{"id":"F2006B04908","name":"AD/CESSNA 120/8 - Forward Door Posts","slug":"ad-cessna-120-8-forward-door-posts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44752,"registerId":"commonwealth-F2006B04908-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\n![](image.001.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\nCessna 120 and 140 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/CESSNA 120/8 Forward Door Posts 5/200","sectionType":"part","heading":"AD/CESSNA 120/8 Forward Door Posts 5/2003","content":"# AD/CESSNA 120/8 Forward Door Posts 5/2003\n\nApplicability: Model 120 and 140 aircraft, serial numbers 8001 through 8799.\n\nRequirement: Inspect the forward door posts for cracks, particularly the flange section leading from the post to the instrument panel at the base of the windshield, and the post itself below the rivet cluster at the top. Remove all the inside fairings attached to the post to permit a thorough inspection.\n\nFollowing inspection, before further flight, repair cracks in the flange section that do not exceed 0.75- inch in length by stop drilling.\n\nIf cracks exceed 0.75- inch in length in the flange or if any cracks are evident in the door post structure itself, before further flight, replace the door post with the Cessna later type post, part numbers 0411867-2 and 0411867-3, in accordance with the installation instructions supplied by Cessna.\n\nNote: FAA AD 47-06-11 and Cessna Service Letter No. 20 refer.\n\nCompliance: Within 100 hours time in service or within 12 months after 15 May 2003, whichever occurs first. Thereafter at intervals not to exceed 100 hours time in service, until later type door posts are installed.\n\nThis Airworthiness Directive becomes effective on 15 May 2003.\n\nBackground: The FAA requires inspection of the forward door posts until revised posts are installed.\n\n![](image.002.jpeg)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 4 April 2003\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 23 April 2003.","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD stays within its original safety-focused scope: require inspection and corrective action for forward door-post cracking on a specific range of Cessna 120/140 serial numbers until later-type posts are fitted. The Background explicitly states it aligns with the FAA requirement to inspect until revised posts are installed. There is no evident expansion beyond that original purpose (no added obligations, broader aircraft types, or secondary policy goals)."},"complexity_factors":["Short, single-issue AD (inspection and remedial action for forward door posts).","Clear applicability limited to Model 120 and 140, serial numbers 8001–8799.","One numerical repair threshold (0.75-inch) with two discrete remedial paths (stop-drill vs replace).","Simple compliance timing: initial within 100 hours or 12 months from a fixed date, then recurring every 100 hours until replacement.","Minor cross-references to FAA AD 47-06-11 and Cessna Service Letter No. 20 (external documents for detail).","Technical installation requirement referencing specific replacement part numbers (0411867-2 and 0411867-3)."],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- **Applies to:** Cessna Model 120 and 140 aeroplanes with serial numbers 8001–8799. (Applicability)\n\n- **Action required:** Inspect the forward door posts for cracks. To do this you must remove the internal fairings attached to the post so the post and the flange area (where the post meets the instrument panel/windshield base) can be thoroughly checked. (Requirement)\n\n- **If a crack is found and is 0.75 inches or shorter in the flange area:** stop-drill the crack (a standard method to arrest crack growth) and that repair must be done before the aircraft flies again. (Requirement)\n\n- **If the crack is longer than 0.75 inches in the flange, or any crack is found in the door-post structural member itself:** replace the door post with Cessna later-type parts, part numbers 0411867-2 or 0411867-3, and install them according to Cessna's supplied instructions — replacement must be done before further flight. (Requirement)\n\n- **When to do it:** Perform the first inspection within 100 hours time-in-service or within 12 months after 15 May 2003, whichever comes first. After that, inspect at intervals not exceeding 100 hours time-in-service until the later-type door posts are fitted. (Compliance)\n\n- **Reference material:** The AD notes related FAA AD 47-06-11 and Cessna Service Letter No. 20. (Note/Requirement)\n\n\n**Who is affected and who pays**\n\n- Aircraft owners/operators of the specified Cessna 120/140 serial numbers must perform the inspections and any required repairs or replacements. (Applicability / Requirement / Compliance)\n- The owner/operator bears the cost of inspection labour, removal/reattachment of fairings, any stop-drilling repairs, and, if required, the cost of replacement door-post parts and installation according to Cessna's instructions. Maintenance organisations performing the work will charge for labour and parts.\n\n\n**Why the AD matters (stated purpose) and how that maps to costs and incentives**\n\n- The AD's stated purpose (Background) is to address a potential unsafe condition by requiring inspection until revised door posts are installed. That is, the rule aims to detect and remedy cracking that could compromise the door-post structure.\n\n- Trade-offs and costs: the measure imposes recurring inspection costs (every 100 hours) on affected aircraft until the upgraded door posts are installed. Owners face a choice: pay repeated inspection/repair costs or replace the posts (one-time higher cost) to remove the inspection requirement. This creates an economic incentive to replace the posts when replacement costs are lower than ongoing inspection and repair costs.\n\n- Compliance burden and implementation risks: inspections require removal of inside fairings (increases labour/time). Stop-drilling is a standard but technical repair — if done improperly it may not arrest crack growth. Correct replacement requires following Cessna installation instructions (technical compliance risk and dependence on parts availability). There is also the risk a crack is missed if the inspection is not thorough. (Requirement / Compliance)\n\n- Effects on market and service providers: maintenance providers will carry out inspections, repairs and replacements, increasing demand for parts and labour for these serial-numbered aircraft. Owners of affected aircraft bear concentrated costs; the safety benefit is concentrated to those aircraft and to anyone using them.\n\n\n**Concrete behavioural changes required by the AD**\n\n- Operators must schedule and perform the initial inspection within the specified deadline (100 hours or 12 months from 15 May 2003) and then at most every 100 hours until replacement posts are installed. (Compliance)\n- If cracks are detected, operators must either stop-drill (if ≤ 0.75 in flange) before next flight, or replace the post (if > 0.75 in flange or any crack in the post itself) before next flight. (Requirement)\n- Operators choosing not to replace immediately will incur ongoing inspection obligations. (Compliance)\n\n\n**Source section pointers (where each point comes from)**\n\n- Applicability: \"Model 120 and 140 aircraft, serial numbers 8001 through 8799.\" (Applicability)\n- Inspection and removal of fairings: \"Inspect the forward door posts... Remove all the inside fairings attached to the post to permit a thorough inspection.\" (Requirement)\n- Repair thresholds and actions: \"...repair cracks in the flange section that do not exceed 0.75-inch in length by stop drilling... If cracks exceed 0.75-inch ... or any cracks are evident in the door post structure itself, ... replace the door post with ... part numbers 0411867-2 and 0411867-3...\" (Requirement)\n- Timing: \"Within 100 hours time in service or within 12 months after 15 May 2003, whichever occurs first. Thereafter at intervals not to exceed 100 hours ... until later type door posts are installed.\" (Compliance)\n- Background: \"The FAA requires inspection of the forward door posts until revised posts are installed.\" (Background)\n\n\n**Net practical effect**\n\nOwners/operators of the specified Cessna 120/140 serial-numbered aeroplanes must inspect and, where necessary, repair or replace forward door posts to address cracking. They face a repeated inspection obligation until they fit the later-type door posts identified by the AD; fitting those parts ends the recurring inspection requirement but requires purchase and installation per Cessna instructions."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard airworthiness directive with focused scope. It addresses a specific structural defect in specific aircraft models with clear, limited requirements. No scope creep is evident."},"complexity_factors":["Single, clearly defined applicability (specific aircraft models and serial numbers)","Straightforward two-tier requirement structure (inspect, then repair or replace based on findings)","Only one defined measurement (0.75-inch crack threshold)","Simple compliance timeline with clear alternative triggers (100 hours OR 12 months)","No cross-references to other legislation sections (only references to FAA AD and Cessna Service Letter as background)","No conditional exceptions or nested logic","Short document (approximately 250 words of substantive text)"],"plain_english_summary":"The Civil Aviation Safety Authority requires owners/operators of Cessna 120 and 140 aircraft (serials 8001–8799) to inspect forward door posts for cracking where they join the instrument panel and near top rivets. Small cracks must be stop‑drilled; larger cracks or damaged posts must be replaced before flight. Initial inspection is within 100 flight hours or 12 months from May 2003, then every 100 hours until replacement. This preserves structural integrity and flight safety."},"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-cessna-120-8-forward-door-posts","history":"/api/acts/ad-cessna-120-8-forward-door-posts/history","analysis":"/api/acts/ad-cessna-120-8-forward-door-posts/analysis","conflicts":"/api/acts/ad-cessna-120-8-forward-door-posts/conflicts","importantCases":"/api/acts/ad-cessna-120-8-forward-door-posts/important-cases","documents":"/api/acts/ad-cessna-120-8-forward-door-posts/documents"}}