{"id":"F2006B07140","name":"AD/SUPP/13 Amdt 1 - Air Equipment Hoists - Earth Bonding","slug":"ad-supp-13-amdt-1-air-equipment-hoists-earth-bonding","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48975,"registerId":"commonwealth-F2006B07140-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SUPP/13 Amdt 1 - Air Equipment Hoists - Earth Bonding","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nSupplementary Equipment\n\nAD/SUPP/13\n\nAmdt 1\n\n  \nAir Equipment Hoists \\- Earth Bonding 1/92\n\nApplicability: Air-Equipment Hoists P/Nos 76370. All variants, up to and including Serial Numbers 493.\n\nRequirement: 1. Measure the motor current limit resistors P/N 709967 with a milliohmmeter \\- Maximum permissible value is 0.040 OHM for the two resistors in series.\n\nNote: These can be measured on 76370-30 models using the shunt terminals on the hoist control box.\n\n    2. Measure the resistor terminals to ground (the resistor mounting plate) with a megohmmeter - Minimum resistance should be 20 Meg OHM.\n\n    3. Install bonding cables and carry out a bonding check in accordance with the Lucas Air Equipment Service Bulletin 25-62-0L.\n\nNote 1: Hoists which have already had bonding jumpers installed in accordance with the original issue 1 of this AD are still required to comply with the requirements of Lucas Air Equipment SB 25-62-0L.\n\nNote 2: Bonding resistance checks are to be carried out with a milliohmmeter capable of resolving to 0.002 OHM.\n\nNote 3: Carry out all checks with main connectors disconnected.\n\nNote 4: Compliance with Lucas Air Equipment SB 25-62-0L is considered Mandatory, French DGAC AD 91-125 refers.\n\n    4. Examine all relevant documents to identify any hoists which have exhibited a history of slow operation. All hoists which have exhibited a history of slow operation or have blown circuit breakers in operation shall be returned to an approved overhaul facility for internal inspection.\n\nCompliance: 1. For Requirements 1 and 2. In accordance with the original issue of this AD, ie. prior to hoist operations with cable cutter squib installed, after 9 January 1991.\n\n    2. For Requirement 3. For installed hoists; prior to 12 March 1992. For uninstalled hoists; prior to installation in an aircraft.\n\n    3. For Requirement 4. In accordance with the original issue of this AD, ie. prior to further hoist operations.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\nBackground: An electrical failure introducing ground currents in the hoist body may cause an uncommanded cable cut.\n\nIn the absence of any advice from the hoist manufacturer of the French DGAC, the original issue of this AD was raised to address the problem.\n\nBoth the hoist manufacturer and DGAC have now issued instructions to improve and check the electrical bonding of the hoist installation, and Amendment 1 to this AD has been issued to reflect these instructions.\n\nIn addition, Aerospatiale have issued Mandatory Service Bulletins applicable to hoists installed in particular Aerospatiale helicopters. DGAC have also issued Airworthiness Directives mandating compliance with the Aerospatiale SBs. Details and cross reference to corresponding Australian ADs is as follows:\n\n| Aircraft | Manufacturers SB | DGAC AD       | AUSTRALIAN AD  |\n| -------- | ---------------- | ------------- | -------------- |\n| AS 350   | 35-42            | 91-165-058(B) | AD/ECUREUIL/47 |\n| AS 355   | 25-30            | 91-164-042(B) | AD/AS 355/39   |\n| SA 341   | 25-05            | 91-203-035(B) | AD/GAZELLE/16  |","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"The original 1991 directive (referenced as 'original issue 1') addressed immediate electrical safety risks. Amendment 1 significantly expanded the scope by: (1) incorporating formal manufacturer service bulletin requirements that didn't exist when the original was issued, (2) adding specific measurement tolerances and equipment specifications (0.002 OHM resolution), (3) introducing the historical performance check (Requirement 4) for slow operation and circuit breaker failures, and (4) creating a comprehensive cross-reference system to French DGAC directives and Aerospatiale-specific bulletins. The amendment transformed a simple grounding check into a multi-layered inspection regime with retrospective component history analysis."},"complexity_factors":["Technical aviation terminology requiring specialised knowledge (part numbers, serial number ranges, megohmmeters, milliohmmeters)","Multiple compliance deadlines with different dates for installed vs uninstalled equipment","Cross-references to foreign regulatory documents (French DGAC AD 91-125, Lucas Air Equipment Service Bulletin 25-62-0L)","Conditional logic: different requirements apply depending on whether hoists already had bonding jumpers installed under the original directive","Nested notes and exceptions (4 notes modifying Requirement 3, plus additional notes on measurement specifications)","Tabular cross-reference to three related aircraft-specific directives at the end"],"plain_english_summary":"This AD requires operators of Air‑Equipment hoists (P/N 76370, serials up to 493) to address a poor earth‑bonding fault that can let stray current trigger the cable cutter and cause unexpected load release.  \n\nAffected operators—notably rescue and offshore helicopters—must test hoist motor resistors, install additional bonding cables per the manufacturer bulletin, and send hoists with slow operation or blown breakers for internal inspection to eliminate the life‑safety hazard."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"Amendment 1 refines and prescribes specific bonding and test requirements (installation of bonding cables per Lucas SB 25‑62‑0L, clarified measurement methods and resolution) to address the same safety hazard identified in the original AD (ground currents causing possible uncommanded cable cut). It does not broaden the set of affected hoists (still P/N 76370 up to SN 493) or add unrelated obligations; rather it makes the manufacturer/DGAC instructions mandatory and adds procedural detail. Therefore the instrument’s scope has been clarified and tightened but not significantly expanded beyond its original safety purpose."},"complexity_factors":["Single equipment type narrow applicability (P/N 76370, serials up to 493) but multiple requirements (4 numbered requirements).","Cross‑references to an external service bulletin made mandatory (Lucas SB 25‑62‑0L).","Measurement specifications with tight tolerances and instrument resolution requirements (0.040 ohm max for two resistors in series; milliohmmeter capable of 0.002 ohm resolution; 20 MΩ minimum insulation).","Multiple timing/ compliance conditions: different deadlines for installed vs uninstalled hoists and references to actions required prior to certain operations (see Compliance para 1–3).","Operational condition triggers: requirement 4 depends on historical operational evidence (slow operation or blown circuit breakers) rather than a simple calendar trigger.","Background cross‑references to other manufacturer/DGAC service bulletins and related ADs for specific aircraft types (table of cross‑references).","Notes and measurement procedure constraints (connectors disconnected, shunt terminal measurement permitted on some models) increase procedural detail."],"plain_english_summary":"**What this instrument requires (mechanical change)**\n\n- Applies to Air-Equipment Hoists part number 76370 (all variants) up to and including serial number 493.\n- Four discrete actions are required:\n  - Measure the two motor current‑limit resistors in series with a milliohmmeter; the combined resistance must not exceed 0.040 ohm (Requirement 1).\n  - Measure the resistance from the resistor terminals to the hoist ground (resistor mounting plate) with a megohmmeter; minimum insulation resistance 20 megaohm (Requirement 2).\n  - Fit earthing/bonding cables and perform a bonding check exactly as set out in Lucas Air Equipment Service Bulletin 25‑62‑0L (Requirement 3).\n  - Review maintenance/operational records for any hoists that have been slow or that have tripped/blown circuit breakers; any such hoist must be returned to an approved overhaul facility for internal inspection (Requirement 4).\n\n- Practical notes: measurements must be done with connectors disconnected; milliohmmeter must resolve to 0.002 ohm for bonding resistance checks; some models allow the resistor measurement via shunt terminals; the Lucas service bulletin compliance is mandatory and tied to a corresponding French DGAC AD.\n\n**Who this affects**\n\n- Aircraft operators, maintenance organisations and approved overhaul facilities that own or service hoists P/N 76370 (serials up to 493).\n- Technicians must have or access specific test equipment (milliohmmeter and megohmmeter with stated resolution) and follow the Lucas service bulletin.\n- Small operators without in‑house overhaul capability will need to arrange approved overhaul facility work if hoists show the specified fault history.\n\n**Why it matters (stated purpose and mechanical effect)**\n\n- The stated safety concern is that an electrical failure allowing ground currents to flow through the hoist body can lead to an unintended (uncommanded) cable cut. The AD’s mechanical purpose is to detect degraded resistors or insulation and to ensure conductive bonding so stray ground currents cannot produce that unsafe outcome.\n\n**Costs, incentives and trade‑offs (practical effects)**\n\n- Who pays: the direct costs fall to operators and maintenance providers — time for inspections, equipment usage or purchase, possible parts (bonding cables), and downtime while hoists are out of service or sent for overhaul.\n- Compliance burden: requires specific instruments (milliohmmeter resolving to 0.002 ohm and a megohmmeter), measurement with connectors disconnected, adherence to a manufacturer service bulletin which is made mandatory by the AD (Requirements 1–3, Notes 2–3). That creates an administrative and technical burden on maintainers.\n- Behaviour change: operators will add routine resistance and insulation checks and fit bonding jumpers where not already present; hoists with slow operation or breaker trips will be withdrawn for internal inspection at approved facilities.\n- Effects on private enterprise and competition: larger operators with in‑house test capability or approved overhaul capacity will absorb the cost more easily than small operators who may face outsourcing expenses and downtime; mandatory compliance with a particular service bulletin concentrates technical remedy and may advantage providers already aligned with the manufacturer.\n- Opportunity cost: time and money spent on the AD’s checks and retrofits are diverted from other maintenance priorities.\n\n**Implementation risks and uncertainties**\n\n- Technical competence: accurate low‑ohm measurements and correct bonding installation require trained technicians and calibrated instruments; mismeasurement or improper bonding could give false assurance.\n- Chain of authority: the AD makes the Lucas service bulletin mandatory, so the adequacy of the remedy depends on the content and correct application of that SB. The AD also cross‑references other manufacturer/DGAC instructions for particular airframes (background table), so maintainers must identify aircraft‑specific actions.\n- Enforcement and discretion: compliance timing is prescribed (see Compliance section) and some work (internal inspections) must be done at an approved overhaul facility — that approval regime delegates selection of an appropriate facility to regulators/maintainers.\n\n**Summary statement of mechanics and incentives**\n\n- Mechanically: the instrument mandates specific electrical checks and the installation of bonding cables per the Lucas service bulletin, and it requires internal inspection of hoists that have shown slow operation or tripped breakers.\n- Incentives: it creates a clear safety testing and retrofit incentive for operators at the cost of added maintenance, equipment, and potential downtime. Benefits (reduced risk of uncommanded cable cut) are concentrated on safety outcomes; costs are concentrated on operators and maintainers."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-supp-13-amdt-1-air-equipment-hoists-earth-bonding","history":"/api/acts/ad-supp-13-amdt-1-air-equipment-hoists-earth-bonding/history","analysis":"/api/acts/ad-supp-13-amdt-1-air-equipment-hoists-earth-bonding/analysis","conflicts":"/api/acts/ad-supp-13-amdt-1-air-equipment-hoists-earth-bonding/conflicts","importantCases":"/api/acts/ad-supp-13-amdt-1-air-equipment-hoists-earth-bonding/important-cases","documents":"/api/acts/ad-supp-13-amdt-1-air-equipment-hoists-earth-bonding/documents"}}