{"id":"F2005L01769","name":"AD/PC-6/51 Amdt 1 - Stabiliser-Trim Attachment Components - Inspection/Replacement","slug":"ad-pc-6-51-amdt-1-stabiliser-trim-attachment-components-inspection-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":35890,"registerId":"commonwealth-F2005L01769-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Pilatus Porter PC-6 Series Aeroplanes","sectionType":"division","heading":"Pilatus Porter PC-6 Series Aeroplanes","content":"### Pilatus Porter PC-6 Series Aeroplanes\n\n| AD/PC-6/51 Amdt 1 | Stabiliser-Trim AttachmentComponents - Inspection/Replacement | 8/2005 |\n| ----------------- | ------------------------------------------------------------- | ------ |\n\n| Applicability: | All Model PC-6 Series aircraft, all serial numbers up to and including MSN 946.All Model PC-6 Series aircraft, manufactured by Fairchild Industries, MSN 2001 through MSN 2092.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Perform an inspection for crack damage in the applicable stabiliser-trim attachment and structural components, in accordance with Pilatus Aircraft Service Bulletin No. 53-001 Revision 1, dated 1 June 2005.If are cracks are found during the Requirement 1 inspection, before further flight, replace any crack damaged components.Replace without inspection any Fairchild type connecting pieces part number 6232.0026.xx installed in Config. 2 aircraft with Pilatus type connecting pieces.Replace without inspection any fittings part number 116.40.06.033 without an index after the part number with new fittings part number 116.40.06.033 with an index after the part number or with new fittings part number 116.40.06.112.Note: FOCA AD HB-2005-263 refers. |\n| Compliance:    | At the next 100 hour inspection or 3 months after 4 August 2005.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |\n|                | This Amendment becomes effective on 4 August 2005.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |\n| Background:    | This Directive is prompted by an occurrence where a PC-6 aircraft had to make an emergency landing outside an airport after the failure of the lower attachment bracket of the horizontal stabiliser. This type of failure could result in loss of control of the aircraft.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |\n\n|     | Amendment 1 is issued in response to a new FOCA AD, which supersedes existing ADs HB-86-042 (AD/PC-6/40) and HB-2005-080. The AD mandates the replacement of certain part number fittings which provides terminating action for the repetitive inspections required by HB-86-042. Furthermore, the new AD introduces Revision 1 of the Requirement document, which includes a correction of the tolerance of the actuator attachment hole diameters in fitting part number 116.40.06.033 of Config. 1 aircraft; and extends and specifies aircraft applicability. |\n| --- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n21 June 2005","sortOrder":0},{"sectionNumber":"AD/PC-6/51 Amdt 1","sectionType":"part","heading":"AD/PC-6/51 Amdt 1","content":"## AD/PC-6/51 Amdt 1","sortOrder":1},{"sectionNumber":"Stabiliser-Trim AttachmentComponents - I","sectionType":"part","heading":"Stabiliser-Trim AttachmentComponents - Inspection/Replacement","content":"## Stabiliser-Trim Attachment  \nComponents - Inspection/Replacement","sortOrder":2},{"sectionNumber":"8/2005","sectionType":"part","heading":"8/2005","content":"## 8/2005","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment remains focused on its original purpose: addressing stabiliser-trim attachment safety in PC-6 aircraft. While it expands applicability to additional serial numbers and adds terminating actions (replacement options that end repetitive inspection requirements), these changes are evolutionary safety improvements within the same technical domain rather than scope creep into unrelated areas."},"complexity_factors":["Multiple configuration types referenced (Config. 1 and Config. 2) with different requirements for each","Specific part number references with wildcard notation (6232.0026.xx) and version distinctions (with/without index)","Cross-reference to foreign aviation authority directive (FOCA AD HB-2005-263)","Dual compliance timeframe (next 100-hour inspection OR 3 months after effective date)","Amendment structure requires understanding of superseded directives (HB-86-042, HB-2005-080, AD/PC-6/40)"],"plain_english_summary":"This AD requires owners/operators of specified Pilatus and Fairchild-built PC‑6 (stabiliser‑trim) aircraft to inspect stabiliser‑trim attachment components for cracks and to replace damaged parts before further flight. It affects Pilatus PC‑6s up to MSN 946 and Fairchild PC‑6s MSN 2001–2092.\n\nAffected aircraft must also carry out mandated replacements of certain connecting pieces and fittings (some configurations require immediate replacement rather than inspection). Comply by the next 100‑hour check or within three months of 4 Aug 2005. It addresses a failure that led to an emergency landing and prevents loss of control."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"This amendment expands and alters the original regulatory approach. It extends and specifies the aircraft applicability (adding Fairchild-manufactured MSNs 2001–2092 and clarifying serial-number coverage) and replaces recurring inspection requirements with mandatory, unconditional replacement for certain connecting pieces and fittings — thereby converting an ongoing inspection regime into a one‑time replacement obligation for those parts. It also introduces a corrected tolerance in the Service Bulletin for a particular fitting's actuator attachment hole. The amendment supersedes prior ADs (HB-86-042 / AD/PC-6/40 and HB-2005-080), so the scope moved from repetitive inspection surveillance toward terminating corrective action for designated parts, increasing immediate compliance costs for operators while removing some future inspection obligations."},"complexity_factors":["Short document but contains conditional instructions (inspect-and-replace if cracks found vs unconditional replacement for specific parts).","Multiple part numbers and two aircraft configurations (Config. 1 and Config. 2) with different actions for each.","Cross-reference to an external technical document: Pilatus Service Bulletin No. 53-001 Revision 1 (inspection details delegated to another document).","Reference to an external foreign AD (FOCA AD HB-2005-263) for context.","Timing condition with a choice of triggers (next 100-hour inspection or 3 months after a date).","Amendment modifies prior directives and terminates repetitive inspection obligations for certain parts (interaction with legacy ADs)."],"plain_english_summary":"**What this directive does (mechanically)**\n\n- Requires operators of Pilatus PC-6 series aeroplanes within the stated serial-number ranges to inspect specific stabiliser-trim attachment parts for cracks and to replace certain fittings and connecting pieces. (Requirement — see \"Requirement\" and the referenced Pilatus Service Bulletin No. 53-001 Rev 1.)\n- If cracks are found in the inspected components, the cracked parts must be replaced before the aircraft flies again. (Requirement.)\n- Certain Fairchild-manufactured connecting pieces (part number 6232.0026.xx) installed in Config. 2 aircraft must be replaced without inspection by Pilatus-type connecting pieces. (Requirement.)\n- Specific fittings (part number 116.40.06.033 without an index) must be replaced without inspection by a later indexed version of the same part number or by part number 116.40.06.112. (Requirement.)\n- The inspections must be done at the next 100-hour inspection or within 3 months after 4 August 2005, whichever comes first. (Compliance.)\n\n**Who this affects**\n\n- Owners and operators of all Pilatus PC-6 series aeroplanes up to and including MSN 946, and all PC-6 aircraft manufactured by Fairchild Industries with MSN 2001 through 2092. (Applicability.)\n- Maintenance organisations and mechanics who perform the 100‑hour inspections and part replacements called for by the directive.\n\n**Why it matters (safety mechanics and background)**\n\n- The directive was issued because a failure of the lower attachment bracket of the horizontal stabiliser resulted in an emergency landing. Such a failure can lead to loss of control of the aircraft. The inspections and mandated replacements are intended to detect and remove crack-damaged parts or remove susceptible parts entirely (Background; Requirement). \n\n**How it changes operator behaviour and who pays**\n\n- Operators must schedule and carry out the additional inspection work at the next mandated 100-hour inspection or within three months, and must replace parts if cracks are found before flying again. (Compliance; Requirement.)\n- Where the directive requires unconditional replacement (certain Fairchild connecting pieces and unindexed fittings), operators must procure replacement parts and install them, regardless of inspection results. (Requirement.)\n- The immediate costs fall on aircraft owners/operators: parts, labour, and aircraft downtime. The regulator (Civil Aviation Safety Authority delegate) decides and enforces the directive. (Covering signature and issuance.)\n\n**Implementation mechanics and cross-references**\n\n- The inspection procedure and acceptance criteria are contained in Pilatus Aircraft Service Bulletin No. 53-001 Revision 1, dated 1 June 2005, which the directive mandates to be followed. The directive also notes a related FOCA (Swiss) AD as a reference. (Requirement; Note.)\n\n**Trade-offs, incentives and practical consequences (source-grounded)**\n\n- The directive replaces repeated inspections for certain fittings with mandatory replacement (a one-off cost) — this converts a recurring surveillance cost into an upfront replacement cost for operators. (Amendment notes.)\n- Replacing unindexed fittings and certain connecting pieces without inspection removes ambiguity about their safety but creates immediate parts-procurement and downtime costs for operators. (Requirement.)\n- The Service Bulletin revision corrected actuator attachment hole diameter tolerances for certain fittings; that is a technical fix to the inspection/replacement specification rather than a change in substantive regulatory approach. (Amendment notes.)\n- Potential implementation risks visible from the text include parts availability, scheduling and aircraft downtime, and ensuring maintenance organisations apply the Service Bulletin procedures correctly. These follow directly from the directive's requirement to replace or inspect particular parts and to do so by specified times. (Requirement; Compliance.)\n\n**Source citations (where each point comes from)**\n\n- Applicability: the serial-number ranges and affected aircraft lists. (Applicability.)\n- What to do and which parts to replace/inspect: Requirement and referenced Service Bulletin No. 53-001 Rev 1. (Requirement.)\n- Timing: next 100-hour inspection or 3 months after 4 August 2005. (Compliance.)\n- Reason for the directive: emergency landing after failure of lower stabiliser attachment bracket. (Background.)\n- How this amendment alters prior approach: replaces repetitive inspections with terminating replacements for certain parts; corrects a tolerance in the Service Bulletin; extends/specifies applicability; supersedes earlier ADs. (Amendment notes.)\n\n"},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-pc-6-51-amdt-1-stabiliser-trim-attachment-components-inspection-replacement","history":"/api/acts/ad-pc-6-51-amdt-1-stabiliser-trim-attachment-components-inspection-replacement/history","analysis":"/api/acts/ad-pc-6-51-amdt-1-stabiliser-trim-attachment-components-inspection-replacement/analysis","conflicts":"/api/acts/ad-pc-6-51-amdt-1-stabiliser-trim-attachment-components-inspection-replacement/conflicts","importantCases":"/api/acts/ad-pc-6-51-amdt-1-stabiliser-trim-attachment-components-inspection-replacement/important-cases","documents":"/api/acts/ad-pc-6-51-amdt-1-stabiliser-trim-attachment-components-inspection-replacement/documents"}}