AD/JETSTREAM/109 - State of Design Airworthiness Directives

This AD is structured around a small number of interlocking concepts that determine obligations and options for aircraft operators and maintainers. Each concept appears explicitly in the Directive text.

• State of Design Airworthiness Directives. The AD expressly implements "State of Design Airworthiness Directives" by reference to the UK CAA ADs listed in Table 1. The instrument thus operates by requiring Australian compliance with the State of Design mandated actions where they are applicable to Australian-registered aircraft (see title and Background).

• Applicability determination. The Directive does not itself set out technical inspection or modification schedules; instead it requires the responsible person to determine whether each UK CAA AD in Table 1 is applicable to a particular Jetstream 3100/3200 aircraft. The first required action is a determination of applicability (Requirement 1).

• Adoption of State-of-Design actions or later approved revisions. Where a listed UK CAA AD is applicable and its actions have not been previously accomplished, the responsible person must perform the actions required by that AD or a later EASA‑approved revision. The Directive thus imports the substantive technical mandates from the UK CAA ADs, and permits later EASA‑approved revisions to govern compliance where they exist (Requirement 2).

• Alternative Methods of Compliance (AMOC). The Directive recognises Service Bulletins approved by EASA as Alternative Methods of Compliance to the listed UK CAA ADs as acceptable for compliance with this AD. This provides a pathway to use manufacturer or other service documents, provided EASA approval as AMOC exists (Requirement, sentence on Service Bulletins).

• Once‑only actions with lapsed compliance dates. The Background states that the UK CAA ADs listed "require once-only actions for which the compliance date has passed." By design, the Directive addresses ADs whose original compliance windows are in the past.

• Compliance timing keyed to certificate of airworthiness status. The Directive contains two alternative timing triggers: for aircraft not yet issued with a certificate of airworthiness, compliance must be completed before the certificate is issued; for aircraft already certificated, compliance must be completed before further flight after 30 days from the AD effective date (see Compliance).

• Access to external AD source. The Directive provides a URL where the UK CAA ADs may be accessed: http://ad.easa.europa.eu/ (Note 1). This links the domestic requirement to an external repository of the State of Design ADs and their texts.

These concepts combine an obligation to import State of Design requirements into the Australian regulatory milieu, a procedural obligation to check applicability, an explicit allowance for EASA‑approved AMOCs, and a concrete deadline regime tied to certification status.

The Directive identifies by aircraft type and by implied roles who bears the obligations created by the instrument.

• Affected aircraft. The text states the applicability as "Jetstream 3100 series and 3200 series aeroplanes." Therefore any Australian-registered aeroplane in those model series is within the scope of the Directive (Applicability line).

• Responsible persons. The Directive does not define the term "operator" within its text. However, the mandated acts are framed as requirements to determine applicability and to accomplish the actions required by the applicable UK CAA ADs or later EASA‑approved revisions. That framing places operational responsibility on whoever is legally tasked with continuing airworthiness and maintenance for a particular aircraft, typically the holder of the certificate of registration, the operator, or the maintenance organisation responsible for airworthiness. The AD uses imperative language "Determine the applicability" and "perform the actions required" (Requirement paragraphs 1 and 2).

• Prospective certificate holders and certificated aircraft. The compliance timing differentiates between aircraft which do not yet have a certificate of airworthiness and those that do. For aircraft without a certificate of airworthiness, compliance is required before issue of the certificate. For aircraft already certificated, compliance is required before further flight after 30 days from the AD effective date. This distinction specifically affects prospective certificate applicants and current operators (Compliance).

• Maintenance organisations and engineers. The AD imports the technical content of the listed UK CAA ADs by reference. Those ADs may prescribe inspections, replacements, modifications, or other maintenance actions. Persons charged with performing those maintenance tasks, including licensed engineers and maintenance organisations, are practically affected because they must carry out the required actions where applicable and may need to accept Service Bulletins approved as AMOCs (Requirement 2; Service Bulletins as AMOCs).

• CASA and delegated decision‑makers. The AD is signed by Mike Higgins, Delegate of CASA. The presence of a signature line shows CASA as the issuing authority responsible for notifying and enforcing the requirement. The Directive also points readers to external State of Design documents (Note 1), which implies a coordination role for CASA in enforcing State of Design directives domestically (signature and Background).

The Directive notes that some of the listed UK CAA ADs may not be applicable to aircraft presently registered in Australia because of aircraft manufacture date or configuration and modification status. That caveat recognises that applicability is a non‑trivial factual assessment and that not every airframe in the two model series will be within the substantive reach of each UK AD (Background).

The Directive prescribes discrete duties and recognises one explicit compliance concession.

Duties

• Determine applicability. The primary duty is to determine whether each UK CAA AD listed in Table 1 applies to the particular aircraft. The Directive places that duty in mandatory terms: "Determine the applicability of the UK CAA Airworthiness Directives (AD) listed in Table 1" (Requirement 1). The text does not specify who exactly must make the determination, but the duty is phrased as an obligation the addressee must fulfil in relation to the aircraft.

• Perform required actions for applicable ADs. Where a listed UK CAA AD is determined to be applicable and has not already been accomplished, the responsible person must perform the actions required by that AD or a later EASA‑approved revision. The AD imports the State of Design's substantive requirements by reference (Requirement 2).

• Meet timing requirements tied to certificate status. If a certificate of airworthiness has not been issued, the required actions must be completed prior to issuance. If the aircraft already holds a certificate of airworthiness, actions must be completed before further flight after 30 days from the effective date of the Directive (Compliance).

Rights and concessions

• Use of EASA‑approved AMOCs. The Directive expressly allows Service Bulletins that are approved by EASA as Alternative Methods of Compliance to be used as compliant methods with respect to the equivalent requirements of this AD. That provides the holder a specified route to compliance where EASA has approved an alternative method (Requirement; sentence regarding Service Bulletins as AMOCs).

• Use of later EASA‑approved revisions. The obligation to perform the actions required by a listed UK CAA AD is qualified by the phrase "or later EASA-approved revision," thereby allowing compliance to follow a newer EASA‑approved version of the State of Design AD in place of the UK CAA AD text as listed (Requirement 2).

Constraints and limits in the text

• No express delegation framework or dispute mechanism. The Directive requires determinations and actions but does not set out a process in the text for resolving disputes over applicability or for seeking formal exemptions, other than the AMOC pathway for Service Bulletins which must be EASA approved. The absence of an explicit domestic AMOC process or appeal mechanism in the Directive text is notable because the AD nevertheless imports external documents and standards.

• No express extension or variance provision. The Directive contains fixed compliance triggers (before certificate issuance or within 30 days of effective date for certified aircraft). It does not in its text provide for extensions, staged compliance, or phased-in implementation beyond the two timing alternatives provided.

The duties therefore combine an investigative obligation (determine applicability), a substantive obligation (perform the imported State of Design actions or EASA‑approved revisions), and timing constraints keyed to certificate status, while providing limited rights to comply using EASA‑approved alternative methods.

The Directive text itself specifies compliance obligations and deadlines but does not set out penalties or enforcement mechanisms within its four corners.

What the AD sets out

• Deadlines. The AD imposes two concrete timing requirements. For aircraft without a certificate of airworthiness compliance is required before issuance of the certificate. For aircraft already holding a certificate of airworthiness the required actions must be performed before further flight after 30 days from the Directive's effective date. The AD becomes effective on 24 December 2010 (see Compliance and Effective Date).

• Importation of State of Design mandates. The Directive makes performance of the actions required by particular UK CAA ADs or later EASA‑approved revisions a compliance obligation for affected Australian aircraft. This converts the substantive technical prescriptions of those State of Design ADs into obligations under this CASA AD.

What the AD does not say

• No penalty provisions in the AD. The text contains no express penalty, fine, or sanction provision attached to non‑compliance. The AD does not articulate any civil penalty regime, criminalisation, or specified administrative sanction inside the AD itself.

• No enforcement process described. The AD does not describe how CASA will monitor compliance, how evidence of compliance should be recorded or produced, or the procedural steps CASA will take in the event of non‑compliance. The only enforcement‑adjacent statements are the timing deadlines and the effective date.

Consequences for practitioners

• In the practical regulatory context, the AD’s mandatory language and the fixed deadlines function as enforceable obligations within the aviation safety regulatory system. However, because the AD does not itself delineate penalties, practitioners must look to CASA’s broader regulatory framework, aviation safety legislation, and enforcement instruments outside the AD text to determine the consequences of non‑compliance. The Directive text does not supply those external enforcement details.

• The AD makes clear that listed State of Design AD actions are to be treated as required measures for relevant Australian aircraft, and the deadlines create immediate operational consequences in that aircraft may not lawfully continue to operate without carrying out the required actions as the Directive prescribes. The AD does not in text say so explicitly, but the Compliance provisions impose conditions on further flight or certification that will practically affect operations.

Because the Directive does not include express penalty or enforcement mechanics, any statement about fines, suspension of certificates, or other sanctions would lie beyond the text of this instrument and must be sought in the broader statutory and regulatory materials that govern CASA’s enforcement powers.

The AD explicitly ties domestic compliance to State of Design directives and to EASA approvals. The text gives only limited internal cross‑references, but the operational interactions are explicit in the instrument.

• Importation of State of Design requirements. The AD’s stated purpose in the Background is to "ensure compliance with all State of Design ADs." The Directive therefore functions as a domestic mechanism that identifies specific State of Design ADs (UK CAA ADs) and requires applicable Australian aircraft to comply with the actions those State of Design ADs impose (Background; Requirement 2). In effect, the AD operates as a vehicle by which CASA requires Australian operators to meet obligations that originate in another State’s airworthiness directive regime.

• Reliance on UK CAA ADs and EASA. The Directive explicitly lists UK CAA AD reference numbers in Table 1 and provides a URL for accessing UK CAA ADs via the EASA portal (Note 1). It also permits EASA‑approved revisions of the listed UK CAA ADs and EASA‑approved Service Bulletins as AMOCs to be used to discharge compliance (Requirement 2 and the Service Bulletins sentence). Thus the AD integrates the domestic requirement with the regulatory outputs of the UK CAA and EASA.

• Interaction with aircraft certification. The AD ties compliance to issuance of a certificate of airworthiness and to the permission to conduct further flights. The compliance schedule differentiates un‑certificated aircraft (compliance before issuing the certificate) and certificated aircraft (compliance before further flight after 30 days). Therefore the Directive interfaces with the domestic process of issuing certificates of airworthiness and the operational constraints on continuing airworthiness for certified aircraft (Compliance). The AD does not describe the certification process itself, but it overlays a compliance requirement that conditions certification and flight status.

• No express cross‑reference to domestic statutes or enforcement instruments within the AD. The instrument does not cite any Australian statutory provision, regulation, or standard beyond the general CASA signature. Consequently, the AD must be read together with the broader statutory framework that gives CASA authority to issue ADs and to regulate airworthiness. Those enabling or enforcement provisions are not included in the AD text.

• Practical effect on continuing airworthiness obligations. The importation of State of Design actions means that the content of those UK CAA ADs (inspections, replacements, design corrective actions) will, where applicable, become a part of the aircraft’s continuing airworthiness obligations for Australian registration purposes. The Directive permits later EASA‑approved revisions and EASA‑approved AMOCs, thereby mapping domestic compliance options onto the international certification ecosystem (Requirement 2 and Service Bulletins sentence).

In short, the AD anchors domestic compliance to external State of Design directives and to EASA approval processes, and it conditions certification and flight rights on completion of those imported actions. The AD text itself does not set out the enabling legislation or enforcement instruments it sits within; those interactions must be located in CASA’s broader regulatory materials.

The AD text supplies limited material about its own history. What is included is the AD identifier, the effective date, and the signature block.

• AD identifier and numbering. The Directive is titled AD/JETSTREAM/109 and carries the notation "25/2010." The repetition of "AD/JETSTREAM/109" and "25/2010" appears in the header and elsewhere in the document, indicating the internal reference and the calendar year in which it was recorded (document header).

• Effective date and signature. The Directive states it "becomes effective on 24 December 2010" and is signed by Mike Higgins, Delegate of the Civil Aviation Safety Authority, with a date of 6 December 2010 on the signature block. Those two dates show the signature and the later effective date and provide a record of issuance and commencement (Compliance; signature block).

• No express amendments or historical versions shown in the text. The AD does not include any amendment schedule, previous versions, superseded ADs, or a footnote indicating that it varies or supersedes an earlier CASA instrument. The text refers to "later EASA‑approved revision" as relevant to the imported UK CAA ADs, but that provision relates to the State of Design documents rather than to this AD's internal amendment history (Requirement 2).

• Relation to State of Design ADs whose compliance dates have passed. The Background notes that the UK CAA ADs listed "require once-only actions for which the compliance date has passed." That observation explains why CASA issued this AD at the time it did, but the AD text does not include a record of later amendment to incorporate changes in the external ADs beyond the permission to follow later EASA‑approved revisions (Background; Requirement 2).

• No record of domestic subsequent amendments in the AD text. The Directive as provided shows its original text and effective date, but it contains no later amendment annotations, revocation wording, or consolidated amendment notes.

For practitioners seeking an amendment history of this CASA AD itself, the text contains no such history and the only dates recorded are the signature date and the effective date. Any subsequent amendments, revocations, or supersessions would not be visible in this AD text and would need to be located in CASA's AD bulletin records or official register.

The Directive text contains no litigation history and does not reference any court or tribunal proceedings.

• No cases or decisions cited. The AD does not mention any judicial or administrative litigation, appeals, or disputes concerning the AD itself or the listed UK CAA ADs.

• No indications of challenge or judicial review within the text. The AD is a statement of regulatory obligation and its Background explains the policy rationale that the listed State of Design ADs have once-only actions with passed compliance dates and that CASA determined those ADs may apply to Australian aircraft. There is nothing in the body of the Directive mentioning any past or pending legal challenge.

• Implication for research. If a practitioner requires litigation history concerning AD/JETSTREAM/109, or any judicial treatment of its substance, that material is not provided here and would need to be sourced externally from court or tribunal records, statutory registers, or CASA's public records. The AD text itself contains none of that information.

Therefore, within the instrument provided, there is no litigation history to report.

The text contains several practical traps and points that warrant careful attention by operators, maintainers, and certifiers. The following are concrete operational and legal‑compliance risks that follow from the Directive text.

• Applicability is not automatic: determination required. The AD requires the responsible person to "Determine the applicability of the UK CAA Airworthiness Directives (AD) listed in Table 1." That is a factual and technical assessment that will often require review of the aircraft’s configuration history, maintenance records, modification status, and serial‑number‑specific data. Mis‑determining applicability can expose an operator to non‑compliance, but the AD text offers no procedural guidance or checklist for making the determination (Requirement 1).

• Actions are once-only and original compliance dates have passed. The Background states the UK CAA ADs require "once-only actions for which the compliance date has passed." This means CASA is asking operators to perform measures that, under the State of Design timing, should already have been completed. Practically, those actions may be backlog work and could disrupt operations or require immediate grounding until achieved if the aircraft is found to be non‑compliant and the certificate status demands action before further flight (Background; Compliance).

• Timing linked to certificate status can force immediate operational decisions. For certificated aircraft the AD requires completion "before further flight after 30 days from the effective date." The AD became effective on 24 December 2010. Operators who had not determined applicability and completed required tasks prior to that date had a narrow window to assess applicability and carry out any required works or else refrain from further flight after the 30‑day grace period. The Directive leaves limited room for staged compliance and no explicit provision for extensions (Compliance).

• Reliance on external documents. The AD imports the State of Design ADs by reference and points users to an external URL for accessing the UK CAA ADs. Practically, compliance requires accurate retrieval of the correct UK CAA AD texts and any later EASA‑approved revisions. If a practitioner uses an incorrect version or misses a later EASA‑approved revision, the Directive’s requirement to perform the actions in "that AD or later EASA‑approved revision" may not be satisfied. The AD does not provide the full text of those ADs; it merely lists references and a retrieval URL (Table 1; Note 1; Requirement 2).

• Use of Service Bulletins as AMOCs is limited to EASA approval. The AD permits Service Bulletins approved by EASA as Alternative Methods of Compliance to be accepted. This concession is conditional on EASA approval. Service Bulletins without EASA AMOC approval are not stated to be acceptable in this AD. Practically, operators relying on manufacturer service documents must ensure EASA approval exists (Service Bulletins sentence).

• Not all listed UK CAA ADs will be applicable to every aircraft. The Background acknowledges that, due to manufacture date or configuration and modification status, some listed ADs "will not be applicable to any aircraft presently registered in Australia." That is a caution that the list is broad and that not every AD applies to every airframe, making applicability determinations non‑trivial (Background).

• No internal guidance on records and proof of compliance. The AD specifies what must be done and when, but it does not set out the documentation required to evidence compliance for audit or oversight. Operators must therefore rely on standard continuing airworthiness record‑keeping practices, but the AD text itself does not say so.

• No penalties set out in the AD. The AD does not state the consequences for non‑compliance within its text. While a regulatory authority often enforces AD compliance by administrative measures, the AD itself contains no penalty provisions or enforcement steps, which may create uncertainty about immediate legal consequences if compliance is late. The AD sets mandatory deadlines but leaves enforcement detail to other instruments or to customary regulatory practice (Compliance; Penalties and enforcement).

These "gotchas" arise directly from the instrument’s structure: it imports external requirements, leaves applicability determinations to responsible persons, provides limited timing options, recognises only EASA‑approved AMOCs, and does not include procedural or enforcement detail.

The Directive prescribes a concise sequence of compliance steps and timing windows. The following is a stepwise compliance recipe strictly derived from the AD text.

1. Identify affected aircraft. Confirm whether the airframe in question is a Jetstream 3100 series or Jetstream 3200 series aeroplane. The AD’s Applicability line confines its scope to those series.

2. Retrieve the listed UK CAA ADs. Use the reference list in Table 1 to identify the specific UK CAA AD numbers and corresponding service bulletin references:

   • UK CAA AD 001‑02‑98, Service Bulletin 29‑A‑JA970940, "Corrosion of Hydraulic Components".
   • UK CAA AD 014‑02‑92, Service Bulletin 27‑A‑JM7771, "Rudder Gust Lock".
   • UK CAA AD 019‑11‑88, Service Bulletin 26‑A‑JA881142, "Engine Fire Extinguisher Cartridges".
   • UK CAA AD 011‑06‑86, Service Bulletin 28‑JA850911, "Valve Spindle".
   • UK CAA AD 013‑04‑85, Service Bulletin 57‑JM7314, "Bottom Wing Skin".
   • UK CAA AD 004‑03‑85, Service Bulletin 27‑A‑JA841132, "Aileron Servo Cable Guard".
   • UK CAA AD 012‑11‑85, Service Bulletin 22‑A‑JA851141, "Autopilot and Electric Trim". Access the full texts via the indicated EASA portal URL: http://ad.easa.europa.eu/ (Note 1).

3. Determine applicability for each listed UK CAA AD. For each AD in Table 1 perform a factual and technical assessment to determine whether the AD’s scope and compliance requirements apply to your specific aircraft. Consider aircraft serial number, production/modification/configuration history, records of previous compliance, and any differences that would render the AD inapplicable. The AD requires you to "Determine the applicability" as the first step (Requirement 1).

4. Check prior accomplishment. For each applicable AD, determine whether the work required by that UK CAA AD has already been accomplished on the aircraft. The AD only requires performance of AD actions that "has not been previously accomplished" (Requirement 2).

5. Select the compliance method. If the UK CAA AD is applicable and the required action has not been performed, perform the actions required by that UK CAA AD or perform the actions required by a later EASA‑approved revision of that AD. If there is a Service Bulletin that has been approved by EASA as an Alternative Method of Compliance to the listed UK CAA AD, that Service Bulletin is acceptable for compliance with this CASA AD. Ensure that any Service Bulletin relied upon is actually EASA‑approved as an AMOC (Requirement 2 and Service Bulletins sentence).

6. Meet the timing requirements. If the aircraft does not yet have a certificate of airworthiness, complete the required actions before issuing the certificate of airworthiness. If the aircraft already has a certificate of airworthiness, complete the required actions before further flight after 30 days from the effective date of the Directive. The AD became effective on 24 December 2010; calculate the 30‑day window accordingly for certificated aircraft (Compliance).

7. Document compliance. Although the AD does not specify record formats, given the AD’s importation of State of Design mandates, maintain records demonstrating the applicability assessment, the AD text or EASA‑approved revision relied upon, the Service Bulletin or AMOC relied upon if used, the maintenance actions performed, and dates of accomplishment to support any future audit or oversight inquiry. The AD requires the actions be "performed" but does not itself prescribe the documentary format. Retain the documents consistent with normal continuing airworthiness record‑keeping best practice.

8. Verify any EASA approvals. Where the AD permits use of later EASA‑approved revisions or EASA‑approved Service Bulletins as AMOCs, verify that the revision or Service Bulletin in question bears the relevant EASA approval. The AD explicitly conditions these options on EASA approval (Requirement 2 and Service Bulletins sentence).

9. Consider non‑applicability outcomes. For items in Table 1 that your determination finds not applicable because of manufacture date, configuration, or modification status, retain the basis for that determination. The Directive itself notes that some listed ADs may not apply to any aircraft presently registered in Australia for those reasons (Background).

10. Use the AD’s references when interacting with certifiers or regulators. If CASA or another certificating authority requests evidence of compliance during the certification or continuing airworthiness process, present the applicability determinations, the UK CAA AD texts or later EASA‑approved revisions used, and evidence of performance of the required actions or use of an EASA‑approved AMOC.

This sequence follows the Directive’s two mandates and its timing rules exactly. The AD provides no alternative compliance pathway except through EASA‑approved AMOCs and later EASA‑approved revisions. Practitioners should therefore ensure they rely only on those specified permissive alternatives.