{"id":"F2006B04231","name":"AD/BEECH 90/40 Amdt 1 - Propeller Secondary Low Pitch Stop System - Modification","slug":"ad-beech-90-40-amdt-1-propeller-secondary-low-pitch-stop-system-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43991,"registerId":"commonwealth-F2006B04231-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEECH 90/40 Amdt 1 - Propeller Secondary Low Pitch Stop System - Modification","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Beechcraft 90 and 65-90 (King Air) Series Aeroplanes\n\n \n\nAD/BEECH 90/40\n\nAmdt 1\n\n\nPropeller Secondary Low Pitch Stop System - Modification\n\n\n5/77\n\n \n\nApplicability: Models C-90, S/Nos. LJ-584, LJ-586 to LJ-589, LJ-591, LJ-594 to LJ-600, LJ-602, LJ-603, LJ-605 to LJ-611, LJ-613 to LJ-618, LJ-621, LJ-623 to LJ-651, LJ-653 to LJ- 691. Models E-90, S/Nos. LW-1 to LW-190.\n\n \n\nDocument: Beechcraft SI No. 0808-247, Rev. 1. or FAA AD 77-02-07.\n\nCompliance: Within 100 hours’ time in service after 31 May 1977.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a narrow, technical safety directive focused on a specific mechanical modification for specific aircraft. It has not expanded beyond its original purpose of addressing a known propeller system defect in identified Beechcraft models."},"complexity_factors":["Very short document (approximately 200 words)","Only 4 defined elements: applicability (specific aircraft models/serial numbers), document reference, compliance deadline, and subject matter","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Simple conditional logic: if you own one of these specific aircraft, you must do this specific modification by this specific deadline","No nested exceptions or conditional exemptions","Single compliance pathway with clear technical reference documents"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of specific **Beechcraft King Air aircraft** to modify their propeller systems.\n\n**What it does:**\n- Mandates a modification to the **\"Secondary Low Pitch Stop System\"** on the propellers. This system prevents the propeller blades from rotating too flat (into \"low pitch\"), which could cause the engine to overspeed and potentially fail.\n\n**Who it affects:**\n- Owners and operators of specific **Beechcraft Model C-90 and E-90 King Air aeroplanes** with particular serial numbers (listed in the document).\n\n**What must be done:**\n- Aircraft operators must comply with the technical instructions in **Beechcraft Service Instruction No. 0808-247, Revision 1**, or the equivalent **FAA Airworthiness Directive 77-02-07**.\n- The modification must be completed **within 100 hours of flight time after 31 May 1977**.\n\n**Why it matters:**\n- This is a **flight safety issue**. A faulty low pitch stop system could allow the propeller to go \"flat\" in flight, causing loss of power and potentially a crash. The directive ensures all affected aircraft are modified before the system can fail."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"The instrument is presented as Amendment 1 to AD/BEECH 90/40 (labelled \"Amdt 1\"), which indicates it amends a prior airworthiness directive. The text supplied sets mandatory modification requirements for specified C-90 and E-90 serial numbers, references Beechcraft Service Instruction No. 0808-247 Rev. 1 or FAA AD 77-02-07 for the technical procedure (Document), and imposes a compliance window of 100 hours' time in service after 31 May 1977 (Compliance). The original AD text is not included in the supplied material, so the specific differences from the prior version cannot be determined from this source; only that this instrument is an amendment and that the applicable airframes, referenced documents, and compliance timing are as stated above."},"complexity_factors":["Narrow, serial‑numbered applicability requiring operators to identify eligible airframes (Applicability).","Compliance deadline measured in flight hours after a historical date (100 hours after 31 May 1977) rather than a simple calendar date, which affects scheduling (Compliance).","Technical modification procedure is not reproduced; compliance depends on external documents (Beechcraft SI No. 0808-247 Rev. 1 or FAA AD 77-02-07), requiring operators to obtain and follow those documents (Document).","Mandatory regulatory form (Airworthiness Directive, Amendment 1) leaving little regulatory discretion but requiring coordination between operators, maintenance providers and possibly the regulator for alternate methods.","Potential operational costs and downtime for owners/operators to complete the modification, which may vary by location and parts/skills availability (implicit in Applicability/Compliance)."],"plain_english_summary":"This directive requires owners/operators of the listed Beechcraft C‑90 and E‑90 serial numbers to modify the propeller secondary low‑pitch‑stop system, using Beechcraft Service Instruction No. 0808‑247 Rev.1 or FAA AD 77‑02‑07, within 100 hours' time‑in‑service after 31 May 1977. It makes the modification mandatory for those airframes, imposing scheduling, compliance recordkeeping and the direct cost of parts, labour and downtime on operators."}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-90-40-amdt-1-propeller-secondary-low-pitch-stop-system-modification","history":"/api/acts/ad-beech-90-40-amdt-1-propeller-secondary-low-pitch-stop-system-modification/history","analysis":"/api/acts/ad-beech-90-40-amdt-1-propeller-secondary-low-pitch-stop-system-modification/analysis","conflicts":"/api/acts/ad-beech-90-40-amdt-1-propeller-secondary-low-pitch-stop-system-modification/conflicts","importantCases":"/api/acts/ad-beech-90-40-amdt-1-propeller-secondary-low-pitch-stop-system-modification/important-cases","documents":"/api/acts/ad-beech-90-40-amdt-1-propeller-secondary-low-pitch-stop-system-modification/documents"}}