AD/SUPP/16 Amdt 1 — Electrical Hoist Assemblies - Earth Bonding Testing

This instrument, styled AD/SUPP/16 Amdt 1 and titled "Electrical Hoist Assemblies - EarthBonding Testing", prescribes mandatory bonding-resistance testing for specified aircraft hoist assemblies. It requires operators or maintainers to check electrical bonding between "all adjacent component parts of the hoist assembly, (including the control box, electrical motor casing, hoist body, hoist arm, and attachment bracket) and between the hoist assembly and the aircraft" and to ensure measured bonding resistance does not exceed 0.010 ohm. The tests must be performed using "a bonding tester capable of resolving to 0.002 OHM" (Requirement).

The AD applies only "For aircraft to which Part 42 of CASR 1998 applies" and only to "All electrical hoist assemblies which do not have specific bonding testing requirements called up in any other Australian AD" (Applicability). The compliance schedule differentiates uninstalled and installed hoists: for uninstalled hoists the test is required "prior to installation"; for installed hoists there is an initial requirement "prior to 12 March 1992, and thereafter at intervals not exceeding 24 months" (Compliance). The AD's effective date is 26 February 2016 (Effective date). Amendment 1 explicitly limits the AD's applicability to Part 42 aircraft only and states the AD "will be repealed after the requirements are incorporated into a future amendment of the Part 42 Manual of Standards" (Amendment 1).

The stated safety rationale is in the Background: electrical hoists incorporating pyrotechnic cable cutting devices have experienced "uncommanded initiation of the explosive squib resulting in the hoist cable being severed", and a large number of those events have been attributed to "ineffective bonding between various component parts of the hoist assembly or between the hoist assembly and the aircraft". The AD is described as addressing an anomaly where not all hoist/aircraft bonding requirements are captured in manufacturers' data or other ADs (Background). The instrument is signed by a CASA delegate, Pieter van Dijk, dated 22 February 2016.

Mechanically, the AD creates a technician/organisation duty to perform specified resistance measurements with specified accuracy on defined interfaces at specified times, except where another AD provides a different bonding-testing requirement or where the aircraft is outside Part 42. It also sets a maximum acceptable resistance and a minimum resolution for test equipment. The instrument is temporary pending incorporation of the requirements into the Part 42 Manual of Standards.

The instrument rests on a small set of concrete technical and regulatory concepts, stated in plain terms in the source.

• Scope of equipment and interfaces to be tested. The AD requires checks of electrical bonding "between all adjacent component parts of the hoist assembly" and explicitly lists "the control box, electrical motor casing, hoist body, hoist arm, and attachment bracket", and also requires checks "between the hoist assembly and the aircraft" (Requirement). The concept is interface-by-interface continuity assessment rather than testing a single point.

• Quantitative acceptance and measurement precision. Two numeric thresholds define compliance: a maximum permissible bonding resistance of 0.010 ohm, and a metrological requirement that the bonding resistance tests "are to be carried out using a bonding tester capable of resolving to 0.002 OHM" (Requirement). The pairing means that test equipment must have resolution substantially finer than the acceptance criterion.

• Timing and recurrence. The AD prescribes when tests must be carried out: for uninstalled hoists, "prior to installation"; for installed hoists, tests were mandated "prior to 12 March 1992, and thereafter at intervals not exceeding 24 months" (Compliance). The inclusion of a 1992 date in an AD with an effective date of 26 February 2016 introduces an historical scheduling element in the compliance regime.

• Hierarchy and carve-outs. Applicability is limited to aircraft under Part 42 of CASR 1998, and only to hoist assemblies that do not already have "specific bonding testing requirements called up in any other Australian AD" (Applicability). The AD is therefore a residual, fallback requirement intended to catch cases not already regulated by more specific directives.

• Temporary regulatory mechanism. Amendment 1 narrows applicability and expressly contemplates repeal once the requirements are "incorporated into a future amendment of the Part 42 Manual of Standards" (Amendment 1). The AD is therefore presented as an interim, corrective instrument pending amendment of a standing Manual of Standards.

• Safety problem motivating the directive. The Background links the technical requirement to an operational hazard: "uncommanded initiation of the explosive squib" used to sever hoist cables, with "a large number of these uncommanded cable cuts" attributed to "ineffective bonding". The AD claims some manufacturers have addressed the issue for certain installations, but that potential gaps remain in manufacturer data and other ADs, producing the need for this directive (Background).

The AD names categories and circumstances that determine which parties are subject to the requirement.

• Aircraft and operators governed by Part 42 of CASR 1998. The Applicability begins "For aircraft to which Part 42 of CASR 1998 applies" and Amendment 1 confirms the AD has been limited to "Part 42 aircraft only" (Applicability; Amendment 1). Consequently, owners and operators of aircraft outside Part 42 are not captured by this instrument as drafted.

• Owners/operators of electrical hoist assemblies lacking other AD-mandated bonding tests. The Applicability confines the requirement to "All electrical hoist assemblies which do not have specific bonding testing requirements called up in any other Australian AD." That imposes the obligation only where no other Australian AD has already specified bonding testing for a particular hoist or installation.

• Maintenance organisations and maintenance personnel. The Requirement imposes a technical testing duty , checking bonding between specified parts and between the hoist assembly and aircraft , using a tester of specified resolution. That duty falls on whoever has maintenance responsibility under the operator’s maintenance arrangements or contract for installation and upkeep.

• Installers of uninstalled hoists. The Compliance provision requires testing "prior to installation" for uninstalled hoists. The test therefore applies to organisations that install hoists on aircraft governed by Part 42.

• Manufacturers and modifier organisations, indirectly. The Background notes that "Various hoist and aircraft manufacturers have adequately addressed this problem for specific hoists and aircraft, however it is possible that not all hoist and aircraft bonding requirements are adequately covered by manufacturers data or other ADs." That situates manufacturers as parties whose data may displace the AD’s application, and as parties whose technical practices might be relevant evidence in compliance.

• Regulators and delegated representatives. The AD is issued by CASA and signed by a delegate, Pieter van Dijk. The instrument sits within CASA’s airworthiness directive framework and will be repealed once the Part 42 Manual of Standards is amended. CASA and its delegates decide applicability and the timing of repeal.

Absent any express statements of penalty, the AD nonetheless imposes operational obligations on the above parties by setting mandatory testing, acceptance limits and intervals for certain hoist assemblies on Part 42 aircraft. The source text does not list third-party compliance service providers, but the technical requirement to use a bonding tester capable of 0.002 ohm resolution implies engagement of personnel or organisations that can supply that test capability where the operator cannot.

The AD lays out a narrow set of affirmative duties and a limited number of carve-outs; it does not enumerate rights in the conventional statutory sense.

Duties

• Conduct specified bonding checks. The principal duty is to "check the electrical bonding between all adjacent component parts of the hoist assembly, (including the control box, electrical motor casing, hoist body, hoist arm, and attachment bracket) and between the hoist assembly and the aircraft" (Requirement). This is a component-by-component continuity inspection of the listed interfaces.

• Meet the quantitative acceptance criterion. Measured bonding resistance must not exceed "0.010 OHM" (Requirement). The duty is therefore both procedural (perform specified checks) and substantive (achieve specified electrical performance).

• Use equipment meeting a stated resolution. Tests "are to be carried out using a bonding tester capable of resolving to 0.002 OHM" (Requirement). This creates an equipment and measurement standard that must be met in order for a test to be acceptable.

• Observe timing requirements. For uninstalled hoists the required test must be performed "prior to installation". For installed hoists there is an initial requirement "prior to 12 March 1992, and thereafter at intervals not exceeding 24 months" (Compliance). The latter creates a recurring duty at a 24-month maximum interval for installed hoists.

Carve-outs and limits

• Exclusion where other ADs apply. The Applicability explicitly limits the AD to hoists "which do not have specific bonding testing requirements called up in any other Australian AD". Where another AD prescribes bonding testing, that other AD takes precedence for that installation.

• Applicability limited to Part 42 aircraft. Amendment 1 reduces the instrument’s scope to aircraft to which Part 42 of CASR 1998 applies. Aircraft outside Part 42 are not within the AD’s stated applicability (Amendment 1).

Rights and procedural features not stated

• The AD does not set out appeal rights, processes for showing alternative compliance, or record-keeping obligations in the text provided. The source also does not specify any approved means of compliance beyond the numerical and equipment requirements it states. It does not provide for derogations, nor does it describe an alternative compliance pathway; it instead states the testing method and thresholds directly.

The instrument as provided contains no express penalty clauses, sanctioning provisions or enforcement mechanisms within its text. The AD prescribes technical and temporal compliance obligations but does not state the legal consequences of non-compliance in the body of the document supplied.

What the source does and does not say

• Not stated in the AD text: There are no provisions in the supplied text specifying administrative penalties, criminal offences, suspension of certificates, or administrative enforcement procedures tied directly to this AD. The document is a directive setting out required actions; it does not itself narrate enforcement steps or fines.

• Implied regulatory context: The AD is issued by the Civil Aviation Safety Authority (CASA) and signed by a delegate (Pieter van Dijk, 22 February 2016). In the Australian aviation regulatory system, CASA issues airworthiness directives under its powers; enforcement and penalties for non-compliance with aviation safety obligations typically arise under the broader statutory regime and associated regulations rather than within each AD. The source, however, does not include those statutory enforcement provisions or cross-references.

Practical enforcement considerations visible from the text

• Detectability of non‑compliance. The AD’s requirements are technical and documentable , tests with specified equipment and numeric results. That makes compliance (or failure) potentially demonstrable in maintenance records, if such records are available, and detectable during oversight or audits. The text itself does not require record-keeping, but the technical nature of the tests means that authorities or third parties could seek evidence.

• Overlap with other ADs. The Applicability excludes hoists that "have specific bonding testing requirements called up in any other Australian AD." Where multiple directives apply, enforcement would turn on which AD or manufacturer requirement was applicable; the AD does not set rules for resolving conflicts beyond exclusion.

• Temporary status. Amendment 1 states the AD "will be repealed after the requirements are incorporated into a future amendment of the Part 42 Manual of Standards." The repeal mechanism and the timeframe are not specified; enforcement consequences may shift when the Manual of Standards is amended and the AD withdrawn.

In short, the instrument creates enforceable technical obligations within the airworthiness framework, but the AD text itself does not state penalties or detailed enforcement procedures. Any sanctions for non-compliance would rely on the broader regulatory enforcement tools available to CASA and the statutory framework governing airworthiness, which are not contained in the AD extract provided.

The AD situates itself expressly within an existing regulatory hierarchy and cross-references other instruments.

Primary cross-reference: Part 42 of CASR 1998

• Applicability. The AD explicitly applies "For aircraft to which Part 42 of CASR 1998 applies" and Amendment 1 limits the AD to "Part 42 aircraft only" (Applicability; Amendment 1). This places the AD as a derivative instrument in the Part 42 regulatory ecosystem rather than a free-standing national rule.

Relationship with other ADs

• Exclusion where other ADs specify. The Applicability carves out hoist assemblies that "do have specific bonding testing requirements called up in any other Australian AD." In other words, where another Australian AD already specifies bonding testing for a particular hoist or installation, that other AD will supply the operative requirement; AD/SUPP/16 Amdt 1 fills gaps not covered by other ADs.

Future incorporation into the Part 42 Manual of Standards

• Temporary measure and transition. Amendment 1 states the AD "will be repealed after the requirements are incorporated into a future amendment of the Part 42 Manual of Standards" (Amendment 1). That confirms a planned migration of the technical requirements from an AD into the standing Manual of Standards that governs Part 42 aircraft. When that migration occurs, the Manual of Standards will be the primary source and AD/SUPP/16 Amdt 1 will be withdrawn. The AD therefore functions as an interim regulatory layer.

Interaction with manufacturer data

• Manufacturer data may displace or supplement. The Background recognises that "Various hoist and aircraft manufacturers have adequately addressed this problem for specific hoists and aircraft," while also noting "it is possible that not all hoist and aircraft bonding requirements are adequately covered by manufacturers data or other ADs." This positions manufacturer maintenance data and service bulletins as potentially relevant compliance instruments; where manufacturer data exist and are adequate, the residual AD may not apply. Conversely, where manufacturers have not addressed the issue, the AD fills that regulatory gap.

Scope limitations relevant to cross-border or non-Part 42 regimes

• Aircraft outside Part 42. Because the AD is limited to Part 42 aircraft, aircraft regulated under other parts of CASR or under foreign registers are not controlled by this instrument, as drafted. The AD does not purport to override foreign regulators or international standards.

The instrument as supplied identifies an initial AD and a single amendment, and records dates and signature.

• Original AD: The document refers to an "original issue of this AD" which "was issued to address this anomaly and ensured that adequate and effective bonding exists between the component parts of the hoist and between the hoist and the aircraft" (Background). The precise date of the original AD is not provided in the supplied extract, but the Background describes the purpose of that original issue.

• Amendment 1 (AD/SUPP/16 Amdt 1). The table heading and the textual note state "Amendment 1 is issued to limit the AD’s applicability to Part 42 aircraft only. This AD will be repealed after the requirements are incorporated into a future amendment of the Part 42 Manual of Standards." The AD is therefore the first amendment to the instrument and its explicit function is scope limitation and temporary continuation pending incorporation into the Manual of Standards (Amendment 1).

• Effective date and signature dates. The AD states "The effective date of this AD is 26 February 2016." The signature block shows "Pieter van Dijk, Delegate of the Civil Aviation Safety Authority, 22 February 2016." Those dates indicate the delegate signed the instrument on 22 February 2016 and set an effective date of 26 February 2016. The AD is also identified by number and amendment year in the heading: "AD/SUPP/16 Amdt 1" and "5/2016" (header).

• Repeal planned upon incorporation into Manual of Standards. Amendment 1 plainly contemplates that the AD is an interim device: "This AD will be repealed after the requirements are incorporated into a future amendment of the Part 42 Manual of Standards." The source does not give a timetable for that Manual of Standards amendment nor define which procedural step will trigger repeal.

• Document titles and formatting anomalies. The supplied extract repeats headings (for example, multiple lines of "AD/SUPP/16 Amdt 1") and contains typographical oddities ("EarthBondi", repeated date labels "5/2016 5/2016"). These anomalies appear in the AD text as provided; they do not change the substantive requirements but may complicate referencing or citation.

The amendment history in the document therefore is short: an original AD of unspecified date, followed by Amendment 1 which narrows applicability to Part 42 aircraft and schedules repeal once the Manual of Standards is amended. The AD was signed 22 February 2016 and effective 26 February 2016.

The supplied instrument contains no account of litigation, dispute, judicial review, or appeals related to AD/SUPP/16 or AD/SUPP/16 Amdt 1. The text does not list case names, court decisions, or references to legal proceedings. Therefore, based solely on the material provided, there is no recorded litigation history available in the source.

What the document does show relevant to potential disputes

• The AD was issued by CASA and signed by a delegate; it presents a technical compliance obligation. The Background acknowledges that manufacturers and other ADs have in some cases addressed the issue, and the Applicability references the possibility that other ADs may call up specific bonding-testing requirements. Those features mean disputes about which instrument governs a given hoist (this AD, another AD, or manufacturer data) could arise, but the supplied text does not record any such disputes or decisions.

• The AD is temporary pending incorporation into the Part 42 Manual of Standards. Repeal and transition could raise procedural issues, but again the supplied extract contains none of the material that would record or predict litigation outcomes.

In sum, the document contains no litigation history. Any inquiry about judicial or tribunal treatment of this AD would require sources beyond the AD text supplied.

Several items in the AD text are likely to catch readers or implementers by surprise or generate practical complications. These are explicit in the text and should be checked when operationalising the requirement.

• Apparent retroactive initial compliance date for installed hoists. The Compliance row requires testing for installed hoists "prior to 12 March 1992, and thereafter at intervals not exceeding 24 months." An AD with an effective date of 26 February 2016 that refers to an initial compliance date decades earlier is atypical and may reflect carryover language from an original AD issue. Practically, operators will need to interpret whether this means that any hoist installed before 12 March 1992 must be tested immediately and then biennially, or whether the clause is intended to capture periodicity for hoists put into service on or after that date. The AD text itself gives no interpretive guidance beyond the literal clause.

• Narrow applicability to Part 42 aircraft only. Amendment 1 "is issued to limit the AD’s applicability to Part 42 aircraft only." Operators must confirm whether their aircraft are regulated under Part 42 of CASR 1998. Aircraft outside Part 42 are not within the AD’s scope. The AD does not describe the criteria that determine Part 42 applicability; operators must cross-check the CASR framework.

• Exclusion where other ADs apply. The Applicability excludes hoists that "have specific bonding testing requirements called up in any other Australian AD." Operators must cross-reference the universe of Australian ADs to ascertain whether the hoist in question is already covered by another AD. That creates an administrative mapping task and possible uncertainty where multiple ADs or manufacturer bulletins exist.

• Required measurement resolution. The requirement that tests "are to be carried out using a bonding tester capable of resolving to 0.002 OHM" imposes a specific metrological standard. Testers without that resolution will not meet the AD’s stated test methodology. Operators must source appropriate equipment or a service provider; the AD does not specify whether equivalent demonstrated accuracy is acceptable.

• Clear numeric pass/fail threshold. The maximum resistance of "0.010 OHM" is strict. The AD does not specify measurement tolerance, repeat measurements, or environmental conditions affecting readings. The absence of procedural detail may give rise to questions about test procedures, which the AD does not resolve.

The AD sets a compact, testable compliance regimen. Based on the text, implementers should take the following steps to meet the instrument’s requirements.

1. Determine applicability for each aircraft and hoist

   • Confirm whether the aircraft is regulated under Part 42 of CASR 1998, because Amendment 1 limits the AD to Part 42 aircraft (Applicability; Amendment 1).
   • Identify whether the specific hoist assembly in question is already subject to "specific bonding testing requirements called up in any other Australian AD." If it is, AD/SUPP/16 Amdt 1 does not apply to that hoist (Applicability).

2. For uninstalled hoists: test prior to installation

   • Before installing any electrical hoist assembly on a Part 42 aircraft subject to this AD, conduct the required bonding-resistance checks. The AD states tests for uninstalled hoists must be performed "prior to installation" (Compliance).

3. For installed hoists: ensure initial and recurrent testing

   • The AD requires testing for installed hoists "prior to 12 March 1992, and thereafter at intervals not exceeding 24 months" (Compliance). Given the historical initial date, the practical interpretation for modern compliance is to: a) If a hoist has not been tested to these criteria previously, treat the AD as requiring immediate testing to establish a baseline, and thereafter schedule tests at intervals not exceeding 24 months; or b) If records show compliance to an equivalent standard prior to the stated date, confirm that those records meet the AD’s numeric and equipment requirements.
   • Because the AD text is literal about the 1992 date, operators should document their interpretation and the basis for any immediate action, and consider raising clarifying queries to CASA where necessary.

4. Perform the specified tests and meet the thresholds

   • Test "the electrical bonding between all adjacent component parts of the hoist assembly, (including the control box, electrical motor casing, hoist body, hoist arm, and attachment bracket) and between the hoist assembly and the aircraft" (Requirement).
   • Use a bonding tester "capable of resolving to 0.002 OHM" and ensure each measured interface shows bonding resistance at or below "0.010 OHM" (Requirement).

5. Equipment and personnel