{"id":"F2005L00093","name":"AD/BEECH 76/19 - Trailing Edge Flaps","slug":"ad-beech-76-19-trailing-edge-flaps","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":33467,"registerId":"commonwealth-F2005L00093-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Beechcraft 76 (Duchess) Series Aeroplane","sectionType":"division","heading":"Beechcraft 76 (Duchess) Series Aeroplanes","content":"### Beechcraft 76 (Duchess) Series Aeroplanes\n\n| AD/BEECH 76/19 | Trailing Edge Flaps | 2/2005 |\n| -------------- | ------------------- | ------ |\n\n| Applicability: | All Beechcraft 76 series.                                                                                                                                                                                                                                         |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Inspect flap internal structure at the flap hinge bracket attachment ribs for corrosion.This inspection will require leading edge skin removal or installation of inspection panels to a scheme approved by the Authority or a suitably authorised CAR 35 person. |\n| Compliance:    | Unless already accomplished, within 25 hours time in service after 17 February 2005 or 3 months, whichever occurs first and thereafter at intervals not exceeding 3 years.                                                                                        |\n|                | This Airworthiness Directive becomes effective on 17 February 2005.                                                                                                                                                                                               |\n| Background:    | Numerous Major Defect Reports have indicated that an advanced state of corrosion can exist without external indications. In some instances more than half of the hinge bracket was corroded away.                                                                 |\n\n![](image.001.png)  \nNeville Probert  \nDelegate of the Civil Aviation Safety Authority\n\n21 December 2004\n\nThe above AD is notified in the Commonwealth of Australia Gazette on 26 January 2005.","sortOrder":0},{"sectionNumber":"AD/BEECH 76/19","sectionType":"part","heading":"AD/BEECH 76/19","content":"## AD/BEECH 76/19","sortOrder":1},{"sectionNumber":"Trailing Edge Flaps","sectionType":"part","heading":"Trailing Edge Flaps","content":"## Trailing Edge Flaps","sortOrder":2},{"sectionNumber":"2/2005","sectionType":"part","heading":"2/2005","content":"## 2/2005","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"},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive sticks to the typical scope of an airworthiness action: identifying a specific hidden defect (corrosion at flap hinge bracket attachment ribs) and mandating inspection and subsequent remedial action. It does not broaden powers beyond inspection and repair requirements, nor add unrelated regulatory obligations. Therefore it has not materially changed scope beyond the original safety-focused intent described in the Background."},"complexity_factors":["Short, single-subject instrument (limited length).","One principal mandatory action: internal inspection of flap hinge bracket attachment ribs.","A small number of defined logistical conditions: removal of leading edge skin or installation of inspection panels to an approved scheme.","Authority approval requirement for inspection scheme or use of CAR 35 authorised person introduces an external approval dependency.","Clear, simple compliance timing: initial within 25 flight hours or 3 months, then every 3 years (few temporal conditions).","No layered exceptions or extensive cross-references in the text provided."],"plain_english_summary":"**What this instrument does (mechanics)**\n\n- Applies to: all Beechcraft 76 (Duchess) series aeroplanes. (Applicability)\n- Requires: an internal inspection of the flap hinge bracket attachment ribs for corrosion. That inspection will need either removal of the flap leading edge skin or installation of inspection panels. The removal or panel installation must follow a scheme approved by the civil aviation regulator (the Authority) or by a suitably authorised CAR 35 person (a person authorised under the maintenance rules). (Requirement)\n- Timing/recurrence: If not already done, the first inspection must be completed within 25 hours time-in-service after 17 February 2005 or within 3 months of that date, whichever comes first. After the first inspection, repeat inspections must occur at intervals not exceeding 3 years. (Compliance)\n\n**Who this affects**\n\n- Owners and operators of Beechcraft 76 (Duchess) series aircraft. They are responsible for arranging and paying for the inspections, any removal and reinstallation of skin or panels, and any repairs discovered by the inspection.\n- Maintenance organisations and CAR 35 authorised maintenance personnel who will perform the inspections and who may be required to prepare or follow an inspection scheme approved by the Authority.\n- The Civil Aviation Safety Authority (CASA) as the approval authority for inspection schemes (referred to here as “the Authority”).\n\n**Why it matters (stated purpose and technical risk)**\n\n- The stated reason is that multiple defect reports showed that severe corrosion can develop inside the flap hinge area without visible external signs; in some cases more than half of a hinge bracket had corroded away. The inspection requirement is intended to detect hidden corrosion before a structural failure or unsafe condition occurs. (Background)\n\n**Who decides, who pays, and what behaviour changes**\n\n- The Authority (CASA) or a CAR 35 authorised person decides the detailed inspection method by approving an inspection scheme. (Requirement)\n- Aircraft owners/operators pay for inspections, any temporary modifications (inspection panels), labour to remove/replace skin where required, and any repairs or parts replacement if corrosion is found. This also includes aircraft downtime while the work is done.\n- Operators must schedule an early inspection (within 25 flight hours or 3 months of the effective date) and set up recurring inspections every 3 years. They must choose a maintenance provider able to follow an approved scheme or use a suitably authorised CAR 35 person.\n\n**Costs, incentives and trade-offs**\n\n- Direct costs: labour, possible panel fabrication or skin removal/repair, parts replacement if corrosion is found, and aircraft downtime. These are borne by private owners/operators. (Requirement, Compliance)\n- Incentives: because corrosion can be hidden, owners have an incentive to comply to avoid unexpected structural failure and potential liability. Operators with limited maintenance budgets face the trade-off between immediate inspection cost and the risk (and potentially higher future repair cost) of undetected corrosion.\n- Market effects: modest increase in demand for specialised maintenance and corrosion-repair services for Beechcraft 76 aircraft. Small operators may face proportionally higher administrative and downtime costs.\n\n**Implementation risks and compliance burden**\n\n- Implementation risk: Removing and reinstalling leading edge skin or installing inspection panels is an intrusive maintenance task that carries risk of damage if done poorly. It requires competent maintenance personnel and an approved inspection method.\n- Compliance burden: the directive imposes an early mandatory inspection (short lead-time of 25 flight hours or 3 months) and a recurring 3-year cycle. There is some procedural burden in obtaining or following an Authority-approved inspection scheme or engaging an authorised CAR 35 person. (Requirement, Compliance)\n\n**Opportunity costs and substitution effects**\n\n- Owners/operators will divert maintenance resources and hangar time to comply; that time cannot be used for other maintenance tasks or operations. Some operators might delay non-essential upgrades to fund the inspection and any remedial work.\n- If inspection reveals corrosion, repair or replacement of parts may be required, increasing lifecycle maintenance costs for the fleet.\n\n**Concrete mechanism for safety**\n\n- The regulation addresses the specific failure mode (internal corrosion at flap hinge bracket attachment ribs) by mandating internal inspection steps that external checks would miss. The Authority retains control over the inspection method, which aims to standardise acceptable procedures and competence of persons carrying them out. (Requirement)\n\n**Source claims vs costs and trade-offs**\n\n- The instrument’s stated purpose is to detect hidden corrosion early to prevent structural failure. That purpose is achievable by intrusive inspection methods mandated here, but that outcome requires competent execution, funding from aircraft owners/operators, and possible temporary grounding while work is done. The directive shifts short-term costs onto owners/operators in exchange for reducing the operational risk posed by hidden corrosion. (Background, Requirement, Compliance)\n\n(Referenced sections: Applicability; Requirement; Compliance; Background.)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with focused, narrow scope targeting a specific safety defect in a specific aircraft model. It has not expanded beyond its original purpose of mandating corrosion inspections."},"complexity_factors":["Very short document (approximately 200 words of substantive content)","Only one defined term ('CAR 35 person' — explained in context)","Single, straightforward compliance requirement with clear timeline","No cross-references to other legislation or regulations","Simple conditional logic: 'unless already accomplished' is the only qualifier","Background section provides clear rationale without legal caveats"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order for aircraft owners and operators.\n\n**What it does:**\nIt requires owners of **Beechcraft 76 Duchess aircraft** to inspect the internal structure of the trailing edge flaps (the movable surfaces on the wings that help with takeoff and landing) for **corrosion** (rust or deterioration of metal).\n\n**Why it matters:**\nCorrosion was found eating away at the metal brackets that attach the flaps to the wing — in some cases destroying more than half the bracket without any visible warning from the outside. This is dangerous because if those brackets fail, the flaps could detach or malfunction during flight.\n\n**Who must comply:**\nAnyone who owns or operates a Beechcraft 76 series aircraft.\n\n**What must be done:**\n- **Inspect** the internal flap structure where the hinge brackets attach\n- To do this, you must either remove the leading edge skin or install inspection panels\n- The inspection method must be approved by the aviation safety authority or an authorised aircraft engineer (a \"CAR 35 person\" — someone certified under Civil Aviation Regulation 35)\n\n**When:**\n- First inspection due within **25 flight hours** or **3 months** after 17 February 2005 (whichever comes first)\n- Then repeat the inspection **every 3 years**\n\n**The bottom line:**\nThis is a safety-critical maintenance requirement. Skip it, and you risk flap failure. The directive became legally binding on 17 February 2005."}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-76-19-trailing-edge-flaps","history":"/api/acts/ad-beech-76-19-trailing-edge-flaps/history","analysis":"/api/acts/ad-beech-76-19-trailing-edge-flaps/analysis","conflicts":"/api/acts/ad-beech-76-19-trailing-edge-flaps/conflicts","importantCases":"/api/acts/ad-beech-76-19-trailing-edge-flaps/important-cases","documents":"/api/acts/ad-beech-76-19-trailing-edge-flaps/documents"}}