{"id":"F2006B06250","name":"AD/PITTS S-2/5 - Induction Air Box Door - Inspection and Modification","slug":"ad-pitts-s-2-5-induction-air-box-door-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47224,"registerId":"commonwealth-F2006B06250-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PITTS S-2/5 - Induction Air Box Door - Inspection and Modification","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)  \nPitts S-1 and S-2 Series Aeroplanes\n\nAD/PITTS S-\n\n2/5\n\n  \n\nInduction Air Box Door \\- Inspection and Modification\n\n  \n9/73\n\nApplicability: Model S-2A with S/Nos. 2001 to 2059\\. Requirement: 1. Inspection:\n\nVisually inspect the induction air box flapper door assembly, Pitts P/N 2-7112-7, for cracks in the welded areas.\n\nNote: This inspection may be performed by the pilot.\n\n2. Modification:\n\nInstall stiffener, Pitts P/N 2-7112-16, to the induction air box flapper door assembly in accordance with Pitts SL No. 2; or\n\nPitts SL No. 2 \\- For Aircraft with more than 50 hours time in service from new.\n\nCompliance: 1. Inspection: Prior to first flight of each day until incorporation of the modification.\n\n2. Modification: Within 100 hours time in service after 28 September 1973.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive for a specific aircraft component. It has not expanded beyond its original purpose of addressing a known airworthiness issue with the Pitts S-2A induction air box door."},"complexity_factors":["Very short document (under 300 words)","Only 2 defined terms (Applicability and Compliance)","No cross-references to other legislation or regulations beyond the enabling authority (CAR 1998 Part 39)","Simple conditional logic: inspection required 'until' modification completed","Single exception noted: different service letter applies for aircraft with >50 hours time in service","Clear, sequential numbering (1. Inspection, 2. Modification)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety notice issued by Australia's aviation safety regulator (CASA) for specific aircraft.\n\n**What it does:**\nIt requires owners and operators of certain **Pitts S-2A aerobatic biplanes** (specifically serial numbers 2001 to 2059) to:\n\n- **Inspect** the induction air box flapper door (a component that controls airflow to the engine) for cracks in welded areas before every day's first flight\n- **Modify** the door by installing a stiffener part within 100 flight hours after 28 September 1973\n\n**Who it affects:**\n- Owners and operators of early-model Pitts S-2A aircraft (built roughly 1971–1973)\n- Licensed aircraft maintenance engineers who perform the modification\n- Pilots (who can legally perform the daily visual inspection themselves)\n\n**Why it matters:**\nCracks in this engine air intake component could cause the door to fail, potentially leading to **engine power loss** during flight — a serious safety risk in aerobatic aircraft where reliable engine performance is critical. The stiffener prevents the door from flexing and cracking.\n\n**Key point:** This AD creates a two-stage compliance — daily inspections as a temporary safety measure, followed by a permanent hardware fix within a set timeframe."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument applies only to Pitts Model S-2A aircraft with serial numbers 2001–2059 and sets out inspection and modification requirements for a specific component. The source text contains no indication that the scope was altered from an earlier or different intent; the requirements and applicability are stated directly in the instrument (Applicability; Requirement; Compliance)."},"complexity_factors":["Narrow applicability (single model and specific serial numbers) reduces scope complexity.","Only two required actions: a visual inspection and a single modification (low procedural complexity).","Daily inspection requirement until modification introduces recurring operational burden and requires tracking of status.","Reliance on an external document (Pitts Service Letter No. 2) for the modification procedure adds a cross-reference to a non‑included source.","The directive specifies exact part numbers (P/N 2-7112-7 and P/N 2-7112-16), so compliance is precise but leaves little flexibility.","Compliance timing tied to flight hours and a historic calendar date requires record-keeping of hours-in-service."],"plain_english_summary":"Owners/operators of Pitts Model S-2A aircraft (serial numbers 2001–2059) must visually inspect the induction air box flapper door welded areas for cracks before the first flight each day (pilot may perform this) and install a reinforcement stiffener (Pitts P/N 2-7112-16) per Pitts Service Letter No. 2. Daily inspections continue until the stiffener is fitted; the modification had to be completed within 100 hours TIS after 28 Sep 1973."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pitts-s-2-5-induction-air-box-door-inspection-and-modification","history":"/api/acts/ad-pitts-s-2-5-induction-air-box-door-inspection-and-modification/history","analysis":"/api/acts/ad-pitts-s-2-5-induction-air-box-door-inspection-and-modification/analysis","conflicts":"/api/acts/ad-pitts-s-2-5-induction-air-box-door-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-pitts-s-2-5-induction-air-box-door-inspection-and-modification/important-cases","documents":"/api/acts/ad-pitts-s-2-5-induction-air-box-door-inspection-and-modification/documents"}}