{"id":"F2005L02377","name":"AD/PHZL/81 - Propeller Attachment Bolts","slug":"ad-phzl-81-propeller-attachment-bolts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":36780,"registerId":"commonwealth-F2005L02377-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Propellers - Variable Pitch - Hartzell","sectionType":"division","heading":"Propellers - Variable Pitch - Hartzell","content":"### Propellers - Variable Pitch - Hartzell\n\n| AD/PHZL/81 | Propeller Attachment Bolts | 10/2005 |\n| ---------- | -------------------------- | ------- |\n\n| Applicability: | Hartzell Propeller Inc. models HC-B3TN-2, HC-B3TN-3, HC-B3TN-5,HC-B3MN-3, HC-B4TN-3, HC-B4TN-5, HC-B4MN-5, HC-B4MP-3, HC-B4MP-5, and HC-B5MP-3 propellers installed with propeller mounting bolts, part number (P/N) B-3339. |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | Visual Inspections and Torque Checks1. Perform initial visual inspection and torque check of all eight mounting flange bolts when P/N B-3339 bolts from LFC manufacturing Lot No. 12 or Lot No. 56 are present. For the location of bolt identification marks, see Figure 1 of Hartzell Propeller Inc. Alert Service Bulletin (ASB) No. HC-ASB-61-279, Revision 2, dated 6 May 2005.2. For all aeroplanes except Aerospatiale (Nord) Model 262(A) aeroplanes modified by STC SA2369SW, perform repetitive torque checks on all eight mounting flange bolts when P/N B-3339 bolts from LFC Manufacturing Lot No. 12 or Lot No. 56 are present.3. For Aerospatiale (Nord) Model 262(A) aeroplanes modified by STC SA2369SW, perform repetitive torque checks on all eight mounting flange bolts when P/NB-3339 bolts from LFC Manufacturing Lot No. 12 or Lot No. 56 are present.4. If any bolt fails the torque check, replace all eight bolts with P/N B-3339 bolts that are not from LFC Manufacturing Lot No. 12 or Lot No. 56, or with approved equivalent part number bolts.Perform the actions specified in Requirements 1, 2, 3 and 4 of this Directive, using paragraphs 3.A through 3.B.(5) of the Accomplishment Instructions of Hartzell Propeller Inc. ASB No. HC- ASB-61-279, Revision 2.Mandatory Terminating Action5. Replace all P/N B-3339, LFC Manufacturing Lot No. 12 and Lot No. 56 bolts with P/N B-3339 bolts that are not from LFC Manufacturing Lot No. 12 or Lot No. 56, or with approved equivalent part number bolts in accordance with paragraph 3.C of Accomplishment Instructions of Hartzell Propeller Inc. ASB No. HC- ASB-61-279, Revision 2.Note: FAA AD 2005-14-12 Amendment 39-14189 refers. |\n| Compliance: | 1. Within 50 hours time-in-service (TIS) or 12 months after the effective date of the Directive, whichever occurs first.2. Within 120 hours TIS since-last-inspection.3. Within 100 hours TIS since-last-inspection.4. Before further flight.5. Within 12 months after the effective date of this Directive. |\n| | This Airworthiness Directive becomes effective on 29 September 2005. |\n| Background: | This Directive results from the discovery during routine propeller installation that a bolt from a certain manufacture lot did not properly absorb the installation torque. This Directive also results from the discovery that other bolts of the same part number from a different manufacture lot had material surface pitting. This Directive is being issued to prevent propeller mounting bolt failures or improperly secured propellers, which could lead to separation of the propeller from the aeroplane. |\n\n![](image.001.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n18 August 2005","sortOrder":0},{"sectionNumber":"AD/PHZL/81","sectionType":"part","heading":"AD/PHZL/81","content":"## AD/PHZL/81","sortOrder":1},{"sectionNumber":"Propeller Attachment Bolts","sectionType":"part","heading":"Propeller Attachment Bolts","content":"## Propeller Attachment Bolts","sortOrder":2},{"sectionNumber":"10/2005","sectionType":"part","heading":"10/2005","content":"## 10/2005","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The Directive is tightly focused on specified Hartzell propeller models and P/N B-3339 bolts from two manufacturing lots; it does not broaden applicability beyond those parts/models or add new categories of equipment. It operates as a corrective safety action addressing identified manufacturing/quality issues (improper torque absorption and surface pitting) and mandates inspections and replacement to eliminate the defect."},"complexity_factors":["Technical specificity: identifies a single part number (P/N B-3339) and two manufacturing lot numbers (LFC Lot No. 12 and Lot No. 56).","Multiple affected models: covers several Hartzell variable‑pitch propeller models across HC-B3, HC-B4 and HC-B5 series.","Diverse required actions: visual inspections, torque checks, immediate replacement if torque fails, and a mandatory terminating replacement action.","Varied compliance windows: several different time limits (50 hours TIS or 12 months; 120 hours; 100 hours; before further flight; 12 months), increasing scheduling complexity for operators.","Dependence on external service document: procedural steps and bolt identification refer to Hartzell ASB No. HC-ASB-61-279 Rev 2 (including Figure 1).","Different treatment for an STC-modified aeroplane (Aerospatiale Nord 262(A) modified by STC SA2369SW) introduces conditional applicability."],"plain_english_summary":"Requires owners/operators to visually inspect and torque‑check all eight propeller mounting flange bolts on specified Hartzell variable‑pitch propellers when the bolts are part number B‑3339 from LFC Manufacturing Lot No. 12 or 56, and to replace those bolts (or immediately replace all eight if any fail torque). The rule applies to listed Hartzell models and sets staged compliance times; the stated purpose is to prevent bolt failures and potential propeller separation, shifting inspection and replacement costs to operators and their maintenance providers."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This AD maintains focused scope on propeller bolt safety. The differentiation between Aerospatiale 262(A) aircraft with STC SA2369SW and other aircraft appears to reflect operational differences (likely flight cycle intensity or mounting configuration) rather than scope creep. The directive remains tightly targeted at the specific defective bolt lots identified in the background."},"complexity_factors":["Multiple conditional requirements based on aircraft type (Aerospatiale 262(A) with specific STC vs all other aircraft)","Cross-reference to external technical document (Hartzell Alert Service Bulletin HC-ASB-61-279, Revision 2) for detailed procedures","Five distinct compliance deadlines with different triggering events (hours time-in-service, calendar months, since-last-inspection, before further flight)","Specific manufacturing lot numbers (LFC Lot No. 12 and Lot No. 56) creating precise applicability criteria","Reference to FAA AD 2005-14-12 indicating harmonisation with US aviation safety requirements","Nested action structure: initial inspection → repetitive checks → conditional replacement → mandatory terminating action"],"plain_english_summary":"This AD requires owners/operators of aircraft fitted with certain Hartzell variable-pitch propellers to inspect and, if needed, replace specific propeller mounting bolts (B-3339) from two defective batches. It mandates initial and recurring torque checks and replacement of any failing bolts and ultimately removal of the affected batch within a set period.\n\nAction is critical because defective bolts can allow a propeller to detach in flight, posing a catastrophic safety risk."}},"importantCases":[],"_links":{"self":"/api/acts/ad-phzl-81-propeller-attachment-bolts","history":"/api/acts/ad-phzl-81-propeller-attachment-bolts/history","analysis":"/api/acts/ad-phzl-81-propeller-attachment-bolts/analysis","conflicts":"/api/acts/ad-phzl-81-propeller-attachment-bolts/conflicts","importantCases":"/api/acts/ad-phzl-81-propeller-attachment-bolts/important-cases","documents":"/api/acts/ad-phzl-81-propeller-attachment-bolts/documents"}}