AD/CHA/23 Amdt 4 - Wing Spars

The AD is constructed around a small set of interlocking technical and regulatory concepts anchored in the safety oversight framework. Those concepts are:

• Applicability by model and configuration: The AD separates affected aircraft into Group 1 and Group 2 based on model series and engine modification status (Applicability). Group 1 lists a set of models that have not been modified to incorporate engines greater than 90 hp. Group 2 covers another set of models and additionally any Group 1 aircraft modified to have engines greater than 90 hp. This creates a classification mechanism that changes inspection frequency and adds coverage to modified airframes.
• Detailed visual inspection as the compliance mechanism: The AD uses "detailed visual inspection of the entire length of the front and rear wood wing spars" as the primary compliance action (Requirement 1). The inspection is defined by defect types to look for: cracks, compression cracks, longitudinal cracks through boltholes or nail holes, and loose or missing rib nails (Requirement 1). The AD ties the inspection procedure to a particular service technical document , ACAC Service Letter No. 406 Rev A , and prescribes the use of a high-intensity flexible light for part of the inspection (Requirement 1).
• Event-driven inspection trigger: The AD requires the same inspection to be performed in the event of any accident or incident involving wing damage occurring after the effective date (Requirement 2). This creates an immediate pre-flight gate: if an accident/incident causes wing surface deformation or other wing damage, inspection must be completed before further flight (Compliance 2).
• Repair-or-replace remedy standardised to accepted data: If damage is discovered, the AD does not prescribe a single repair design. Instead it requires repair or replacement "in accordance with Advisory Circular 43.13-1B, Acceptable Methods, Techniques, and Practices; or other data that is FAA-approved for wing spar repair or replacement" (Requirement 3). The AD thus delegates the technical acceptability to recognised FAA-approved practices and data.
• Timing and recurrence rules: The compliance regime is time-based and hours-based. For both groups there is an initial inspection deadline tied to annual inspection scheduling relative to 22 March 2001, and Group 2 is subject to repeating inspections "not to exceed 500 hours time in service or 12 calendar months, whichever occurs first" (Compliance 1). Additionally, post-accident or post-damage inspections must be done "before further flight" (Compliance 2-3).
• Regulatory provenance and interaction with FAA ADs: The AD explicitly references and aligns with FAA actions (Background, Note). It revokes the earlier amendment and replaces it with this amended directive (opening paragraph). The background states the amendment responds to a new FAA AD, retains prior actions for some models, and extends actions to other series (Background).

Each of these concepts defines practical choices for operators and maintainers: how to classify an airframe; what inspection technique and tools to use; when inspections must be scheduled; what constitutes a defect; what repair standards are acceptable; and how the AD fits with prior Australian and FAA directives. The AD therefore blends prescriptive inspection methodology with delegated technical approval for repairs, while imposing enforceable time and event triggers.

The AD affects a defined set of stakeholders directly and indirectly. The primary impacted parties are:

• Aircraft owners and operators of the listed American Champion (Aeronca, Bellanca) models. The AD lists two groups of models in the Applicability paragraph. Group 1 models are those that have not been modified to incorporate engines greater than 90 horsepower; Group 2 lists additional models and explicitly incorporates any Group 1 aircraft that have been modified to incorporate engines greater than 90 horsepower. Owners/operators of those models must comply with the inspection and repair requirements set out in the AD (Applicability; Requirements; Compliance).
• Maintenance organisations and certificated aircraft maintenance engineers (AMEs) responsible for annual inspections and for carrying out the detailed visual inspections. The AD requires the inspections to be performed in accordance with ACAC Service Letter No. 406 Rev A (Requirement 1) and repairs to follow AC 43.13-1B or FAA-approved data (Requirement 3). Those documents are the technical standard referenced by the AD and therefore define the methods, tooling and acceptance criteria maintenance personnel must use.
• Pilots and operators who must not return an aircraft to flight if an inspection reveals damage: the AD requires repairs before further flight when damage is found and also mandates inspection before further flight after any post-22 March 2001 accident/incident involving wing damage (Compliance 2-3). That creates a gate on flight operations for the operator until the maintainers confirm compliance.
• Owners who have modified engines greater than 90 horsepower. The AD increases the scope of affected aircraft by including modified Group 1 aircraft in Group 2; such owners are subject to Group 2 repetitive inspection intervals that differ from Group 1 (Applicability; Compliance 1).
• CASA and its delegate, who exercise enforcement discretion and administrative action. The AD is issued under subregulation 39.1(1) of CAR 1998 by the CASA delegate, whose signature appears on the document. That delegate revoked the prior amendment and established the new inspection and repair regime (opening paragraph; signature).
• Suppliers of inspection tooling and parts: the AD prescribes a high-intensity flexible light as the FAA-approved inspection option (Requirement 1) and prohibits the use of a regular flashlight for that portion of the inspection. Suppliers of Bend-A-Light type devices or equivalent FAA-approved flexible lights will be relevant to compliance. Similarly, suppliers of repair materials and components acceptable under AC 43.13-1B or FAA-approved data will be in demand if spars require repair or replacement.

Indirectly affected parties include insurers and operators of shared or club aircraft, where costs and grounding time imposed by the inspection/repair schedule will be borne by owner/operators; and any third-party maintenance providers whose workflow is altered by the repeated inspections, the tool requirement and the repair standard referenced.

The AD's applicability and compliance structure assigns duties to individual aircraft owners/operators and certifying maintenance entities rather than to manufacturers; however it references manufacturer service letters (ACAC Service Letter No. 406 Rev A) and FAA ADs as part of the compliance chain, so implementers must coordinate with the technical material provided by the original equipment activity (ACAC) and FAA-approved methods.

The AD sets out a concise set of mandatory duties and prescribes permitted technical standards for remedies. The duties and rights it creates are:

Mandatory duties

• Conduct an initial, detailed visual inspection of the entire length of the front and rear wood wing spars for specific defects. The defects listed are cracks, compression cracks, longitudinal cracks through boltholes or nail holes, and loose or missing rib nails. The inspection must be accomplished "in accordance with the instructions in ACAC Service Letter No. 406, Revision A, dated May 6, 1998" (Requirement 1).
• Use the specified inspection means for part of the check: the Service Letter "specifies, as an FAA-approved inspection option, using a high-intensity flexible light (e.g., 'Bend-A-Light'). A regular flashlight must not be used for this portion of the inspection" (Requirement 1). This is a duty to use the approved inspection technique rather than any substitute torchlight.
• Perform the inspection after any accident or incident involving wing damage occurring after 22 March 2001 (Requirement 2).
• Repair or replace any wood spar where damage is found, following Advisory Circular 43.13-1B or other FAA-approved data for wing spar repair or replacement (Requirement 3).
• Adhere to the timing and recurrence rules: initial inspections at the first annual inspection occurring 30 calendar days or more after 22 March 2001, or within the next 13 calendar months after that date, whichever is later (Compliance 1). Group 2 must thereafter repeat inspections at intervals not to exceed 500 hours time in service or 12 calendar months (Compliance 1). Inspections must also be completed before further flight after an accident/incident or after discovering damage (Compliance 2-3).

Prescribed rights and permitted technical options

• The AD permits the use of "other data that is FAA-approved for wing spar repair or replacement" as an alternative to AC 43.13-1B (Requirement 3). That is a right to rely on FAA-approved repair data as acceptable repair authority for compliance.
• The Service Letter offers an FAA-approved inspection option (Requirement 1). The AD thereby recognises certain alternative inspection methods authorised by the FAA, subject to the Service Letter's content.
• The AD does not mandate a single repair design or force a conversion away from wooden spars; it allows repair or replacement consistent with the accepted maintenance standard (Requirement 3).

Operational effects of duties

• Duty to ground until compliance: the requirement to inspect and to repair before further flight after damage is found or after an accident/incident (Compliance 2-3) is a functional duty to ground the aircraft until an AME or maintenance organisation performs the work and certifies the aircraft as airworthy.
• Scheduling duty: the timing rules (initial timing tied to the annual inspection cycle and recurrent intervals for Group 2) create a duty for operators to schedule inspections within those windows and to maintain records demonstrating compliance.

Delegation and discretion

• Technical discretion is delegated to those authorised to use FAA-approved data and AC 43.13-1B. The AD does not prescribe exact repair drawings; rather it requires compliance with those recognised technical authorities.
• Administrative discretion sits with CASA in issuing the AD and its amendments; the AD revokes the prior amendment and establishes the new requirements under subregulation 39.1(1) of CAR 1998 (opening paragraph), reflecting the regulator’s authority to modify airworthiness directives in light of new information.

In sum, the AD imposes specific inspection and repair duties, prescribes accepted technical standards as the route to compliance, and requires operators and maintenance organisations to schedule and certify work before flight. It also sets out particular tools and inspection methods that must be used as specified in the referenced Service Letter.

The AD is issued under subregulation 39.1(1) of CAR 1998 (opening paragraph), which supplies the regulatory authority for CASA to require corrective action for unsafe conditions. The AD itself sets out mandatory actions and compliance times; however the AD text does not specify monetary penalties, infringement notice amounts, or judicial sanction provisions within the document. The enforcement mechanism indicated by the AD is administrative: CASA, through its delegate, revokes the prior amendment and issues the AD as an enforceable direction.

What the AD explicitly provides on enforcement and effect:

• Legal provenance: the AD is issued under the regulatory authority granted by CAR 1998 (opening paragraph), signalling that non-compliance would engage the regulatory enforcement regime administered by CASA under the Civil Aviation Regulations (as referenced). The AD replaces the prior AD/CHA/23 Amdt 2 (opening paragraph).
• Effective date and notification: the directive becomes effective 22 March 2001 and was notified in the Commonwealth of Australia Gazette on 21 February 2001, with the delegate’s signature dated 9 February 2001 (effective date statement; Gazette notice; signature). These administrative steps create a clear effective date for compliance windows.
• Operability gating: the AD creates operational enforcement in practice because it requires inspections and repairs "before further flight" in specified circumstances (Compliance 2-3). This means that an aircraft that has not complied with the directive after sustaining wing damage may be considered unfit for flight under the AD’s terms until the required action is completed. That practical gating is an enforcement lever , operators must either comply or accept aircraft grounding.
• Delegated technical acceptance: the AD permits repairs in accordance with AC 43.13-1B or "other data that is FAA-approved." Enforcement therefore rests partly on whether repairs were performed in conformity with those referenced, FAA-approved standards. Compliance records showing adherence to those standards will be material in any enforcement action.
• Reference to FAA ADs: the AD notes FAA ADs and FAA-approved options (Requirement note and Background). Aligning with FAA documents does not alter CASA’s enforcement authority, but it does create technical criteria CASA can review to determine compliance.

What the AD does not state

• The AD does not itself enumerate specific penalties for failure to comply; it does not provide infringement amounts, disqualification provisions, or criminal penalties within the text. The enforcement consequences must therefore be inferred as falling within the broader regulatory enforcement toolkit of CASA and the Civil Aviation Regulations; the AD provides the mandatory standard that enforcement will apply against.
• The AD does not set out an appeal, exemption or alternative method of compliance process within the text. It references FAA-approved alternative methods in technical terms (for example, FAA-approved repair data and FAA-approved inspection options in the Service Letter), but it does not include procedural instructions for seeking CASA approval of alternative methods in this document.

For practitioners advising clients, the AD is an enforceable regulatory instrument whose practical enforcement levers are aircraft grounding until compliance, review of maintenance records for conformity with the referenced AC and FAA-approved data, and any discretionary regulatory action CASA may take under the broader CAR 1998 enforcement scheme. The AD itself supplies the substantive standards; enforcement details (penalties, notices, appeals) are not specified in this text.

The AD situates itself within a network of regulatory instruments and technical standards, and the text explicitly cross-references several non‑statutory technical documents and foreign airworthiness directives. The interactions are as follows:

• Civil Aviation Regulations (CAR 1998): The AD is issued under subregulation 39.1(1) of CAR 1998 (opening paragraph). That reference places the AD within the statutory/regulatory framework administered by CASA. The AD therefore derives its legal force from the CAR 1998 provision that empowers CASA to require corrective action for unsafe conditions. The AD text, however, does not reproduce subregulation 39.1(1) or detail procedural matters under CAR 1998; it simply identifies the issuing authority.
• Prior ADs: The AD revokes AD/CHA/23 Amdt 2 and replaces it with Amendment 3 (opening paragraph). The Background states Amendment 2 required repetitive inspections and installation of inspection holes (Background). Amendment 3 is said to retain some actions of FAA AD 98-05-04 for Model 8GCBC and to extend actions to other series (Background). The AD therefore operates as a successor instrument that alters the prior AD’s scope and methods.
• FAA airworthiness directives and FAA-approved data: The AD expressly references FAA documentation. There is a Note that "FAA AD 2000-25-02 Amdt 39-12036 refers" and the Background describes the AD as issued "in response to a new FAA AD" which retains and extends FAA actions (Note; Background). Additionally, the AD requires repairs in accordance with Advisory Circular 43.13-1B or "other data that is FAA-approved" (Requirement 3) and references an ACAC Service Letter that specifies an FAA-approved inspection option (Requirement 1). These cross-references mean that the technical compliance standards for repairs and inspection methods are anchored to FAA-approved material and manufacturer service letters. Practically, compliance with the AD entails reliance on foreign (FAA) technical approvals as acceptable methods under CASA’s AD.
• Manufacturer service letter: ACAC Service Letter No. 406 Rev A, dated 6 May 1998, is the technical procedural document specified for accomplishing the inspections (Requirement 1). The AD’s inspection method and tooling (high-intensity flexible light) are drawn from that service letter. The AD therefore requires compliance with a manufacturer-provided procedure; its obligations interact with contractual and technical obligations between operators and maintenance organisations.
• Advisory Circulars: The AD references Advisory Circular 43.13-1B as the standard for "Acceptable Methods, Techniques, and Practices" for repair/replacement (Requirement 3). Although AC 43.13-1B is a non-binding advisory in some regulatory regimes, the AD makes compliance with the AC a mandatory path to satisfying the AD’s repair requirement by explicitly adopting it as acceptable repair data. This effectively elevates the AC to a required standard for AD compliance.
• Gazette notification and administrative law: The AD was notified in the Commonwealth of Australia Gazette on 21 February 2001 (closing paragraph). That administrative step is evidence of formal publication and administrative procedural compliance for the directive’s promulgation. The sequence of signature (9 February 2001), Gazette notice (21 February 2001) and effective date (22 March 2001) reflects the administrative timeline for the AD to take effect.

Gaps and delegation interactions

• No domestic penalty clause in the AD: The AD itself does not set out penalty provisions; enforcement will be via the CAR 1998 regime and CASA’s enforcement powers, so practitioners must look to the broader regulatory law to understand penalty mechanics. The AD interacts with those laws by creating the substantive standard that enforcement assesses.
• Reliance on foreign approvals: The AD’s reliance on FAA-approved methods and FAA ADs establishes a technical dependency on foreign technical approvals and documents for compliance. The AD does not state any domestic equivalence process; it simply prescribes FAA-approved data and the AC as the acceptable avenues.

Overall, the AD integrates with technical and regulatory documents across manufacturer service letters, Advisory Circulars, and FAA-approved data, while operating under CASA’s statutory authority under CAR 1998. Operators must therefore coordinate compliance across these documents to meet the AD’s requirements.

The AD itself contains a succinct amendment history embedded in the text. The relevant chronology and changes are:

• Original AD: The original issue of Airworthiness Directive AD/CHA/23 became effective on 3 December 1987 (Background).
• Amendment 1: Amendment 1 became effective on 16 May 1991 (Background).
• Amendment 2: Amendment 2 became effective on 12 August 1999. According to the Background, Amendment 2 required repetitive inspections of the front and rear spars for damage, and included installing any necessary inspection holes, and repairing or replacing any damaged spar. The FAA actions that prompted Amendment 2 resulted from an in-flight wing structural failure on one of the affected aircraft and additional incidents and service difficulty reports (Background).
• Amendment 3 (current): Amendment 3 revokes AD/CHA/23 Amdt 2 and issues the current AD. Amendment 3 was issued in response to a new FAA AD; it retains the actions of FAA AD 98-05-04 for the Model 8GCBC aircraft, extends the actions to all 7, 8, and 11 series aircraft, and "incorporates alternative methods of accomplishing the actions." The Background states Amendment 3 arises from a review of the service history of affected aircraft that incorporate wood wing spars and from damage found on the spars (Background). The current AD became effective on 22 March 2001 (effective date statement). The delegate signed the AD on 9 February 2001 and it was notified in the Commonwealth Gazette on 21 February 2001 (signature and Gazette notice).

What the amendment history shows in procedural terms

• Progressive extension and refinement: The AD history reflects an incremental approach: the original AD in 1987, subsequent amendments in 1991 and 1999, and the current amendment in 2001 extending scope and adopting alternative methods. Each amendment appears to respond to accumulating service data: incidents, accidents and service difficulty reports (Background).
• Shifts in technical scope: Amendment 2 introduced more prescriptive measures such as inspection holes and repetitive inspections (Background). Amendment 3 retains some previous FAA actions while explicitly extending coverage to additional model series and incorporating alternative methods , the current AD therefore both broadens applicability and allows FAA-approved alternatives (Background; Requirements).
• Synchronisation with FAA action: The AD states that Amendment 3 was issued in response to a new FAA AD, and the AD text notes the FAA AD reference (Note; Background). This suggests the amendment process was coordinated to align CASA’s AD with FAA findings and directive actions.

Practical effect for operators

• Operators with aircraft that were in compliance with earlier ADs must note that Amendment 3 changes coverage and methods. For example, the Background references an in‑flight failure on an aircraft in compliance with AD 87-18-09 plus multiple other incidents that prompted broader action; Amendment 3 responds by expanding inspection scope and methods (Background).
• The effective dates set the windows for initial and recurring inspections; Amendment 3’s effective date (22 March 2001) is the anchor for the compliance timing rules in the current AD (Compliance 1).

The AD’s internal amendment history is the authoritative source for how the directive evolved, what prior actions were replaced, and when the current obligations became effective.

The AD text contains no references to litigation, court decisions, or administrative appeals. It refers only to administrative and technical documents (FAA ADs, ACAC Service Letter No. 406 Rev A, Advisory Circular 43.13-1B) and to the administrative actions of CASA (revocation of Amdt 2, issuance of Amdt 3, signature and Gazette notice). The document does not cite any legal cases, does not summarise litigation around the AD or affected aircraft, and does not indicate any pending or resolved litigation relating to the AD within the text.

Therefore, based solely on the supplied AD document:

• There is no litigation history recorded in this AD.
• The AD’s background references accidents and service difficulty reports as factual bases for regulatory action, but it does not reference any judicial or tribunal proceedings arising from those accidents or from the AD itself.
• Any litigation, appeals, or enforcement actions that may have occurred outside the AD are not documented in this text.

Practitioners seeking litigation history or precedent related to this AD, affected models, or the underlying safety incidents will need to consult external court and tribunal records or CASA enforcement records. Those materials are not contained in, nor summarised by, the AD text supplied here.

The AD contains several details and implicit operational consequences that invite careful attention; these are concrete "gotchas" drawn from the text that can produce non‑compliance risk or unexpected costs if missed:

• The tool requirement is specific and restrictive. The Service Letter specifies using a "high-intensity flexible light (e.g., 'Bend-A-Light')" as the FAA-approved inspection option and states "A regular flashlight must not be used for this portion of the inspection" (Requirement 1). Using a standard torch for the high‑intensity inspection portion will not meet the AD’s prescribed method and could be considered non‑compliant. Ensure inspection tooling meets the Service Letter’s specification and document tool calibration/condition.
• Applicability depends on engine modification status. Group 2 includes "any of the Group 1 aircraft that have been modified to incorporate an engine with greater than 90 horsepower" (Applicability). Owners who have performed engine modifications must ensure their classification is accurate. Misclassification could result in incorrect inspection intervals (Group 2 has repetitive inspection intervals while Group 1 does not).
• Initial inspection timing is anchored to a specific date. The initial inspection occurs at "the first annual inspection that occurs 30 calendar days or more after 22 March 2001 or within the next 13 calendar months after 22 March 2001, whichever occurs later" (Compliance 1). Operators must calculate this window correctly relative to their annual inspection schedule and the effective date; miscalculation could leave an aircraft out of compliance.
• Repetitive inspection intervals apply only to Group 2. The AD requires Group 2 to "repetitively inspect thereafter at intervals not to exceed 500 hours time in service or 12 calendar months, whichever occurs first" (Compliance 1). Group 1 has no repetitive interval specified in the AD text beyond the initial inspection; presuming recurrence for Group 1 could be erroneous, and failing to apply the Group 2 recurrence to modified Group 1 aircraft would be non‑compliant.
• Post-accident/incident inspections impose immediate pre‑flight gates. Requirement 2 requires inspection "If, after 22 March 2001 any aircraft is involved in an accident/incident that involves wing damage ... accomplish the inspection specified in Requirement 1." Compliance 2 demands inspection "Before further flight after each accident/incident that involved wing damage." Operators must not resume flight until the inspection is completed and any necessary repairs certified.
• The AD references other technical documents for repairs and inspection methods. Repairs must be done "in accordance with Advisory Circular 43.13-1B ... or other data that is FAA-approved for wing spar repair or replacement" (Requirement 3). The AD therefore requires operators to rely on and keep access to those external documents and to demonstrate that repairs were performed using the accepted data. If a repair uses non-FAA-approved methods, it may be non‑compliant even if technically sound.
• Amendment 2 required installing inspection holes; Amendment 3’s Requirement does not repeat that language. The Background states Amendment 2 required installing any necessary inspection holes (Background), but Requirement 1 in Amendment 3 requires inspection "in accordance with the instructions in ACAC Service Letter No. 406 Rev A." Operators must check whether Service Letter No. 406 Rev A retains the inspection hole requirement; do not assume the AD’s Background alone authorises or cancels installation of inspection holes without consulting the Service Letter.
• The AD permits FAA-approved alternatives but does not set a domestic alternative approval process in the text. The Background and Requirements reference FAA-approved options, but the AD does not describe how to obtain CASA approval for alternative methods or repairs that rely on non-FAA but otherwise acceptable data. Operators should document FAA-approval status and be prepared to show the linkage.
• The AD does not specify recordkeeping formats or documentation retention periods. Although the AD mandates inspections and repairs against referenced standards, it does not detail how to record compliance. Practitioners must therefore rely on normal maintenance recordkeeping practices and anticipate that CASA will expect documentation demonstrating that the inspection followed ACAC Service Letter No. 406 Rev A and repairs followed AC 43.13-1B or FAA‑approved data.

These are concrete operational points where attention to the AD text, the referenced Service Letter, and the repair standards is required to avoid non-compliance and unexpected grounding or rework.

Compliance under this AD requires a mix of scheduling, technical adherence to referenced documents, tooling, and certification steps. The AD’s Requirements and Compliance sections provide the substantive obligations. Suggested practical steps consistent with the AD text are:

1. Determine applicability and classification

   • Review each aircraft’s model and engine configuration against the AD’s Applicability list. If the aircraft model is listed under Group 1 and has not been modified to incorporate an engine greater than 90 hp, it is Group 1. If the model appears in Group 2, or if a Group 1 aircraft has been modified to >90 hp, classify it as Group 2 (Applicability).
   • Record this classification in the aircraft’s maintenance records and any continuing airworthiness documentation.

2. Schedule initial inspections according to the AD timetable

   • For both Group 1 and Group 2, the initial inspection is at the first annual inspection that occurs 30 calendar days or more after 22 March 2001, or within 13 calendar months after 22 March 2001, whichever is later (Compliance 1). Calculate the appropriate window and schedule the inspection during that annual inspection.
   • For Group 2 aircraft, schedule subsequent recurring inspections at intervals not to exceed 500 hours time in service or 12 calendar months, whichever occurs first (Compliance 1). Implement a tracking mechanism (logbook entry, maintenance tracking software) to ensure inspections are triggered by hours or calendar time.

3. Acquire and use the specified inspection documentation and tooling

   • Obtain ACAC Service Letter No. 406 Revision A, dated 6 May 1998, and use it as the operative inspection procedure (Requirement 1). Ensure maintenance personnel have read and understand that Service Letter.
   • Acquire a high-intensity flexible light (e.g., "Bend-A-Light") or an equivalent that is recognised in the Service Letter as the FAA‑approved inspection option. Do not use a regular flashlight for that portion of the inspection, as the Service Letter disallows it (Requirement 1). Document the type and condition of inspection lighting used.

4. Perform the detailed visual inspection

   • Inspect the entire length of the front and rear wood wing spars for the defects specified in the AD: cracks, compression cracks, longitudinal cracks through boltholes or nail holes, and loose or missing rib nails (Requirement 1).
   • Follow the step-by-step instructions in ACAC Service Letter No. 406 Rev A for visual access, inspection angles, and any specific probing or use of the flexible light for internal visualisation.

5. Post-accident/incident inspection trigger

   • If the aircraft is involved in any accident or incident after 22 March 2001 that involves wing damage (such as surface deformations, abrasions, gouges, scratches, or dents), perform the inspection specified in Requirement 1 before any further flight (Requirement 2; Compliance 2). Do not return the aircraft to service until the inspection and any necessary repairs are completed and certified.

6. Repair or replace damaged spars under the prescribed standards

   • If the inspection reveals damage, repair or replace the wood spar "in accordance with Advisory Circular 43.13-1B" or using other FAA-approved data for wing spar repair or replacement (Requirement 3). Obtain and apply the specific repair data, drawings or instructions that are FAA-approved and appropriate to the damage discovered.
   • Ensure repairs are certified by appropriately authorised maintenance personnel and that work packs and entries demonstrate adherence to AC 43.13-1B or to the cited FAA-approved data.

7. Certify and document compliance

   • Record inspection results, tools used, Service Letter reference, findings, corrective actions and the identity of the certifying maintenance personnel in the aircraft maintenance records.
   • For recurring Group 2 inspections, maintain a schedule and entries showing hours/time in service calculations and calendar dates for the next required inspection.

8. Consider interaction with prior AD requirements and inspection holes

   • Review ACAC Service Letter No. 406 Rev A to determine if installation of inspection holes is required or recommended in practice; the AD’s Background notes that Amendment 2 required installing any necessary inspection holes, but the current Requirement references the Service Letter for inspection instructions (Background; Requirement 1). Follow the Service Letter’s current revision instructions for access methods and any hole installations, and document any airframe modifications.

9. Maintain access to FAA-approved data and AC 43.13-1B

   • Keep copies of Advisory Circular 43.13-1B and any FAA-approved repair data used so maintenance records can reference the exact repair standard relied upon, as the AD requires FAA-approved data for repairs (Requirement 3).

10. Prepare for CASA review and enforcement

    • Because the AD is issued under subregulation 39.1(1) of CAR 1998 and the effective date is 22 March 2001, ensure that maintenance records demonstrably show that the required actions were completed within the prescribed windows and to the referenced technical standards. Operators should be ready to show this documentation to CASA if requested.

By following these practical steps, an operator aligns work with the AD’s explicit mandates: using ACAC Service Letter No. 406 Rev A for inspection procedures, the specified high-intensity flexible light option, and AC 43.13-1B or FAA-approved repair data for corrective work. The AD’s text makes these references the operative standards for compliance.