{"id":"F2006B10220","name":"AD/GAF-N22/70 Amdt 2 - Wing Strut Upper End Fitting","slug":"ad-gaf-n22-70-amdt-2-wing-strut-upper-end-fitting","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55878,"registerId":"commonwealth-F2006B10220-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/GAF-N22/70 Amdt 2 - Wing Strut Upper End Fitting","content":"![](image.001.png)\n\n![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/GAF-N22/70 Amdt 1 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\n![](image.001.png)  \n\nGAF N22 and N24 Series Aeroplanes\n\nAD/GAF-N22/70\n\nAmdt 2\n\n  \nWing Strut Upper End Fitting 3/2003\n\nApplicability: All Models\n\nRequirement: Inspect the attachment holes of the wing strut upper end fitting for cracks. Inspect in accordance with the eddy current method of Nomad Alert Service Bulletin ANMD- 57-12, Revision 2 dated 25 May 1999.\n\nCompliance: 1. For aircraft which have exceeded the time in service given in Table 2 of Nomad Alert Service Bulletin ANMD-57-12 Revision 2, inspect before further flight after 24 March 2003, unless inspected within the previous interval given in paragraph 3 below.\n\n    2. For aircraft which have exceeded the time in service in Table 1 of Nomad Alert Service Bulletin ANMD-57-12 Revision 2 but have not yet reached the Table 2 limits, inspect before 10 hours time in service after 24 March 2003, unless inspected within the previous interval given in paragraph 3 below.\n\n    3. Repeat the inspection at intervals not more than the following:\n\n    Models N24, N24A, N22S, N22C and N22F where the average flight duration is less than 45 minutes - 900 hours,\n\n    b. Models N24, N24A, N22S, N22C and N22F where the average flight duration exceeds 45 minutes - 1200 hours,\n\n    c. Model N22B where the average flight duration is less than 45 minutes \\- 1200 hours,\n\n    d. Model N22B where the average flight duration exceeds 45 minutes \\- 1800 hours.\n\nThis Amendment becomes effective on 20 March 2003.\n\nGAF N22 and N24 Series Aeroplanes\n\nAD/GAF-N22/70 Amdt 2 (Continued)\n\nBackground: Fatigue tests on the wing strut upper end fitting have shown consistently early failures and rapid crack growth. Many aircraft have already exceeded the safe thresholds established by these tests, and are at risk of a fitting failure. Amendment 1 extends the repeat inspection interval based on the results of fractographic analysis. Further testing is being conducted.\n\nAmendment 2 updates the Requirement document for this AD to Revision 2 of SB ANMD-57-12 and adds the N24 model to the applicability.\n\nAmendment 1 of this Airworthiness Directive became effective on 17 August 1995.\n\n![](image.002.png)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 28 January 2003\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 26 February 2003.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"The original AD (and Amendment 1) applied only to N22 series aircraft. Amendment 2 explicitly expands applicability to include N24 models, broadening the safety mandate beyond the original scope. Additionally, the technical requirements have been updated to reference Revision 2 of the service bulletin rather than the original version."},"complexity_factors":["Multiple conditional compliance deadlines based on aircraft flight hours (Table 1 vs Table 2 thresholds)","Four-tiered repeat inspection interval system depending on aircraft model and average flight duration","Cross-reference to external technical document (Nomad Alert Service Bulletin ANMD-57-12 Revision 2) for inspection methodology","Nested exception clauses ('unless inspected within the previous interval')","Requires understanding of aviation-specific terminology (time in service, eddy current method, flight duration averaging)"],"plain_english_summary":"This CASA safety order requires owners/operators of GAF N22 and newly included N24 aeroplanes to inspect the wing strut upper end fitting for cracks using eddy‑current testing because fatigue testing showed earlier-than-expected crack growth that could lead to wing‑strut separation and catastrophic structural failure.\n\nIt mandates immediate and recurring inspections based on aircraft hours/times and updates the referenced technical document to a newer revision."},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":true,"description":"Yes. Compared with the original AD, this amendment expands scope by adding the N24 model to the applicability and by updating the Requirement to reference Revision 2 of Nomad Alert Service Bulletin ANMD-57-12 (which contains the Tables and inspection procedure). Amendment 1 had already altered repeat intervals; Amendment 2 continues that evolution by changing the controlling SB and enlarging the set of affected aircraft, so the instrument has grown beyond the original model-specific text into broader model coverage and revised procedural specification."},"complexity_factors":["Cross-reference to an external document: Nomad Alert Service Bulletin ANMD-57-12 Revision 2 (procedural details and Tables 1 and 2 are in the SB).","Multiple conditional initial deadlines: different immediate actions depending on whether the aircraft exceeded SB Table 1 or Table 2 limits.","Four repeat-interval variants based on model and average flight duration (N24/N24A/N22S/N22C/N22F vs N22B, and <45 min vs >45 min).","Conditional exception language: 'unless inspected within the previous interval' creates look-back logic for prior compliance.","Reference to prior amendments (revocation of Amdt 1) and historical changes (Amendment 1 extended intervals), requiring reading of amendment history for full context.","Technical inspection method mandated (eddy-current), imposing equipment and competency requirements not described in the AD itself."],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- Revokes the earlier AD/GAF-N22/70 Amdt 1 and replaces it with AD/GAF-N22/70 Amdt 2. (Background & opening paragraph.)\n- Requires visual/eddy-current inspection of the attachment holes in the wing strut upper end fitting for cracks, using the eddy current method specified in Nomad Alert Service Bulletin ANMD-57-12 Revision 2 (dated 25 May 1999). (Requirement.)\n- Sets mandatory compliance timings and repeat intervals that depend on the aircraft model and the average flight duration. (Compliance.)\n\n**Who it applies to**\n\n- All GAF Nomad N22 and N24 series aeroplanes. Amendment 2 explicitly adds the N24 model to the applicability. (Applicability; Background.)\n\n**What operators must do and when**\n\n- Inspect the wing strut upper end fitting attachment holes for cracks using the eddy-current inspection method in Nomad Alert SB ANMD-57-12 Rev 2. (Requirement.)\n- If an aircraft has already exceeded the life limit in Table 2 of the SB, it must be inspected before next flight after 24 March 2003 unless it has been inspected within the previous repeat interval. (Compliance ¶1.)\n- If an aircraft has exceeded the life in Table 1 but not yet reached Table 2, it must be inspected within 10 hours time-in-service after 24 March 2003 unless it has been inspected within the previous repeat interval. (Compliance ¶2.)\n- After the initial inspection, repeat inspections are required at model- and usage-based intervals: for N24/N24A/N22S/N22C/N22F the interval is 900 hours if average flight <45 min, or 1200 hours if average flight >45 min; for N22B the interval is 1200 hours if average flight <45 min, or 1800 hours if average flight >45 min. (Compliance ¶3.)\n\n**Why the regulator says this is required (stated rationale)**\n\n- Fatigue testing showed early failures and rapid crack growth in the wing strut upper end fitting. Many airframes exceeded the safe thresholds found in those tests and are therefore at risk of a fitting failure. Amendment 2 updates the Requirement to the later service bulletin revision and adds the N24 model. (Background.)\n\n**Who pays and who decides**\n\n- Aircraft owners/operators pay for the inspections, any required repairs or part replacements, and the aircraft downtime while inspected or repaired. (Compliance & Requirement: mandatory inspections.)\n- The Civil Aviation Safety Authority (CASA), through its delegate, enforces the AD and determined the required action under the regulatory power cited in the AD. The AD sets the mandatory work and the compliance schedule. (Opening paragraph; Background.)\n\n**Practical implementation points, trade-offs and risks**\n\n- The mandated inspection technique (eddy current) requires appropriate non‑destructive testing equipment and trained personnel. Operators without that capability will pay for contracted maintenance or have to equip and train staff. (Requirement.)\n- The AD cross‑references external documents (Nomad Alert SB ANMD-57-12 Rev 2). Operators must obtain and follow that service bulletin exactly to meet the AD. This creates dependency on the SB for procedural details and the SB's Tables 1 and 2 for timing thresholds. (Requirement & Compliance.)\n- Short initial deadlines for aircraft that already exceeded the SB thresholds (inspect before next flight or within 10 hours TIS after 24 March 2003) may cause immediate operational disruption or grounding until inspection is done. (Compliance ¶1–2.)\n- Repeat intervals vary with model and average flight length; this rewards operators who track average flight duration accurately and penalises those who do not. Misreporting or miscalculating average flight duration can lead to non‑compliance. (Compliance ¶3.)\n- If cracks are found, there will be repair or replacement costs and additional downtime. The AD does not specify repair instructions here; operators must follow the SB or manufacturer guidance for corrective action. (Requirement & Background.)\n\n**Who benefits and who bears costs**\n\n- Direct safety benefit accrues to occupants and third parties if the inspection prevents in‑service failure of the wing strut upper end fitting. The benefit is concentrated on operators of affected models. (Background; Requirement.)\n- Costs (inspection, equipment, contracted labour, repair, downtime) are borne by aircraft owners/operators. The regulator incurs enforcement and oversight costs, and manufacturers/maintainers may capture maintenance revenue. (Compliance & Requirement.)\n\n**Implementation risks and monitoring**\n\n- Effectiveness depends on proper execution of the eddy‑current inspection and correct interpretation of results per the SB. If operators or maintenance providers lack proficiency, cracks could be missed. (Requirement.)\n- The AD references Tables in the service bulletin; any ambiguity or updates to the SB will materially affect compliance timing and technique. (Requirement & Compliance.)\n\n**Net mechanical effect**\n\n- Operators of GAF Nomad N22/N24 series aircraft must implement recurring eddy‑current inspections of the wing strut upper end fitting at defined intervals and meet short initial deadlines where life thresholds have already been exceeded. Failure to comply risks regulatory enforcement and continued exposure to fatigue‑related fitting failure. (Requirement & Compliance.)"},"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-n22-70-amdt-2-wing-strut-upper-end-fitting","history":"/api/acts/ad-gaf-n22-70-amdt-2-wing-strut-upper-end-fitting/history","analysis":"/api/acts/ad-gaf-n22-70-amdt-2-wing-strut-upper-end-fitting/analysis","conflicts":"/api/acts/ad-gaf-n22-70-amdt-2-wing-strut-upper-end-fitting/conflicts","importantCases":"/api/acts/ad-gaf-n22-70-amdt-2-wing-strut-upper-end-fitting/important-cases","documents":"/api/acts/ad-gaf-n22-70-amdt-2-wing-strut-upper-end-fitting/documents"}}