AD/BEECH 90/48 Amdt 2 - Wing Spar Fitting Fatigue - Inspection

The directive relies on three core concepts: targeted inspection of a known fatigue-prone structural detail, model-specific inspection options calibrated to the fitting geometry, and a prescriptive repair-before-flight requirement when fatigue cracking is detected.

1. Targeted inspection of “bathtub” fittings. The AD is focused on the “bathtub” portion of the four outer wing to centre section main spar lower attachment fittings, a location with “known fatigue history” according to the Background. The scope is limited to aircraft that retain the bathtub-type fittings; later-production aircraft fitted with clevis fittings are excluded from applicability (Applicability; Background). The AD therefore defines a discrete structural population for surveillance rather than a fleetwide generic rule.

2. Model-tailored NDT procedures. The AD specifies fluorescent liquid penetrant inspection as the primary method for most models (Requirement 2). It authorises eddy current (pencil probe) as an alternative in the SIRM for non-F90 models, with the operational trade-off that if eddy current is used the recurring inspection interval may be doubled (Requirement 2; Compliance). For F90 aircraft the SIRM provides different charts and index numbers and allows either penetrant (Requirement 3) or a separate eddy current procedure (Requirement 4). The text therefore treats the choice of NDT method as a lever for inspection frequency and for paint-stripping requirements (paint strip required for penetrant inspections, not required for eddy current per Requirement 2 and Requirement 4).

3. Immediate, component-level safety control. The AD imposes a before-further-flight replacement obligation when certain cracks are found: replacement of the complete outer wing main spar lower cap where a fatigue crack is found in an outer wing fitting, and replacement of the affected component only where the crack is in a centre section fitting (Requirement after 4). That rule converts detection into an immediate operational constraint on aircraft availability and repair action.

Ancillary technical management issues are embedded in the notes: the AD instructs operators to disregard a SIRM “Warning” advising against paint removal where the AD requires paint strip (Note 1), to apply protective treatment after paint removal to prevent corrosion (Note 1), to prefer solvent removers and avoid mechanical/abrasive paint removal (Note 2), to use a fine brush for penetrant application to minimise false indications (Note 3), and to avoid polishing suspect indications so as not to obscure cracks (Note 4). Inspection of bolts and nuts is delegated to a separate AD (AD/BEECH 90/69) (Note 5).

Mechanically, the AD sets inspection thresholds and recurring intervals in hours component time in service or calendar years depending on aircraft model and chosen NDT method (Compliance). It also provides transitional relief by recognising prior inspections carried out under previous AD issues as satisfying the initial inspection requirement (Note 6).

The directive directly affects three identifiable groups named in the AD text.

1. Aircraft operators and owners of specified Beechcraft models. The Applicability section names all model 65-90, 65-A90, B90, C90, and E90 aircraft, except serial nos. LJ-1085 and LJ-1088 and subsequent, and all model F90 aircraft except serial nos. LA-226 and subsequent. Operators of those serial-numbered aeroplanes that remain within the listed population must carry out the inspections and repairs required by the AD. The Background clarifies that later-production aircraft fitted with clevis fittings are excluded; operators must therefore determine conformity of fittings to decide applicability.

2. Maintenance organisations and NDT providers. The Requirements and Notes set out specific inspection technologies and methods: fluorescent liquid penetrant inspection, eddy current pencil-probe inspection, paint stripping and protective priming, solvent choice, and penetrant application technique (Requirements 2-4; Notes 1-3). Those tasks will fall to certificated maintenance organisations, licensed engineers and specialist nondestructive testing (NDT) technicians. Note 4 explicitly directs seeking specialist NDT advice where suspect indications require confirmation.

3. Regulators and compliance personnel. The AD is issued by CASA under subregulation 39.1(1) of the Civil Aviation Regulations 1998 and is entered in the Schedule of Airworthiness Directives (opening paragraph and final paragraph). CASA delegates (as exemplified by the signing delegate) are identified as the issuing authority, and regulatory staff will need to track compliance, maintain the AD schedule and link to cross-referenced ADs (such as AD/BEECH 90/69 for bolt and nut inspection). The AD’s effective date and Gazette notification are administrative points for regulators (effective 2 November 2000; Gazette notified 4 October 2000).

Indirectly the AD affects supply and logistics chains: spare parts providers for outer wing main spar lower caps and centre section fittings will face demand if cracks are found; paint suppliers and consumables (zinc chromate primer, solvent removers) and providers of NDT equipment and training will be engaged; and aircraft downtime will shift scheduling for operators and possibly impact charter or scheduled operations. The AD itself specifies replacement before further flight when fatigue cracks are found, which converts inspection findings directly into parts procurement and maintenance labour costs. The text also cross-references AD/BEECH 90/69 for bolt and nut inspection, creating a linked compliance obligation for operators to monitor.

Duties imposed by the AD are explicit and prescriptive. Rights are limited to specified alternatives and the recognition of prior compliant inspections.

Key duties

• Remove bolts and strip paint: Requirement 1 mandates removal of the wing main spar lower attachment bolts “in accordance with the manufacturer’s instructions” and stripping all paint from the “bathtub” portion of the four fittings. The duty to follow the manufacturer’s instructions places responsibility on operators and maintenance organisations to consult and implement SIRM or other approved maintenance instructions when removing bolts.

• Conduct specified inspections: For non-F90 models Requirement 2 requires a fluorescent liquid penetrant inspection of all four fittings in accordance with SIRM P/N 98-39006B3 (revised 28 May 1999), Chapter 57-13-01 or 57-13-02 as applicable. The AD specifies attention to the bolt counterbore and fillet radius when inspecting the bathtub portion. For model F90 Requirement 3 prescribes fluorescent penetrant inspection per SIRM Chapter 57-14-01 Chart 201 Index No. 1, with attention to specified radii; Requirement 4 authorises an eddy current inspection per SIRM Chapter 57-14-01 Chart 201 Index No. 2. Each inspection must be carried out at the times in the Compliance section.

• Repair before flight: Where a fatigue crack is found the AD mandates replacement before further flight: for an outer wing fitting crack the entire outer wing main spar lower cap must be replaced; for a centre section fitting crack replace the affected component only (post-Requirement paragraph). That duty converts a finding into an immediate operational constraint.

• Follow SIRM references: Inspections must be carried out “in accordance with the Beechcraft Structural Inspection and Repair Manual (SIRM) P/N 98-39006B3 as revised May 28 1999” where the AD references specific chapters and charts (Requirements 2-4). The AD also instructs operators to disregard a SIRM “Warning” about not removing paint where the AD requires paint removal (Note 1).

Permitted rights/alternatives

• Choice of NDT method where authorised: The AD allows an alternative eddy current inspection to the fluorescent penetrant inspection for non-F90 models (Requirement 2) where eddy current is detailed in Chapter 20-00-00 of the SIRM; that alternative removes the paint-strip requirement. For F90 models, Requirement 4 provides an eddy current procedure as an alternative to penetrant inspection, again without a paint-strip requirement.

• Extended inspection interval with eddy current: For the non-F90 models, if the eddy current procedure is used the recurring inspection interval may be doubled (Compliance). This trade-off is explicitly permitted in the AD and represents an operational choice available to operators who can perform eddy current inspection.

• Transition recognition: Note 6 recognises inspections performed under previous issues of this AD or related ADs as satisfying the initial inspection requirement of this amendment. That gives operators a limited retrospective credit where previous inspections were carried out under predecessor ADs.

Ancillary duties specified in notes

• Apply protective treatment after paint removal to prevent corrosion (Note 1).

• Use solvent removers wherever possible and ensure complete removal of stripper residue when chemical removal is unavoidable; avoid mechanical or abrasive means of paint removal (Note 2).

• Apply penetrant with a fine artist’s brush to simplify penetrant removal and minimise false indications (Note 3).

• Do not polish out suspect indications; seek specialist NDT advice if confirmation is required (Note 4).

• Inspect bolts and nuts per AD/BEECH 90/69 (Note 5).

Taken together the AD prescribes specific technical steps, timing and repair outcomes; it allows operator choice between two NDT techniques in certain circumstances, but converts detection of fatigue cracking into an immediate mandatory repair obligation before further flight.

The AD is issued under the regulatory authority of subregulation 39.1(1) of the Civil Aviation Regulations 1998, which is the provenance the AD explicitly cites in its opening paragraph. The AD itself is placed in the Schedule of Airworthiness Directives and records effective date and Gazette notification (effective on 2 November 2000; notified in the Commonwealth Gazette on 4 October 2000). The AD text does not set out monetary penalties or a schedule of sanctions; rather, the instrument is presented as a regulatory requirement issued under CAR 1998.

Enforcement therefore flows from the Civil Aviation Regulations framework; the AD’s legal effect derives from being issued under subregulation 39.1(1). The document identifies the CASA delegate as the issuer of the AD and records the revocation of the prior amendment in favour of this consolidated AD. The AD makes compliance mandatory by specifying that the actions set out are “action that the delegate considers necessary to correct the unsafe condition” and must be taken “in relation to the aircraft” in the circumstances and at the times stated (opening paragraph). That language signals the AD’s status as a regulatory instrument under CASA’s powers.

Because the AD text does not set out penalties, the precise enforcement tools and sanctions for non-compliance are those provided elsewhere in the Civil Aviation Regulations 1998. The AD does supply procedural enforcement elements relevant to compliance monitoring: specific inspection thresholds and intervals (Compliance), model and serial-numbered applicability (Applicability), mandatory removal and inspection steps (Requirements 1-4), and mandatory replacement before further flight when fatigue cracks are found. Those prescriptions create clear compliance obligations that CASA inspectors or authorised persons can verify during maintenance audits, airworthiness checks or continuing airworthiness oversight.

Practical enforcement implications for operators are therefore these: failure to have carried out inspections at the required times or to have completed required repairs when cracks are found would mean the aircraft was continued in service contrary to an AD issued under CAR 1998. The AD’s recognition of prior inspections (Note 6) provides limited relief for meeting initial inspections, but record evidence of prior compliant inspections will be material for enforcement assessments. The AD does not elaborate on appeals, waivers or alternative means of compliance; any such relief or exemptions would need to be sought through the established regulatory mechanisms in CAR 1998 and CASA procedures, which are not spelled out in the AD text.

The AD explicitly situates itself within the Civil Aviation regulatory architecture by being issued “under subregulation 39.1 (1) of CAR 1998” and placed in the Schedule of Airworthiness Directives, signalling that its force and enforceability are derived from CAR 1998. The AD therefore operates as an instrument implementing the continuing airworthiness regime under those Regulations. The AD is not a standalone contractual instruction; it is a regulatory requirement with operational and maintenance consequences for aircraft registered or operating under Australian jurisdiction.

Interaction with the manufacturer’s instructions. The AD requires inspections “in accordance with the Beechcraft Structural Inspection and Repair Manual (SIRM) P/N 98-39006B3 as revised May 28 1999” (Requirements 2-4). The AD therefore cross-references and depends on the SIRM for specific NDT procedures and chart/index references. However the AD also modifies how the SIRM is to be applied in practice: Note 1 instructs operators to disregard the SIRM Chapter 20-00-00 “Warning” regarding not removing paint for penetrant inspections where the AD requires paint strip, and mandates application of protective treatment after paint removal to prevent corrosion. That creates an explicit regulatory override of a manufacturer warning where safety surveillance requires paint removal for inspection.

Cross-reference to other ADs. The AD cross-references AD/BEECH 90/69 in Note 5 for inspection of bolts and nuts. It also consolidates AD/BEECH 90/47 and AD/BEECH 90/48 Amdt 1 into the single AD/BEECH 90/48 Amdt 2 (Background). Note 6 recognises inspections carried out under previous issues of this or related ADs as satisfying initial inspection requirements, creating a continuity link for regulatory compliance. Operators therefore must manage a set of ADs as an integrated compliance package rather than treating this AD in isolation.

Interaction with international directives. The Background recounts an in-flight failure on a King Air 65-90 aeroplane in Canada and references Canadian emergency AD CF 79-06 as the basis for an earlier amendment. While the current AD is an Australian instrument issued by CASA, the Background shows that foreign occurrences and foreign authority directives have influenced the development and tightening of inspection intervals historically. The AD text itself, however, does not incorporate foreign law; it remains an Australian regulatory instrument.

Operational and maintenance law interplay. The AD conditions maintenance tasks (paint removal, NDT method selection, component replacement) on compliance with the SIRM where referenced and on the AD’s own notes where they instruct departure from SIRM warnings. This creates a hierarchy for technicians and organisations: comply with the AD as the regulator’s mandatory instruction; use the SIRM for techniques and charts where the AD references it; follow AD notes where they instruct a different approach to SIRM guidance (e.g. paint removal and post-stripping treatment). Any alternative procedures, waivers or different inspection philosophies would need regulatory approval under CAR 1998 processes; the AD text does not authorise other deviations.

Recordkeeping, airworthiness certificates and continuing airworthiness obligations are implicated but not detailed in the AD. The AD’s obligations will feed into statutory continuing airworthiness duties under CAR 1998 and into maintenance release and aircraft logbook records that operators are required to keep under those Regulations; the AD itself does not specify those recordkeeping procedures but places actions and intervals that must be reflected in an aircraft’s maintenance history.

The AD text contains its own amendment chronology and the rationale for the current reissue.

• Original AD: The document records that the original issue of this Airworthiness Directive became effective on 30 June 1977. The genesis was the “known fatigue history of the ‘bathtub’ fittings” which prompted the initial surveillance requirement (Background).

• Amendment 1: Amdt 1 was issued by Telex on 24 May 1979. The 1979 amendment reduced the inspection threshold and interval for most models after an in-flight failure of an outer wing fitting on a King Air 65-90 in Canada, and following the Canadian emergency AD CF 79-06 (Background). That suggests the first amendment tightened the schedule in response to an operational failure.

• Consolidation and Amdt 2: The present document is Amendment 2 and it revokes AD/BEECH 90/48 Amdt 1. The Background describes Amdt 2 as the outcome of a review which “confirmed the need for the requirement and the appropriateness of the inspection intervals.” It consolidates AD/BEECH 90/47 and AD/BEECH 90/48 Amdt 1 into a single AD, curtails applicability to exclude later-production aircraft with clevis fittings, aligns the AD requirements with the Beechcraft SIRM to the extent possible, allows eddy current inspection as an optional alternative to fluorescent penetrant with an associated increase in the repetitive inspection interval, adds the E90 model that shares the same fittings as earlier models, and adds the F90 model which uses different fittings and for which SIRM inspection procedures and intervals have been adopted (Background).

• Effective and notification dates: The amendment becomes effective on 2 November 2000, and the AD is notified in the Commonwealth Gazette on 4 October 2000 (final paragraph). The document is signed by the CASA delegate, giving it formal administrative effect (signed 22 September 2000).

• Relationship to SIRM updates: The AD points to a specific revision of the SIRM, P/N 98-39006B3 as revised 28 May 1999, for procedural guidance in Requirements 2-4. This indicates that the AD aligns with a then-current manufacturer revision. Where SIRM guidance conflicts with the AD (specifically the SIRM warning discouraging paint removal for penetrant inspections), the AD instructs operators to disregard that particular SIRM warning (Note 1). This indicates an amendment history not only of the AD but an interplay with manufacturer documentation revisions.

• Transitional recognition: Note 6 provides transitional accommodation by recognising prior inspections conducted under earlier AD issues as satisfying the initial inspection requirements of this amendment. That reduces redundant inspection burden for operators already compliant prior to this amendment.

The amendment history therefore shows an initial directive prompted by a known fatigue problem, a tightening in response to a field failure and foreign regulator action, and a later consolidation and technical alignment with manufacturer procedures while retaining regulator-specified departures where necessary for safety surveillance.

The AD text itself does not record any litigation associated with this instrument. It provides a factual background of operational events and regulatory amendments, including the in-flight failure in Canada that prompted the 1979 amendment and the existence of Canadian emergency AD CF 79-06 (Background). Beyond these historical events and the statement of administrative action (revocation of the prior amendment and reissue under CAR 1998), there are no case names, litigation outcomes, judicial reviews, or tribunal decisions referenced in the text.

For readers seeking legal challenge or judicial context, the AD should be treated as a regulatory instrument issued under CAR 1998. The text states the basis of issuance (subregulation 39.1(1) of CAR 1998) and records administrative steps (effective date, Gazette notification, delegate signature). Any challenges to an AD would therefore arise under the procedural and substantive review mechanisms applicable to administrative decisions under CAR 1998 and general administrative law. The AD does not itself set out appeal procedures or administrative review routes.

Because the AD explicitly revokes a prior scheduled AD amendment and consolidates other ADs, the administrative record may include service history and correspondence between CASA and industry stakeholders; none of that is reproduced in this AD text. The only historical enforcement-like event recorded is the operational failure in Canada cited as the impetus for Amendment 1. The absence of litigation citations in the AD means the AD text does not provide any source-grounded litigation history to report.

If parties require information on any enforcement actions, administrative reviews or judicial proceedings that may have followed the AD’s issuance, that material is not contained in this AD document and would have to be located in CASA files, Federal Court records or other administrative law repositories; it is not presented within the source text.

This AD contains a number of technical and administrative pitfalls operators and maintainers must be alert to when implementing it.

1. Applicability is serial-number specific and tied to fitting type. The Applicability section excludes serial nos. LJ-1085, LJ-1088 and subsequent for the 65-90 family, and LA-226 and subsequent for F90 aircraft. The Background clarifies that later production aircraft fitted with clevis fittings are excluded. Operators must verify actual fitting configuration and serial number against the AD before assuming applicability; misidentifying the fitting type or serial number could result in applying unrequired procedures or, conversely, failing to inspect a relevant aircraft.

2. Paint removal versus SIRM warning conflict. The SIRM Chapter 20-00-00 contains a “Warning” discouraging removal of paint for penetrant inspections; the AD expressly instructs operators to disregard that SIRM warning (Note 1). The practical gotcha is confusion among technicians trained to follow the SIRM warning. The AD requires paint strip for penetrant inspections on non-F90 aircraft (Requirement 1 and 2) and directs application of protective treatment afterwards. Maintenance personnel must follow the AD where it conflicts with SIRM warnings, and apply the protective treatment specified to prevent corrosion (Note 1).

3. Choice of NDT affects frequency and paint stripping. If eddy current is used for non-F90 models, paint strip is not required and the recurring inspection interval may be doubled (Requirement 2; Compliance). For F90 the eddy current procedure is a separately referenced chart with different threshold and recurring hour requirements (Requirements 3 and 4; Compliance). Misapplication of intervals (e.g. using the doubled interval without having used eddy current, or misunderstanding the different interval regime for F90) is a compliance risk.

4. Replacement-before-flight imposes parts and downtime costs. The AD requires replacement before further flight when fatigue cracks are found: complete outer wing main spar lower cap replacement for outer wing fitting cracks; only the affected component for centre section fittings (post-Requirement paragraph). For outer wing fittings this means a substantial component change and likely significant downtime and parts expense. Operators must plan for parts inventory and maintenance capacity.

5. Paint-stripping methods and corrosion. The AD specifies solvent removers are preferred, that if other paint strippers are used residue must be completely removed, and that mechanical or abrasive paint removal must be avoided (Note 2). Failure to remove stripper residue or use abrasive removal could either obscure defects or cause corrosion initiation sites. Note 1 also warns to apply protective treatment (e.g. standard zinc chromate primer) between inspections to prevent corrosion where paint has been removed.

6. False indications and evidence treatment. Note 3 recommends applying penetrant with a fine brush to minimise false indications, and Note 4 warns against polishing suspect indications because that practice has obscured large cracks in the past. The gotcha is that improper handling of suspect indications,polishing, misinterpreting a false indication, or failing to seek specialist NDT confirmation,can lead to either missed cracks or unnecessary disassembly and parts replacement.

7. Bolt and nut inspection is elsewhere. Note 5 points maintenance personnel to AD/BEECH 90/69 for inspection of bolts and nuts. A gotcha is assuming this AD covers bolt and nut condition; it does not. Operators must coordinate compliance across linked ADs.

8. Records and prior inspections. Note 6 recognises inspections carried out in accordance with previous issues of this or related ADs as satisfying the initial inspection requirement. The practical trap is poor recordkeeping: operators must have verifiable maintenance records of earlier inspections to claim that recognition. If records are incomplete, the operator may have to perform the initial inspection.

9. Model-specific attention points. The AD prescribes particular attention to bolt counterbore and fillet radius in the bathtub portion, and for F90s to the radius at the end of the barrel nut recess in the outer wing fitting (Requirements 2 and 3). Missing these targeted attention points can result in undetected fatigue cracks in locations that the AD highlights as critical.

10. Timing units differ: hours versus calendar years. Compliance intervals are expressed differently for different models and methods. For non-F90 models the initial and recurring intervals are tied to component hours and may be doubled with eddy current; for F90 the penetrant interval is expressed as not exceeding 5 calendar years (Requirement 3), while the F90 eddy current regime is in hours (initial before exceeding 20,000 hours and recurring at intervals not exceeding 1,200 hours,Requirement 4). Misreading or mixing these units can lead to missed inspections.

Operators and maintainers should therefore pay careful attention to model and serial-number applicability, the specific SIRM chart/index references cited, the distinctions between penetrant and eddy current procedures, and the AD notes that alter or qualify SIRM guidance.

Compliance requires a sequence of checks, inspections and remedial actions conforming to the AD text and the referenced SIRM. The AD supplies both the procedures to be followed and the timing; this section sets those out as a practical checklist strictly grounded in the AD.

1. Confirm applicability. Check the aircraft model and serial number against the Applicability section: all model 65-90, 65-A90, B90, C90, and E90 aircraft except serial nos. LJ-1085, and LJ 1088 and subsequent; all model F90 aircraft except serial nos. LA-226 and subsequent. Verify the fitting type: if the aircraft has later-production clevis fittings then the AD’s bathtub-focused requirements do not apply (Background).

2. Review SIRM references. Obtain and review Beechcraft SIRM P/N 98-39006B3 as revised May 28 1999, and identify the correct chapter/chart/index for your model: for non-F90 models use Chapter 57-13-01 Chart 201 Index Nos. 1 and 10, or Chapter 57-13-02 Chart 201 Index Nos. 1 and 5 as applicable (Requirement 2); for F90 use Chapter 57-14-01 Chart 201 Index No. 1 for penetrant or Index No. 2 for eddy current (Requirements 3-4). If using the eddy current alternative for non-F90 models, follow the eddy current procedure detailed in Chapter 20-00-00 of the SIRM (Requirement 2).

3. Schedule inspections at required intervals. For models 65-90, 65-A90, B90, C90 and E90, perform Requirements 1 and 2 prior to exceeding 3,000 hours component time in service and thereafter at intervals not exceeding 200 hours component time in service; if eddy current is used for these models, the recurring inspection interval may be doubled (Compliance). For model F90: perform Requirement 3 (penetrant) at intervals not exceeding 5 calendar years; or perform Requirement 4 (eddy current) prior to exceeding 20,000 hours component time in service and thereafter at intervals not exceeding 1,200 hours component time in service (Compliance). Record previous inspections; Note 6 recognises prior inspections under earlier ADs as satisfying the initial inspection where applicable.

4. Execute Requirement 1: removal and paint strip. Remove the wing main spar lower attachment bolts in accordance with the manufacturer’s instructions (Requirement 1). For penetrant inspections, strip all paint from the “bathtub” portion of the four fittings. Follow Note 2 guidance on paint removal: prefer solvent removers; ensure complete removal of residue if non-solvent strippers are used; avoid mechanical/abrasive means of paint removal.

5. Perform the specified inspection method. For non-F90 models, perform a fluorescent liquid penetrant inspection per the cited SIRM chapter/chart/index, paying particular attention to bolt counterbore and fillet radius in the bathtub portion (Requirement 2). As an alternative for non-F90, perform an eddy current (pencil probe) inspection per Chapter 20-00-00 of the SIRM; if eddy current is used paint strip is not required (Requirement 2). For F90 aircraft, perform fluorescent penetrant inspection per Chapter 57-14-01 Chart 201 Index No. 1 with the attention points specified, or perform the eddy current inspection per Chapter 57-14-01 Chart 201 Index No. 2 which does not require paint strip (Requirements 3-4).

6. Apply penetrant technique and handling notes. If using penetrant, follow Note 3: apply the penetrant to the counterbore and recess radii using a fine artist’s paint brush to simplify removal and minimise false indications; ensure full coverage of the fillet radius and at least 5 mm into the cylindrical portion of the counterbore, particularly on the side adjacent to the “bottom of the bathtub.” Do not attempt to polish out suspect indications (Note 4). If confirmation of a suspect indication is needed, seek specialist NDT advice (Note 4).

7. If paint has been removed, apply protective treatment. After paint stripping, apply a protective treatment, such as a standard zinc chromate primer, between inspections to prevent corrosion as directed in Note 1.

8. Deal with findings immediately. If a fatigue crack is found in an outer wing fitting, replace the complete outer wing main spar lower cap before further flight; if a crack is found in a centre section fitting, replace the affected component only (Requirement after 4). Do not return the aircraft to service pending these mandatory replacements.

9. Coordinate bolt and nut inspection. Note 5 directs inspection of bolts and nuts in the current issue of AD/BEECH 90/69. Ensure that those inspections are scheduled and performed in coordination with the bathtub fitting inspections, and that any bolt or nut defects identified are rectified per AD/BEECH 90/69.

10. Maintain records and verification. Although the AD does not prescribe recordkeeping detail, Note 6’s recognition of prior compliant inspections for initial inspection credit highlights the importance of verifiable maintenance records. Keep inspection records, NDT reports, and parts replacement documentation that show compliance with the AD’s intervals and repair-before-flight obligations.

11. Use qualified personnel and equipment. The AD explicitly contemplates specialist NDT involvement when suspect indications require confirmation (Note 4). Ensure that personnel performing penetrant or eddy current work are qualified for the method used, that they follow the SIRM chart instructions referenced in the AD, and that equipment is calibrated and suitable for the procedure.

12. Administrative compliance. Ensure paperwork reflects the AD’s effective date (2 November 2000) and that maintenance releases or continuing airworthiness statements reference the AD where appropriate. If an operator seeks alternatives to the methods or intervals in the AD, this will require engagement with CASA under CAR 1998 procedures; the AD text does not authorise ad hoc deviations.

Following these steps, strictly as prescribed in the AD and by reference to the SIRM chapters cited, will place an operator in the position of compliance as defined by AD/BEECH 90/48 Amdt 2.