASB and the specific torque or visual inspection criteria. Any error in performing the work (e.g., failing to tighten a connector correctly, or omitting the sleeve) could lead to non-compliance and potential safety issues.

CASA is the issuing authority and enforcer. The directive was signed by a delegate of CASA (James Coyne) and published as AD/EC 225/3 with reference 11/2008 DM. CASA may conduct surveillance, audit maintenance records, and take enforcement action for non-compliance. The AD also interacts with EASA because the helicopter type certificate is European; CASA’s AD largely mirrors the European directive.

Commercial operators face direct economic consequences: pre-flight checks under Requirement 1 require additional crew or maintenance time before each flight until the modification is done. For a helicopter flying multiple sectors per day, that recurring labour cost adds up. The 50-hour/3-month modification window imposes a deadline that may require scheduling aircraft out of service. The 85-hour repetitive inspection creates ongoing downtime. These costs are modest per flight hour but real, and they reduce the aircraft’s availability and profitability.

Lessors and financiers with EC 225s on lease may be indirectly affected if non-compliance leads to grounding or if maintenance costs are passed through under lease agreements. The AD may also be referenced in lease return conditions.

Passengers and clients of helicopter services (e.g., oil platform workers) are beneficiaries of the safety improvement but also potentially affected by service disruptions if aircraft are grounded for inspection. However, the AD is unlikely to cause significant schedule changes given the compliance intervals.

From a competition perspective, the AD applies uniformly to all EC 225 operators, so no operator gains a competitive advantage from avoiding the cost. New operators entering the market must factor compliance into their cost base. There is no evidence that the AD favours particular suppliers: heat-shrinkable sleeves are generic parts, and the ASB is available from the manufacturer. The directive does not mandate a specific brand or supplier.

Duty to perform pre-flight tightness check (Requirement 1): From the effective date of 29 August 2008 until complete compliance with Requirement 2, operators must check the tightness of the five connectors on the slip-ring assembly side before each flight. This is a recurring duty with a termination condition: once the modification (locking system check and sleeve installation) is accomplished, this pre-flight check ceases. The duty is substantial because it requires a physical inspection before every flight, adding to the pre-flight routine. Failure to perform it is a breach.

Duty to perform locking system check and install sleeves (Requirement 2): Within 50 hours TIS or three months (whichever occurs first) from 29 August 2008, operators must, unless already done per EASA EAD 2007-0012-E, check the locking system operation and fit heat-shrinkable sleeves on all five connectors. This is a one-time modification. The duty includes obtaining and following the ASB 05A006 or later approved revision. Compliance with this requirement triggers the start of the repetitive inspection interval.

Duty to perform repetitive tightness checks (Requirement 3): Within 85 hours TIS after initial compliance with Requirement 2 or the equivalent paragraph of EASA EAD 2007-0012-E (whichever applied first) and thereafter at intervals not exceeding 85 hours TIS. This is an ongoing duty with no end date: it continues for the life of the aircraft. Operators must track 85-hour intervals accurately, including after any major maintenance or part replacement.

Duty to install sleeve on each disconnection (Requirement 4): Each time any of the five connectors is disconnected and reconnected for any reason (e.g., during other maintenance, component replacement, or inspection), a new heat-shrinkable sleeve must be installed. This duty attaches to the event of disconnection, not to a calendar or TIS deadline. It creates a recurring consumable cost and labour requirement each time the harness is disturbed.

Right to use later revisions of ASB: The AD expressly states that later revisions of ASB 05A006 approved by EASA are acceptable for compliance. This gives operators flexibility to use updated procedures without seeking individual CASA approval, as long as the revision is EASA-approved. However, it also means operators must monitor EASA approvals for any new revision.

Right to rely on prior EASA compliance: If an operator had already accomplished the actions required by paragraph 2 of EASA EAD 2007-0012-E before the Australian AD’s effective date, they do not need to repeat Requirement 2. They must still perform Requirement 1 until that prior compliance, and Requirement 3’s initial interval is measured from that prior compliance (or from the last compliance with paragraph 3 of the EASA EAD, whichever is later). This avoids duplication of work for operators already in compliance with the European directive.

No right to alternative means of compliance (AMOC) stated: The AD itself does not mention an AMOC process. Under CASR, a person may apply to CASA for an alternative method of compliance, but the AD does not carve out any specific AMOC provision. Operators seeking to deviate from the ASB procedures would need to obtain CASA approval separately. This is a gap: the AD is rigid in requiring the ASB’s accomplishment instructions.

Duty to maintain records: Operators must document compliance with each requirement: date, TIS, technician, results, and part numbers (including heat-shrinkable sleeves). The AD does not explicitly list record-keeping, but standard CASR provisions require maintenance records for any AD. A prudent operator will log each check and sleeve installation.

Non-compliance with an airworthiness directive is a breach of the Civil Aviation Safety Regulations 1998. Under CASR 42.080 (as in force at the time; note the AD is from 2008), an operator must not fly an aircraft unless it complies with applicable ADs. Enforcement options include:

• Civil penalties: CASA can issue infringement notices (on-the-spot fines) for minor breaches, or seek civil penalty orders in the Federal Court for more serious or repeated non-compliance. Penalty amounts under the Civil Aviation Act 1988 are indexed and can reach significant sums per offence.
• Criminal prosecution: Wilful non-compliance or reckless operation of an unairworthy aircraft can lead to criminal charges, with potential fines and imprisonment under the Civil Aviation Act.
• Grounding: CASA can issue a written direction under CASR 42.105 requiring the aircraft not be operated until the AD is complied with. Grounding is immediate and can be enforced by airport authorities or police.
• Suspension or cancellation of certifications: CASA may suspend or cancel an air operator’s certificate (AOC), a maintenance organisation approval, or an individual engineer’s licence if they are found to have knowingly operated non-compliant aircraft.
• Impact on airworthiness release: A maintenance release (e.g., a Certificate of Release to Service) cannot be issued if the aircraft does not comply with applicable ADs. This blocks the aircraft from returning to service after maintenance.

For AD/EC 225/3 specifically, enforcement risk concentrates on the pre-flight check (Requirement 1) because it is short-cycle and easy to skip. An operator who flies an EC 225 without performing the pre-flight tightness check between August 2008 and the date of modification commits an offence each flight. The 85-hour repetitive check (Requirement 3) is also high-risk because it can be accidentally overlooked during busy operations. Requirement 4 (sleeve on each disconnection) is event-dependent and may be missed if the maintenance system does not require its inclusion in the disconnection task card.

CASA typically audits maintenance records and may sample logbooks during ramp checks. For an AD of this age (2008), most affected aircraft should have long since complied with the one-time modification, but the repetitive Requirement 3 continues indefinitely, so a failure to continue the 85-hour checks could be discovered years later. An operator that has not maintained the repetitive interval could be grounded until a new baseline is established.

There is no specific penalty provision in the AD itself; enforcement relies on the general civil aviation framework. The delegate (James Coyne) signed the AD, but enforcement is handled by separate CASA officers. The AD does not carry a direct fine amount; the penalty is determined by the Act and Regulations.

From a compliance-cost perspective, the penalties create a strong deterrence effect. The cost of compliance (labour and sleeves) is small compared to the cost of grounding or a civil penalty. Yet the 85-hour interval may still be overlooked because it is not part of a manufacturer’s mandatory scheduled maintenance program; it is a stand-alone AD requirement that must be tracked separately. This tracking burden is a hidden cost.

Civil Aviation Act 1988: The enabling statute under which CASA issues ADs. Section 28B(1)(b) empowers CASA to issue directions (including ADs) in the interests of aviation safety. Compliance with an AD is a condition of the airworthiness certificate.

Civil Aviation Safety Regulations 1998: Specifically, CASR Part 42 (Continuing Airworthiness) and Part 43 (Maintenance). CASR 42.080 requires that an aircraft must not be operated unless it complies with applicable ADs. CASR 43.025 requires that maintenance be performed using approved data; the ASB 05A006 constitutes approved data for this AD. The AD also interacts with CASR 42.120 (defect reporting) if a fault is found during the inspection.

EASA regulatory system: The AD incorporates and cross-references EASA EAD 2007-0012-E. Australian ADs often follow European ones because the EC 225 is type-certificated by EASA. The AD allows use of later EASA-approved revisions of the ASB, recognising EASA’s role as the primary design authority. There is no direct statutory interaction between CASA and EASA, but CASA’s practice is to align ADs to avoid conflicting requirements. Operators with aircraft on both European and Australian registers must satisfy both sets of ADs; in this case they are convergent.

Australian Consumer Law (ACL): Not directly applicable to airworthiness regulation. However, if a defect in the harness connector caused an accident, the passenger or cargo owner could bring a claim for damages against the operator or manufacturer. Compliance with ADs is evidence that the operator took reasonable care, but is not a complete defence. Conversely, non-compliance could be strong evidence of negligence. The AD does not create a private right of action.

Work Health and Safety (WHS) laws: Operators have duties to ensure, so far as reasonably practicable, the health and safety of workers performing maintenance. The AD tasks (checking tightness, installing sleeves) are standard and do not impose unusual WHS risks, but an employer must provide safe systems of work for the maintenance personnel.

Contract law: Leases, maintenance agreements, and insurance policies typically require compliance with all applicable ADs. Non-compliance can trigger default under a lease or void insurance cover. The AD creates an implied contractual obligation even if not explicitly stated.

Other CASA instruments: The AD does not mention any other Australian ADs. It stands alone. However, the EC 225 may be subject to many other ADs (for engines, gearbox, rotor, etc.). Operators must manage a portfolio of ADs; this one is a single item in that portfolio.

International law: The Convention on International Civil Aviation (Chicago Convention) obliges Australia to ensure aircraft on its register meet minimum airworthiness standards. ADs are the mechanism. This AD is consistent with international practice.

The interaction is relatively straightforward: the AD sits within a hierarchy of CASA instruments, incorporates by reference an EASA directive and a manufacturer’s service bulletin, and has downstream effects on contracts and tort law. There is no conflict with other laws; the AD prevails over any inconsistent operational or commercial arrangement.

The source document does not contain any amendment history. It is the original directive as issued on 25 August 2008, effective 29 August 2008. There is no indication that it has been superseded, varied, or repealed. However, based on standard CASA practice, ADs may be amended by later instruments (e.g., AD/EC 225/3 Amdt 1). The text states that later revisions of ASB 05A006 approved by EASA are acceptable for compliance, which is a forward-looking accommodation rather than an amendment to the AD itself.

The AD references prior regulatory actions: DGAC ADF-2005-214 (issued 1 February 2006 by France’s civil aviation authority) and EASA EAD 2007-0012-E. The Australian AD effectively replaces or supplements those for the Australian register. It does not repeal or amend them; it merely notes that prior compliance with the EASA EAD satisfies part of the new requirements.

Because the AD is a standalone document with no visible amendment history, operators must use the version published by CASA. If CASA later issues a superseding AD (e.g., AD/EC 225/4), it would be listed separately. As of late 2008, this was the current AD. For the purpose of a deep dive grounded only in the source, we can only state what the source shows: no amendments are recorded.

However, it is noteworthy that the AD is nearly 16 years old at time of writing. In practice, the EC 225 fleet may have had subsequent ADs modifying the compliance intervals or adding new tasks. But that is outside the scope of this source.

The source does not mention any litigation. No cases are cited in the AD text. Australian airworthiness directives are rarely the subject of judicial review; they are administrative decisions that courts treat with deference on technical matters. It is possible that an operator challenged an AD in the Administrative Appeals Tribunal (AAT) or a court on procedural grounds, but if so, not for this AD.

There is no known litigation specifically about AD/EC 225/3. The EC 225 model has been involved in several high-profile accidents (e.g., the 2012 North Sea ditches and 2016 Norwegian crash) but those were attributed to other components (epicyclic module failure, main gearbox issues), not the de-icing harness. No accident reports cite disconnection of this harness as a cause.

From a legal risk perspective, the absence of litigation is positive for the regulator: the AD has not been tested in court, so its validity remains assumed. For operators, it means there is no case law interpreting the AD’s requirements (e.g., what constitutes “correct tightness” or “locking system operates correctly”). Compliance relies entirely on the ASB and standard engineering practice.

Several subtleties in the AD can trap an unwary operator or maintainer:

1. Pre-flight check scope: Requirement 1 applies “before each flight” from the effective date until compliance with Requirement 2. But Requirement 2 has a 50-hour/3-month window. If an operator accomplishes Requirement 2 earlier (say, at 10 hours TIS), the pre-flight check still applies until that moment. An operator who flies 5 flights per day for 50 hours (roughly 10 days at typical offshore tempo) must perform the check before each of those 50 flights. Missing even one flight is a breach. The AD does not allow a grace period for the pre-flight check; it is absolute.

2. Interaction with EASA EAD: The AD says Requirement 2 need not be accomplished if already done per paragraph 2 of EASA EAD 2007-0012-E. But Requirement 1 must be performed until that previous compliance was achieved. So if an operator had complied with EASA EAD paragraph 2 on 1 January 2008, they still had to do the pre-flight check from 29 August 2008 until that date? That seems illogical because the check was already done. However, the wording: “If not previously accomplished in accordance with ... EASA EAD ... for each of the five connectors ... check that the locking system ... and fit the harness connectors with heat-shrinkable sleeves.” The pre-flight check in Requirement 1 is a separate duty that terminates only when compliance with Requirement 2 is achieved. If the operator already had compliance with the EASA EAD, they have already achieved the substantive action, but the AD’s wording suggests Requirement 1 still applies until the effective date of that prior compliance? Careful reading: Requirements 1 and 2 are separate. Requirement 1 requires checking tightness before each flight from effective date until compliance with Requirement 2. Requirement 2 says “If not previously accomplished ... check that the locking system operates correctly and fit ...”. So if previously accomplished, Requirement 2 is not required, but Requirement 1 still applies until the earlier compliance? The AD does not say “until the earlier compliance with Requirement 2 or prior compliance with EASA EAD”. It only says “until compliance with Requirement 2 is achieved”. If Requirement 2 is excused, there is no “compliance with Requirement 2”. This creates an ambiguity: does the pre-flight check ever end for operators who already complied with the EASA EAD? The likely answer is that CASA intended the pre-flight check to end once the connector modifications were in place, regardless of when. A sensible reading: if the operator already has heat-shrinkable sleeves installed per EASA EAD, the risk is mitigated and the pre-flight check is not needed. But the AD’s text is not explicit. An operator should document prior compliance and consider whether the pre-flight check can cease.

3. Repetitive interval start point: Requirement 3 says compliance must be within 85 hours TIS after “initial compliance with Requirement 2 of this Directive or paragraph 2 of EASA EAD 2007-0012-E or the last compliance with paragraph 3 of EASA EAD 2007-0012-E”. That gives three possible start points. If an operator complied with EASA EAD paragraph 2 in 2007, then later performed the paragraph 3 85-hour check, which start point applies? The AD says “or the last compliance with paragraph 3 of EASA EAD 2007-0012-E”. So the later of the two. But if the operator had not done paragraph 3 before this AD, the initial compliance with Requirement 2 (or prior paragraph 2) is the start. This requires careful record-keeping: the operator must know the TIS at the time of each previous check.

4. Requirement 4 scope creep: “Each time a main rotor blade de-icing harness connector is disconnected and reconnected” means any disconnection, even for unrelated maintenance (e.g., replacing a slip-ring assembly). The sleeve must be installed each time. This creates a consumable cost and a potential logistics issue if sleeves are not in stock. Also, the sleeve installation may require the connector to be undone again to apply the sleeve, adding extra steps.

5. Later revisions of ASB: The AD says “Later revisions of ASB 05A006, approved by the EASA, are acceptable for compliance with the relevant parts of this Directive.” But the AD does not say that such later revisions automatically update the AD without CASA action. An operator using a later revision must verify that it is EASA-approved and that the “relevant parts” match the AD’s requirements. If the later revision changes the inspection interval or omits some check, it may not satisfy the AD’s mandatory requirements. The AD only accepts later revisions for compliance with “the relevant parts”, not to vary the compliance times or conditions.

6. DGAC ADF-2005-214 reference: The background mentions this earlier French directive but the AD does not incorporate it. It is historical context only. Operators should not rely on it for compliance; only the ASB and the AD provisions matter.

7. Effective date and publication gap: The AD was signed 25 August 2008 and effective 29 August 2008. That gave operators four days to begin the pre-flight check. For an operator that did not become aware until after 29 August, they may have flown non-compliant. The AD does not include a delayed effective date for awareness.

8. Heat-shrinkable sleeve specification: The AD does not specify the part number or material of the sleeve; it refers to the ASB. The ASB may require a specific type. Using an incorrect sleeve (wrong size, temperature rating) could constitute non-compliance even if the action is performed.

9. No provision for weather or operating conditions: The pre-flight check is required regardless of whether the helicopter will fly in icing conditions. The AD mandates the check for all flights, even those in clear skies where de-icing is not needed. This appears conservative but adds the compliance cost of the check irrespective of risk.

10. Enduring effect: Once the modification is done and repetitive checks begin, the AD never expires. Even if the helicopter is retired and later returned to service, the 85-hour interval continues. The operator must maintain records indefinitely.

Compliance requires a documented process managed by the continuing airworthiness management organisation (CAMO) or the accountable person under CASR Part 42. The following steps represent a practical implementation:

1. Identify affected aircraft: Determine which EC 225 helicopters on your register have harness part number 42994. This can be found in the aircraft parts catalogue or maintenance records. The AD applies to all serial numbers of the EC 225 LP, so if the harness is fitted, the aircraft is affected.

2. Obtain ASB 05A006: Source the original service bulletin dated 21 December 2006 from Eurocopter (now Airbus Helicopters) or an authorised distributor. Check if EASA has approved a later revision. If so, obtain that revision. Retain the approved revision for the maintenance records.

3. Establish compliance baseline: Determine whether any aircraft already complied with EASA EAD 2007-0012-E. If yes, record the date and TIS of compliance with paragraph 2 (locking system check and sleeve installation) and paragraph 3 (85-hour check). These records will define the start point for Requirement 3.

4. Pre-flight check procedure: From 29 August 2008 until the modification is done, before each flight, the engineer or qualified person must check the tightness of the five connectors on the slip-ring assembly side using the criteria in the ASB (likely visual and torque check). Document each check in the technical log or a dedicated AD status sheet. Do not fly if any connector is found loose; rectify per the ASB.

5. Perform one-time modification (Requirement 2): Within 50 hours TIS or three months of the effective date (whichever occurs first), accomplish the following for each of the five connectors: (a) check that the locking system operates correctly (e.g., by manually verifying the self-locking function); (b) install a heat-shrinkable sleeve per the ASB. Use approved parts. Record the TIS and date in the aircraft maintenance record. This action satisfies Requirement 2 and terminates the pre-flight check requirement (Requirement 1).

6. Commence repetitive inspections (Requirement 3): After initial compliance with Requirement 2 (or prior compliance with EASA EAD), begin the 85-hour TIS inspection interval. The first inspection must be accomplished within 85 hours TIS after the initial compliance. Thereafter, repeat within every 85 hours TIS. The inspection is a tightness check only (not necessarily a full locking system check, unless the ASB requires it). Log each inspection with TIS, date, and result. If a connector is found loose, rectify per the ASB.

7. Implement condition-based sleeve replacement (Requirement 4): Each time any of the five connectors is disconnected and reconnected for any reason (including during the 85-hour inspection if the connector is undone), install a new heat-shrinkable sleeve. Make this a mandatory step in any maintenance task card that involves disconnection of the de-icing harness. Document the sleeve part number and installation date.

8. Track compliance intervals: Use a software system or manual log to calculate the next due date for the 85-hour inspection. Because the interval is TIS-based, the due time changes with each flight. The operator must subtract TIS since last inspection from the 85-hour limit and enforce a termination point (i.e., the check must be done before the aircraft reaches 85 hours TIS from the last check). No calendar extension is provided for Requirement 3.

9. Apply later ASB revisions: Monitor CASA and EASA for approval of later revisions to ASB 05A006. If a revision is approved, evaluate whether it changes the inspection criteria or sleeve specification. If it does, you may adopt it for compliance, but ensure you continue to meet the AD’s mandatory requirements (e.g., interval cannot be lengthened by a later revision unless the AD itself is amended).

10. Maintain records indefinitely: Keep a dedicated AD compliance record for the life of the aircraft, including: evidence of initial pre-flight checks (logbook entries), the modification record with part numbers, each 85-hour inspection entry, and each sleeve replacement triggered by disconnection. Records must be retained per CASR Part 42 (typically until the aircraft is permanently withdrawn from service).

11. Train personnel: Ensure engineers understand the difference between the pre-flight check (tightness only), the one-time modification (locking check and sleeve), and the repetitive inspection (tightness only). Emphasise the requirement to install a sleeve every time a connector is disconnected, even during routine maintenance.

12. Liaise with CASA if issues arise: If the aircraft reaches the 85-hour due point and is unable to be inspected (e.g., on a remote site), seek a ferry permit or extension from CASA. The AD does not allow automatic extension. If the ASB cannot be followed due to a non-approved revision, contact CASA for alternative means of compliance.

Compliance costs are modest per action but recurring. A pre-flight check may take 10-15 minutes (labour and documentation). The one-time modification may take an hour per connector. The 85-hour inspection repeats about 4 times per year on typical usage (assuming 350-400 hours annually). The sleeve cost is negligible. The main cost is administrative tracking. However, the risk of missing a check due to oversight is real; operators should assign clear responsibility to an individual or system.

The AD is still in force for any EC 225 still operating in Australia. New operators acquiring an aircraft with harness P/N 42994 must verify that the repetitive 85-hour check is current and that the last sleeve replacement was done on each disconnection. If records are lost, the operator may need to perform the modification again to re-establish a baseline. Given the AD’s age, most aircraft will have been modified long ago, but the repetitive checks continue.