{"id":"F2006B07550","name":"AD/VAT/18A - Limitation of Flap Movement - Modification","slug":"ad-vat-18a-limitation-of-flap-movement-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":50144,"registerId":"commonwealth-F2006B07550-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/VAT/18A - Limitation of Flap Movement - 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)  \nVicta and A.E.S.L. Airtourer Series Aeroplanes\n\nAD/VAT/18A Limitation of Flap Movement \\- Modification 5/64\n\nApplicability: Victa Airtourer 100 and 115. All AESL model 115 with S/Nos. 501 to 513 except 506\n\nand 509.\n\nRequirement: 1. Modify the flap selector quadrant to allow selection of only the first 3 positions, in accordance with Victa SB No. 34 or Victa Modification No. B129; or\n\n    2. Victa Modification No. B129 (SB No. 34) may be removed following incorporation of Air Navigation Order AD/VAT/34 and also provided the aircraft is test flown by a pilot endorsed for the type and holding at least a Commercial Pilot Licence immediately following removal of the Modification No. B129 in order to check the general handling and controllability with fourth notch of flap extended.\n\nThe tests shall determine whether:\n\n    (a) any excessive wing drop or other undesirable Characteristics occur when the aircraft is stalled power “on” and power “off” in both level and turning flight; and\n\n    (b) approaches and landings including precautionary landings can be safely executed under all normal operating conditions.\n\nA signed copy of the flight test report shall be forwarded to the Secretary within 7 days of completion of the tests.\n\nNote: An amendment to the aircraft flight manual will be forwarded to the owner on receipt of the satisfactory test report.\n\nCompliance: Before 1 September 1971.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted airworthiness directive addressing a specific technical safety issue with defined aircraft models. It has not expanded beyond its original purpose of mandating flap limitation modifications for flight safety."},"complexity_factors":["Single discrete requirement with two alternative compliance paths","Specific applicability limited to narrow aircraft serial number range","References to external technical documents (Victa SB No. 34, Modification B129, AD/VAT/34) without reproducing their content","Conditional logic in option 2 requiring sequential modifications and flight testing","Specific procedural requirements for flight testing (pilot qualifications, test parameters, reporting timeline)","Short document length (approximately 200 words)","No defined terms section or extensive cross-referencing within the instrument itself"],"plain_english_summary":"This Airworthiness Directive orders owners of certain Victa Airtourer light aircraft (models 100 and 115, and early AESL 115s, s/n 501–513 excluding 506 & 509) to restrict flap extension to the first three positions or, if they wish to retain full flaps, to install a prior modification and complete a qualified flight test proving safe handling.  \n\nIt’s a mandatory safety measure addressing hazardous handling with full flaps; compliance (and a signed test report, if applicable) was required by 1 September 1971."},"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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive confines its effect to limiting flap selection or permitting conditional removal of that limitation for the listed aircraft. It does not expand applicability beyond the named models/serials and preserves a safety‑testing condition for any reversal; therefore it does not change the instrument's original, model‑specific scope as stated."},"complexity_factors":["Narrow applicability: specific models and serial numbers (Applicability).","Two alternative compliance paths: mandatory modification (Requirement 1) or removal conditional on actions (Requirement 2).","Technical flight-test specification: immediate test by a type‑endorsed pilot with Commercial Licence checking stalls and approach/landing characteristics (Requirements 2(a)–(b)).","Administrative reporting: signed flight test report to be forwarded to the Secretary within 7 days (Requirement 2).","Regulatory linkage: removal option depends on incorporation of AD/VAT/34 and leads to AFM amendment on satisfactory outcome (Requirement 2; Note).","Hard compliance deadline: before 1 September 1971 (Compliance)."],"plain_english_summary":"This airworthiness directive requires Victa Airtourer 100/115 and specified AESL 115 serial numbers to have the flap selector physically limited to the first three flap positions by modifying the flap-selector quadrant (per Victa SB No. 34 / Mod B129). Alternatively, the limitation may be removed only after AD/VAT/34 is incorporated and an immediate flight test by a type‑endorsed pilot with a Commercial Licence confirms safe handling with the fourth‑notch flap; a signed test report must be sent to the Secretary within seven days.\n\nAircraft owners fund and arrange the modification or the test flights and must comply by 1 September 1971; the regulator will issue an AFM amendment if tests are satisfactory."}},"importantCases":[],"_links":{"self":"/api/acts/ad-vat-18a-limitation-of-flap-movement-modification","history":"/api/acts/ad-vat-18a-limitation-of-flap-movement-modification/history","analysis":"/api/acts/ad-vat-18a-limitation-of-flap-movement-modification/analysis","conflicts":"/api/acts/ad-vat-18a-limitation-of-flap-movement-modification/conflicts","importantCases":"/api/acts/ad-vat-18a-limitation-of-flap-movement-modification/important-cases","documents":"/api/acts/ad-vat-18a-limitation-of-flap-movement-modification/documents"}}