{"id":"F2006B01868","name":"AD/A320/121 - Passenger Door Upper Safety Pin","slug":"ad-a320-121-passenger-door-upper-safety-pin","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41064,"registerId":"commonwealth-F2006B01868-current","compilationNumber":null,"startDate":"2026-04-01","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 CAR 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\nAirbus Industrie A319/A320/A321 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/A320/121 Passenger Door Upper Safety ","sectionType":"part","heading":"AD/A320/121 Passenger Door Upper Safety Pin 8/2001","content":"# AD/A320/121 Passenger Door Upper Safety Pin 8/2001\n\nApplicability: All Model A319, A320, and A321 aircraft without Airbus Industrie modification 27142 in production or Service Bulletin A320-52-1105 in-service.\n\nRequirement: Carry out the actions specified in DGAC AD 2001-100(B).\n\nNote: All Operators Telex A320/AOT 52-06, and Service Bulletins A320-52-1105 and A320-52-1057 refer.\n\nCompliance: As specified in the Requirement document.\n\nThis Airworthiness Directive becomes effective on 9 August 2001.\n\nBackground: Reports were received of the inability to open passenger doors due to jamming during translation of the upper safety pin; as a result of migration of guide bushes. This condition , unless corrected, could delay the evacuation of passengers during an emergency.\n\nThis Directive requires the incorporation of a single recessed bush with a screwed grease fitting.\n\n![](image.002.png)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 26 June 2001\n\n![](image.001.png)","sortOrder":1}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD stays within the original safety-focused purpose: to correct the passenger door upper safety pin jamming caused by migration of guide bushes. It prescribes a specific corrective modification (recessed bush with screwed grease fitting) and limits applicability to aircraft not already modified. There is no expansion beyond that single corrective objective."},"complexity_factors":["Short, single-issue AD focused on one hardware change (low inherent complexity)","Applicability contains a conditional exclusion (aircraft already modified by mod 27142 or SB A320-52-1105) which requires fleet-level checking","Mandatory compliance depends on external documents (DGAC AD 2001-100(B), Airbus All Operators Telex A320/AOT 52-06, Service Bulletins A320-52-1105 and A320-52-1057)","Cross-jurisdictional reference (DGAC) increases procedural complexity because operators must obtain and follow another authority's AD","Technical implementation requires specific parts and maintenance actions which create operational scheduling complexity (parts supply, shop time) but not regulatory complexity","No layered exceptions or nested conditional logic within the AD text itself"],"plain_english_summary":"**What this directive does (mechanically)**\n\n- This Airworthiness Directive (AD) requires operators of certain Airbus A319/A320/A321 aeroplanes to carry out a specific modification to the passenger door upper safety pin assembly. (Requirement)\n- Concretely, the fix is the incorporation of a single recessed guide bush with a screwed grease fitting to stop the upper safety pin from jamming during translation. (Background; Requirement)\n- Compliance is to be completed in accordance with the referenced French DGAC AD 2001-100(B) and the Airbus service information and telexes listed. (Requirement; Note; Compliance)\n\n**Which aircraft are affected**\n\n- All Airbus A319, A320 and A321 aircraft that do NOT already have Airbus modification 27142 fitted in production or do NOT already have Service Bulletin A320-52-1105 embodied in-service. (Applicability)\n\n**Who must act and who pays**\n\n- The aircraft operator (the airline or owner) is responsible for arranging and paying for the inspections/modification specified by the referenced DGAC AD and Airbus service documents. (Applicability; Requirement)\n- Maintenance organisations or parts suppliers will perform the physical work and supply the recessed bush and grease fitting; they will capture the direct maintenance revenue. (Inference from Requirement and typical practice)\n\n**Why it matters (safety mechanism and risk addressed)**\n\n- Reports showed that the passenger door could not be opened because the upper safety pin jammed during its movement, caused by migration (wear/movement) of guide bushes. (Background)\n- If an upper safety pin jams, it could delay passenger evacuation in an emergency. This AD directs a design/maintenance change to remove that failure mode. (Background; Requirement)\n\n**How it works in practice and what changes for operators**\n\n- Operators must check whether each aeroplane already has mod 27142 or Service Bulletin A320-52-1105 applied. If not, they must follow DGAC AD 2001-100(B) and the Airbus service instructions to fit the recessed bush and grease fitting. (Applicability; Requirement; Compliance)\n- The AD cross-references specific Airbus service bulletins and an operator telex, so compliance requires obtaining and following those external technical documents. (Note)\n- Implementation will require maintenance downtime for each aeroplane, procurement of the specified part(s), and the recordkeeping typical for AD compliance. (Inference from Requirement and standard maintenance practice)\n\n**Costs, incentives and trade-offs (practical test of the stated purpose)**\n\n- Direct costs: parts, labour and aircraft downtime are borne by operators. The AD does not set compensation or subsidies. (Applicability; Requirement)\n- Incentives: operators have a safety incentive to comply to keep aircraft certificated for flight; maintenance providers have an incentive to supply the part and perform the work. (Requirement)\n- Opportunity cost: resources allocated to this modification (shop time, parts) displace other maintenance activities or aircraft utilisation in the short term. (Implementation inference)\n- Implementation risk: effectiveness depends on correct embodiment of the part per the referenced documents and on subsequent maintenance (greasing schedule) where appropriate; failure to follow the referenced instructions could leave the risk unmitigated. (Requirement; Note)\n- Compliance burden and administrative discretion: the AD prescribes compliance via the DGAC AD and Airbus documents, leaving limited operational discretion to the operator except for scheduling and logistics. The CASA delegate issued the AD under the CAR regulation cited. (Requirement; Compliance)\n\n**Effects on markets and competition**\n\n- Small, concentrated benefit: manufacturers of the bush/grease fitting and maintenance organisations receive concentrated revenue for parts and labour. (Inference)\n- Diffuse cost: airline passengers and the public bear the cost indirectly through operator expenses (fleet-wide), but that cost is distributed across an operator's customers rather than concentrated on a single party. (Inference)\n- No direct effect on ownership, pricing policy, or competition beyond the usual maintenance market dynamics; independent approved maintenance organisations can compete to supply the service and parts. (Inference)\n\n**References to specific sections of the directive**\n\n- Applicability: which aeroplanes are covered and the exclusion for already-modified aircraft. (Applicability)\n- Requirement: mandates following DGAC AD 2001-100(B). (Requirement)\n- Note: identifies Airbus Telex and Service Bulletins that provide the technical detail. (Note)\n- Background: explains the failure mode (guide bush migration causing pin jamming) and the corrective change (recessed bush with screwed grease fitting). (Background)\n\n**Bottom line**\n\n- This AD imposes a narrowly targeted technical modification on A319/A320/A321 aeroplanes that lack a specified prior modification, to remove a door-jamming failure mode and reduce the risk of delayed evacuation. Operators must follow a foreign (DGAC) AD and Airbus service documents to comply, bearing the direct cost and logistical burden of scheduling the work and obtaining parts."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive addressing a specific mechanical defect on specific aircraft models. The scope remains tightly focused on the passenger door upper safety pin issue as originally identified. There is no evidence of scope creep or expansion beyond the original safety concern."},"complexity_factors":["Very short document (approximately 250 words)","Only 3 defined applicability criteria (aircraft models and modification status)","Single requirement referencing external document (DGAC AD 2001-100(B))","No nested conditional logic or exceptions","No cross-references to other legislation beyond the cited Service Bulletins and French AD","Straightforward compliance timing ('as specified in the Requirement document')","Technical but narrow scope — single mechanical component on specific aircraft types"],"plain_english_summary":"This Airworthiness Directive orders operators of certain Airbus A319/A320/A321 aircraft to fix a door‑mechanism defect: worn guide bushes can jam the upper safety pin of passenger doors, risking evacuation failure. It applies to aircraft not already modified by Airbus mod 27142 or SB A320‑52‑1105.\n\nOperators must install an improved recessed guide bush with a grease fitting per DGAC AD 2001‑100(B). The requirement has been mandatory since 9 August 2001."}},"importantCases":[],"_links":{"self":"/api/acts/ad-a320-121-passenger-door-upper-safety-pin","history":"/api/acts/ad-a320-121-passenger-door-upper-safety-pin/history","analysis":"/api/acts/ad-a320-121-passenger-door-upper-safety-pin/analysis","conflicts":"/api/acts/ad-a320-121-passenger-door-upper-safety-pin/conflicts","importantCases":"/api/acts/ad-a320-121-passenger-door-upper-safety-pin/important-cases","documents":"/api/acts/ad-a320-121-passenger-door-upper-safety-pin/documents"}}