{"id":"F2006B06173","name":"AD/PFP/15 - Sensenich Propeller - Engine Combination","slug":"ad-pfp-15-sensenich-propeller-engine-combination","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47014,"registerId":"commonwealth-F2006B06173-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PFP/15 - Sensenich Propeller - Engine Combination","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nPropellers \\- Fixed Pitch\n\nAD/PFP/15 Sensenich Propeller \\- Engine Combination 6/89\n\nApplicability: All Sensenich model M76AM-2 or 76AM6-2 series propellers installed on Lycoming O-290-D2 engines.\n\nRequirement: Remove from service and metal stamp the word \"UNSERVICEABLE\" on the propeller hub.\n\nNote: M74DM or 74DM6 propellers may be installed as replacements.\n\nCompliance: Within 25 hours time in service after 25 April 1989 or by 31 May 1989 which ever occurs first.\n\nBackground: Due to recurring tip failures, Sensenich issued SB No 3, dated November 1956, requiring M76AM-2 or 76AM6-2 propellers to be retired from service. This was advised via AD/PA-20/6 but due to a recurrence of this combination on other aircraft types it has now been extended to all installations involving this engine and propeller combination.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The directive expands scope from the prior instruction (Sensenich Service Bulletin No. 3 and earlier AD/PA-20/6) by extending the retirement requirement to all installations of the M76AM-2 or 76AM6-2 propeller when paired with the Lycoming O-290-D2 engine. The Background states this is due to recurrences on other aircraft types, and the AD explicitly applies to all such installations (Background; Applicability)."},"complexity_factors":["Highly specific applicability (only Sensenich M76AM-2 or 76AM6-2 on Lycoming O-290-D2 engines) (Applicability)","Single prescriptive action: remove from service and metal-stamp \"UNSERVICEABLE\" (Requirement)","Short, fixed compliance window (within 25 hours TIS after 25 April 1989 or by 31 May 1989) (Compliance)","Replacement option explicitly stated (M74DM or 74DM6) reducing ambiguity about acceptable substitutes (Note)","Underlying safety history referenced (recurring tip failures and prior Sensenich SB No. 3) but no new technical inspection protocol provided (Background)"],"plain_english_summary":"This AD mandates retirement of Sensenich M76AM-2 and 76AM6-2 propellers fitted to Lycoming O-290-D2 engines: remove within 25 hours TIS after 25 April 1989 or by 31 May 1989 and metal-stamp the hub \"UNSERVICEABLE\". Owners/operators must fit permitted replacements (M74DM or 74DM6) or otherwise reconfigure.\n\nIssued because of recurring tip failures, the rule forces prompt removals that create near-term cost and downtime to address a safety risk."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope — addressing a specific known safety defect in a particular propeller-engine combination. The extension mentioned in the background (applying to 'all installations' rather than just specific aircraft types) is a natural expansion of the safety mandate rather than scope creep, as it addresses the same underlying defect across all affected aircraft."},"complexity_factors":["Very short document (under 200 words)","Only 2 defined model numbers in applicability section","Single, unambiguous requirement with no conditional logic","No cross-references to other legislation or regulations beyond citation","Clear compliance deadline with simple 'whichever occurs first' formula","No exceptions, exemptions, or nested provisions"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of specific aircraft to take immediate action to prevent accidents.\n\n**What it does:**\n- **Targets:** Sensenich model M76AM-2 or 76AM6-2 propellers when paired with Lycoming O-290-D2 engines\n- **Action required:** These propellers must be **removed from service immediately** and permanently marked \"UNSERVICEABLE\" by metal stamping the hub\n- **Replacement option:** M74DM or 74DM6 propellers can be used instead\n\n**Why it matters:**\nThese propellers have a dangerous history of **tip failures** — where the blade tips break off during flight. This poses catastrophic risk to aircraft and occupants. The manufacturer identified this problem back in 1956 and issued a service bulletin, but the dangerous combination kept appearing on different aircraft types, so CASA made this safety order apply universally to all installations.\n\n**Deadline:**\nOperators had to comply within **25 flight hours** after 25 April 1989, or by 31 May 1989 — whichever came first.\n\n**Who it affects:**\nAircraft owners, maintenance organisations, and operators using this specific propeller-engine combination."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pfp-15-sensenich-propeller-engine-combination","history":"/api/acts/ad-pfp-15-sensenich-propeller-engine-combination/history","analysis":"/api/acts/ad-pfp-15-sensenich-propeller-engine-combination/analysis","conflicts":"/api/acts/ad-pfp-15-sensenich-propeller-engine-combination/conflicts","importantCases":"/api/acts/ad-pfp-15-sensenich-propeller-engine-combination/important-cases","documents":"/api/acts/ad-pfp-15-sensenich-propeller-engine-combination/documents"}}