AD/SWSA226/86 Amdt 3 - Wing Spar Centre Web Cutout

The central structural concept is the wing spar centre web cutout , a manufactured opening (cutout) in the vertical web of the main wing spar, located between Wing Stations 8 and 17.5 (approximately the inboard section of the wing). This cutout is a stress concentration point subject to fatigue cracking under repeated flight loads (manoeuvring and gust loads). The Directive treats the cutout as a life-limited fatigue-critical location. The concept of time in service (TIS) governs compliance: for the first inspection, the trigger is 6,500 hours TIS on each spar, not on the airframe overall. This means that if left and right spars have different accumulated hours (e.g., due to part replacements or different utilisation), each spar must be tracked separately. The 2,000-hour repetitive inspection interval is a recurring calendar of inspections measured in flight hours. The repair termination concept is important: a cracked cutout can be repaired using an approved structural repair manual procedure, and once that repair is done on a given wing spar, that spar no longer requires the repetitive 2,000-hour inspections. However, the repair does not apply to the other spar unless it is also repaired. The Directive does not specify whether the repair is permanent or has its own life limit; the repair manuals may contain additional inspection requirements not referenced here. The term "before further flight" for the repair means that if a crack is found, the aircraft cannot be flown again until the repair is completed , no grace period or ferry permit is provided in the Directive itself. The compliance cascade (the "whichever occurs later" test) means that an operator must calculate three dates: when the spar reaches 6,500 hours TIS, when the last previously required inspection (under the Airworthiness Limitations Manual) was done plus 2,000 hours, and 500 hours after 7 July 2005. The first inspection must be done at the latest of these three. This creates a complex compliance date that may differ for each aircraft and each spar. The Applicability table is precise: only specific model designations (e.g., SA226-AT, SA226-TC, SA226-T, SA226-T(B), SA227-TT, SA227-TT(300), SA227-AC, SA227-AT, SA227-BC, SA227-CC/DC) and specific serial number ranges are covered. Aircraft outside these series or serial numbers, even if structurally similar, are not required to comply. The Directive uses the term "each wing spar" to require both left and right spars to be inspected independently.

The primary duty-holders are the registered operators and owners of any Fairchild (Swearingen) SA226 or SA227 series aeroplane that falls within the specified model and serial number ranges. This includes private operators, corporate flight departments, charter operators, air taxi services, commuter airlines, and any entity that places such an aircraft on the Australian civil aircraft register. The Directive also directly affects maintenance organisations (approved by CASA or under a maintenance arrangement) that perform inspections or structural repairs on these aircraft. Licenced aircraft maintenance engineers (LAMEs) and certifying staff must follow the mandated manuals and procedures and must record the inspection and any repairs in the aircraft maintenance records. Importers and prospective purchasers of these models should be aware that the AD imposes a recurring inspection obligation and potential repair cost, which affects aircraft value and operational planning. The Civil Aviation Safety Authority is the enforcing body and the issuer of the Directive; its delegates (such as David Punshon, the signatory) have the power to issue, amend, and enforce ADs. Insurance companies underwriting hull and liability policies for affected aircraft will have a direct interest in compliance because a failure to comply can void coverage or affect claims if a structural failure occurs. Manufacturers (Fairchild, now possibly out of production or with limited support) are indirectly affected because the Directive references their proprietary manuals; operators must obtain those manuals, and the repair procedures are manufacturer-specific, creating a dependency on continued availability of technical data. Parts distributors who supply repair kits or replacement spars may see increased demand. The Directive also affects overseas operators who fly into Australia: foreign registered aircraft of the same models must comply with the applicable airworthiness directives of their state of registry, but if they operate in Australia, they must meet Australian requirements, which may be equivalent or more stringent. The compliance burden is concentrated: there are not many of these aircraft in Australia (the serial ranges suggest perhaps a few hundred worldwide, with a fraction in Australia), but for those operators the cost is significant , inspection requires skilled labour, access to manuals, and possibly special tooling; repair requires structural repair expertise and parts.

The primary duty is to inspect each wing spar centre web cutout as specified: by the later of the three trigger events (6,500 hours TIS, 2,000 hours after last manual inspection, or 500 hours after 7 July 2005), and thereafter repetitively at intervals not exceeding 2,000 hours TIS. The inspection must be carried out strictly in accordance with the applicable Fairchild manual and revision level listed in the Directive. There is no discretion to use a different method or to accept a risk assessment that the crack is acceptable; the Directive mandates the inspection method. If a crack is found, there is a duty to repair before further flight. The repair must be in accordance with the applicable Structural Repair Manual (SRM) pages and revision specified. The repair terminates the repetitive inspection requirement for that individual spar only. The operator or owner has the right to choose not to repair a cracked spar, but the aircraft cannot be flown unless that spar is repaired (or the aircraft is grounded permanently). There is an implicit right to seek an alternative means of compliance (AMOC) from CASA under the general provisions of the Civil Aviation Safety Regulations (CASR) Part 39, though the Directive itself does not mention this; practically, an operator could apply to CASA for an alternative inspection method or repair if they can show an equivalent level of safety. The Directive does not impose a duty to replace the entire wing spar; only to repair the cutout. The right to continue flying after repair is conditional on the repair being accomplished. The operator has the duty to maintain records of inspections, repairs, and compliance with the interval , while not spelled out in the AD itself, the Civil Aviation Act and CASR require maintenance records to be kept. The operator also has the duty to not exceed the 2,000-hour interval between inspections. There is a duty on the maintenance organisation performing the work to use the correct manual revision and to certify the work in the aircraft logbook or maintenance release. The Directive does not create a right to compensation for the cost of compliance; the operator bears the full expense.

The Directive itself does not set out specific penalty amounts. Enforcement occurs under the broader framework of the Civil Aviation Act 1988 and the Civil Aviation Safety Regulations 1998. Operating an aircraft that does not comply with an applicable airworthiness directive is a contravention of regulation 42.420 of CASR (if the AD is issued under Part 39), which can attract civil penalty provisions under the Act. The maximum penalty for a breach of an airworthiness directive by an individual is 50 penalty units (currently $15,600) and by a body corporate is 250 penalty units ($78,000), though these amounts adjust with indexation. Additionally, CASA can take administrative action: it can suspend or cancel the aircraft's certificate of airworthiness (CofA), issue a direction to ground the aircraft, or impose conditions on the CofA. If an operator flies an aircraft with a known crack in the wing spar cutout (i.e., non-compliance with the repair requirement), CASA can issue an immediate grounding notice under regulation 39.035. Criminal prosecution could also arise if the non-compliance leads to an accident involving death or serious injury, under the Work Health and Safety Act 2011 or criminal negligence provisions. The Australian Transport Safety Bureau (ATSB) could investigate any accident involving wing spar failure, and non-compliance with the AD would be a critical finding. CASA also has powers to require an operator to produce records of compliance. The Directive is issued by a delegate of CASA; failure to comply is effectively a breach of a statutory condition. The enforcement approach is risk-based: CASA may audit operators of these older aircraft types if it becomes aware of operations. The cost of enforcement action (including legal fees, grounding, lost revenue) far exceeds the cost of compliance, so the penalty structure is designed to incentivise early compliance. However, the practical likelihood of detection for a single non-compliant aircraft operating in remote areas is low; detection typically occurs during routine surveillance, maintenance audits, or after an incident.

This Directive operates under the national aviation safety framework. The primary enabling legislation is the Civil Aviation Act 1988 (Cth), which gives CASA power to issue Airworthiness Directives. The Civil Aviation Safety Regulations 1998 (CASR) Part 39 (Airworthiness Directives) sets the procedural framework for issuing, amending, and enforcing ADs. Regulation 39.001 defines an airworthiness directive as a legally enforceable requirement, and 39.005 provides that compliance with an AD is a condition of the Certificate of Airworthiness. The Directive interacts with maintenance regulations under CASR Part 42 (Continuing Airworthiness) and Part 145 (Approved Maintenance Organisations). Operators must have the aircraft maintained under an approved maintenance program, which must incorporate this AD as a scheduled inspection task. The Swiss-type manuals referenced (e.g., ST-UN-M001) are themselves part of the approved maintenance data; under CASR 42.040, maintenance must be performed in accordance with approved data, so the AD effectively mandates mandatory revisions of those manuals. The FAA AD 2005-06-13 Amdt 39-14023 is the foreign counterpart; the Australian AD cites it but does not incorporate it by reference for compliance in Australia , the Australian AD has its own requirement text. Where an aircraft is imported from the United States, the operator must ensure compliance with both the FAA AD (for the FAA type certificate) and the Australian AD (for the Australian CofA). If differences exist (e.g., different compliance times), the stricter requirement applies. The Directive does not interact with state or territory workplace health and safety laws directly, but if a repair is performed in a hangar, the general duties under the Work Health and Safety Act 2011 apply to the maintenance organisation. The Australian Consumer Law (ACL) may apply if an aircraft operator purchases a repair service that is defective; but the AD itself is not a consumer law instrument. The Directive is consistent with the Chicago Convention and Australia's obligations under Annex 8 (Airworthiness of Aircraft) to maintain continued airworthiness. There is no interaction with privacy laws or competition law, though the requirement to use proprietary Fairchild manuals could raise issues of access to essential facilities if the manuals become unavailable , but that is a practical problem, not a legal conflict.

This is Amendment 3 to AD/SWSA226/86. The original AD was issued in 1986 (AD/SWSA226/86), before the current CASR framework, likely under the previous Air Navigation Regulations. Amendment 1 was issued to align the Australian AD with the latest FAA AD (2005-06-13) at that time, with no change to technical content. Amendment 2 updated the revision status of the referenced requirement documents (the Fairchild manuals) to more current revisions. Amendment 3 (the current version, effective 9 April 2009) again updated the revision status of the requirement documents to those specified in the Directive , specifically, Revision C-10 of ST-UN-M001 dated 27 October 2008, Revision A-11 of ST-UN-M002 dated 27 October 2008, and Revision 8 of ST-UN-M003 dated 5 October 2005. The amendments did not change the inspection area, the crack criteria, the repair requirement, or the compliance times. The compliance times in the current Directive are explicitly stated to remain unchanged by this Amendment. The history reflects a pattern of periodic administrative updates to keep the referenced manuals current as the manufacturer released new revisions. The original 1986 AD likely had different compliance times (possibly 6,500 hours TIS) and may have originally applied to fewer models. The amendment chain shows that the regulator treats these directives as living documents that need to track the manufacturer's latest data. The Background section notes that FAA AD 2005-06-13 was adopted because of reported cracks from fatigue; the Australian AD adopted the same safety rationale. The amendments do not reveal any legal challenges or policy shifts. It is notable that the revision dates of the manuals are quite specific (e.g., page iii dated 16 August 1995); this indicates that the AD does not accept the latest version of the manual automatically but only certain revision combinations. Operators must check that their copy of the manual matches the allowed revision level, which adds administrative burden.

There is no litigation history mentioned in the source text. The Directive itself is a routine safety instrument; it is unlikely to have been litigated in Australian courts. Challenges to airworthiness directives are rare because they are technical and safety-based, and courts typically defer to the expertise of CASA. An operator could theoretically seek judicial review of a CASA decision to issue or amend an AD under the Administrative Decisions (Judicial Review) Act 1977 on grounds such as procedural error or unreasonableness, but no such challenge appears in the public record for this specific AD. The narrow question of whether the compliance times were properly set (the "whichever occurs later" formula) could be disputed if an operator believed CASA miscalculated the effective date or misinterpreted the FAA AD. However, the source text does not refer to any court cases, and no case law is cited. The reference to FAA AD 2005-06-13 indicates that the US version may have been litigated in US courts, but that is not relevant under Australian law. In the absence of litigation, the Directive operates without judicial interpretation. For a compliance professional, the lack of litigation history offers no guidance on ambiguous terms; one must rely on the plain text and CASA's likely interpretation. The potential for future litigation exists if a crack goes undetected and causes an accident , civil liability claims for negligence against the operator, maintenance organisation, or CASA could arise, but that would be tort law, not a challenge to the AD itself. The AD could be used as evidence of the required standard of care in a negligence action.

Several features of this Directive can trap the unwary operator or maintenance provider. First, the applicability is model-specific and serial-number-specific: an aircraft may appear to be an SA227 but if its serial number is outside the listed ranges, the AD does not apply. Conversely, a SA227-TT(300) with serial TT(300)447 is covered, but one with serial TT(300)448 (if it exists) might not be , the list is exhaustive and does not include later production. Operators must carefully cross-check their aircraft dataplate. Second, the compliance time uses "each wing spar" separately: if the aircraft has had one spar replaced (e.g., after a previous crack or corrosion), the new spar may have much lower hours TIS than the original. The AD does not allow prorating or a single inspection date for both spars. For example, if left spar has 7,000 hours TIS and right spar has 4,000 hours TIS (due to replacement), the left spar may already be overdue while the right spar still has time before its first inspection. The operator must track spar history meticulously. Third, the repair terminates inspections only for that specific spar: many operators assume that once a repair is done on one side, the whole aircraft is relieved. Not so , the unrepaired spar continues on its 2,000-hour cycle. If the left spar is repaired at 8,000 hours and the right spar is not repaired, the right spar must still be inspected every 2,000 hours until it is also repaired (or the aircraft is scrapped). Fourth, the manuals referenced are proprietary and may be expensive or hard to obtain: Fairchild ceased production years ago; current ownership of the technical data may have transferred, and the specified revisions (e.g., Revision C-10 of 2008) may no longer be in print. Operators may need to contact the current data holder (possibly M7 Aerospace or a design organisation) and pay for a copy. Using a later revision that is not listed may not comply , the AD only accepts the specific revisions and dates. Fifth, the repair must be done "before further flight": there is no provision for a ferry permit or a time extension to fly the aircraft to a repair facility. If a crack is found during a scheduled inspection at a field maintenance base that is not equipped for structural repair, the aircraft is grounded until the repair is done or the aircraft is dismantled. Sixth, the 2,000-hour TIS repetitive inspection interval is measured from the last inspection "per the applicable Airworthiness Limitations Manual": if an operator has been conducting inspections under a different manual or at different intervals (e.g., 1,500 hours), the starting point for the 2,000-hour cycle may be earlier than expected. The AD overrides any previous maintenance schedule. Seventh, the repair itself may introduce new inspection thresholds: the SRM reference given (pages 77 through 89) likely includes its own inspection or life limit after repair. The Directive does not describe post-repair requirements; the operator must read the SRM and comply with any additional limitations. **Eighth, the AD does not specify record-keeping requirements explicitly, but under CASR Part 42, operators must record compliance with all mandatory continuing airworthiness information. Failure to keep a log of spar hours and inspection dates could be treated as non-compliance if audited. Ninth, there is no grace period for completing a repair if parts are unavailable: the repair must be done before further flight, so operators should pre-order repair kits and obtain the structural repair manual in advance of the inspection. **Tenth, the Directive is silent on what constitutes a "crack": it does not specify a minimum detectable length or whether hairline cracks are reportable. The inspection method (likely eddy current or dye penetrant) will detect micro-cracks; any crack found, regardless of size, triggers the repair requirement. Operators cannot defer repair on small cracks in the hope they will not propagate.

Compliance requires a systematic process of identification, inspection, repair (if needed), and ongoing tracking. Step 1: Determine applicability. Locate the aircraft type certificate data plate and confirm that the model (e.g., SA227-AC) and serial number fall within the ranges listed in the Directive. If the aircraft is not listed (e.g., serial AC407, which is between AC406 and AC415), the AD does not apply, but the operator should still check if a later amendment extends the range. If the aircraft is imported, verify that the Australian register reflects the correct model and serial.

Step 2: Obtain the correct manuals. Based on the model, obtain the applicable manual at the specified revision level and dated pages. For SA227-TT, SA227-AT, SA227-AC, SA227-BC: either Fairchild Airframe Airworthiness Limitations Manual ST-UN-M001, Revision C-10 dated 27 October 2008, or the earlier Reissue C with specific revision pages dated 16 August 1995, 8 March 2004, and 27 October 2008. For SA226 models: ST-UN-M002 Revision A-11 dated 27 October 2008, or earlier version with pages dated 7 April 1998, 5 October 2005, and 27 October 2008. For SA227-CC/-DC: ST-UN-M003 Revision 8 dated 5 October 2005, or initial issue 6 December 1991 with pages dated 29 July 2003 and 5 October 2005. Obtain the applicable Structural Repair Manual (P/N 27-10054-079 or 27-10054-127) at Revision 38 or 17 dated 30 April 2008, as appropriate. Do not rely on digital copies without verifying revision level.

Step 3: Determine the compliance time for each spar. Calculate for each wing spar (left and right) the later of:

• The date (or hours) when the spar accumulated 6,500 hours TIS.
• 2,000 hours TIS after the last inspection accomplished per the applicable Airworthiness Limitations Manual (i.e., not per this AD, but per any earlier requirement under that manual , likely a previous repetitive inspection on the cutout).
• 500 hours TIS after 7 July 2005.

If the spar has already exceeded all three dates at the effective date of the amendment (9 April 2009), the inspection must be performed immediately. If not yet due, note the due date and start the 2,000-hour recurring cycle from that first inspection.

Step 4: Perform the inspection. Have a licenced engineer or approved maintenance organisation perform the inspection of the wing spar centre web cutout between WS 8 and WS 17.5 on each spar, using the methods prescribed in the applicable manual (likely eddy current or dye penetrant). Record the inspection in the aircraft maintenance log with reference to the AD and manual used. Note the hours TIS on each spar at the time of inspection.

Step 5: If no crack found: Reset the 2,000-hour TIS countdown from this inspection date. Schedule the next inspection accordingly. Ensure that the log book entry clearly states "No cracks found" and references the AD.

Step 6: If a crack is found: The aircraft is grounded immediately. Do not fly until the repair is completed. Obtain the correct SRM pages and perform the repair (or contract an approved repair facility). Completed repair must be recorded in the logbook with reference to the SRM page and revision. After repair, that spar is no longer subject to the repetitive 2,000-hour inspections for the cutout. However, record the repair and the hours at repair for future reference (e.g., if the other spar is later repaired). The unrepaired spar continues to require inspections every 2,000 hours.

Step 7: Ongoing compliance. Maintain a tracking system (e.g., spreadsheet or maintenance software) with separate entries for left and right spars, recording each inspection date and hours TIS. Ensure that the 2,000-hour interval is not exceeded. If the other spar is repaired at a later date, update the tracking accordingly. Keep copies of all manual revisions used, as CASA may audit compliance with the exact revision level.

Step 8: Apply for AMOC if needed. If the required manual revision is unavailable or the manufacturer has issued a superseding revision that is not listed in the AD, apply to CASA for an alternative means of compliance before proceeding. Do not assume that a later revision is automatically acceptable. Similarly, if an inspection method other than that in the manual is proposed (e.g., thermography), seek CASA approval. Document all communications.

Step 9: Review after each amendment. Monitor CASA's website for future amendments to AD/SWSA226/86. Each amendment may update manual revisions or change compliance times. If introduced, recalculate compliance times immediately.

Step 10: Ensure that any foreign operations (e.g., flying an Australian-registered aircraft abroad) comply with the host country's equivalent AD. Some countries may have different compliance dates or inspection intervals; the aircraft must meet the stricter of the two requirements.