AD/F100/85 Amdt 1 - Flight Controls - Elevator Booster Control Unit

Applicability: The AD applies to all serial numbers of F28 Mark 0070 and Mark 0100 aircraft. The applicability clause is categorical and does not carve out particular serial number ranges or operators (Applicability).

Identified part numbers: The AD singles out specific Goodrich Elevator BCU part numbers:

• P/N 23400‑3B and P/N 23400‑7, and
• P/N 23400‑3 and P/N 23400‑5. Actions differ depending on which of these four part numbers is installed (Requirement 1-5).

Primary actions and document references:

• One‑time inspection in accordance with Part 1 of the Accomplishment Instructions in Fokker Service Bulletin SBF100‑27‑088 dated 4 June 2007 (Requirement 1 and 2).
• Replacement or modification in accordance with Goodrich CSB 23400‑27‑27 and Part 2 of Fokker SBF100‑27‑088 (Requirements 3-5).
• Explicit prohibition on installing specified unmodified BCUs after set dates (Requirements 6-7).
• The AD permits compliance using later approved revisions of the referenced documents (compliance flexibility clause).

Timing and staged compliance:

• Requirement 1 is left unchanged from the original AD (stated to remain unchanged as detailed in the original issue of the AD prior to 25 October 2008).
• Requirement 2 must be completed within 12 months from the effective date of the amendment.
• Requirement 3’s deadline depends on the result of the inspection, and refers to Table 2 on page 8 of the referenced Fokker service bulletin.
• Requirement 4 requires replacement of remaining unmodified P/N 23400‑3B and 23400‑7 within five years after 25 October 2007.
• Requirement 5 requires replacement of remaining unmodified P/N 23400‑3 and P/N 23400‑5 within five years after the effective date of the AD.
• Installation prohibitions take effect from 29 August 2012 and 3 March 2014 respectively (Compliance).

Regulatory cross‑reference: The AD explicitly refers to EASA AD 2009‑0032 dated 17 February 2009 and states it supersedes EASA AD 2007‑0228 (Note). The AD is issued under CASA authority and signed by James Coyne, Delegate of the Civil Aviation Safety Authority (signature block, 26 March 2009).

Technical rationale: The AD states a concrete safety reason: excessive wear of the backlash remover mechanism has been observed several times. The wear can cause (partly) blocked operation of the elevator system in normal (hydraulic) mode. The AD describes the modification agreed with Goodrich to address the risk and frames the AD’s inspections and replacements as means to detect and correct excessive wear (Background).

Document reliance and access: Compliance depends on external manufacturer documents (Goodrich CSB 23400‑27‑27 and Fokker SBF100‑27‑088). The AD requires referencing Table 2 (page 8) of the Fokker service bulletin for timing in Requirement 3. The AD also accepts later approved revisions of those documents for compliance, which introduces a compliance pathway through an approved modification record.

Aircraft operators and owners: The AD applies to all serial numbers of the F28 Mark 0070 and Mark 0100. Therefore every owner or operator of those aircraft is directly affected because they must perform the required inspections and, where necessary, replacement or modification actions (Applicability; Requirements 1-5). Where an operator uses spare BCUs, the prohibition on installing specified unmodified BCUs after set dates affects spares management (Requirements 6-7).

Maintenance organisations and licensed maintenance personnel: The AD mandates inspections and component replacement/modifications in accordance with specific service bulletins and a component service bulletin. Maintenance organisations will need access to Fokker Service Bulletin SBF100‑27‑088 (including Table 2, page 8) and Goodrich CSB 23400‑27‑27 to carry out the prescribed work correctly and to determine required intervals for replacement under Requirement 3. The AD accepts later approved revisions, so maintainers also need to track revisions that are approved for compliance (Requirement text; compliance note).

Parts suppliers, stockholders and supply chain: Suppliers and spares stockholders who hold Goodrich P/N 23400‑3B, 23400‑7, 23400‑3 or 23400‑5 BCUs are affected by the staged prohibitions on installing unmodified parts. From 29 August 2012, unmodified 23400‑3B and 23400‑7 may not be installed. From 3 March 2014, unmodified 23400‑3 and 23400‑5 may not be installed. This affects inventory valuation, part allocation, and procurement planning (Requirements 6-7).

Manufacturers: Goodrich and Fokker are named parties in the AD text. The AD refers to Goodrich CSB 23400‑27‑27 and Fokker SBF100‑27‑088 and records that the modification was decided in co‑operation with Goodrich. The manufacturer documentation becomes the technical standard for compliance (Background; Requirements).

Regulator and delegate: The Civil Aviation Safety Authority (CASA) is the issuing authority, with the AD signed by James Coyne, Delegate of CASA. The AD cross‑references EASA ADs, indicating international regulatory alignment and prior EASA activity relevant to the same technical issue (signature block; Note).

Other affected parties: Operators of aircraft that use the same BCUs in other aircraft types might need to check whether they fall under the applicability (the AD itself, however, is limited to F28 Mark 0070 and Mark 0100). Insurers, lessors and registries will be interested because the AD imposes mandatory maintenance and installation restrictions that may affect airworthiness, leasing agreements and insurability.

Who pays: The source does not set out funding arrangements or compensation. The mandatory nature of the AD means that costs associated with inspections, modifications and replacement will fall on aircraft operators and owners (the compliance obligations specify the actions and timeframes; the AD text does not allocate cost responsibility to any party other than by prescribing the operator actions).

Key duties (expressed in the AD)

• Inspect: Perform a one‑time inspection of the Elevator BCU as defined in Part 1 of the Accomplishment Instructions of Fokker Service Bulletin SBF100‑27‑088 dated 4 June 2007. This is Requirement 1 for P/N 23400‑3B/23400‑7 and Requirement 2 for P/N 23400‑3/23400‑5 (Requirements 1-2).

• Replace or modify: Where required by inspection results, replace the Elevator BCU with a P/N 23400‑3B or P/N 23400‑7 unit that has been modified per Goodrich CSB 23400‑27‑27. Replace remaining unmodified units in accordance with Goodrich CSB 23400‑27‑27 and Part 2 of Fokker SBF100‑27‑088 (Requirements 3-5). Requirement 3’s timing depends upon inspection results and refers to Table 2 of the Fokker service bulletin for the specific interval (Requirement 3).

• Prohibition on installation: Do not install a spare Goodrich P/N 23400‑3B or P/N 23400‑7 Elevator BCU on any aircraft unless it has been modified in accordance with Goodrich CSB 23400‑27‑27. Do not install Goodrich P/N 23400‑3 or P/N 23400‑5 Elevator BCU on any aircraft (Requirements 6-7). Those prohibitions have activation dates in the Compliance section: from 29 August 2012 for P/N 23400‑3B/23400‑7, and from 3 March 2014 for P/N 23400‑3/23400‑5.

• Follow referenced documents: The inspections and modifications are specified by the Fokker service bulletin and the Goodrich component service bulletin referenced in the AD. The AD requires compliance with those documents' Accomplishment Instructions (Requirements 1-5).

Rights and permitted flexibilities (expressed in the AD)

• Acceptance of later approved revisions: The AD explicitly states that the use of later approved revisions of the referenced documents is acceptable for compliance with the requirements of this AD. That provides a pathway to comply using updated editions of the CSB or service bulletin once those later editions are approved (compliance flexibility clause).

• Conditional timing for replacement: Requirement 3 directs that replacement timing depends on inspection results and references a table in the Fokker service bulletin (Table 2, page 8). That creates a conditional compliance window based on the technical state found during inspection, rather than an unconditional immediate replacement for every unit.

• Staged deadlines: The AD sets staged replacement deadlines (five years after a date for certain P/Ns) and staged installation prohibitions with future activation dates. Operators may plan retrofit and procurement to meet those deadlines rather than face an immediate blanket replacement duty (Compliance section).

Duties of recordkeeping and traceability (implied): The AD requires inspections and part modifications in accordance with manufacturer instructions. Although not stated expressly, compliance with those documents typically requires documenting the inspection and modification actions. The AD does not provide a recordkeeping regime within its text, but reliance on service bulletins implies the need to follow the Accomplishment Instructions and maintain evidence sufficient to demonstrate compliance to the regulator.

No penalties specified in the text: The AD prescribes mandatory actions, but does not itself specify penal consequences or the enforcement mechanisms. The regulatory source and signature indicate the AD is an instrument of CASA, and operators must follow the requirements. The AD does not allocate funding, make allowances for operators unable to source modified units, nor provide alternative means of compliance other than using later approved revisions of the referenced documents (Requirements; compliance flexibility).

The AD text does not contain a penalty schedule, monetary fines, or criminal sanctions within its own wording. The document is a regulatory instrument issued by the Civil Aviation Safety Authority and signed by James Coyne, Delegate of CASA (signature block 26 March 2009). The AD prescribes mandatory technical actions (inspection, replacement, prohibition of installation of certain parts), sets timeframes for compliance, and references technical documents to define the required work (Requirements 1-7; Compliance).

Because the AD itself does not spell out enforcement procedures or penalties, the following points are grounded on what the AD says and what it leaves unspecified:

• Regulatory command and compliance expectancy: The AD records obligations and deadlines that operators must meet to be in compliance with the AD. The AD does not state enforcement mechanisms or administrative penalties in this text; it is a direction from the regulator that an operator must meet to keep the aircraft in an airworthy state.

• Absence of explicit sanctions in the AD: There are no express provisions in the AD text for penalties, suspension, grounding, or administrative fines. The AD also does not specify remedial steps for operators who cannot source modified parts by the stated deadlines. The absence of such provisions in the text means any enforcement procedures, penalties or follow‑up compliance measures will rely on CASA’s broader regulatory powers and enforcement protocols rather than on this AD’s text itself.

• Reference to external documents and approvals: Compliance must be achieved in accordance with manufacturer service documents or later approved revisions of those documents. The AD’s acceptance of later approved revisions implies some regulatory discretion exists to approve alternative compliance paths or updated instructions, but the AD text does not describe how such approvals are obtained or granted.

Practical enforcement considerations (implicit): Enforcement of ADs in practice typically involves the regulator checking maintenance records, airworthiness status and certificate conditions. The AD creates a compliance obligation that would be used as a reference point in regulatory oversight. The AD’s requirements, deadlines and part‑number prohibitions give clear criteria to evaluate compliance. The AD also refers to EASA ADs (Note), indicating parallel or prior regulatory actions by a foreign regulator that may be relevant in oversight or international operations. The AD does not specify dispute resolution mechanisms, or an explicit appeal process for operators asserting inability to comply.

In sum, the AD prescribes mandatory technical corrective actions and deadlines, but it does not itself include penalty provisions or detailed enforcement mechanisms. Any enforcement is governed by the regulator’s broader statutory powers and normal supervisory practices, which are not spelled out in the AD text provided.

The AD explicitly references and situates itself relative to other regulatory instruments and manufacturer documents. The interactions recorded in the AD text are the following:

• Interaction with EASA ADs: The AD contains a Note that EASA AD 2009‑0032 dated 17 February 2009 is referred to and states that this AD supersedes EASA AD 2007‑0228. That places the CASA AD in a sequence with European Aviation Safety Agency directives addressing the same technical matter. The AD therefore functions in a regulatory dialogue with EASA instruments, at least by cross‑reference (Note).

• Interaction with manufacturer service documents: The AD makes compliance conditional on carrying out work "as defined in Part 1 of the Accomplishment Instructions" and "Part 2 of the Accomplishment Instructions" of Fokker Service Bulletin SBF100‑27‑088 dated 4 June 2007, and on modification "in accordance with Goodrich CSB 23400‑27‑27". Those service bulletins and component service bulletins are technical documents produced by manufacturers. The AD thus imposes regulatory force on manufacturer instructions: operators must perform the actions in those documents to meet the AD requirements (Requirements 1-5).

• Acceptance of later approved revisions: The AD states that "The use of later approved revisions of these documents is acceptable for compliance with the requirements of this AD." That creates a direct legal connection between the AD and the processes that approve later revisions of those service documents. It implies that an approved revision to the relevant CSB or service bulletin, once approved, can be used as a compliance instrument under this AD.

• Supersession and sequencing: The AD declares that it supersedes a prior EASA AD, indicating that it may replace or update prior regulatory instructions. The AD itself is an amendment (AD/F100/85 Amdt 1) and records that the original issue became effective on 25 October 2007, with this amendment effective 7 May 2009. This demonstrates iterative regulatory action on the same safety issue, with the AD being part of a series of steps.

• No express interaction with non‑aviation statutes in text: The AD does not refer to civil liability statutes, commercial law, contract law, workplace health and safety legislation, customs or export controls, or criminal provisions. The AD is focused on airworthiness requirements and references other aviation safety directives and manufacturer documents.

• Operational and contractual effects (implicit): Although not stated in the text, an AD of this nature can affect contractual relations (lessor‑lessee obligations, maintenance contracts) and insurance underwriting, because it prescribes mandatory maintenance actions and part‑installation prohibitions. The AD itself, however, does not include provisions addressing contractual or insurance consequences.

• Regulator authority: The AD is issued by CASA and signed by a CASA delegate. That situates the AD within the administrative law framework where CASA has statutory authority to issue mandatory airworthiness directives. The AD text does not summarise the statutory power used, but the signature block unambiguously indicates regulator authorship and authority to issue ADs.

In summary, the AD interacts primarily with other aviation regulatory instruments (EASA ADs) and with manufacturer technical documents by making those documents the operative instructions for compliance. It accepts later approved revisions of those documents as valid compliance instruments. The AD does not itself discuss interactions with broader legal frameworks in its text.

The AD contains a brief and concrete amendment history within its text. The sequence and components recorded are:

• Original AD: The original issue of this AD became effective on 25 October 2007. The Compliance section notes that Requirement 1 "remains unchanged as detailed in the original issue of this AD as prior to 25 October 2008." This indicates there was an original AD issued in 2007 that set initial requirements (Background; Compliance).

• Amendment 1: The document present is AD/F100/85 Amdt 1. This Amendment 1 "includes inspections for addition BCUs and eventual replacement of all affected units." The AD text states "This Amendment becomes effective on 7 May 2009." The signature block records a date of 26 March 2009 for the delegate signature. The AD header repeats AD/F100/85 Amdt 1 and includes the issue date 5/2009, indicating the amendment was published in 2009 (AD heading; signature).

• EASA references and supersession: The AD contains a Note: "EASA AD 2009‑0032 dated 17 February 2009 refers. This AD supersedes EASA AD 2007‑0228." Thus, the amendment takes account of a later EASA AD and positions this CASA AD as superseding a prior EASA AD (Note).

• Timed changes introduced by amendment: The Compliance section sets new or clarified timeframes for Requirements 2-7. For example, Requirement 2 must be done within 12 months from the effective date of this AD; Requirement 4 requires replacement within five years after 25 October 2007; Requirement 5 requires replacement within five years after the effective date of this AD; and Requirements 6 and 7 set specific dates from which the installation prohibitions apply (29 August 2012 and 3 March 2014 respectively). Those timing rules are part of the amendment's effect on prior obligations.

• Nature of amendment: The AD text explains the operational reason for the amendment: Amendment 1 includes inspections for additional BCUs and eventual replacement of all affected units. The Background also states that the original AD required a one‑time inspection and eventual replacement of affected Elevator BCUs, and that Amendment 1 expands inspections and replacements to additional BCUs (Background).

What the AD does not specify about amendment history

• The AD does not list earlier versions, consultation comments, or a changelog beyond the above statements. It does not reproduce the text of the original AD for line‑by‑line comparison, nor does it include the EASA text that it refers to. The AD does not set out the administrative law basis for the amendment in the text provided. The AD does not state whether operators were consulted or whether alternative means of compliance were considered, other than permitting later approved revisions of the referenced technical documents.

Synthesis: The amendment history recorded in the AD shows an initial AD effective 25 October 2007, an amendment (Amdt 1) effective 7 May 2009 that expands inspection coverage and sets staged replacement deadlines, and acknowledgment of EASA ADs with which the AD is associated and which it supersedes or references.

The AD text does not record any litigation, court decisions, or judicial review related to the AD. There are no court cases, appeals, enforcement proceedings, or disputes documented in the AD’s content. The document is a regulatory directive setting technical and compliance obligations and contains administrative signatures and dates, but no litigation narrative.

What the absence of litigation history in the AD means for practitioners:

• No case law recorded: Since the AD does not reference any judicial outcomes, there is no litigation precedent in the document that would interpret its provisions, deadlines or technical requirements. Practitioners seeking authority or interpretation in litigation contexts will not find judgments in this text.

• Potential for disputes exists but is unrecorded: The AD prescribes technical actions with timing and prohibition rules; disputes could in principle arise over interpretation, availability of parts, the adequacy of inspections, or alternative compliance methods. However, the AD does not record any instances of such disputes. Any future litigation or administrative proceedings would be external to this document.

• Reliance on regulatory record: For enforcement or defence, practitioners will need to rely on regulatory administrative procedures and any CASA guidance or correspondence external to the AD to show compliance or to contest enforcement. The AD itself does not set out dispute resolution mechanisms, variances or exemptions.

• Document as primary source for obligations: In absence of litigation, the AD functions as the authoritative statement of obligations. For legal, contractual or insurance questions concerning compliance with this AD, parties must start with the AD’s text and with the referenced technical documents (Fokker Service Bulletin SBF100‑27‑088 and Goodrich CSB 23400‑27‑27). Any legal contest would need to reference other law or administrative processes not reproduced in the AD.

For those needing to advise on compliance risk, contractual remedies or potential enforcement exposures, the AD provides the operative technical duties and dates but no judicial interpretative material. Any litigation history would need to be sought outside the AD text itself.

Several practical and legal pitfalls emerge directly from the AD text and the way it ties compliance to external technical documents and timeframes.

1. Applicability is broad and unqualified: The AD applies to "F28 Mark 0070 and Mark 0100 aircraft, all serial numbers." There is no carve‑out by operator, country of registration, or configuration. Operators of any of these airframes should assume the AD applies unless they have an express regulatory exemption. Missing this scope could leave an operator non‑compliant (Applicability).

2. Compliance depends on external documents that must be obtained and read in full: The AD requires inspections "as defined in Part 1 of the Accomplishment Instructions of Fokker Service Bulletin SBF100‑27‑088 dated 4 June 2007" and replacements "in accordance with Goodrich CSB 23400‑27‑27 and Part 2 of the Accomplishment Instructions of Fokker Service Bulletin SBF100‑27‑088." Requirement 3’s timetable refers to Table 2 on page 8 of the Fokker SB. Practically, compliance cannot be verified against the AD text alone; the operator must obtain these specific documents, read the referenced parts and ensure any later approved revisions used are indeed approved for compliance (Requirements 1-5; compliance note).

3. Requirement 3 timing dependency: The AD says the timeline for Requirement 3 depends on inspection results "as indicated in Table 2 on page 8 of the referenced Fokker SB." Without direct access to Table 2, an operator cannot determine the required interval. This creates a dependency trap: you must retrieve and apply the exact table to schedule replacements correctly (Requirement 3).

4. Staged and distant deadlines require planning: The AD sets staggered cut‑off dates for installation prohibitions (29 August 2012 and 3 March 2014) and replacement windows that measure from different base dates (e.g., five years after 25 October 2007 for Requirement 4 and five years after the effective date of this AD for Requirement 5). Operators must carefully track which part numbers they have installed, when initial inspections were done, and which calendar deadlines apply to each part (Compliance).

5. Prohibition on installing certain unmodified parts may strand spares or require modification of existing spares: The AD disallows installation of unmodified P/N 23400‑3B/23400‑7 from 29 August 2012, and disallows installation of P/N 23400‑3/23400‑5 from 3 March 2014. If an operator holds unmodified spares, they cannot be installed after those dates and must either be modified in accordance with the CSB or otherwise managed. The AD does not provide allowance for use of unmodified spares beyond those dates (Requirements 6-7).

6. "Later approved revisions" are acceptable but require approval verification: The AD permits use of later approved revisions of the referenced documents for compliance. That raises a compliance process question: which authority must approve a later revision for it to be acceptable under the AD, and how is that approval documented? The AD does not spell out the administrative mechanism for that approval. Operators should ensure they have formal evidence that the revision used is approved for compliance (compliance flexibility clause).

7. Original Requirement 1 unchanged: The AD indicates that Requirement 1 remains unchanged from the original AD as prior to 25 October 2008. If an operator relies on older paperwork or older maintenance schedules, they must ensure that they are following the original Requirement 1 text as it stood prior to that date. The AD does not reproduce the original requirement text, so operators must retrieve the original AD text to be certain of Requirement 1 content and timing (Compliance).

8. Reliance on manufacturer modifications: The AD drives mandatory modifications "in accordance with Goodrich CSB 23400‑27‑27." If Goodrich’s CSB contains optional steps, tooling requirements, or replacement part lead times, those practicalities are binding for regulatory compliance. The AD does not provide alternatives to the CSB method except allowing later approved revisions, so any practical constraint in executing the CSB steps becomes a compliance constraint (Requirements 3-5; Background).

9. No penalties or enforcement detail in text: The AD does not set out enforcement or penalty provisions. That means operators must consult CASA’s broader enforcement framework to understand consequences for non‑compliance. The absence of explicit penalties in the AD could be a surprise for those who expect the AD to stipulate enforcement steps directly (Penalties and enforcement).

10. International regulatory interplay: The AD refers to EASA ADs and supersedes one. Operators involved in cross‑jurisdiction operations should be mindful of how this CASA AD aligns with EASA instructions and any others. The AD does not explain harmonisation or differences in detail; operators should reconcile the CASA AD with other regulatory obligations they may be subject to (Note).

11. Record evidence and traceability: Because the AD binds compliance to actions in external documents, a regulatory audit will require documentary proof that the inspection, modification and replacement actions followed the specified parts of the referenced documents. The AD does not detail recordkeeping standards; operators must ensure maintenance records explicitly reference the service bulletin sections and CSB used and the part numbers modified, including serial numbers where applicable.

These "gotchas" flow from the AD’s reliance on external technical documents, staged deadlines, installation prohibitions and the requirement to follow manufacturer instructions for modification, coupled with limited operational detail in the AD itself about approval processes and enforcement.

Compliance must be demonstrable against the AD’s specific requirements and the referenced manufacturer documents. The AD sets a sequence of tasks, timing rules and prohibitions. The practical steps below are grounded in the AD’s text.

1. Confirm applicability

• Verify whether the aircraft is an F28 Mark 0070 or Mark 0100. The AD covers "all serial numbers" of these models (Applicability). If aircraft is outside those models, this AD does not apply per its text.

2. Obtain the referenced technical documents

• Obtain Fokker Service Bulletin SBF100‑27‑088 dated 4 June 2007, including Part 1 and Part 2 of its Accomplishment Instructions and Table 2 on page 8. The AD’s inspection and replacement instructions reference those parts directly (Requirements 1-5).
• Obtain Goodrich Component Service Bulletin CSB 23400‑27‑27. The AD requires modifications to be made "in accordance with Goodrich CSB 23400‑27‑27" for the specified part numbers (Requirements 3-5).
• If using later revisions of those documents, ensure the later revision is approved for compliance as the AD accepts "later approved revisions" (compliance flexibility clause).

3. Perform the mandated inspections

• For aircraft equipped with Elevator BCU P/N 23400‑3B or P/N 23400‑7: Perform the one‑time inspection of the Elevator BCU as defined in Part 1 of the Accomplishment Instructions of Fokker SBF100‑27‑088 dated 4 June 2007 (Requirement 1).
• For aircraft equipped with BCU P/N 23400‑3 or P/N 23400‑5: Perform the one‑time inspection as defined in Part 1 of the same Fokker service bulletin (Requirement 2). Requirement 2 must be completed within 12 months from the effective date of the AD.

4. Assess inspection results and follow replacement timing

• If the inspection indicates corrective action is required, follow the timing for replacement set out in Table 2 on page 8 of the Fokker service bulletin. Requirement 3 ties its deadline to the inspection outcome and Table 2,retrieve Table 2 and apply the inspection result codes to determine the correct replacement interval.

5. Replace or modify units as required

• Replace affected Elevator BCUs with P/N 23400‑3B or P/N 23400‑7 units that have been modified in accordance with Goodrich CSB 23400‑27‑27 (Requirement 3).
• Replace all remaining unmodified Elevator BCU P/N 23400‑3B and P/N 23400‑7 with units modified in accordance with Goodrich CSB 23400‑27‑27 and Part 2 of the Accomplishment Instructions of Fokker SBF100‑27‑088 within five years after 25 October 2007 (Requirement 4).
• Replace all remaining unmodified Elevator BCU P/N 23400‑3 and P/N 23400‑5 with respectively P/N 23400‑3B and P/N 23400‑7 modified in accordance with Goodrich CSB 23400‑27‑27 and Part 2 of the Fokker SB within five years after the effective date of this AD (Requirement 5).

6. Stop installing unmodified spare parts after the specified dates

• From 29 August 2012, do not install a spare Goodrich P/N 23400‑3B or P/N 23400‑7 Elevator BCU on any aircraft unless it has been modified in accordance with Goodrich CSB 23400‑27‑27 (Requirement 6).
• From 3 March 2014, do not install Goodrich P/N 23400‑3 or P/N 23400‑5 Elevator BCU on any aircraft (Requirement 7).
• Adjust spares procurement, inventory and maintenance planning accordingly to avoid use of prohibited unmodified parts after these dates.

7. Document and retain compliance evidence

• Record the inspection date, the inspector, the exact Accomplishment Instruction sections followed, the part numbers involved and serial numbers where applicable, results of the inspection, the nature and date of any modification or replacement work, and references to Goodrich CSB 23400‑27‑27 or the Fokker SB revision used for compliance.
• If using a later approved revision of the SB or CSB, retain documentary proof that the specific revision used was approved for compliance. The AD permits later approved revisions, but the operator is responsible for demonstrating approval (compliance flexibility clause).

8. Check for regulatory updates and EASA cross‑references

• The AD refers to EASA AD 2009‑0032 and supersedes EASA AD 2007‑0228. Operators with international operations should check relevant foreign ADs and whether any different or additional obligations apply in other jurisdictions (Note).

9. Plan procurement and scheduling

• The staged deadlines and future installation prohibitions require advance procurement of modified BCUs or planned modification of existing spares. Operators should coordinate with Goodrich, parts suppliers, and maintenance organisations to secure modified units or arrange modification slots well before the prohibitions take effect (Requirements 4-7).

10. Seek approval for alternative compliance methods if necessary

• The AD accepts later approved revisions for compliance but does not outline alternative means of compliance. If an operator cannot comply with the CSB method for technical or supply reasons, the operator should engage CASA (or the relevant approving authority) to seek approval of an alternative compliance method before the AD’s deadlines. The AD text does not describe the approval process; operators should rely on CASA’s usual approval pathways.

11. Be ready for audits and enforcement checks

• Since the AD prescribes mandatory actions without listing penalties in the text, operators should nonetheless assume CASA may check maintenance records and compliance. Maintain traceable records that map each action to the AD’s Requirements and to the specific parts of the referenced documents used.

In summary, compliance is a process of identification, document acquisition, inspection, conditional replacement or modification according to inspection outcomes and tables in the Fokker SB, staged replacement deadlines, prohibition of certain part installations after specified dates, and maintenance of documentary evidence that inspections and modifications were carried out in accordance with the referenced documentation or later approved revisions.