{"id":"F2006L01066","name":"AD/CONVAIR/16 - Wing Front Spar Lower Rail","slug":"ad-convair-16-wing-front-spar-lower-rail","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":58376,"registerId":"commonwealth-F2006L01066-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Kelowna Flightcraft (General Dynamics/Co","sectionType":"division","heading":"Kelowna Flightcraft (General Dynamics/Convair) Series Aeroplanes","content":"### Kelowna Flightcraft (General Dynamics/Convair) Series Aeroplanes\n\n| AD/CONVAIR/16 | Wing Front Spar Lower Rail | 5/2006 |\n| ------------- | -------------------------- | ------ |\n\n| Applicability: | Model 340 and 440 aircraft, and all such model aircraft converted to turbopropeller power.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. For aircraft with 23,500 or more hours time in service:Remove the wing leading edge and perform a visual inspection of the left and right wing front spar lower rail between wing stations 240 and 490 for cracks. If cracking is detected, repair in accordance with Requirement 3 before further flight.2. For aircraft with less than 23,500 hours time in service:Remove the wing leading edge and perform a visual inspection of the left and right wing front spar lower rail between wing stations 240 and 490 for cracks. If cracking is detected, repair in accordance with Requirement 3 before further flight.During the inspections pay particular attention to the areas immediately adjacent to the leading edge joints at wing stations 248, 264, 363, and 484. All reported cracks have originated in the rail forward flange at or near the leading edge attach screw holes.3. If a crack is confined to the wing front spar lower rail, repair in accordance with General Dynamics/Convair Service Engineering Report No.057-0/67-340-64/440-64/640-35, Revision 1 or later FAA Approved revision. If a crack extends beyond the spar rail into adjacent components, contact the Type Certificate Holder for technical advice.The repetitive inspections required in Requirements 1 and 2 may be discontinued when all cracks, if any, have been repaired in accordance with Requirement 3, and unless already accomplished in accordance with Requirement 3, a reinforcing strap has been installed in accordance with details (a) and (b), Figure 1, of General Dynamics/Convair Service Engineering Report No.057-0/67-340-64/440-64/640-35, Revision 1.Note: FAA AD 68-10-04 Amdt 39-2247 refers. |\n\n| Compliance: | 1. Unless the initial inspection is already accomplished, within 300 hours time in service after 11 May 2006 unless accomplished within the last 700 hours time in service. Thereafter at intervals not to exceed 1,000 hours time in service.2. Before the accumulation of 23,800 hours time in service. Thereafter at intervals not to exceed 1,000 hours time in service.3. Before further flight. |\n| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|             | This Airworthiness Directive becomes effective on 11 May 2006.                                                                                                                                                                                                                                                                                                                                        |\n| Background: | The FAA received several reports of cracks in the wing front spar lower rail. Undetected cracking could result in failure of the outboard wing.                                                                                                                                                                                                                                                       |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n31 March 2006","sortOrder":0},{"sectionNumber":"AD/CONVAIR/16","sectionType":"part","heading":"AD/CONVAIR/16","content":"## AD/CONVAIR/16","sortOrder":1},{"sectionNumber":"Wing Front Spar Lower Rail","sectionType":"part","heading":"Wing Front Spar Lower Rail","content":"## Wing Front Spar Lower Rail","sortOrder":2},{"sectionNumber":"5/2006","sectionType":"part","heading":"5/2006","content":"## 5/2006","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with focused scope. It addresses a specific safety-critical structural defect identified by the FAA and applies only to the affected Convair aircraft models. The scope remains tightly constrained to the wing spar inspection and repair requirements without expansion into unrelated operational or maintenance areas."},"complexity_factors":["Short, single-purpose document focused on one specific structural issue","Clear applicability section limiting scope to specific aircraft models","Straightforward conditional logic (two categories based on flight hours)","Minimal cross-referencing (only one external engineering document and one FAA AD)","No nested exceptions or complex defined terms","Simple compliance timeline with two alternative pathways","Single technical requirement (visual inspection) with prescribed repair method"],"plain_english_summary":"This AD mandates removal of the wing leading edge and visual inspection of the front spar lower rail on certain Convair 340/440 aircraft (including turboprop conversions) for cracks, with time‑based repeat inspections and required repairs before further flight. Repetitive inspections cease only after crack repair and installation of a reinforcing strap.\n\nIssued by CASA’s delegate, it responds to discovered spar cracking that could lead to outboard wing failure, so it affects operators of the listed Convair types and is legally mandatory."},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":false,"description":"This AD is narrowly focused on addressing reported cracking in the wing front spar lower rail of Convair Model 340 and 440 aeroplanes. Its measures—inspection, repair per the Type Certificate Holder's service report, and optional discontinuation of repetitive inspections after reinforcement—are consistent with a remedial safety action limited to that structural problem. The instrument does not broaden coverage beyond those models or add unrelated regulatory obligations, so it does not represent a significant change in scope beyond the original safety‑correction purpose."},"complexity_factors":["Two time‑based condition sets (aircraft with ≥23,500 hours and <23,500 hours) with different initial compliance triggers (Requirement 1–2; Compliance 1–2)","Intrusive inspection requirement (removal of wing leading edge) across a defined wing station range (stations 240–490) with specified local focus points (stations 248, 264, 363, 484) (Requirement 1–2)","Mandatory repair standard cross‑referencing an external engineering report (General Dynamics/Convair Service Engineering Report No.057‑0/67‑340‑64/440‑64/640‑35, Revision 1 or later FAA‑approved revision) (Requirement 3)","Conditional logic allowing discontinuation of repetitive inspections only after repair and installation of a reinforcing strap to specific drawing details (Requirement 3)","Different compliance timing rules (300 hours unless inspection done within last 700 hours; before 23,800 hours for lower‑time aircraft; recurring 1,000‑hour intervals) (Compliance)","Cross‑reference to FAA AD and requirement to consult Type Certificate Holder if cracks extend beyond the rail (Note; Requirement 3)","Technical ambiguity risk where repair scope extends into adjacent components and requires bespoke Type Certificate Holder advice (Requirement 3)"],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- Requires visual inspections of the wing front spar lower rail on Convair Model 340 and 440 aeroplanes (including those converted to turboprop power). The inspection is done after removal of the wing leading edge and covers the left and right spar lower rails between wing stations 240 and 490, with special attention to the areas around the leading edge joints at stations 248, 264, 363 and 484. (Requirement 1–2)\n- If cracks are found that are confined to the spar rail, the operator must repair them in accordance with the specified General Dynamics/Convair Service Engineering Report (Revision 1 or later FAA‑approved revision). If cracks extend beyond the rail into other parts, the operator must contact the Type Certificate Holder for technical advice. (Requirement 3)\n- Repetitive inspections may be stopped only after all cracks, if any, are repaired and a reinforcing strap has been installed as shown in Figure 1 of the Service Engineering Report. (Requirement 3)\n- The AD expressly refers to the related FAA airworthiness directive and the General Dynamics/Convair Service Engineering Report for repair and reinforcement details. (Note)\n\n**Who is affected**\n\n- Owners and operators of Convair Model 340 and 440 aircraft, including aircraft converted to turboprop power. (Applicability)\n- Maintenance organisations and licensed engineers who perform the inspections and repairs (they must follow the Service Engineering Report and obtain Type Certificate Holder advice where required). (Requirement 3)\n\n**Key timing and compliance rules**\n\n- For aircraft with 23,500 or more hours total time in service: initial inspection if not already done, within 300 flight hours from 11 May 2006 (unless the inspection was done in the previous 700 hours). Thereafter, repeat inspections at intervals not exceeding 1,000 flight hours. (Compliance 1)\n- For aircraft with less than 23,500 hours: inspect before reaching 23,800 hours total time in service. Thereafter, repeat inspections at intervals not exceeding 1,000 flight hours. (Compliance 2)\n- Repairs must be completed before further flight if cracking is found. (Compliance 3)\n\n**Why it matters (stated purpose and mechanical effect)**\n\n- The FAA received multiple reports of cracks in the wing front spar lower rail; undetected cracking could lead to outboard wing failure. The AD’s stated purpose is to find and repair such cracks to maintain structural integrity. (Background)\n\n**Practical implications, incentives and trade‑offs**\n\n- Who pays: aircraft owners/operators pay for removal of the leading edge, inspections, any repairs, and installation of the reinforcing strap. (Requirement/Compliance)\n- Who decides: operators decide inspection scheduling within the prescribed windows; licensed maintenance providers must carry out the inspection and repair work; the Type Certificate Holder must be consulted where cracks extend beyond the rail. (Requirement 3)\n- Behavioural change required: operators must schedule and perform intrusive inspections earlier and more frequently than routine line maintenance, and must complete mandated repairs before next flight if cracks are found. (Requirements and Compliance)\n- Costs and opportunity costs: the measure imposes direct maintenance costs and aircraft downtime (leading edge removal is non‑trivial work), and may reallocate maintenance shop capacity toward these inspections and repairs for affected aircraft types.\n- Effects on private enterprise: creates demand for specialised maintenance work (benefit to authorised repair facilities), may temporarily reduce aircraft availability and revenue for operators, and may raise operating costs for older Convair 340/440 fleets.\n- Implementation risk and compliance burden: the inspection requires removal of the leading edge (logistical and technical burden), accurate inspection to detect small cracks, and correct repair per the Service Engineering Report; if cracking extends into adjacent components, additional engineering input from the Type Certificate Holder is mandatory, adding time and potential cost variability. (Requirement 3)\n- Scope and permanence: the AD imposes continuing repetitive inspections (1,000‑hour intervals) until the structural repair and reinforcing strap are installed, at which point the repetitive inspections may be discontinued. This gives operators a path to a one‑time modification to remove recurring inspection burden. (Requirement 3)\n\n**Cross‑references and sources to follow for technical work**\n\n- Repairs and reinforcing strap installation must follow General Dynamics/Convair Service Engineering Report No.057‑0/67‑340‑64/440‑64/640‑35, Revision 1 or later FAA‑approved revision. The AD also references FAA AD 68‑10‑04 Amdt 39‑2247 for related material. (Requirement 3 and Note)\n\n"},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-convair-16-wing-front-spar-lower-rail","history":"/api/acts/ad-convair-16-wing-front-spar-lower-rail/history","analysis":"/api/acts/ad-convair-16-wing-front-spar-lower-rail/analysis","conflicts":"/api/acts/ad-convair-16-wing-front-spar-lower-rail/conflicts","importantCases":"/api/acts/ad-convair-16-wing-front-spar-lower-rail/important-cases","documents":"/api/acts/ad-convair-16-wing-front-spar-lower-rail/documents"}}