{"id":"F2006B05340","name":"AD/P68/13 Amdt 2 - Longitudinal Trim Indicator - Check and Modification","slug":"ad-p68-13-amdt-2-longitudinal-trim-indicator-check-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":45834,"registerId":"commonwealth-F2006B05340-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/P68/13 Amdt 2 - Longitudinal Trim Indicator - Check and Modification","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nPartenavia P68 Series Aeroplanes\n\nAD/P68/13\n\nAmdt 2\n\n  \nLongitudinal Trim Indicator \\- Check and Modification 7/79\n\nApplicability: All models P68 and P68B aircraft with trim system and indicator not modified in accordance with schemes approved by the Secretary.\n\nRequirement: 1. To check accuracy of longitudinal trim indicator until incorporation of Partenavia S/B No. 41.\n\n    (a) Set trim indicator to zero by rotating trim wheel.\n\n    (b) Position stabilator leading edge to zero reference point (rivet reference on fuselage left hand side) and check that trim tab is streamlined with stabilator. If this is the case, trim indicator is correct.\n\n    (c) If trim tab not streamlined with stabilator, maintaining leading edge to zero, rotate trim wheel until streamlined and consider this position of trim indicator as zero.\n\n    (d) Set take off trim with reference to new zero position.\n\n    (e) If reference rivet referred to in para. (b) above is not fitted consider zero reference point for stabilator to be 4.17 inches below upper longitudinal row of rivets.\n\n    2. Modify in accordance with Partenavia SB No. 41 and install trim indicator Type B P/N S.6041B or later equivalent.\n\n    3. Modify trim indicator by fitting an approved transparent cover or guard to prevent displacement of the pointer from the associated driving scroll.\n\nNote: Registro Aeronautico Italiano AD No. 78-216/P68-19 refers to paras. 1 and 2 of this requirement.\n\nCompliance: 1. Before each flight after 13 June 1979 until modified in accordance with paras. 2 and 3. For aircraft maintained in accordance with ANO 100.5.1, this Directive shall be entered on the maintenance release as maintenance required. The inspection may be performed by the pilot in command in which case certification is not required. In all other cases certification may be made on the maintenance release. This inspection may also be performed and certified by any Licensed Aircraft Maintenance Engineer.\n\n    2. Within 10 hours time in service after 13 June 1979.\n\n    3. Within 100 hours time in service after 13 June 1979.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The Directive applies only to P68/P68B aircraft whose trim systems/indicators have not been modified (Applicability) and prescribes immediate repetitive checks plus mandated modifications (Requirements and Compliance). The text does not expand or narrow that applicability beyond its stated condition, so scope remains aligned with the Directive's stated objective to ensure indicator accuracy."},"complexity_factors":["Technical measurement and alignment procedure for the stabilator and trim tab (Requirement paras 1(a)–(e)).","Multiple, staged compliance deadlines: repetitive pre‑flight checks until modification, installation within 10 hours, cover within 100 hours (Compliance paras 1–3).","Different authorised certifiers and recordkeeping routes: pilot in command may perform checks where allowed, otherwise certification on maintenance release or by a Licensed Aircraft Maintenance Engineer (Compliance para 1).","Cross‑reference to a manufacturer Service Bulletin and a specific part number (Partenavia SB No.41; P/N S.6041B) creates dependency on external approval/equivalents (Requirement para 2).","Applicability condition limited to aircraft not already modified, requiring operators to determine modification status before applying requirements (Applicability).","A fallback physical reference if a rivet is missing (4.17 inches) introduces a non‑standard measurement that must be used consistently (Requirement para 1(e)).","Administrative burden: maintenance‑release entries required for aircraft maintained under ANO 100.5.1 (Compliance para 1)."],"plain_english_summary":"Requires operators of Partenavia P68/P68B aeroplanes whose longitudinal trim systems haven’t been modified to check the trim indicator before each flight and to fit specified modifications. The check sets the indicator to a zero position and verifies trim‑tab alignment; if misaligned, a new zero is established. Within 10 hours the approved replacement indicator or Partenavia SB No.41 modification must be installed; a transparent cover must be fitted within 100 hours. Operators bear compliance costs; pilots or licensed engineers may perform and certify checks."},"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":3,"scope_assessment":{"changed":false,"description":"This is an amendment (Amdt 2) to an existing Airworthiness Directive. The scope remains tightly focused on the original safety issue: ensuring accurate longitudinal trim indication in Partenavia P68 aircraft. The amendment appears to refine or update the original directive without expanding its purpose beyond the specific trim indicator problem."},"complexity_factors":["Short, single-purpose directive focused on one aircraft type and one system","Only 3 main requirements with clear sequential numbering","Minimal defined terms (only standard aviation abbreviations like 'P/N' for part number)","Simple conditional logic limited to applicability clause ('All models...not modified')","No cross-references to other legislation beyond a note about an Italian aviation authority document","Compliance dates are straightforward calendar/flight hour deadlines without nested exceptions","Technical but not legally complex — written for aircraft mechanics and pilots rather than lawyers"],"plain_english_summary":"This CASA Airworthiness Directive mandates safety action for Partenavia P68 and P68B aircraft due to unreliable longitudinal trim indicators. It requires immediate pre‑flight verification of the indicator until an improved Type B unit is installed and a transparent guard fitted within short flight‑hour limits. It affects owners, operators, pilots and maintenance engineers and prevents possible loss of control during critical phases like takeoff."}},"importantCases":[],"_links":{"self":"/api/acts/ad-p68-13-amdt-2-longitudinal-trim-indicator-check-and-modification","history":"/api/acts/ad-p68-13-amdt-2-longitudinal-trim-indicator-check-and-modification/history","analysis":"/api/acts/ad-p68-13-amdt-2-longitudinal-trim-indicator-check-and-modification/analysis","conflicts":"/api/acts/ad-p68-13-amdt-2-longitudinal-trim-indicator-check-and-modification/conflicts","importantCases":"/api/acts/ad-p68-13-amdt-2-longitudinal-trim-indicator-check-and-modification/important-cases","documents":"/api/acts/ad-p68-13-amdt-2-longitudinal-trim-indicator-check-and-modification/documents"}}