{"id":"F2006B09292","name":"AD/DO 228/2 - Horizontal Stabiliser Front Spar and Supports","slug":"ad-do-228-2-horizontal-stabiliser-front-spar-and-supports","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":53365,"registerId":"commonwealth-F2006B09292-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DO 228/2 - Horizontal Stabiliser Front Spar and Supports","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nDornier 228 Series Aeroplanes\n\nAD/DO 228/2 Horizontal Stabiliser Front Spar and Supports 10/89\n\nApplicability: All models.\n\nRequirement: 1. Action in accordance with Dornier Service Bulletin 228-035 Rev 1 dated 18 February 1986.\n\n2. Action in accordance with Dornier Service Bulletin 228-024, Rev 1 dated 25 April 1986.\n\nNote 1. Accomplishment of Requirement 2 constitutes terminating action for the inspection requirements of Requirement 1.\n\nNote 2. West German AD 85-97/3 dated 22 July 1986 refers.\n\nCompliance: 1. As detailed in Requirement Document 1.\n\n2. Prior to accumulating 5000 flight cycles.\n\nBackground: During ground runs and take-offs with 100% power setting the horizontal stabiliser is subject to asymetrical loads, which could result in cracking in the stabiliser front spar and connection areas.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific airworthiness concern on a specific aircraft type. It has not expanded beyond its original purpose of mandating inspection and repair of the horizontal stabiliser front spar."},"complexity_factors":["Very short document (under 200 words)","Only 2 substantive requirements, both referencing external technical documents rather than spelling out actions in the text itself","Minimal defined terms (only standard aviation terminology like 'flight cycles')","Simple conditional logic: Requirement 2 terminates Requirement 1","No cross-references to other legislation or regulations beyond the enabling regulation (CAR 1998 Part 39)","Single applicability criterion ('All models') with no exceptions or carve-outs"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nOrders owners and operators of **Dornier 228 series aeroplanes** to carry out specific safety inspections and repairs on the **horizontal stabiliser** (the small wing at the tail that keeps the plane level). The concern is potential **cracking in the front spar and support structures** — critical parts that hold the stabiliser in place.\n\n**Who must act:**\nAnyone who owns or operates any model of Dornier 228 aircraft in Australia.\n\n**What must be done:**\n- **Requirement 1:** Follow Dornier Service Bulletin 228-035 (dated 18 February 1986) — this involves inspections for cracks.\n- **Requirement 2:** Follow Dornier Service Bulletin 228-024 (dated 25 April 1986) — this involves a structural modification or repair.\n\n**Key point:** If you complete Requirement 2 (the modification), you don't need to keep doing the inspections from Requirement 1 — the fix is permanent.\n\n**When it must be done:**\n- Requirement 1: As specified in the original Dornier document.\n- Requirement 2: Before the aircraft reaches **5,000 flight cycles** (roughly, one take-off and landing equals one cycle).\n\n**Why it matters:**\nHigh-power settings during ground runs and take-offs put uneven stress on the tail. Without this fix, cracks could develop and potentially lead to **structural failure of the tail section** — a serious flight safety risk."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD, as published, applies to all Dornier 228 models and prescribes specific corrective and terminating actions referenced by service bulletins. The text shows no expansion or narrowing of that applicability within the instrument itself; it is focused on addressing the stated structural cracking risk in the horizontal stabiliser front spar using the two referenced service bulletins. [Applicability; Requirement 1; Requirement 2; Background]"},"complexity_factors":["Reference to external technical documents (two Dornier Service Bulletins) for the actual work steps, requiring users to obtain and follow those documents [Requirement 1; Requirement 2].","A compliance deadline expressed in flight cycles (5000 flight cycles) rather than calendar time, which requires tracking operational usage [Compliance 2].","A terminating-action mechanic where completing one service bulletin cancels recurring inspections from the other, creating a binary choice for operators [Note 1].","Cross-reference to a foreign airworthiness directive (West German AD), which may require coordination or comparison with other regulatory requirements [Note 2].","Applicability to all models of the type, which broadens the number of affected operators but does not add technical detail [Applicability]."],"plain_english_summary":"This AD requires all Dornier 228 operators to perform the maintenance actions in Service Bulletins 228‑035 Rev 1 (recurring inspections/mods) or 228‑024 Rev 1 (terminating modification); completing 228‑024 removes the need for further inspections and must be done before 5,000 flight cycles.\n\nIssued to prevent cracking of the horizontal‑stabiliser front spar from asymmetrical loads, it places costs and scheduling on operators and forces a choice between ongoing inspections or a one‑off terminating modification."}},"importantCases":[],"_links":{"self":"/api/acts/ad-do-228-2-horizontal-stabiliser-front-spar-and-supports","history":"/api/acts/ad-do-228-2-horizontal-stabiliser-front-spar-and-supports/history","analysis":"/api/acts/ad-do-228-2-horizontal-stabiliser-front-spar-and-supports/analysis","conflicts":"/api/acts/ad-do-228-2-horizontal-stabiliser-front-spar-and-supports/conflicts","importantCases":"/api/acts/ad-do-228-2-horizontal-stabiliser-front-spar-and-supports/important-cases","documents":"/api/acts/ad-do-228-2-horizontal-stabiliser-front-spar-and-supports/documents"}}