{"id":"F2006B10204","name":"AD/GAF-N22/56 Amdt 1 - Rudder Pedal Pivot Arms","slug":"ad-gaf-n22-56-amdt-1-rudder-pedal-pivot-arms","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55862,"registerId":"commonwealth-F2006B10204-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/GAF-N22/56 Amdt 1 - Rudder Pedal Pivot Arms","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)  \nGAF N22 and N24 Series Aeroplanes\n\nAD/GAF-N22/56\n\nAmdt 1\n\n  \nRudder Pedal Pivot Arms 10/95\n\nApplicability: All N22 and N24 aircraft (including pre Mod N33 configuration). Requirement: 1. For pre Mod N794 Rudder Pedal Pivot Arms:-\n\n    (a) Remove the rudder pedal pivot arms from the aircraft and perform a fluorescent dye penetrant inspection around the shaft housing in accordance with ASTA Service Bulletin ANMD-27-42, Revision 3, Accomplishment Instructions A.Part 1.(1).\n\n    (b) Treat the inside of the rudder pedal pivot arms for corrosion in accordance with ASTA Service Bulletin ANMD-27-42, Revision 3, Accomplishment Instructions B.Part 2.(6),(12)&(13).\n\nIt is recommended that Mod N794 be incorporated in its entirety at this time. If Mod N794 is incorporated at a later time, it will be necessary to repeat the corrosion protection treatment after welding. Pedal pivot arms exhibiting severe corrosion, in the form of loose rust flakes or severe pitting, are to be scrapped.\n\n    2. For post Mod N794 Rudder Pedal Pivot Arms:-\n\n    (a) Visually inspect the rudder pedal pivot arms using 10x magnification, in accordance with ASTA Service Bulletin ANMD-27-42, Revision 3, Accomplishment Instructions A.Part 1.(2).\n\nCompliance: 1. (a) Action in accordance with Requirement paragraph 1(a) before 1000 hours component time in service, or before 14 October 1995, whichever occurs last. Repeat the inspection at intervals not to exceed 300 hours component time in service.\n\n    (b) Unless previously done, action in accordance with Requirement paragraph 1(b) not later than the next fluorescent dye penetrant inspection after 30 September 1995.\n\n    2. Action in accordance with Requirement paragraph 2 at intervals not exceeding 1800 hours component time in service or before 14 October 1995, whichever occurs last.\n\nBackground: Major defect reports have been received of cracking in both pilot and co-pilot rudder pedal pivot arms at times in service as low as 1400 hours. If not detected, cracks could progress to a point where aircraft control may be impeded. The omission of internal corrosion treatment at manufacture, and subsequent internal corrosion, exacerbates the problem. This Amendment reduces the inspection threshold and introduces a corrosion treatment for unmodified arms, and introduces a visual inspection for modified arms.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope — safety-critical inspection and maintenance of rudder pedal pivot arms on specific GAF aircraft models. The amendment refines and tightens existing requirements rather than expanding into new operational areas."},"complexity_factors":["Multiple conditional branches based on aircraft modification status (pre/post Mod N794)","Cross-references to external technical document (ASTA Service Bulletin ANMD-27-42, Revision 3) for detailed procedures","Layered compliance deadlines involving 'whichever occurs last' logic and calendar dates now historical","Interdependent requirements (corrosion treatment timing linked to inspection schedule)","Technical aviation terminology requiring domain knowledge (e.g., 'fluorescent dye penetrant inspection', 'component time in service')"],"plain_english_summary":"This directive mandates inspections and corrosion treatment of rudder-pedal pivot arms on GAF N22/N24 (including early “pre Mod N33”) aircraft after cracks — sometimes appearing by ~1,400 flight hours — were found. If undetected, failures can cause loss of rudder control.\n\nOwners/operators of older, unmodified aircraft must remove and dye‑penetrant inspect and treat or replace corroded arms; modified aircraft get periodic magnified visual checks. Amendment 1 brings earlier inspections, required corrosion treatment, and a simpler check for modified planes."},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"This amendment widens the practical obligations compared with a basic inspection directive by (a) lowering inspection thresholds, (b) introducing mandatory internal corrosion treatment for unmodified rudder pedal pivot arms, and (c) creating a separate, less frequent visual inspection regime for arms modified by Mod N794. It therefore goes beyond solely requiring crack inspections to add corrosion treatment, scrapping rules for severely corroded parts, and instructions about repeating corrosion protection after welding — increasing the directive’s operational and cost footprint for operators (see Requirement paragraphs 1 and 2 and Compliance)."},"complexity_factors":["Two alternative compliance tracks depending on Mod N794 status (pre‑Mod vs post‑Mod).","Cross‑reference to external technical document: ASTA Service Bulletin ANMD‑27‑42 Revision 3 with multiple specific accomplishment instruction parts.","Multiple timing conditions combining component time thresholds and fixed calendar dates (e.g. before 1000 hours or before 14 Oct 1995; repeat every 300 hours; visual inspection every 1800 hours or before 14 Oct 1995).","Procedural differences in inspection method (fluorescent dye penetrant inspection vs visual 10× magnification).","Requirement to perform corrosion treatment and to repeat it after welding if Mod N794 is incorporated later.","Conditional disposal rule (scrap parts exhibiting loose rust flakes or severe pitting).","Recommendation to incorporate Mod N794 (optional action that changes ongoing compliance obligations).","Dependence on accurate tracking of ‘component time in service’ for compliance scheduling.","Fixed historical deadlines (30 Sept 1995, 14 Oct 1995) creating retrospective compliance windows and potential interpretive complexity."],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- Applies to all GAF N22 and N24 aeroplanes (including those in the older pre‑Mod N33 configuration). (See “Applicability”.)\n- Divides the fleet into two groups depending on whether the rudder pedal pivot arms have had Mod N794 applied:\n  - **Pre‑Mod N794 pivot arms:** Must be removed from the aircraft and inspected using a fluorescent dye penetrant test around the shaft housing (Requirement 1(a)). The inside of these arms must be treated for corrosion as specified by the manufacturer’s service bulletin (Requirement 1(b)). Pedal pivot arms showing severe corrosion (loose rust flakes or severe pitting) must be scrapped. The service bulletin referenced is ASTA Service Bulletin ANMD‑27‑42, Revision 3, and specific accomplishment instruction parts are cited.\n  - **Post‑Mod N794 pivot arms:** Must be inspected visually with 10× magnification in accordance with the same service bulletin (Requirement 2(a)).\n- Sets timing and repeat intervals (Compliance):\n  - For pre‑Mod arms, the initial dye penetrant inspection must be done before 1,000 hours component time in service or before 14 October 1995, whichever is later, and repeated at intervals not exceeding 300 hours component time.\n  - The internal corrosion treatment for pre‑Mod arms must be completed by the next dye penetrant inspection after 30 September 1995 if it hasn’t already been done.\n  - For post‑Mod arms, visual inspections are required at intervals not exceeding 1,800 hours component time or before 14 October 1995, whichever occurs last.\n- Recommends incorporation of Mod N794 in full when performing the work; if Mod N794 is applied later, corrosion treatment must be repeated after any welding.\n\n**Why the rule was made (official rationale)**\n\n- The directive follows reports of cracking in both pilot and co‑pilot rudder pedal pivot arms at component times as low as about 1,400 hours. Cracking plus internal corrosion (which was sometimes omitted at manufacture) can allow cracks to progress and potentially impede aircraft control. The amendment therefore tightens inspection thresholds, adds corrosion treatment for unmodified arms, and prescribes a visual inspection regime for modified arms (Background).\n\n**Who it affects and who pays**\n\n- Affected parties: Owners and operators of GAF N22 and N24 aircraft, maintenance organisations that perform inspections and repairs, and parts suppliers who supply replacement pivot arms.\n- Costs fall on the aircraft operator/owner: removal and reinstallation labour, fluorescent dye penetrant inspection costs, corrosion treatment labour/materials, replacement parts if scrapped, and potentially the cost of incorporating Mod N794 if chosen.\n- The Civil Aviation Safety Authority (CASA) issues and enforces the directive; the operator and certified maintenance personnel decide how and when to carry out the required inspections and treatments to meet the compliance times.\n\n**Behavioral and operational effects**\n\n- Increases inspection frequency and introduces a mandatory corrosion treatment step for unmodified pivot arms (so operators will allocate maintenance hours and budget accordingly).\n- Encourages or nudges operators to adopt Mod N794 (the directive recommends incorporating it, and doing so changes the inspection method and interval).\n- Creates a disposal pathway for severely corroded parts (must be scrapped), which raises replacement demand.\n\n**Trade‑offs, implementation risks and compliance burdens**\n\n- Implementation relies heavily on a manufacturer service bulletin (ASTA ANMD‑27‑42 Rev 3). Operators must have access to that document and the capability to perform fluorescent dye penetrant inspections to the specified instruction parts.\n- Costs and downtime: removing pivot arms for inspection increases maintenance downtime compared with in‑situ checks; dye penetrant inspection and corrosion treatment add labour and materials costs relative to simple visual inspection.\n- Parts availability risk: scrapping severely corroded pivot arms increases demand for replacement parts; if spares are scarce or long‑lead, aircraft may be grounded longer.\n- Welding and subsequent re‑treatment: if Mod N794 is incorporated after corrosion treatment, the instruction requires repeating the corrosion protection after welding — this adds an additional step and scheduling complexity.\n- Enforcement and interpretation: the AD references specific accomplishment instruction parts and defines thresholds by component hours and fixed dates, which requires accurate component time tracking and clear maintenance records.\n\n**Concrete citation of where these effects arise in the text**\n- Applicability: \"All N22 and N24 aircraft (including pre Mod N33 configuration).\"\n- Requirements: paragraphs 1(a)/(b) (pre‑Mod N794) and 2(a) (post‑Mod N794).\n- Compliance timings: the numbered Compliance paragraph specifying hours and dates.\n- Background: explains defect reports and why thresholds/treatments were changed.\n\n**Net practical takeaway**\n- Operators of GAF N22/N24 aircraft must inspect rudder pedal pivot arms more frequently than before, treat unmodified arms internally for corrosion, and scrap severely corroded arms. Incorporating Mod N794 reduces the inspection frequency but triggers a different inspection method; if Mod N794 is applied after corrosion treatment the treatment must be repeated. The operator bears the direct costs and operational disruption, while the directive aims to reduce the safety risk posed by cracking and internal corrosion (Background)."},"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-gaf-n22-56-amdt-1-rudder-pedal-pivot-arms","history":"/api/acts/ad-gaf-n22-56-amdt-1-rudder-pedal-pivot-arms/history","analysis":"/api/acts/ad-gaf-n22-56-amdt-1-rudder-pedal-pivot-arms/analysis","conflicts":"/api/acts/ad-gaf-n22-56-amdt-1-rudder-pedal-pivot-arms/conflicts","importantCases":"/api/acts/ad-gaf-n22-56-amdt-1-rudder-pedal-pivot-arms/important-cases","documents":"/api/acts/ad-gaf-n22-56-amdt-1-rudder-pedal-pivot-arms/documents"}}