{"id":"F2019L00291","name":"AD/INST/10Amdt 2 Mechanical Fatigue Meters","slug":"ad-inst-10amdt-2-mechanical-fatigue-meters","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":98894,"registerId":"commonwealth-F2019L00291-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Instruments and Automatic Pilots","sectionType":"part","heading":"Instruments and Automatic Pilots","content":"# Instruments and Automatic Pilots\n\n| AD/INST/10Amdt 2 | Mechanical Fatigue Meters | 6/2019 |\n| ---------------- | ------------------------- | ------ |\n\n```html\n

Applicability:

All Meggitt PLC, Mechanisms Ltd and Negretti and Zambra Ltd mechanical fatigue meters installed in aircraft.

Requirement:

The mechanical fatigue meters must be calibrated and overhauled.

Compliance:

The calibration and overhaul must be performed at intervals not exceeding the following time periods:

Fatigue Meter Type

Calibration Interval

Overhaul Interval

Single Spring Units

Every Six months

Every Two Years

Dual Spring Units

Every Twelve months

Every Four Years

Table 1 - Calibration and Overhaul Intervals.

Note: Compliance with the requirement of AD/INST/10 or AD/INST/10 Amdt 1 constitutes compliance with a requirement of this AD.

This AD commences on 22 March 2019.

Background:

Amendment 2 of this AD was issued to take into account a change of manufacturer’s name. Amendment 2 of this AD:

  • updated the title,
  • updated the manufacturer’s name, and
  • removed obsolete fatigue meter part number examples.
\n```\n\n \n\n| | Amendment 1 extended calibration and overhaul intervals for dual type spring meter units as experience showed they are more reliable and hold their calibration longer than the single spring units, and added fatigue meter part number examples. |\n| --- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.jpeg)\n\nPieter van Dijk \nDelegate of the Civil Aviation Safety Authority\n\n12 March 2019","sortOrder":0},{"sectionNumber":"AD/INST/10Amdt 2","sectionType":"part","heading":"AD/INST/10Amdt 2","content":"## AD/INST/10Amdt 2","sortOrder":1},{"sectionNumber":"Mechanical Fatigue Meters","sectionType":"part","heading":"Mechanical Fatigue Meters","content":"## Mechanical Fatigue Meters","sortOrder":2},{"sectionNumber":"6/2019","sectionType":"part","heading":"6/2019","content":"## 6/2019","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is Amendment 2 of an existing Airworthiness Directive. The background explicitly states this amendment only updates the manufacturer's name and removes obsolete part number examples. The substantive requirements (calibration and overhaul intervals) remain unchanged from Amendment 1. The scope has not expanded beyond the original purpose of ensuring mechanical fatigue meters are properly maintained."},"complexity_factors":["Very short document (approximately 300 words)","Only 2 defined equipment categories (Single Spring Units and Dual Spring Units)","Simple table-based compliance structure with clear time intervals","No cross-references to other legislation beyond noting previous versions of the same AD","Single operative requirement with straightforward exceptions (dual vs single spring)","Plain language throughout with minimal aviation jargon"],"plain_english_summary":"This AD mandates recurring calibration and overhaul schedules for mechanical fatigue meters (Meggitt PLC, Mechanisms Ltd, Negretti & Zambra) used to track structural stress: single-spring units require calibration every 6 months and overhaul every 2 years; dual-spring units require calibration every 12 months and overhaul every 4 years. \n\nIt matters because accurate meters prevent undetected structural fatigue. This amendment only updates a manufacturer name and removes obsolete part-number examples—previous compliance with AD/INST/10 or Amendment 1 remains valid."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Amendment 2 does not change the AD's substantive scope or the calibration/overhaul intervals. It makes administrative updates only (title change, updated manufacturer name, removal of obsolete part‑number examples). The calibration and overhaul requirements (including the interval differences introduced in Amendment 1 for dual‑spring units) remain in force."},"complexity_factors":["Applicability limited to named manufacturers (Meggitt PLC, Mechanisms Ltd, Negretti & Zambra) — requires operators to check whether their meters fall within the listed scope (Applicability table).","Two distinct meter types (single‑spring vs dual‑spring) with different calibration and overhaul schedules — increases scheduling and inventory complexity (Calibration and Overhaul Intervals table).","Cross‑reference to other airworthiness directives (AD/INST/10 and AD/INST/10 Amdt 1) for compliance equivalence — introduces legal cross‑checking (Note under Table 1).","Amendment 2 is administrative (title and manufacturer name change; removal of obsolete part numbers) rather than substantive — limits regulatory drafting complexity but requires document tracking (Background).","Explicit commencement date (22 March 2019) — creates a fixed implementation deadline for operators to meet maintenance intervals (Commencement paragraph).","Operational compliance burden: operators must integrate the intervals into maintenance programs, arrange calibration/overhaul logistics, and retain evidence of compliance (Requirement and Compliance sections).","Historical change: Amendment 1 extended intervals for dual‑spring units based on service experience — shows prior substantive adjustment that operators must observe (Amendment 1 note)."],"plain_english_summary":"Mandates periodic calibration and overhaul of specified mechanical fatigue meters (Meggitt PLC, Mechanisms Ltd, Negretti & Zambra) installed in aircraft. Calibration/overhaul intervals are: single‑spring — calibration every 6 months and overhaul every 2 years; dual‑spring — calibration every 12 months and overhaul every 4 years. Amendment 2 updates the title and manufacturer name and removes obsolete part‑number examples; compliance with AD/INST/10 or its Amendment 1 also satisfies this AD."}},"importantCases":[],"_links":{"self":"/api/acts/ad-inst-10amdt-2-mechanical-fatigue-meters","history":"/api/acts/ad-inst-10amdt-2-mechanical-fatigue-meters/history","analysis":"/api/acts/ad-inst-10amdt-2-mechanical-fatigue-meters/analysis","conflicts":"/api/acts/ad-inst-10amdt-2-mechanical-fatigue-meters/conflicts","importantCases":"/api/acts/ad-inst-10amdt-2-mechanical-fatigue-meters/important-cases","documents":"/api/acts/ad-inst-10amdt-2-mechanical-fatigue-meters/documents"}}