{"id":"F2006B10055","name":"AD/G159/11 Amdt 1 - Engine Mount Chafing","slug":"ad-g159-11-amdt-1-engine-mount-chafing","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55500,"registerId":"commonwealth-F2006B10055-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/G159/11 Amdt 1 - Engine Mount Chafing","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 ORDERS CIVIL AVIATION SAFETY AUTHORITY                            PART 105 SCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  GULFSTREAM (GRUMMAN) G.159 SERIES AEROPLANES\n\n \n\n![](image.002.png)AD/G159/11 Amdt 1 Engine Mount Chafing 11/97\n\nApplicability: All models\n\n \n\nRequirement: In accordance with Grumman Gulfstream Service Change 180:\n\n \n\n1. Inspect the applicable engine mount trusses, and\n\n\n \n\nb.    Install chafe guard Part Number 159WP10017-11\n\n \n\nNote: FAA AD 97-14-13 refers\n\n \n\nCompliance: Unless already accomplished, before the issue of an Australian Certificate of Airworthiness, thereafter inspect the chafe guard at intervals not exceeding 2 500 hours time in service.\n\n \n\nThis directive has effect from 9 October 1997.\n\n \n\nBackground:  This directive provides terminating action for a short time repetitive inspection in the FAA AD.\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\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":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"Yes. The directive converts the FAA AD's short repetitive inspections into a terminating modification by requiring installation of chafe guard PN 159WP10017-11 and sets a new recurring inspection interval of 2,500 hours (\"This directive provides terminating action for a short time repetitive inspection in the FAA AD.\"; \"...before the issue of an Australian Certificate of Airworthiness, thereafter inspect the chafe guard at intervals not exceeding 2 500 hours time in service.\"). The requirement applies to all G.159 models (\"Applicability: All models\")."},"complexity_factors":["Applicability to all models increases administrative reach (\"Applicability: All models\").","Technical task is both an inspection and a parts installation (inspect mount trusses; install chafe guard PN 159WP10017-11) (\"Install chafe guard Part Number 159WP10017-11\").","Compliance timing mixes a one‑off pre‑certificate requirement with recurring inspections every 2,500 hours (\"before the issue of an Australian Certificate of Airworthiness... thereafter... at intervals not exceeding 2 500 hours time in service\").","Interaction with an external FAA AD and a manufacturer Service Change adds regulatory cross‑reference complexity (\"Note: FAA AD 97-14-13 refers\"; \"In accordance with Grumman Gulfstream Service Change 180\").","Implementation logistics: sourcing the specific PN, scheduling maintenance windows, and maintaining records.","Regulatory effect: provides a 'terminating action' for the FAA’s short repetitive inspection, changing the prior inspection regime (\"This directive provides terminating action for a short time repetitive inspection in the FAA AD.\").","Fixed effective date creates retrospective enforcement boundary (\"This directive has effect from 9 October 1997.\")."],"plain_english_summary":"This directive requires operators of Gulfstream (Grumman) G.159 series aeroplanes to inspect engine‑mount trusses and, where applicable, install chafe guard Part Number 159WP10017-11 in accordance with Grumman Gulfstream Service Change 180. It replaces the FAA’s short repetitive inspections by providing a terminating modification and requires inspection before issue of an Australian Certificate of Airworthiness and thereafter at intervals not exceeding 2,500 hours. It affects owners/operators through maintenance, part procurement and ongoing inspection scheduling."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow airworthiness directive focused on a specific mechanical issue (engine mount chafing) on a specific aircraft type. The scope remains tightly constrained to its original safety purpose with no evidence of scope creep."},"complexity_factors":["Very short document (under 200 words)","Only 2 substantive requirements (inspect and install)","Single defined applicability (all G.159 models)","Simple compliance structure: one-time installation plus recurring inspection","Minimal cross-referencing (only one reference to FAA AD 97-14-13 for context)","No nested conditions, exceptions, or alternative compliance methods"],"plain_english_summary":"**What this is:** An Airworthiness Directive (AD) — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific maintenance actions on certain aircraft.\n\n**What it does:** This directive applies to all Gulfstream G.159 series aeroplanes (a type of business aircraft). It requires operators to:\n- **Inspect** the engine mount trusses (the structural framework that holds the engine to the wing)\n- **Install** a protective part called a \"chafe guard\" (Part Number 159WP10017-11) — this is a sleeve or shield that prevents wear from rubbing (chafing) on the engine mount\n\n**Who it affects:** Owners and operators of Gulfstream G.159 aircraft registered in Australia, and anyone seeking to issue an Australian Certificate of Airworthiness for these planes.\n\n**Why it matters:** Engine mounts are critical safety components. If they wear through due to chafing, the engine could detach or shift — a catastrophic failure. This directive provides a **permanent fix** (\"terminating action\") that ends the need for repeated short-term inspections previously required by an American FAA directive.\n\n**Ongoing obligation:** Once the chafe guard is installed, it must be inspected every 2,500 flight hours to ensure it remains effective."}},"importantCases":[],"_links":{"self":"/api/acts/ad-g159-11-amdt-1-engine-mount-chafing","history":"/api/acts/ad-g159-11-amdt-1-engine-mount-chafing/history","analysis":"/api/acts/ad-g159-11-amdt-1-engine-mount-chafing/analysis","conflicts":"/api/acts/ad-g159-11-amdt-1-engine-mount-chafing/conflicts","importantCases":"/api/acts/ad-g159-11-amdt-1-engine-mount-chafing/important-cases","documents":"/api/acts/ad-g159-11-amdt-1-engine-mount-chafing/documents"}}