AD/F100/30 Amdt 1 - Flight Warning Computer Replacement

Applicability: The AD applies to all Fokker F100 (F28 Mk 0070) aeroplanes. The AD initially included other models (notably F28 Mk 100), but Amendment 1 removed F28 Mk 100 from the applicability because that model is covered by a separate AD (Applicability; Background).

Mandatory rectification: The AD establishes a mandatory technical requirement. The operator must replace the existing FWC with a modified unit (P/N 80-0610-3-45) and must modify the wiring as specified in the service bulletin (Requirement; Applicability). The AD points to the exact Fokker Service Bulletins to be followed: SB F100-31-051 (15 August 1998) for the FWC replacement and SB F100-31-047 Revision 1 (21 March 1997) for wiring modifications (Requirement).

Sequencing and timing: The AD prescribes the sequencing of required work: the wiring modification must be carried out either prior to, or concurrently with, the FWC replacement. The compliance deadline recorded in the AD is “Prior to 22 October 2001” for the replacement. The AD carries an amendment effective date of 25 August 2011 but retains the original compliance deadlines (Compliance; Requirement). The AD also records that its initial issue became effective on 22 April 1999 (Background).

Safety objective: The stated safety objective is to reduce an unacceptable delay in flight phase transition detection in the existing FWC that could allow alerts to be generated during flight phases in which they should be suppressed. The AD asserts that the new FWC reduces the flight phase transition time delay to the lowest minimum attainable and modifies the inhibition logic for certain thrust reverser alerts so they are not inhibited during initial climb between 400 and 1000 ft radio altitude (Background).

Cross-reference to other regulators and ADs: The AD explicitly references Netherlands AD 1998-110 and EASA AD 2008-0090 and notes that CASA AD/F100/89 (implementing EASA AD 2008-0090) supersedes the requirement for the F28 Mk 100 model by mandating a different P/N for that aircraft type (Note; Background). The AD thus functions in a regulatory network with other national and European airworthiness directives.

Administrative effect: The AD document is issued by the Civil Aviation Safety Authority (CASA) and signed by a delegate, Mike Higgins (signature block). The AD carries an amendment identifier AD/F100/30 Amdt 1 and administrative issuance details (AD number 17/2011, dates).

Aircraft operators and owners: The primary parties directly affected are operators and owners of Fokker F100 (F28 Mk 0070) aeroplanes. The Applicability section states “All F28 Mk 0070 aeroplanes,” so every operator of that type listed within CASA’s jurisdiction is required to implement the AD’s technical work (Applicability).

Maintenance organisations and engineers: The AD prescribes two specific Fokker Service Bulletins as the method of compliance for replacement and wiring modification, so licensed maintenance organisations and engineers responsible for airworthiness modifications on F100s are affected. They must obtain and implement SB F100-31-051 (dated 15 August 1998) for the FWC replacement and SB F100-31-047 Revision 1 (dated 21 March 1997) for wiring changes (Requirement).

Parts suppliers and manufacturers: The AD mandates a particular replacement unit, FWC part number 80-0610-3-45. Suppliers and the manufacturer (Fokker, or its successors) are implicated because operators must source this part or an approved alternative consistent with the SB instructions referenced in the AD (Requirement).

Regulatory and oversight bodies: CASA, as the issuing authority, is the decision-maker for the AD, evidenced by the delegate’s signature (Mike Higgins) and effective date. The AD also intersects with foreign authorities , it expressly refers to Netherlands AD 1998-110 and EASA AD 2008-0090 , so foreign regulators, and the bodies who issued those ADs, form a regulatory network in relation to this requirement (Background; Note).

Aircraft lessors and financiers: Lessors and financiers who have security interests in F28 Mk 0070 aeroplanes will be affected by any requirement that potentially changes the aeroplane’s configuration and requires downtime for modification. The AD does not address funding or compensation but does impose an obligation on the operator to execute the mandated work prior to the stated compliance date (Compliance; Requirement).

Maintenance planners and flight operations: Flight operations and maintenance planners are affected because the wiring modification and FWC replacement must be scheduled. The wiring must be done either prior to, or concurrently with, the FWC replacement, which affects how an operator schedules invasive maintenance tasks and manages aircraft availability (Compliance).

Other Fokker model operators: The AD explicitly removed F28 Mk 100 aeroplanes from this AD’s applicability by Amendment 1, because they are subject to CASA AD/F100/89 (EASA AD 2008-0090), which requires a different FWC part number (80-0610-3-55). Thus operators of F28 Mk 100 aircraft are affected differently and must follow the separate AD (Background; Note).

Legal advisers and compliance officers: Legal and compliance professionals advising affected operators must account for the AD’s technical prescriptions, compliance deadlines, and cross-references to other ADs. The document’s dates and amendment history will be material to any legal assessment or audit of compliance (Background; Compliance).

Express duties (technical obligations): The AD’s Requirement section imposes two express technical duties. First, replace the Flight Warning Computer (FWC) with the modified unit part number 80-0610-3-45 in accordance with Fokker Service Bulletin F100-31-051 dated 15 August 1998. Second, modify the wiring in accordance with Fokker Service Bulletin F100-31-047 Revision 1 dated 21 March 1997 (Requirement).

Sequencing duty: There is an express sequencing duty in the Compliance section: the wiring modification must be performed either concurrently with, or prior to, the FWC replacement (Compliance). This creates a mandatory order for the work that implicates maintenance planning and aircraft downtime.

Timing duty: The AD sets a compliance time: the specified replacement must be completed prior to 22 October 2001 (Compliance). The AD records that it became effective on earlier dates (22 April 1999 for the initial issue) and that the amendment was effective 25 August 2011 (Background; Compliance). Operators are therefore required to have complied with the technical requirements by that date per the AD text.

Reference duty: The AD delegates technical content to the cited Fokker Service Bulletins. Compliance, as written, must be “in accordance with” those SBs, which means operators must follow the procedures and instructions contained in SB F100-31-051 and SB F100-31-047 Rev 1 for the replacement and wiring modification respectively (Requirement).

Interoperability with other ADs and duties: The AD notes that Netherlands AD 1998-110 and EASA AD 2008-0090 are referenced, and that Amendment 1 removes F28 Mk 100 because CASA AD/F100/89 (EASA AD 2008-0090) supersedes the obligation for that model and requires a different FWC part number (80-0610-3-55). Operators therefore have the duty to be aware of overlapping or superseding ADs depending on model (Background; Note).

Rights and remedial pathways (implicit): The AD text itself does not specify rights of appeal, deferral, or alternative methods of compliance (AMOCs). It does, however, specify exact technical means of compliance by reference to Fokker SBs. Because the AD points to specific SBs and P/Ns, any alternative compliance approach would require engagement with the regulator or reliance on a separate approval process; the AD contains no embedded provision for deviations (Requirement).

Administrative authorisation and signature: The AD is an instrument issued by CASA, executed by a delegate (Mike Higgins), which signals administrative authority to impose the duties described. The AD includes dates of initial issue (22 April 1999) and the amendment (effective 25 August 2011), which are relevant to an operator’s assessment of when obligations became operative (Background; signature block).

Record-keeping and proof of compliance (implicit): While the AD does not list record-keeping obligations, replacement of a certified part and performance of wiring modification per a service bulletin will typically require maintenance records, release-to-service documentation, and logbook entries to demonstrate compliance. The AD’s reference to SB procedures implies technical records will be generated and should be retained, although the AD text does not itself prescribe retention periods or formats (Requirement).

Scope-limiting and model-specific duties: The AD’s duties apply to F28 Mk 0070 aircraft only (Applicability), and Amendment 1 clarifies that F28 Mk 100 is covered separately. Operators must determine whether the AD applies to their airframe by model designation and comply with the model-specific duty set out (Applicability; Background).

Enforcement context within the AD: The AD itself sets mandatory requirements and compliance dates but does not specify monetary penalties, sanctions, or enforcement procedures in the text provided. Enforcement is therefore implicit: the instrument imposes a technical obligation recorded and signed by a CASA delegate (Mike Higgins, 23 August 2011), which binds relevant parties under the regulatory scheme the issuing authority administers (Requirement; Compliance; signature).

Compliance deadlines as enforcement signals: The AD prescribes a specific compliance deadline , “Prior to 22 October 2001” , and an order of works (wiring modification prior to or concurrent with FWC replacement). These deadlines operate as practical enforcement levers: failure to comply by the stated date would leave an aeroplane non-conforming with the AD’s requirements and therefore potentially not airworthy under the regulatory framework enforced by CASA (Compliance). The AD itself, however, does not specify the consequence textually.

Regulator decision and oversight: The AD is issued by CASA and bears the signature of a CASA delegate, which indicates the regulator is the decision-maker for both imposing the requirement and any subsequent oversight action. The text identifies the relevant AD numbers and cross-references to Netherlands and EASA ADs, indicating coordinated regulatory oversight across jurisdictions (Background; Note).

Absence of explicit penalty provisions: Because the AD does not enumerate penalties, readers must look to the broader statutory and regulatory regime that empowers CASA to enforce ADs for the penalties that may attach to non-compliance. The AD text makes no attempt to define fines, grounding powers, or administrative sanctions. Therefore, the AD functions as a technical mandatory instrument; enforcement mechanisms and penalties would be found in enabling legislation or CASA enforcement policy rather than in the AD text itself (AD content: Requirement, Compliance).

Operational enforcement mechanisms (practical): From the AD’s content, practical enforcement will be effected through maintenance release processes and airworthiness certification. Aircraft without the specified FWC and wiring configuration as per the SBs would not meet the AD’s Requirement and would likely be identified during surveillance, airworthiness inspections, ramp checks, or as part of an operator’s continuing airworthiness obligations (Requirement; Compliance). The AD’s cross-references to other ADs and SBs support a compliance auditing trail.

Inter-jurisdictional enforcement risk: The AD references Netherlands AD 1998-110 and EASA AD 2008-0090 and indicates CASA AD/F100/89 supersedes applicability for certain models. This cross-referencing highlights that enforcement and compliance are not solely local concerns: a mismatch in compliance with an AD could expose operators to enforcement measures by multiple authorities depending on where the aircraft is operated or registered, though the AD text does not set out extraterritorial enforcement rules (Background; Note).

Delegated authority and administrative signatory: The AD is signed by a CASA delegate, Mike Higgins. That signature identifies the administrative authorisation for the instrument, and any enforcement action would flow from CASA exercising its powers under enabling statutes and regulations; the AD itself records the instrument’s effective dates but not the enforcement process (signature; Compliance).

Referenced foreign ADs and domestic ADs: The AD expressly references Netherlands AD 1998-110 and EASA AD 2008-0090 as related documents (Requirement, Note). Amendment 1 clarifies that F28 Mk 100 aeroplanes are not included because CASA AD/F100/89, which implements EASA AD 2008-0090, requires a different FWC part number (80-0610-3-55) for that model. Thus the AD operates within a network of national and European ADs and is calibrated to avoid conflicting requirements for the same airframe model (Background; Note).

Supersession and scope management: The AD demonstrates scope management: where a different AD already prescribes a requirement for a specific model (F28 Mk 100), this AD’s Amendment 1 removes that model from its applicability to avoid duplication or conflict. The AD therefore interacts with other ADs by delineating which directive applies to which aircraft model (Background).

Delegation to service bulletins: Technically, the AD delegates detailed means of compliance to Fokker Service Bulletins (SB F100-31-051 and SB F100-31-047 Rev 1). That delegation binds operators to the technical provisions contained in manufacturer documentation; the AD thereby incorporates private-sector technical instructions into a regulatory requirement (Requirement). The legal effect is that compliance is achieved only by following those SBs, as specified.

Temporal relationship with prior instruments: The AD records that the initial issue became effective on 22 April 1999 and that Amendment 1 was issued later with an effective date of 25 August 2011 (Background). The Compliance section retains an earlier compliance deadline (“Prior to 22 October 2001”), which indicates this AD sits in a temporal sequence with earlier regulatory action. Where deadlines have elapsed or where prior ADs applied, operators must consider the history of requirements to establish their current compliance status.

No explicit conflict-resolution clause: The AD does not contain an explicit provision addressing conflicts between it and other laws or instruments. Instead, it manages interaction by reference and by removing models from applicability where other ADs apply (Background). Any legal questions about conflicts or alternative compliance pathways would be resolved pursuant to CASA’s broader regulatory framework rather than by provisions in this AD.

Relation to airworthiness certification and continuing airworthiness obligations: While the AD does not recite the enabling statutory provisions, it imposes a modification that affects the aircraft’s equipment and therefore intersects with continuing airworthiness obligations, maintenance release procedures, and airworthiness certification processes. The AD’s prescription of a specific P/N and SBs implies that the aircraft’s approved configuration is adjusted by compliance, and that continuing airworthiness records will need to reflect the change (Requirement).

Cross-border operations: The AD’s references to EASA and Netherlands ADs highlight that operators engaged in international operations must navigate multiple ADs and ensure compliance with the authority that has jurisdiction over the aircraft’s state of registry. Although the AD does not set extraterritorial rules, it signals the need to reconcile AD obligations across jurisdictions (Background).

Initial issue dates and effective dates: The AD records that its initial issue became effective on 22 April 1999 (Background). The current document is an amendment identified as AD/F100/30 Amdt 1 (17/2011) and the amendment was issued with an effective date of 25 August 2011 (Compliance; signature block). The AD includes an administrative date of 23 August 2011 adjacent to the delegate’s signature.

Amendment 1 content and purpose: Amendment 1 changed the AD’s applicability by removing the F28 Mk 100 aeroplane from the scope of AD/F100/30. The AD explains the reason: the AD requirement for the F28 Mk 100 has been superseded by CASA AD/F100/89 (which implements EASA AD 2008-0090) requiring FWC P/N 80-0610-3-45 to be replaced with P/N 80-0610-3-55 on all F28 Mk 100 aeroplanes (Background). The AD expressly states there is no change to the initial requirement of the AD in relation to F28 Mk 0070; Amendment 1 is limited to applicability (Background).

Administrative identifiers: The AD appears under the heading AD/F100/30 Amdt 1 and is also labelled 17/2011 in the document header. Both identifiers are recorded in the provided text (document headers).

Service bulletin references intact: The Requirement text and the SB references (SB F100-31-051 dated 15 August 1998 and SB F100-31-047 Rev 1 dated 21 March 1997) remain unchanged in the amendment; Amendment 1 is not recorded as modifying those references (Requirement).

Cross-references: The Amendment documents cross-references to Netherlands AD 1998-110 and EASA AD 2008-0090 and states that those are referred to in relation to the AD. Amendment 1’s removal of the F28 Mk 100 model is explicitly tied to CASA AD/F100/89 and EASA AD 2008-0090 (Background).

Signature and date: The amendment is signed by a CASA delegate, Mike Higgins, with a date recorded as 23 August 2011. The AD itself notes the amendment became effective 25 August 2011, indicating administrative processing and dating (signature block; Compliance).

No textual change to core technical requirement: The AD states there is no change to the initial technical requirement,for the F28 Mk 0070 the Requirement remains replacement with P/N 80-0610-3-45 and wiring modification per the two SBs. Amendment 1’s substantive change is to remove the F28 Mk 100 from applicability (Background).

Record of earlier related instruments: The AD refers to an initial issue effective 22 April 1999, meaning this AD has been in the regulatory record for more than a decade before the amendment. The AD does not list every prior administrative action, but it records these key dates (Background).

No litigation recorded in the source: The AD text provided contains no reference to any judicial or administrative litigation, challenges, appeals, or cases that arose from the AD or its amendment. The document lists only regulatory, technical, and administrative material (Requirement; Compliance; Background).

Absence of precedent references: The AD does not cite any case law, determinations, or disputed enforcement outcomes. It cross-references other ADs and service bulletins, but no adjudicative history is recorded in the AD text. Therefore, within this source, there is no litigation history to report.

Implication for legal research: Because the AD contains no litigation references, any legal questions about contestation, interpretation disputes, or enforcement outcomes would need to be sourced from CASA enforcement records, court files, or public administrative law databases rather than from the AD document itself. The AD provides neither a record of disputes nor any procedural history concerning challenges to its terms.

Compliance dates and amendment timing: The AD prescribes a compliance deadline “Prior to 22 October 2001,” yet Amendment 1 was issued and made effective many years later (amendment effective 25 August 2011; delegate signed 23 August 2011). This chronology means the AD as amended continues to state an original compliance date that had already passed at the time of amendment. Operators who review the amended AD without looking at the instrument’s history may find the compliance timing counterintuitive. The AD itself does not explain the administrative reasons for retaining an earlier compliance date in the amended text (Compliance; Background).

Model-specific scope traps: The original AD included additional Fokker models; Amendment 1 removed the F28 Mk 100 because of a separate AD requirement for that model. Operators must take care to identify the precise model designation of their aeroplane (F28 Mk 0070 versus F28 Mk 100) to determine whether AD/F100/30 Amdt 1 applies or whether CASA AD/F100/89 (EASA AD 2008-0090) does. Misclassification could lead to applying the wrong P/N or SB (Applicability; Background).

Exact part number requirement: The AD names a specific replacement FWC part number: 80-0610-3-45. The F28 Mk 100 is subject to a different P/N under the separate AD (80-0610-3-55). Operators must ensure they source the correct P/N for their model and follow the correct SB. Using the wrong P/N or following an incorrect SB would not meet the AD’s Requirement (Requirement; Background).

SB dates and revision specificity: The AD cites precise service bulletin numbers and dates: SB F100-31-051 dated 15 August 1998 and SB F100-31-047 Revision 1 dated 21 March 1997. The AD requires compliance “in accordance with” those SBs; where multiple revisions of an SB exist, operators must confirm they are working to the exact revision and date referenced by the AD, unless otherwise authorised by the regulator (Requirement).

No embedded alternative compliance route: The AD does not provide an alternative method of compliance (AMOC) or deviation procedure within its text. If an operator seeks to comply by an alternative means, that route would require engagement with CASA and cannot be assumed available from the AD alone. The AD’s silence on AMOCs is a potential administrative “gotcha” for operators assuming flexibility (Requirement).

Record-keeping expectation: The AD does not set out explicit recordkeeping or reporting obligations, but compliance will generate maintenance records and airworthiness documentation. Failing to maintain adequate evidence that the SB procedures were followed, the correct P/N was installed, and the wiring modification performed in the required sequence could make it difficult to demonstrate compliance to auditors or inspectors (Requirement; Compliance).

Interaction with other ADs: The AD references Netherlands AD 1998-110 and EASA AD 2008-0090. Operators that operate internationally must understand the interplay among these instruments and the specific requirements they impose, especially where differing P/Ns are mandated for different models (Background; Note).

Potential parts availability and obsolescence: The AD mandates a specific P/N and associated wiring work described in legacy SBs from 1997 and 1998. Operators should anticipate that sourcing legacy parts or ensuring compatibility with later avionics configurations could present logistical challenges. The AD itself does not address parts supply or approved alternatives, so operators must manage procurement and technical compatibility risks (Requirement).

Administrative identifiers and multiple labels: The AD is labelled AD/F100/30 Amdt 1 and also 17/2011 in headers. Different databases or maintenance records may index the AD under different identifiers; failure to cross-check both could lead to missing the instrument in compliance tracking systems (document headers).

Follow the Requirement text exactly: The AD requires two discrete actions. First, replace the Flight Warning Computer with FWC P/N 80-0610-3-45 in accordance with Fokker Service Bulletin F100-31-051 dated 15 August 1998. Second, modify the wiring in accordance with Fokker SB F100-31-047 Revision 1 dated 21 March 1997 (Requirement). These are the operative instructions stated in the AD and compliance is achieved by carrying out the works as specified.

Observe sequence and timing: The wiring modification must be done either prior to or concurrently with the FWC replacement, and the AD specifies the compliance date for the replacement as prior to 22 October 2001. Although that date has passed, the AD as amended retains it; an operator’s maintenance records should demonstrate that the wiring and FWC replacement were completed in the required order and by the specified date (Compliance).

Acquire and apply the exact SBs: Obtain the cited service bulletins: SB F100-31-051 (15 August 1998) and SB F100-31-047 Rev 1 (21 March 1997). Follow the procedures, torque values, wiring diagrams, and test requirements within those SBs when performing the work, since the AD conditions compliance on work being “in accordance with” those SBs (Requirement).

Install specified P/N: Ensure the FWC installed is part number 80-0610-3-45 as specified. For F28 Mk 100 aeroplanes, do not apply this AD’s P/N: Amendment 1 states that F28 Mk 100 aircraft are subject to CASA AD/F100/89 (EASA AD 2008-0090), which requires FWC P/N 80-0610-3-55. Confirm the aircraft is a F28 Mk 0070 before installing P/N 80-0610-3-45 (Applicability; Background).

Document the work: Maintain maintenance records, logbook entries, and release-to-service documentation that show SB references, part numbers installed, serial numbers, dates, technician signatures, and return-to-service tests. Although the AD does not specify recordkeeping, these records form the evidentiary basis of compliance with the AD in the context of airworthiness oversight (Requirement).

Coordinate maintenance scheduling: Because the AD requires the wiring modification to be done prior to or concurrently with the FWC replacement, plan resources, hangar space, and aircraft downtime accordingly. Consider combining the AD work with other scheduled maintenance to minimise aircraft out-of-service time, subject to any constraints in the SBs (Compliance).

Verify compatibility with later modifications: If the aeroplane has undergone other modifications since 1998-1999, verify that installing P/N 80-0610-3-45 and performing the wiring change per the cited SBs will not conflict with later approved modifications. Where uncertainty exists, consult CASA or an authorised design/deviation approval process before proceeding, because the AD provides no express AMOC path (Requirement).

Check cross-jurisdictional requirements: If the aircraft is registered outside Australia or operates in multiple jurisdictions, review Netherlands AD 1998-110, EASA AD 2008-0090, and the relevant state-of-registry ADs to ensure the work chosen aligns with all applicable directives and to avoid applying the wrong P/N or SB for a given model (Background; Note).

Engage the regulator where necessary: If an operator cannot source the specified part, cannot perform the wiring modification in the manner set out in the SBs, or seeks to use an alternative method of compliance, engage CASA early to obtain formal approval or instructions. The AD text provides no internal alternative compliance mechanism and does not discuss AMOCs, so any deviation will require regulator engagement (Requirement).

Confirm return-to-service testing: Perform and document any functional or flight testing required by the cited service bulletins to demonstrate the new FWC and modified wiring operate as intended. The AD ties compliance to SB procedures, which commonly include test and verification steps; follow and record those tests to establish compliance for oversight purposes (Requirement).

Retain evidence for audits and inspections: Keep the SB compliance documentation, parts certificates, minutes/authorisations, and release-to-service entries accessible for inspectors and auditors. The AD itself does not set record retention rules, so align retention with general maintenance recordkeeping obligations applicable under the regulatory regime governing the operator (Requirement).

Be mindful of model classification: Before carrying out work, confirm the aircraft is an F28 Mk 0070. If the aircraft is a F28 Mk 100, follow CASA AD/F100/89 (EASA AD 2008-0090) that requires a different FWC part number (80-0610-3-55), rather than applying the P/N mandated in this AD (Applicability; Background).