{"id":"F2006L01096","name":"AD/CONVAIR/11 - Main Windshield Lower Longeron Splice Channel","slug":"ad-convair-11-main-windshield-lower-longeron-splice-channel","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":58441,"registerId":"commonwealth-F2006L01096-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/11 | Main Windshield LowerLongeron Splice Channel | 5/2006 |\n| ------------- | -------------------------------------------- | ------ |\n\n| Applicability: | Model 340 and 440 aircraft, and all such model aircraft converted to turbopropeller power.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Inspect the main windshield lower longeron splice channel part number (P/N) 340-3110113-15 for cracks in accordance with General Dynamics 640 (340D) Service Bulletin (SB) No. 53-3, dated 24 April 1970.2. If no cracks are detected, repeat the Requirement 1 inspection.3. If cracks are detected, either:a. Replace the longeron splice channel P/N 340-3110113-15, and perform the Requirement 4 inspection; or,b (i) Install on the instrument panel in full view of the pilot and co-pilot, a placard limiting operation to a maximum of 18,000 feet above sea level.(ii) Change the cabin pressure relief valve nominal setting to 3 psi.(iii) Visually inspect the adjacent areas in accordance with SB No. 53-3 until the channel is replaced. A cracked channel must be replaced with a new channel within 1,000 hours time in service from detection of the cracking. Channel P/N 340-3110113-15 must be replaced before further flight if any cracking of the adjacent structure is detected during any repetitive inspection.The cabin pressure relief valve setting may be returned to normal and the placard removed from the instrument panel when the cracked channel is replaced. Compliance with the Requirement 4 inspection intervals is required after replacing the channel.4. Normal inspection intervals may be resumed for a period of 10,000 hours time in service when a cracked channel is replaced with a new channel. Inspect the channel for cracks in accordance with SB No. 53-3.Note: FAA AD 70-13-02 Amdt 39-1016 refers. |\n\n| Compliance: | 1. Unless the initial inspection is already accomplished, within 150 hours time in service after 11 May 2006 or before the accumulation of 10,000 hours time in service, whichever occurs later.2. Within 2,000 hours time in service after the initial inspection, and thereafter at intervals not to exceed 2,000 hours time in service.For Requirements 3.a. and 3.b: Before further flight.For Requirement 3.b.(iii): At intervals not to exceed 150 hours time in service until the channel is replaced.4. Before the accumulation of 10,000 hours time in service after replacement of the channel and thereafter at intervals not to exceed 2,000 hours time in service. |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|             | This Airworthiness Directive becomes effective on 11 May 2006.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |\n| Background: | The FAA requires inspections to detect cracks in the main windshield lower longeron splice channel. Undetected cracking could result in failure of the windshield support structure and consequent loss of pressurisation.                                                                                                                                                                                                                                                                                                                                                                                                                                                      |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n29 March 2006","sortOrder":0},{"sectionNumber":"AD/CONVAIR/11","sectionType":"part","heading":"AD/CONVAIR/11","content":"## AD/CONVAIR/11","sortOrder":1},{"sectionNumber":"Main Windshield LowerLongeron Splice Cha","sectionType":"part","heading":"Main Windshield LowerLongeron Splice Channel","content":"## Main Windshield Lower  \nLongeron Splice Channel","sortOrder":2},{"sectionNumber":"5/2006","sectionType":"part","heading":"5/2006","content":"## 5/2006","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific structural fatigue issue in a particular aircraft type. The document follows standard AD format with applicability, requirements, compliance times, and background. No scope creep is evident; it remains tightly focused on the windshield longeron splice channel inspection and remediation."},"complexity_factors":["Multiple conditional pathways (Requirements 1-4 with branching logic at Requirement 3)","Cross-reference to external technical document (General Dynamics Service Bulletin No. 53-3) for inspection procedures","Time-based compliance calculations using 'whichever occurs later' logic","Nested sub-requirements (3.b has three sub-parts i, ii, iii)","Interdependent compliance periods (replacement triggers different inspection intervals)","Reference to corresponding FAA Airworthiness Directive (70-13-02 Amdt 39-1016)"],"plain_english_summary":"CASA requires owners/operators of Convair 340/440 aircraft (including turboprop conversions) to inspect the main windshield lower longeron splice channel for cracks because failure could cause sudden loss of cabin pressurisation. An initial inspection is mandated within 150 flight hours from 11 May 2006 or before 10,000 total hours (whichever is later), with repeat checks every 2,000 hours. If cracks are found the channel must be replaced or the aircraft may continue with altitude/pressure limits and 150‑hour inspections until replacement."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"This directive stays within the original safety purpose: detect and correct cracking of the main windshield lower longeron splice channel to prevent failure of the windshield support structure and loss of pressurisation (Background; Requirement 1). The text does not materially expand the subject matter beyond that purpose. It provides two compliance pathways (immediate replacement or interim operational limitation + inspections), but those are methods for achieving the same original safety objective rather than a change in scope. The AD does add operational detail (placard, 3 psi relief valve setting, and precise time limits for interim use), which refines compliance options but does not broaden the population, hazard addressed, or the fundamental regulatory aim."},"complexity_factors":["Multiple conditional compliance paths (replace immediately OR use interim operational limitations)","Several prescribed inspection intervals with different triggers (initial 150 hours or before 10,000 hours, recurring 2,000‑hour intervals, 150‑hour interim visual inspections)","Specific part number referenced (P/N 340‑3110113‑15) requiring exact replacement","Cross-reference to an external service bulletin (General Dynamics SB No. 53‑3) for inspection procedure","Reference to an earlier FAA AD (FAA AD 70‑13‑02) creating an external regulatory linkage","Time-bound exceptions (e.g. replacement within 1,000 hours if interim option used; replacement before further flight if adjacent structure cracked)","Operational modification requirements (cockpit placard and cabin pressure relief valve setting) that affect flight crew duties and performance limits"],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- Requires operators of Convair-derived Kelowna Flightcraft (General Dynamics/Convair) Model 340 and 440 aeroplanes (including those converted to turboprops) to inspect a specific cockpit structural part: the main windshield lower longeron splice channel, P/N 340-3110113-15. (See Requirement 1.)\n\n- If no cracks are found, the inspection must be repeated on a recurring schedule. (Requirement 2; Compliance 2.)\n\n- If cracks are found, the operator must either:\n  - Replace the splice channel with a new channel and then follow the post-replacement inspection regime; or\n  - Use an interim operational limitation and maintenance regime: (i) install a cockpit placard limiting operations to a maximum altitude of 18,000 ft (visible to both pilot and co‑pilot), (ii) change the cabin pressure relief valve nominal setting to 3 psi, and (iii) perform frequent visual inspections of adjacent areas until the channel is replaced. A cracked channel replaced under the interim option must be fitted within 1,000 hours time in service from when the crack was detected. If adjacent structure is found cracked, the channel must be replaced before further flight. (Requirement 3.a and 3.b; Compliance items for Requirement 3.)\n\n- After fitting a new channel, the aircraft may resume “normal” (longer) inspection intervals for up to 10,000 hours time in service; thereafter inspections continue at the stated recurring interval. (Requirement 4; Compliance 4.)\n\n- The inspections must follow the procedures in General Dynamics (Convair) Service Bulletin No. 53‑3, dated 24 April 1970 (SB No. 53‑3). The AD also notes its relationship to FAA AD 70‑13‑02. (Requirement 1 and Note.)\n\n**Who is affected**\n\n- Owners/operators of Convair/General Dynamics (Kelowna Flightcraft) Model 340 and 440 aircraft, and any aircraft of those models converted to turboprop engines. Maintenance providers who service those aircraft are also affected because they must perform the inspections and any part replacements to the standard required by the service bulletin. (Applicability.)\n\n**Why it matters (stated purpose and how the measure addresses it)**\n\n- The stated safety risk is that undetected cracking of the splice channel could cause failure of the windshield support structure and consequent loss of pressurisation. The rule therefore mandates inspections and corrective actions to find and remove cracked parts or limit operational conditions until replacement. (Background; Requirement 1.)\n\n**Practical effects, costs and trade-offs**\n\n- Who pays: aircraft owners/operators pay for inspections, repeat inspections, any part replacements, and any downtime caused by compliance. (See Requirements and Compliance timings.)\n\n- Operational choices and behaviour: An operator who finds a crack can either remove the aircraft from full service to fit a new channel (cost and downtime) or continue to operate subject to a ceiling limit (18,000 ft) and reduced cabin pressure differential (3 psi) while undertaking more-frequent visual inspections. The latter eases immediate cost but restricts routing and may affect payload/range economics. (Requirement 3.b; Compliance for Requirement 3.b.)\n\n- Compliance burden and timing: The AD prescribes an initial inspection window (within 150 hours TIS after 11 May 2006 or before 10,000 hours TIS, whichever is later), recurring inspections every 2,000 hours thereafter, and, where interim measures are used, visual inspections every 150 hours until replacement. These overlapping intervals create a predictable recurring maintenance workload. (Compliance 1–4.)\n\n- Parts availability and downtime risk: Older aircraft types may face limited spare-part supply for an exact P/N. If replacement parts are scarce, operators may need longer use of the interim operational limitation or seek non‑standard repairs requiring regulatory approval. The AD requires replacement within 1,000 hours after detection if the interim option is chosen, or immediate replacement before further flight if adjacent structure is cracked—both can force near-term downtime. (Requirement 3; Compliance timings.)\n\n- Safety vs economics trade-off: Allowing an interim operational limitation (placard + pressure valve change) is a cost‑reducing option for operators but moves some risk management from immediate structural repair to repeated inspections and altitude limitation. This spreads costs over time but constrains operational flexibility. (Requirement 3.b.)\n\n- Market and competition effects: The rule raises operating costs for airlines and charter operators flying these specific, older models. Operators with larger fleets or stronger maintenance logistics may absorb costs more easily than small operators, which may influence their competitiveness for certain routes or contracts. Operators may choose to retire affected airframes, replace them with other types, or accept operational constraints. (Applicability; Requirements.)\n\n**Implementation and enforcement mechanics**\n\n- Inspections must follow SB No. 53‑3 (the service bulletin provides the technical steps). The AD sets mandatory intervals and actions; compliance will be enforced through the Civil Aviation Safety Authority’s standard airworthiness and maintenance oversight processes. (Requirement 1 and Note.)\n\n**Concrete failure modes and immediate effects**\n\n- Visual inspections are the detection method required. If an inspection misses a crack, the underlying safety risk remains until discovered or the part is replaced—so inspection quality and access to the splice channel matter. The rule reduces immediate flight risk by requiring replacement or operational limitations when cracks are found. (Requirement 1–3.)\n\n**Citation of key text**\n\n- Inspections and procedures: Requirement 1 (SB No. 53‑3).\n- Options after crack detection: Requirement 3.a (replace) and 3.b (placard/valve/inspections).\n- Timing: Compliance paragraphs 1–4."},"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-11-main-windshield-lower-longeron-splice-channel","history":"/api/acts/ad-convair-11-main-windshield-lower-longeron-splice-channel/history","analysis":"/api/acts/ad-convair-11-main-windshield-lower-longeron-splice-channel/analysis","conflicts":"/api/acts/ad-convair-11-main-windshield-lower-longeron-splice-channel/conflicts","importantCases":"/api/acts/ad-convair-11-main-windshield-lower-longeron-splice-channel/important-cases","documents":"/api/acts/ad-convair-11-main-windshield-lower-longeron-splice-channel/documents"}}