{"id":"F2006B06400","name":"AD/PW-P/12 - Operating Restrictions - Placarding","slug":"ad-pw-p-12-operating-restrictions-placarding","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47723,"registerId":"commonwealth-F2006B06400-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PW-P/12 - Operating Restrictions - Placarding","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nPratt and Whitney Piston Engines\n\nAD/PW-P/12 Operating Restrictions \\- Placarding NK\n\nApplicability: R2000 series installed in Douglas DC4 aeroplanes and fitted with Hamilton Standard 23E50/6507-0 propellers.\n\nRequirement: 1. Avoid steady operation of the engines in the ranges 1550 to 1750 r.p.m. in flight and 1550 to 1800 r.p.m. during ground running when the propeller blades are off the low pitch stops.\n\n    2. The R.P.M. indicators in aeroplanes affected shall be marked with a suitable red sector over the 1550 to 1750 r.p.m. range.\n\n    3. Remove the existing placard covering the 1600 to 1700 r.p.m. range and install a new placard setting out the restrictions specified in paragraph 1.\n\nNote: If desired the placard required by paragraph 3 may incorporate the limitation on the 2310 to 2510 r.p.m. range required by ANO AD/PW-P/8.\n\nor FAA AD 62-26-1.\n\nCompliance: Forthwith.","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 mechanical issue in a specific aircraft configuration. It has not expanded beyond its original technical safety purpose."},"complexity_factors":["Single, specific applicability clause (one engine series, one aircraft type, one propeller model)","Only 3 operational requirements, each straightforward and unconditional","No defined terms section","No cross-references to other legislation (only optional reference to equivalent FAA directive)","Single compliance deadline with no exceptions or phased implementation","Total length: approximately 150 words"],"plain_english_summary":"This is an **Airworthiness Directive** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft engines.\n\n**What it does:**\n- **Targets:** Pratt & Whitney R2000 piston engines installed in Douglas DC-4 aircraft with specific Hamilton Standard propellers.\n- **The problem:** These engines have dangerous vibration or stress issues when operated at certain RPM ranges (roughly 1550–1750 revolutions per minute in flight, and 1550–1800 on the ground).\n- **The fix:**\n  - Pilots must **avoid steady operation** in those RPM ranges\n  - **Mark the RPM gauges** with red warning sectors (1550–1750)\n  - **Replace an old placard** (warning sign) in the cockpit with a new one showing the updated restrictions\n\n**Who it affects:**\n- Operators of vintage Douglas DC-4 aircraft with these specific engine/propeller combinations\n- Maintenance engineers who must install the new placards and markings\n\n**Why it matters:**\nOperating in these RPM ranges can damage the engine or propeller, potentially causing in-flight failure. This directive prevents mechanical failure through operational restrictions and clear cockpit warnings.\n\n**Compliance:** Immediate (\"forthwith\")."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":true,"description":"The directive expands and formalises the placarded r.p.m. restriction previously covering 1600–1700 r.p.m. by replacing that existing placard with one that specifies a wider restricted band of 1550–1750 r.p.m. for flight and an additional 1550–1800 r.p.m. limit for ground running (Requirement 1; Requirement 3). It also permits optional incorporation of a separate 2310–2510 r.p.m. limitation from ANO AD/PW-P/8 onto the same placard (Note). Compliance is required immediately (Compliance: Forthwith)."},"complexity_factors":["Narrow technical applicability: applies only to R2000 series engines in Douglas DC4 aeroplanes with Hamilton Standard 23E50/6507-0 propellers (Applicability).","Clear, limited set of actions: avoid operation in specific r.p.m. bands; mark indicators; replace an existing placard (Requirement 1–3).","Immediate compliance requirement increases operational urgency but not procedural complexity (Compliance: Forthwith).","Conditional language tied to propeller condition (\"when the propeller blades are off the low pitch stops\") introduces an operational qualifier that must be interpreted in practice (Requirement 1).","Cross-reference/optional consolidation with another airworthiness directive creates a small design decision for placard content (Note).","Some operational terms (e.g. \"steady operation\") are not further defined in the text, which may require local procedural clarification."],"plain_english_summary":"This directive immediately requires Douglas DC‑4s with Pratt & Whitney R2000 engines and Hamilton Standard 23E50/6507‑0 propellers to avoid steady operation in specified r.p.m. bands when propeller blades are off the low‑pitch stops, and to mark the r.p.m. indicator with a red sector and replace existing placards to reflect the new limits. It affects operators, pilots, and maintenance/ground crews, who must change operating practices and fit new placards at their own cost to remain compliant."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pw-p-12-operating-restrictions-placarding","history":"/api/acts/ad-pw-p-12-operating-restrictions-placarding/history","analysis":"/api/acts/ad-pw-p-12-operating-restrictions-placarding/analysis","conflicts":"/api/acts/ad-pw-p-12-operating-restrictions-placarding/conflicts","importantCases":"/api/acts/ad-pw-p-12-operating-restrictions-placarding/important-cases","documents":"/api/acts/ad-pw-p-12-operating-restrictions-placarding/documents"}}