AD/B717/26 - Versatile Integrated Avionics Digital Computer

The Directive revolves around three main technical and regulatory concepts: (1) a mandatory software upgrade as an airworthiness corrective action; (2) an immediate parts-installation prohibition for specific VIA part numbers; and (3) the relationship between this Directive, a prior CASA directive (AD/B717/15), and a corresponding FAA AD.

First, the technical corrective action is narrowly framed. Requirement 1 specifies upgrading the VIA digital computer system software to P/N PS4081970-909 and upgrading the ISDAS database software to P/N PS4081642-909 in accordance with the Accomplishment Instructions of Boeing Service Bulletin SB717-31-0013 dated 25 March 2005. The upgrade is expressed as an action that, once done, terminates the need for the AFM restriction imposed by AD/B717/15 for that aeroplane (Requirement 1). The language therefore treats the software change as a terminating modification for a prior operational limitation.

Second, the Directive imposes an immediate hardware control. Requirement 2 states that VIA digital computer part numbers 4081570-904, -905, -906 or -907 may not be installed on any aeroplane as replacement spares as of the effective date. That prohibition is absolute in the text provided; it does not carve out exceptions within the document. The Directive therefore affects not just in-service configuration but spare parts procurement, logistics and maintenance planning.

Third, the Directive sets out the permissible routes for compliance by reference to service material and to FAA approvals. Note 1 identifies Honeywell Alert SB 4081570-31-A6007 dated 9 March 2005 as an additional source of service information for performing Requirement 1. The Directive further accepts later revisions of Boeing SB717-31-0013 if those revisions are approved by the FAA as an Alternate Method of Compliance to FAA AD 2007-19-15, stating they are "considered acceptable for compliance with the equivalent Requirements of this Directive." The Directive explicitly cross-references FAA AD 2007-19-15 Amdt 39-15206 (Note 2). The text therefore imports a degree of regulatory deference to FAA approvals for amendments to the Boeing service bulletin and places a condition on which later SB revisions are acceptable.

Underlying these concepts is the safety problem stated in the Background: reports of two incidents where selected FCP altitude was violated during FMS PROF descents, creating risk of uncommanded descent below the selected level-off altitude and consequent unacceptable reduction in separation from traffic or terrain. The Directive implements a technical software fix (and spare-part restriction) as the measure to eliminate the operational restriction imposed by the prior AD/B717/15. The Directive is explicit that the terminating effect applies to individual aeroplanes on which the upgrade or later P/N is installed.

The Directive applies directly to operators and maintainers of Boeing Model 717-200 aeroplanes identified in Boeing Service Bulletin SB717-31-0013 dated 25 March 2005 (Applicability). That includes airline operators with aircraft listed in the service bulletin, maintenance organisations responsible for modifications and spare parts management, and spare parts suppliers stocking the VIA digital computer units identified by part numbers in Requirement 2.

Specifically, aircraft-level consequences in the text are: for any aeroplane in the SB’s applicability list, the operator or maintenance organisation must upgrade the VIA system software and ISDAS database software within 18 months after the Directive’s effective date (Requirement 1; Compliance). Parties that manage maintenance logistics must ensure that VIA digital computer P/Ns 4081570-904, -905, -906 or -907 are not installed as replacement spares on any aeroplane as of the effective date (Requirement 2; Compliance). Entities responsible for parts procurement will therefore need to account for the immediate prohibition on installing those part numbers and to reconcile existing stock, serviceable units, and supply contracts.

The Directive also affects flight operations insofar as the upgrade, once accomplished for an aeroplane, removes the AFM limitation imposed by AD/B717/15 for that particular aeroplane only (Requirement 1). That means crew and operations teams will need to update AFMs and operational procedures on a per-aircraft basis after the upgrade is installed, and must retain the AFM restriction until the terminating action is completed on that aeroplane.

Regulatory bodies and third-party service providers are indirectly implicated. The Directive accepts later revisions of Boeing SB717-31-0013 if those revisions are approved by the FAA as an AMOC to FAA AD 2007-19-15 (Requirement 2). This imposes a procedural interface: operators seeking to rely on service bulletin revisions must ensure FAA AMOC approval exists. Honeywell Alert SB 4081570-31-A6007 is listed as an additional source of service information (Note 1), so maintainers may coordinate with Honeywell documentation when performing the corrective work.

Who pays. The Directive does not allocate funding or compensation; the text requires the upgrade and prohibits installation of certain spares, therefore operators and maintenance organisations will bear direct costs: procurement and installation of the specified software upgrade, aircraft downtime while the upgrade is performed, administrative costs of updating AFMs and maintenance records, and potential costs associated with replacing or discarding prohibited spare units. The Directive explicitly ties terminating relief from AD/B717/15 to the installation on each aeroplane individually; there is no fleet-wide automatic termination in the text.

Finally, the document is issued by the Civil Aviation Safety Authority and signed by the delegate, David Punshon, dated 2 October 2007, with an effective date of 22 November 2007. That identifies the issuing authority and the date from which the specific compliance deadlines are measured.

Duties

• Upgrade obligation: For each aeroplane within the SB717-31-0013 applicability list, the operator or authorised maintenance organisation must upgrade the VIA digital computer with system software P/N PS4081970-909 and ISDAS database software P/N PS4081642-909, following the Accomplishment Instructions of Boeing SB717-31-0013, if not previously accomplished (Requirement 1). The Directive sets the deadline for this upgrade at within 18 months after the effective date of the Directive (Compliance).

• Spare installation prohibition: As of the Directive’s effective date, VIA digital computer P/N 4081570-904, -905, -906 or -907 may not be installed on any aeroplane as a replacement spare (Requirement 2; Compliance). This is an immediate duty affecting maintenance actions and parts management.

• Conformance to approved service material: The upgrade must be performed in accordance with the Accomplishment Instructions of Boeing SB717-31-0013; Honeywell Alert SB 4081570-31-A6007 is cited as an additional service information source for the action (Note 1). The Directive allows later revisions of Boeing SB717-31-0013 only where those revisions have FAA AMOC approval to FAA AD 2007-19-15; such FAA-approved revisions are considered acceptable for compliance with the equivalent requirements of this Directive (Requirement 2).

Rights and effects granted by compliance

• Termination of prior AFM limitations for individual aircraft: Accomplishing the required VIA upgrade or installing VIA P/N 4081570-909 or later part numbers terminates the requirements of AD/B717/15 for that aeroplane only (Requirement 1). That produces a rights-like effect for that aircraft: removal of the AFM restriction previously required under AD/B717/15. The Directive expressly limits that termination to the aeroplane on which the action is accomplished.

• Acceptance of FAA-approved AMOCs: The Directive accepts later revisions of the Boeing service bulletin if they have FAA AMOC approval to FAA AD 2007-19-15, and considers them acceptable for compliance with the equivalent requirements of this Directive. That gives operators a pathway to compliance using FAA-approved alternate methods, so long as that FAA AMOC is in place.

Operational consequences treated as duties

• AFM amendment removal: The prior AD/B717/15 required a revision to the Limitations Section of the AFM prohibiting FMS PROF mode descent/approach under certain conditions. The current Directive is framed as the terminating action for that requirement. Until a given aeroplane has the upgrade installed or the later P/N fitted, the AFM limitation remains in force for that aeroplane (Background). Therefore a duty persists to maintain the AFM limitation for each aeroplane until the terminating modification is installed.

Scope and limits

• Per-aircraft effect: The Directive repeatedly makes the per‑aeroplane limitation explicit. The termination of AD/B717/15 applies only to individual aeroplanes on which the upgrade or later P/N is installed. The Directive does not provide a fleet-wide automatic termination without per-aeroplane compliance.

• Dependence on external approvals: The Directive links acceptability of later Boeing SB revisions to FAA AMOC approval. The text therefore places a condition on the use of later SB revisions, limiting them to those with an explicit FAA AMOC to FAA AD 2007-19-15. That creates a procedural duty to verify FAA approval where operators seek to rely on a later SB revision.

The Directive does not specify reporting obligations, monetary penalties, or the detailed form of documentation required to evidence compliance. The duties in the document are expressed as mandatory actions with specified part numbers, methods, and compliance dates.

The Directive text, as provided, does not state any monetary fines, criminal penalties, or explicit enforcement actions. It sets mandatory corrective and prohibitory obligations and prescribes compliance timeframes, but it does not include a penalty clause within the text. The document is identified as an Airworthiness Directive issued by the Civil Aviation Safety Authority and signed by its delegate (David Punshon) with an effective date of 22 November 2007. The form and language of the document indicate it is a regulatory instrument that imposes corrective and prohibitory obligations for airworthiness, but the Directive itself provides no express enforcement procedure, inspection regime, or sanction schedule in the text provided.

What the Directive does specify that is enforceable in practice are clear deadlines and absolute prohibitions: Requirement 1 must be completed within 18 months after the Directive’s effective date, and Requirement 2 is effective immediately as of the Directive’s effective date. These timelines create discrete non-compliance states: an aeroplane either has the upgrade installed within the 18-month period or it does not; a replacement spare of the prohibited P/Ns is either installed after the effective date or it is not. The absence of explicit penalties in the text does not alter the fact that these are regulatory obligations, but the Directive does not itself set out how non-compliance will be treated administratively or judicially.

The Directive’s references to FAA AD 2007-19-15 and to FAA AMOCs have compliance implications: later revisions of Boeing SB717-31-0013 that have FAA AMOC approval are "considered acceptable for compliance with the equivalent Requirements of this Directive." This creates a compliance pathway that may be relevant to enforcement determinations, where a maintenance action follows an FAA-approved AMOC. The Directive also states that accomplishing the upgrade or installing the later P/Ns "terminates the requirements of AD/B717/15 for that aeroplane only." That termination language has practical enforcement consequences in the sense that, after performing the terminating action, the prior AFM restriction need no longer be maintained for that aeroplane.

Because the Directive does not include its own enforcement or penalty regime, organisations reviewing potential consequences must look to the broader regulatory framework governing airworthiness directives and aviation safety enforcement for matters such as actions to ground aircraft, administrative sanctions, or other measures. The Directive itself, however, is silent on those instruments in the text provided.

The Directive expressly interacts with at least two other regulatory instruments: the earlier CASA directive AD/B717/15 and the corresponding United States FAA airworthiness directive FAA AD 2007-19-15 Amdt 39-15206. The Directive positions itself as terminating action for AD/B717/15 once the prescribed upgrade or later VIA P/N is installed on an aeroplane. That interaction is explicit: "Accomplishing this upgrade or the installation of VIA P/N 4081570-909 or subsequent terminates the requirements of AD/B717/15 for that aeroplane only" (Requirement 1). The logical effect is that AD/B717/15 continues to apply to any aeroplane that has not yet had the upgrade or later P/N installed.

The Directive also incorporates cross-jurisdictional deference to FAA approvals. It states that later revisions of Boeing SB717-31-0013 are considered acceptable for compliance with the equivalent requirements of this Directive, but only where those later revisions have been approved by the FAA as an Alternate Method of Compliance to FAA AD 2007-19-15. That creates an explicit conditional bridge: Australian acceptance of later Boeing SB revisions is dependent on FAA AMOC approval to the FAA AD. The Directive refers to FAA AD 2007-19-15 Amdt 39-15206 (Note 2). In practice, this means that Australian operators wishing to rely on updated Boeing service material should confirm FAA AMOC approval status for the specific SB revision.

In operational terms, the Directive removes the AFM limitation imposed under AD/B717/15 for any aeroplane on which the upgrade is performed. AD/B717/15 required a limitation to prohibit use of the FMS PROF mode for descent and/or approach operations unless certain conditions were met. The Directive frames the software upgrade as enabling removal of that AFM restriction on a per-aircraft basis. The Background further states that AD/B717/15 will be cancelled in May 2009 when all affected aircraft will be in compliance with this Directive. That ties the lifecycle of the earlier CASA AD to successful implementation of this Directive among affected aeroplanes.

The Directive also references service information issued by equipment manufacturers, namely Boeing SB717-31-0013 and Honeywell Alert SB 4081570-31-A6007. The maintenance and modification actions required are to be performed "in accordance with the Accomplishment Instructions" of the Boeing SB, with the Honeywell alert identified as an additional source of service information. That locates the technical compliance obligation within manufacturer-supplied documentation while still conditioning acceptance of later revisions on FAA AMOC approvals.

No other statutes, regulations, or legal instruments are referenced in the provided text. The Directive does not specify how it interacts with commercial contracts, insurance coverage, or occupational health and safety obligations. Any such interactions would need to be determined by reference to the broader statutory and regulatory framework outside the text of the Directive itself.

The provided text contains a concise amendment and cross-reference history limited to the relationship with AD/B717/15 and the FAA AD. The Directive is presented as AD/B717/26 and explicitly states it "provides terminating action for AD/B717/15." It records that AD/B717/15 currently required a revision to the Limitations Section of the AFM to prohibit use of the FMS PROF mode under certain conditions and that AD/B717/15 "will be cancelled in May 2009 when all affected aircraft will be in compliance with this Directive" (Background). The Directive therefore functions as a successor instrument to AD/B717/15 with a built-in termination pathway for that prior AD once compliance is achieved on affected aeroplanes.

Service bulletin dates and referenced manufacturer documentation are noted, which can be read as part of the administrative history relevant to the Directive. The Boeing Service Bulletin designated SB717-31-0013 is cited and dated 25 March 2005 (Applicability). Honeywell Alert SB 4081570-31-A6007 is cited and dated 9 March 2005 (Note 1). The FAA AD cited, FAA AD 2007-19-15 Amdt 39-15206, serves as an external reference point for AMOCs and later SB revisions (Note 2).

The Directive itself is dated 2 October 2007, signed by the CASA delegate David Punshon, and states an effective date of 22 November 2007 (Compliance). The compliance timetable for Requirement 1 is within 18 months after the Directive’s effective date and for Requirement 2 it is "as of the effective date of this Directive" (Compliance). The text implies future administrative action tied to compliance levels: a planned cancellation of the earlier AD/B717/15 in May 2009, conditional on all affected aircraft being in compliance with AD/B717/26 by that time (Background). No other prior versions or amendments of AD/B717/26 are incorporated or described in the supplied text.

There is no record in the document of prior amendments to AD/B717/26 itself, nor of subsequent amendments to it within the text provided. The document does not list a legislative amendment table, revocation clauses for AD/B717/26 itself, or transitional provisions beyond the per-aircraft termination of AD/B717/15. The only dynamic features are the acceptance of later Boeing SB revisions subject to FAA AMOC approval and the planned cancellation of the prior AD once compliance is complete across the affected fleet.

For practitioners tracking amendment history, the key documented dates and linkages in the text are: Honeywell Alert dated 9 March 2005; Boeing SB717-31-0013 dated 25 March 2005; signature date 2 October 2007; effective date 22 November 2007; AD/B717/15 scheduled cancellation in May 2009 contingent on compliance; and reference to FAA AD 2007-19-15 Amdt 39-15206 as a cross-jurisdictional point for AMOCs.

The Directive text supplied contains no reference to litigation, judicial review, or administrative appeals relating to AD/B717/26. There are no statutory citations, case names, or references to legal proceedings in the document. It is signed by the CASA delegate and presented as an administrative airworthiness instrument; it provides compliance obligations, part‑numbered technical measures, and effective dates, but it does not record any past or pending litigation.

Because the text contains no litigation history, the document does not identify any legal challenges, injunctions, or court decisions that have affected its operation or interpretation. The Directive similarly does not specify a mechanism for appeals or reviews within its text. The only procedural cross-references concern FAA approvals of SB revisions as AMOCs for FAA AD 2007-19-15; those are administrative approvals and the Directive states that FAA-approved AMOCs are acceptable for compliance.

Where litigators or advisers require a litigation history for AD/B717/26, the Directive itself provides no record. Any further information about legal challenges, enforcement actions, or disputes arising from this Directive would need to be sought in external administrative or judicial records, which are not part of the document supplied. The absence of litigation references in the Directive means that the Directive, as issued, stands as a regulatory instrument imposing technical and procedural obligations and does not in itself document contested adjudication or judicial oversight.

For those assessing legal risk or potential grounds for challenge, the Directive does not present within its text any administrative findings, procedural steps taken prior to issuance, or statutory bases beyond its status as a CASA Airworthiness Directive. The document therefore does not supply material that would indicate what administrative record might be used to support or contest the Directive in litigation. Any requests to review that material or to identify challenges would require consultation of CASA administrative files and public records outside the scope of this Directive text.

The Directive contains several features that create practical traps or implementation subtleties for operators, maintenance providers and parts managers. These are grounded directly in the text.

Applicability is limited by service bulletin identification: The Directive applies to Model 717-200 aeroplanes "as identified in Boeing Service Bulletin (SB)717-31-0013, dated 25 March 2005" (Applicability). Practically, an aeroplane is within the scope only if it appears in the SB’s applicability list. Operators must therefore check the SB to determine whether a specific tail number is covered. Mistaking "Model 717-200" alone for blanket applicability could lead to misapplication.

Termination is per aeroplane only: The Directive states that accomplishing the upgrade or installing VIA P/N 4081570-909 or subsequent "terminates the requirements of AD/B717/15 for that aeroplane only" (Requirement 1). That means partial fleet compliance does not remove AFM limitations from non-upgraded aeroplanes. Operators must track compliance at the aircraft level and maintain AFM restrictions where the upgrade has not been performed.

Immediate spare prohibition affects logistics: Requirement 2 prohibits installing VIA P/N 4081570-904, -905, -906 or -907 "on any aeroplane as a replacement spare" as of the effective date (Requirement 2; Compliance). This is effective immediately on 22 November 2007. Organisations that hold stock of these P/Ns must identify whether existing spares are fit-for-service, whether existing installations are captured, and whether contractual obligations with suppliers are impacted. The Directive does not provide phase-out instructions for already-installed units, so care is needed in interpreting whether the prohibition applies only to new installations as replacement spares or also to existing installed units. The text states the prohibition is on installation as replacement spares "may not be installed," which implies the restriction targets future installation actions rather than immediate removal of currently installed units; still, the wording requires attention in compliance planning.

Dependence on FAA AMOC for later SB revisions: The Directive accepts later revisions of Boeing SB717-31-0013 only where those revisions are FAA-approved as AMOCs to FAA AD 2007-19-15 (Requirement 2). This creates a procedural dependency. If Boeing issues a revised SB that lacks FAA AMOC approval, that SB revision is not automatically acceptable under this Directive. Operators seeking to rely on later SB revisions must verify FAA AMOC approval for the specific revision.

Accomplishment Instructions are binding: The upgrade must be performed "in accordance with the Accomplishment Instructions of SB717-31-0013" (Requirement 1). Practitioners should be careful to identify the exact revision of the SB referenced by the Directive and ensure any alternative methods are documented and, where necessary, approved as equivalent or as AMOCs in the ways the Directive allows.

AFM changes remain until upgrade: The Background explains AD/B717/15 required an AFM revision prohibiting FMS PROF descent/approach under certain conditions and that this Directive "provides terminating action" for that prior AD once the upgrade is done. Until an individual aeroplane receives the upgrade, the AFM limitation remains in force. Operations departments must ensure AFMs and crew briefings reflect the current status for each aeroplane.

No penalties or enforcement mechanics in text: The Directive contains no penalty clause or enforcement procedure within the supplied text. Practitioners expecting detailed enforcement rules or appeal processes in the Directive will not find them here, and should not assume their existence based solely on this document.

Dates and timelines: The effective date is 22 November 2007 and the upgrade must be achieved within 18 months after that date (Compliance). Operators that plan to schedule upgrades near the end of the 18-month window should build in time for supply-chain delays, avionics shop capacity and recordkeeping to avoid falling outside the compliance period.

Reliance on Honeywell Alert as "additional" source: Note 1 identifies Honeywell Alert SB 4081570-31-A6007 dated 9 March 2005 "as an additional source of service information" for doing Requirement 1. The word "additional" signals that the Boeing SB Accomplishment Instructions remain the primary source. Relying only on Honeywell documentation without cross-referencing Boeing SB Accomplishment Instructions and any applicable FAA AMOC approvals risks non-conformance with the Directive as written.

Planned cancellation of the earlier AD depends on fleet compliance: The Background says AD/B717/15 "will be cancelled in May 2009 when all affected aircraft will be in compliance with this Directive." That planned administrative action depends on actual compliance across the affected fleet; operators should not assume AD/B717/15 will be cancelled automatically without meeting the per-aircraft termination conditions.

The Directive sets out a narrow set of compliance steps and conditions. Follow these steps to align with the text.

1. Confirm applicability

   • Obtain Boeing Service Bulletin SB717-31-0013 dated 25 March 2005 and check the SB’s applicability list to determine whether each specific Model 717‑200 aeroplane is covered (Applicability).

2. Plan the upgrade

   • Schedule the upgrade of the VIA digital computer and ISDAS database software for each applicable aeroplane that has not already accomplished the action. Requirement 1 must be completed within 18 months after the Directive’s effective date, which is 22 November 2007 (Requirement 1; Compliance).

3. Perform the authorised technical action

   • Upgrade the VIA digital computer system software to part number PS4081970-909 and upgrade the ISDAS database software to part number PS4081642-909, performing the work "in accordance with the Accomplishment Instructions of SB717-31-0013" (Requirement 1). Use the Boeing SB as the primary technical reference.

4. Use Honeywell material as supplementary information where helpful

   • Honeywell Alert SB 4081570-31-A6007 dated 9 March 2005 is listed as an additional source of service information for performing Requirement 1 (Note 1). Use it to the extent it supplements the Boeing Accomplishment Instructions, but do not treat it as a substitute for the Boeing SB unless the Boeing SB, or an FAA-approved AMOC, permits it.

5. Manage spares immediately

   • Do not install VIA digital computer P/N 4081570-904, -905, -906 or -907 on any aeroplane as a replacement spare as of the Directive’s effective date (Requirement 2; Compliance). Immediately identify inventories that include these part numbers and flag them so that they are not installed as replacement spares.

6. Verify acceptance of later SB revisions where relevant

   • If relying on a later revision of Boeing SB717-31-0013 instead of the dated SB provided in the Directive, confirm that the later revision has been approved by the FAA as an Alternate Method of Compliance to FAA AD 2007-19-15. Only those revisions are "considered acceptable for compliance with the equivalent Requirements of this Directive" (Requirement 2; Note 2).

7. Update AFMs and records per aircraft

   • For each aeroplane on which the upgrade or the installation of VIA P/N 4081570-909 (or subsequent) is completed, note that the action "terminates the requirements of AD/B717/15 for that aeroplane only" (Requirement 1). Update the AFM, maintenance records, and operational documentation for that aeroplane to reflect that the AFM limitation imposed by AD/B717/15 may be removed for that aeroplane. For aeroplanes not yet upgraded, retain the AFM revision required by AD/B717/15.

8. Document compliance and retention of records

   • Document the part numbers installed, software P/Ns applied, service bulletin revision used, Accomplishment Instructions followed, dates of accomplishment, and the aeroplane registration. Retain the Boeing SB and any Honeywell service documents used as references. The Directive does not list required record-keeping formats; maintain records in accordance with standard regulatory and operator record-keeping practices.

9. Coordinate with suppliers and maintenance organisations

   • Communicate the immediate spare prohibition to parts suppliers and internal logistics teams so prohibited P/Ns are not installed after the effective date. Confirm that maintenance organisations performing the upgrade are authorised and familiar with the Boeing SB Accomplishment Instructions and any FAA AMOC conditions.

10. Schedule to avoid lapse

    • Because Requirement 1 has a fixed 18-month compliance window from 22 November 2007, schedule upgrades proactively to allow for lead times, avionics shop availability and any necessary coordination with the service bulletin instructions. Track per-aircraft compliance dates so that AFM limitations are removed only after the upgrade is fully installed and documented.

11. Consider AMOC pathway where necessary

    • If there is a proposed alternative method of compliance or a later SB revision that would be preferable for technical reasons, ensure that an FAA AMOC to FAA AD 2007-19-15 covers that revision. The Directive accepts FAA-approved AMOCs as acceptable for compliance with the equivalent requirements.

12. Reconcile with AD/B717/15 cancellation timeline

    • The Directive notes that AD/B717/15 "will be cancelled in May 2009 when all affected aircraft will be in compliance with this Directive" (Background). Keep an inventory-based record of which aircraft remain subject to AD/B717/15 and plan to complete all required upgrades prior to that administrative cancellation date if relying on the cancellation.

Following these steps aligns maintenance and operations actions with the precise obligations and pathways described in the Directive text. The Directive provides part numbers, service bulletin references and deadlines; compliance requires per-aircraft tracking, parts control, and documentation of the actions taken in accordance with the referenced Accomplishment Instructions and any FAA AMOC approvals relied upon.