{"id":"F2008L01213","name":"AD/AC/93 Amdt 2 - Wing to Fuselage Attachment","slug":"ad-ac-93-amdt-2-wing-to-fuselage-attachment","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":73452,"registerId":"commonwealth-F2008L01213-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Twin Commander (Gulfstream/Rockwell/Aero","sectionType":"division","heading":"Twin Commander (Gulfstream/Rockwell/Aerocommander 500, 600 and 700) Series Aeroplanes","content":"### Twin Commander (Gulfstream/Rockwell/Aerocommander 500, 600 and 700) Series Aeroplanes\n\n| AD/AC/93 Amdt 2 | Wing to Fuselage Attachment | 5/2008 |\n| --------------- | --------------------------- | ------ |\n\n| Applicability: | All models, all serial numbers. |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. For all aircraft except models 520 and 560, gain access to, and inspect, the wing forward attachment brackets and straps (left and right wing) in accordance with PART 1 of Twin Commander Service Bulletin (SB) 223, dated October 24, 1996 as amended by Revision Notice No. 1, dated May 8, 1997 and Revision Notice No. 2, dated August 18, 1997. Replace any cracked part or repair the aircraft using an approved scheme.Note 1: The access holes specified in SB 223 are not mandatory. Alternative access provisions installed in the aircraft in accordance with a CAR 35 approved scheme are acceptable, provided that sufficient access to carry out the required inspections is available. For aircraft modified with a titanium leading edge, by way of an STC, installation of access holes in the leading edge is not possible. It will be necessary to remove the wing root fairing to accomplish the inspection on these aircraft.2. Inspect for cracks in accordance with PART II of Twin Commander Service Bulletin (SB) 223, dated October 24, 1996 as amended by Revision Notice No. 1, dated May 8, 1997 and Revision Notice No. 2, dated August 18, 1997. Replace any cracked part or repair the aircraft using an approved scheme.3. For all aircraft except models 690C and 695, inspect in accordance with PART III of Twin Commander Service Bulletin (SB) 223, dated October 24, 1996 as amended by Revision Notice No. 1, dated May 8, 1997 and Revision NoticeNo. 2, dated August 18, 1997. Repair any cracks found during this inspection using an approved scheme.Note 2: Twin Commander SB 213, mandated by a separate FAA AD, specifies inspections equivalent to Requirement 3 for models 690C and 695.Note 3: FAA AD 98-08-19 refers. |\n\n```html\n

Compliance:

1. For requirement 1, unless already accomplished, inspect before 6000 hours total time in service (TIS) or before 100 hours TIS after 16 July 1998, whichever occurs later. Thereafter, re-inspect at intervals not to exceed 1000 hours time in service. Replace or repair any cracked part before further flight. Compliance with the initial issue of this directive is considered to be prior accomplishment of Requirement 1.

2. For requirement 2, inspect in accordance with the table below.

Model

Initial Inspection

Repeat Inspection for Requirement 2

All models except 520 and 560.

Before further flight, if cracks are found after 15 July, 1998 when complying with Requirement 1. Aircraft that have been inspected in accordance with the initial issue of this directive (or per Requirement 1) before
16 July, 1998, and were found to have cracks, are to be inspected before 100 hours TIS after 16 July, 1998 unless PART II has already been accomplished.

If no cracks are found, repeat inspections at intervals not to exceed 1000 hours TIS.

If cracks are found, replace or repair the cracked item and continue to inspect at intervals not to exceed 6000 hours TIS.

Model 520 and 560.

Before 6000 hours total TIS or before 100 hours TIS after 16 July 1998, whichever occurs later.

If no cracks are found, repeat inspections at intervals not to exceed 1000 hours TIS.

If cracks are found, replace or repair the cracked item before further flight and continue to inspect at intervals not to exceed 6000 hours TIS.

3. For requirement 3, inspect as per the following table.

\n```\n\n```html\n

Model

Initial Inspection

Repeat Inspection for Requirement 3

All affected non-pressurised models

Before 12000 hours total TIS, or before 100 hours TIS after 16 July 1998, whichever occurs later.

If no cracks are found, repeat inspections at intervals not to exceed 1000 hours TIS.

If cracks are found, replace or repair the cracked item before further flight and continue to inspect at intervals not to exceed 1000 hours TIS.

All affected pressurised models.

Before 6000 hours total TIS, or before 100 hours TIS after 16 July 1998, whichever occurs later.

If no cracks are found repeat inspections at intervals not to exceed 1000 hours TIS.

If cracks are found, replace or repair the cracked item before further flight and continue to inspect at intervals not to exceed 1000 hours TIS.

This Amendment becomes effective on 8 May 2008.

Background:

Cracks have been found on several affected aircraft in the fuselage frame and surrounding structure at the wing leading edge attachment. Left undetected and uncorrected the structural integrity of the wing to fuselage attachment may be affected and cause catastrophic structural failure.

This amendment is issued to correct a typographical error to the FAA AD reference in Note 3. There is no change to the requirement or compliance section of this AD.

Amendment 1 of this airworthiness directive became effective on 9 November 2005.

The original issue of this airworthiness directive became effective on 9 November 1995.

\n```\n\n![](image.001.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n27 March 2008","sortOrder":0},{"sectionNumber":"AD/AC/93 Amdt 2","sectionType":"part","heading":"AD/AC/93 Amdt 2","content":"## AD/AC/93 Amdt 2","sortOrder":1},{"sectionNumber":"Wing to Fuselage Attachment","sectionType":"part","heading":"Wing to Fuselage Attachment","content":"## Wing to Fuselage Attachment","sortOrder":2},{"sectionNumber":"5/2008","sectionType":"part","heading":"5/2008","content":"## 5/2008","sortOrder":3}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":6,"scope_assessment":{"changed":false,"description":"This is Amendment 2 to an existing Airworthiness Directive. The Background section explicitly states this amendment only corrects a typographical error in Note 3 (the FAA AD reference) and confirms 'There is no change to the requirement or compliance section of this AD.' The scope remains limited to wing-to-fuselage attachment inspections as originally intended in 1995."},"complexity_factors":["Multiple nested compliance tables with model-specific exceptions (520/560, 690C/695, pressurised vs non-pressurised)","Three distinct inspection requirements (Parts I, II, III) with different applicability across aircraft models","Cross-references to external documents: Twin Commander Service Bulletin 223 (with two revision notices), FAA AD 98-08-19, and CAR 35 approval schemes","Conditional logic for repeat inspection intervals that change based on findings (1,000 hours if no cracks found, 6,000 hours if cracks found and repaired for Requirement 2)","Alternative compliance pathways (Note 1 allows alternative access provisions if CAR 35 approved, STC modifications require different inspection methods)","Temporal compliance triggers ('whichever occurs later' calculations involving flight hours and specific calendar dates)"],"plain_english_summary":"Owners and operators of Twin Commander 500/600/700 series aircraft must perform repeated inspections of wing-to-fuselage attachment brackets and surrounding structure for cracks, and repair or replace any cracked components before further flight. The AD targets a risk of catastrophic wing separation and applies varying inspection schedules by model; this Amendment 2 only corrects a typographical reference to the related FAA directive, without changing safety requirements."},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":false,"description":"This Amendment (Amdt 2) only corrects a typographical error to the FAA AD reference cited in Note 3 and states explicitly that there is no change to the requirements or compliance sections of the AD. The core scope — mandatory inspections, repair/replacement obligations, model exceptions and compliance timing — remains the same as the original directive and earlier amendment. (Amendment note; Background)"},"complexity_factors":["Multiple model‑specific exceptions and distinctions (e.g. models 520/560; models 690C/695; pressurised vs non‑pressurised models)","Three separate mandated requirements mapped to Parts I, II and III of Twin Commander SB 223","Cross‑references to external documents: SB 223 (with two revision notices), SB 213, FAA AD 98‑08‑19","Conditional initial compliance timing using both total time in service (TIS) thresholds and a historical 100‑hour-after‑date provision (16 July 1998 / 15 July 1998)","Different repeat intervals depending on whether cracks are found (1000 hours vs 6000 hours) and by Requirement/model","Approval conditions for alternative access (CAR 35) and for repairs (approved repair schemes) introduce regulator discretion and external approval steps","Special access constraint for STC‑modified (titanium leading edge) aircraft requiring removal of wing root fairing","Amendment history and notes (typographical correction only) increasing cross‑document reading to confirm no substantive change","Multiple conditional flows in tables (if no cracks → X interval; if cracks → repair + Y interval)"],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- This is an airworthiness directive requiring inspections of the wing-to-fuselage attachment structure on Twin Commander series aeroplanes (Aero/Gulfstream/Rockwell Commander 500, 600 and 700 series).\n- It mandates three sets of inspections (called Requirement 1, Requirement 2 and Requirement 3) carried out in accordance with Twin Commander Service Bulletin (SB) 223 (Parts I, II and III respectively) as amended by the listed revision notices. Any cracked parts found must be replaced or the aircraft repaired using an approved repair scheme. (Requirements 1–3)\n- The directive applies to all models and serial numbers, but contains model-specific exceptions and timing differences: Requirement 1 and 2 exclude models 520 and 560 in places; Requirement 3 excludes models 690C and 695 (those are subject to a different service bulletin/FAA AD). (Applicability; Requirements 1–3; Notes 2–3)\n- Access-hole drawings in SB 223 are not mandatory: alternative access that has CAR 35 approval is acceptable. Aircraft modified with a titanium leading edge (by STC) must remove the wing root fairing to carry out the inspection because the SB access holes cannot be installed. (Note 1)\n\n**Key compliance timings and repeat intervals (practical summary)**\n\n- Requirement 1 (wing forward attachment brackets and straps, both left and right): initial inspection \"before 6000 hours total time in service (TIS) or before 100 hours TIS after 16 July 1998, whichever occurs later\" for all aircraft except models 520/560. Thereafter re‑inspect at intervals not to exceed 1000 hours TIS. Replace or repair cracked parts before further flight. (Requirement 1)\n\n- Requirement 2 (PART II of SB 223): initial and repeat timing depends on model and whether cracks were found when complying with Requirement 1. For most models initial inspection is \"before further flight\" if cracks were found after 15 July 1998 during Requirement 1; otherwise special transitional timing applies. If no cracks are found, repeat every 1000 hours TIS. If cracks are found, replace/repair and continue inspections at intervals not to exceed 6000 hours TIS (model-dependent). For models 520 and 560 the initial inspection is before 6000 hours TIS (or before 100 hours after 16 July 1998) and repeats are 1000 hours if no cracks; if cracks are found repair before further flight and continue inspections at intervals not to exceed 6000 hours. (Requirement 2; table)\n\n- Requirement 3 (PART III of SB 223): timing differs by pressurised vs non‑pressurised models. Non‑pressurised models: initial inspection before 12000 hours TIS (or before 100 hours after 16 July 1998), repeat every 1000 hours if no cracks; if cracks found, repair before further flight and continue at 1000‑hour intervals. Pressurised models: initial before 6000 hours TIS (or before 100 hours after 16 July 1998), repeat every 1000 hours; if cracks found repair before further flight and continue at 1000‑hour intervals. Models 690C and 695 are excluded from this Requirement because Twin Commander SB 213 (mandated by a separate FAA AD) covers equivalent inspections. (Requirement 3; table; Note 2)\n\n**Official rationale and the directive's stated safety objective**\n\n- The directive says cracks were found in the fuselage frame and surrounding structure at the wing leading edge attachment. It states that, left undetected and uncorrected, this might affect the structural integrity of the wing‑to‑fuselage attachment and could cause catastrophic structural failure. The inspections and mandated repairs are intended to detect and fix such cracks before they compromise structural integrity. (Background)\n\n**Practical effects — who pays, who decides, and what changes**\n\n- Who pays: aircraft owners/operators pay for the inspections, any repairs/replacements, and the associated aircraft downtime and labour. Replacement parts or approved repairs may also incur parts and certification costs. (Requirements 1–3: \"Replace any cracked part or repair the aircraft using an approved scheme\")\n- Who decides/approves: the directive requires repairs \"using an approved scheme\" and allows alternative access only if it has CAR 35 approval, so compliance and repair methods are subject to regulator approval (CASA/approved maintenance organisations). (Note 1)\n- Behaviour change: operators must schedule and perform the specific inspections at the mandated times and intervals, and ground aircraft until cracked items are repaired/replaced. Maintenance organisations will carry out the inspections and approved repairs; some aircraft will need additional disassembly (e.g. remove wing root fairing for titanium leading edge STC aircraft). (Note 1)\n\n**Costs, incentives, trade‑offs and implementation risk**\n\n- Direct costs: recurring inspection labour, non‑destructive testing, potential part replacement or structural repairs, and aircraft downtime. These are borne by operators. (Requirements 1–3)\n- Concentrated vs diffuse impacts: the costs concentrate on operators of affected Twin Commander models; maintenance providers gain demand for inspections and repairs. Parts suppliers for the wing‑fuselage attachment and repair specialists may see concentrated benefit. (Requirements/repair mandate)\n- Incentives and private response: operators facing high repair costs may prefer more frequent inspections to detect problems earlier, or conversely could opt to retire or sell heavily‑used airframes where repair is uneconomic. Aircraft modified under STCs (e.g. titanium leading edge) face higher access costs (removing fairing) and therefore higher inspection costs. (Note 1)\n- Implementation risks: inspection effectiveness depends on access quality and inspector skill; the AD relies on SB 223 Parts I–III (external documents) and on approved repairs—bottlenecks in approval, or limited availability of qualified repair schemes, can delay compliance or increase costs. (Requirement references; repair approval requirement)\n- Compliance burden and operational trade‑offs: mandated intervals (some short, e.g. 1000 hours) create recurring maintenance obligations and possible increased operating cost. If cracks are found and repair is required before further flight, operators may suffer immediate operational disruption. (Requirements 1–3)\n\n**Cross‑references and reliance on external documents**\n\n- The AD mandates inspections \"in accordance with\" Twin Commander SB 223 (Parts I–III) as amended — compliance therefore requires following the external SB details. The AD also references Twin Commander SB 213 and an FAA AD for particular models and equivalence. (Requirements; Note 2; Note 3)\n\n**Bottom line (mechanics and consequence)**\n\n- Mechanically, this AD obliges operators of Twin Commander 500/600/700 series aeroplanes to inspect specified wing‑to‑fuselage attachment components at model‑dependent intervals, repair or replace cracked items with regulator‑approved methods, and follow the inspection schedules set out in SB 223. The stated safety purpose is to prevent structural failure due to undetected cracks. Operators bear the inspection and repair costs, must obtain regulator approval for alternative access or repairs, and may face operational disruption if defects are found. (Requirements 1–3; Notes 1–3; Background)\n"}},"importantCases":[],"_links":{"self":"/api/acts/ad-ac-93-amdt-2-wing-to-fuselage-attachment","history":"/api/acts/ad-ac-93-amdt-2-wing-to-fuselage-attachment/history","analysis":"/api/acts/ad-ac-93-amdt-2-wing-to-fuselage-attachment/analysis","conflicts":"/api/acts/ad-ac-93-amdt-2-wing-to-fuselage-attachment/conflicts","importantCases":"/api/acts/ad-ac-93-amdt-2-wing-to-fuselage-attachment/important-cases","documents":"/api/acts/ad-ac-93-amdt-2-wing-to-fuselage-attachment/documents"}}