{"id":"F2006B05029","name":"AD/CESSNA 177/5 Amdt 2 - Pneumatic Stall Warning System","slug":"ad-cessna-177-5-amdt-2-pneumatic-stall-warning-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44939,"registerId":"commonwealth-F2006B05029-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 177/5 Amdt 2 - Pneumatic Stall Warning System","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)  \nCessna 177 Series Aeroplanes\n\nAD/CESSNA 177/5\n\nAmdt 2\n\n  \nPneumatic Stall Warning System 7/83\n\nApplicability: All models with pneumatic stall warning systems not incorporating horn reed assembly P/N 0413483-2, P/N 0713348-1 or subsequent and protective screens over the horn bell and stall warning system opening on the left wing.\n\nRequirement: 1. Check the pneumatic stall warning system for correct operation by applying a slight suction with the mouth at the stall warning opening in the left wing. A properly functioning horn will provide a sound that is clearly audible. It may be advisable to first cover the opening with a clean piece of cloth. Cessna 100 Series Service Manual 1963 to 1967 Section 16 refers.\n\nNote: This check may be performed and certified by the pilot.\n\n    2. Install the following placard in full view of the pilot:\n\n“PRE-FLIGHT TEST THE PNEUMATIC STALL WARNING SYSTEM”.\n\n    3. The requirements of paragraphs 1 and 2 may be removed by incorporation of the following modifications. Replace the stall warning reed assembly P/N 0413028-1 with reed assembly P/N 0413483-2, P/N 0713348-1 or subsequent and install an 18 x 14 or 18 x 16 mesh screen over the exposed horn bell inside the cabin and over the left wing opening. Flight test the aircraft to assure the stall warning horn sounds at 5 to 10 knots above the stalling speed.\n\nCompliance: For para. 1 \\- Before each flight.\n\nFor para. 2 \\- Within 25 hours time in service after 5 September 1968.\n\nBackground: This amendment reflects latest Cessna Part Number change. This Directive is reissued to correct a typographical error.","sortOrder":0}],"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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a minor amendment (Amendment 2) to an existing Airworthiness Directive. The scope remains unchanged from the original directive — it continues to address the same safety issue with pneumatic stall warning systems on Cessna 177 aircraft. The amendment merely corrects a typographical error and updates the part number reference to reflect the latest Cessna documentation. The core safety requirements and applicability have not expanded beyond the original intent."},"complexity_factors":["Single specific aircraft type (Cessna 177 series) with clearly defined applicability criteria","Only 3 substantive requirements with straightforward compliance timelines","Minimal defined terms (only part numbers and technical specifications)","No cross-references to other legislation or complex conditional logic","Simple alternative compliance path (paragraph 3 modifications remove paragraphs 1-2 requirements)","Short document (approximately 250 words)","Background section provides clear rationale for amendment"],"plain_english_summary":"This AD requires Cessna 177 owners/operators with older pneumatic stall‑warning systems to ensure the horn reliably sounds, affecting pilots (pre‑flight checks), maintenance engineers, and aircraft owners. It mandates visible cockpit warnings and, as an alternative, allows a permanent upgrade to newer reed assemblies and protective screens to eliminate repetitive testing.\n\nIt matters because a silent or unreliable stall warning can leave pilots unaware of an imminent stall, so the directive prevents accidents by ensuring the system works or is modernized."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Background states this amendment updates Cessna part numbers and corrects a typographical error; it does not expand or narrow the stated applicability or add new types of obligations beyond the existing pre‑flight test, placard, and retrofit/flight‑test option."},"complexity_factors":["Technical specificity: exact replacement part numbers (P/N 0413028-1 replaced by P/N 0413483-2, P/N 0713348-1 or subsequent) and mesh sizes (18x14 or 18x16).","Multiple compliance paths: recurring pre‑flight test + placard OR one‑time modification plus flight test to remove recurring duty.","Recurring operational burden: pre‑flight check required before each flight (para. 1; Compliance).","Deadline differentiation: placard must be fitted within 25 hours TIS after specified date (para. 2; Compliance).","Delegated certification: provision allowing the pilot to perform and certify the check reduces mechanic/AMO dependency (Requirement note).","Performance verification: modification route requires a flight test verifying horn operation at 5–10 knots above stalling speed (Requirement para. 3).","Applicability condition: applies only to aircraft lacking specified parts/screens, so compliance depends on existing equipment configuration (Applicability)."],"plain_english_summary":"This directive requires operators of Cessna 177 aeroplanes (those without certain reed assemblies or protective screens) to perform a pre‑flight check of the pneumatic stall warning before every flight and to install a cockpit placard within a short time. As an alternative, owners may fit specified replacement reed assemblies and mesh screens and perform a flight test to remove the recurring checks. The pilot may perform and certify the check, so direct recurring time and retrofit costs fall on aircraft operators and owners."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-177-5-amdt-2-pneumatic-stall-warning-system","history":"/api/acts/ad-cessna-177-5-amdt-2-pneumatic-stall-warning-system/history","analysis":"/api/acts/ad-cessna-177-5-amdt-2-pneumatic-stall-warning-system/analysis","conflicts":"/api/acts/ad-cessna-177-5-amdt-2-pneumatic-stall-warning-system/conflicts","importantCases":"/api/acts/ad-cessna-177-5-amdt-2-pneumatic-stall-warning-system/important-cases","documents":"/api/acts/ad-cessna-177-5-amdt-2-pneumatic-stall-warning-system/documents"}}