AD/T53/22 - Engine Fuel Pump Spline Failure

The instrument uses a small set of operationally significant concepts to achieve its objective. First, it defines Applicability narrowly by engine and regulator assembly models: AlliedSignal/Textron Lycoming T5311A/B, T5313B, T5317A/A‑1, T5317B, and former military Lycoming T53-L-11B/11D/13B/13B/D/703 series engines when fitted with Goodrich TA‑series regulator assemblies TA‑2S, TA‑2G, TA‑2F, TA‑7 or TA‑10 (Applicability). The AD emphasises that the list of aircraft installations is illustrative only: the engines are installed on, but not limited to, particular helicopter types (Applicability). That language preserves the AD’s reach beyond the examples.

Second, the AD prescribes action rather than modification: operators must remove the fuel control regulator assembly and perform visual and dimensional inspections of the main and secondary drive shaft and pump gear splines for wear (Requirement). The inspection work is to follow detailed steps set out in the Goodrich Service Bulletin, specifically paragraphs 2.A through 2.D(7) and 2.E through 2.F(2) (Requirement). The AD therefore delegates technical detail to the manufacturer’s SB while making the SB’s procedures mandatory.

Third, the AD sets a two‑tiered inspection cadence. There is an initial compliance window, "within 150 flight hours after the effective date of this AD, unless previously accomplished", and a repetitive interval, "every 1,250 flight hours since-last-inspection" (Compliance). The AD thus combines an immediate risk‑mitigation check with a recurring surveillance regime.

Fourth, the AD creates a negative obligation on installation: "Do not install any engine fuel control regulator assembly that fails inspection" (Requirement). That converts a maintenance finding into a categorical supply or installation prohibition.

Finally, the AD references external regulatory and technical instruments. It requires adherence to Goodrich SB No. 73‑42 Revision 1 dated 12 August 2004, or a later FAA‑approved revision (Requirement). It also notes FAA AD 2006‑11‑16 (Note 2). Those cross references mean compliance requires operators to consult and follow documents not fully reproduced in the AD.

Together these concepts define the AD’s mechanics: targeted applicability to particular engine/regulator combinations, removal plus visual and dimensional inspection following a manufacturer SB, a defined initial and recurring timetable, a prohibition on installing failed units, and reliance on an external FAA/Goodrich documentation framework.

The AD explicitly affects operators and maintainers of the listed AlliedSignal (Lycoming) and Lycoming T53-series turboshaft engines when those engines are using Goodrich TA-series fuel control regulator assemblies (Applicability). The listed engine models and regulator assembly models name the components and therefore identify the relevant asset owners. The AD also notes typical helicopter installations, naming Bell 204, Bell 205, Kaman K‑1200, Bell AH‑1 and UH‑1 as platforms where those engines are installed, but it expressly states those aircraft types are not exhaustive (Applicability). That language makes the AD applicable to any operator worldwide who has a covered engine/regulator combination installed in any aircraft operated under CASA jurisdiction.

The party who must decide to carry out the mandated action is the operator or the maintenance organisation responsible for the engine and its fuel control regulator assembly. The AD requires removal of the fuel control regulator assembly and inspections "in accordance with paragraphs 2.A. through 2.D.(7) and 2.E through 2.F.(2) of the Accomplishment Instructions of Goodrich Pump & Engine Control Systems, Inc. (TA series) Service Bulletin (SB) No. 73‑42, Revision 1, dated 12 August 2004 or later FAA approved revision." That makes the maintenance provider the immediate decision‑maker about work scope, parts, shop time and scheduling (Requirement).

Who pays is not stated in the AD text, but the directive imposes obligations that logically fall to the aircraft operator as the owner and certificated operator of the aircraft and engines. Those costs will include labour to remove and inspect the regulator assembly, possible replacement parts if assemblies fail inspection, and aircraft downtime for inspection and any follow‑on repairs. The AD does not provide for financial assistance, nor does it offer price or parts subsidies; therefore the economic burden of compliance attaches to operators and maintenance organisations.

Supply‑chain actors are also affected. Goodrich Pump & Engine Control Systems, Inc. is named as the author of the SB whose instructions become mandatory. The AD therefore creates demand for Goodrich service documentation, any replacement assemblies or spline components, and for maintenance labour skilled in performing the SB procedures. The AD’s non‑installation prohibition for failed units also affects parts disposition, spare stock policies and procurement.

Regulatory actors are named implicitly: CASA is the issuing authority, with the delegate signing the AD (signature and date). The AD also cross‑references FAA AD 2006‑11‑16, indicating interaction with FAA regulatory activity that may affect operators who must comply with multiple jurisdictional directives (Requirement; Note 2).

The central duties the AD imposes are threefold and explicit. First, remove the fuel control regulator assembly from the engine and perform an initial visual and dimensional inspection of the main and secondary drive shaft and pump gear splines for wear, following specific paragraphs of Goodrich SB No. 73‑42 (Requirement: 1). Second, perform repetitive visual and dimensional inspections as specified,i.e. the inspections required in the first duty must be repeated at the intervals set out in the Compliance section (Requirement: 2; Compliance). Third, do not install any engine fuel control regulator assembly that fails inspection (Requirement: 3).

The AD exercises prescriptive delegation of inspection detail to the manufacturer SB. The SB paragraphs referenced are 2.A through 2.D(7) and 2.E through 2.F(2) of the SB’s Accomplishment Instructions. That delegation creates a duty to consult and to follow the SB text exactly, including any measurement limits, tooling and acceptance criteria contained in those paragraphs. The AD also specifies that the SB must be either Revision 1 dated 12 August 2004, or a later FAA‑approved revision, which enforces a duty to use an approved SB version (Requirement).

Timing duties are explicit. The initial inspection must be completed "within 150 flight hours after the effective date of this AD, unless previously accomplished" (Compliance). Repetitive inspections are required "every 1,250 flight hours since-last-inspection" (Compliance). The effect of these timing rules is to require operators to track flight hours since the last inspection and to schedule work within the mandated windows.

The AD grants no rights to continue using or installing suspect assemblies. The "do not install" clause is absolute and functions as a categorical prohibition against returning a failed unit to service (Requirement). The AD does not specify remedial actions post‑failure beyond the non‑installation rule, for example replacement options or reporting obligations. Rights to appeal or seek alternative methods of compliance are not stated in the AD text provided.

The AD does not specify exemptions, waivers or alternative compliance routes in the text supplied. It also does not specify whether maintenance carried out prior to the AD’s effective date but within some period satisfies initial compliance; it only notes "unless previously accomplished" for the initial inspection window (Compliance). That phrasing creates limited recognition of pre‑existing work but leaves unsettled whether pre‑AD inspections meet the exact SB paragraph requirements.

Finally, the AD delegates technical discretion to the Goodrich SB and to any later FAA‑approved revision. That means conforming to the AD may require checking for later FAA approvals of the SB and following those approved procedures. The AD therefore imposes duties to (a) carry out removal and specified inspections, (b) adhere to the SB paragraphs cited or later FAA‑approved revisions, (c) observe the initial and repetitive timing, and (d) avoid installing failed assemblies.

The AD document supplied does not specify particular penalties or enforcement mechanisms within its text. It is titled and presented as an Airworthiness Directive, it is signed by a CASA delegate and an effective date is given (3 August 2006), but the AD does not list fines, criminal sanctions or administrative penalties in the excerpt provided (Effective date; signature). The AD does not set out inspection oversight, reporting obligations, or audit protocols in the text reproduced here.

Because the AD references and makes mandatory procedures from Goodrich SB No. 73‑42 (Requirement), enforcement will, in practice, require verification that the specified inspections and prohibitions have been carried out within the times stated. The AD itself defines mandatory actions and timing, which ordinarily are enforceable under the issuing authority’s regulatory regime. The AD text, however, does not include the specific enforcement provisions, penalty amounts or enforcement processes. Therefore, in the absence of additional statutory text or accompanying regulatory guidance reproduced here, the AD communicates what must be done but does not, within the provided text, detail the particular enforcement instruments or sanctions for non‑compliance.

The AD does incorporate references to external documents. It points operators to an FAA AD and to a Goodrich SB, which may include reporting obligations or further compliance requirements that are not reproduced in the AD text. If those external documents contain reporting or certification steps, those obligations would effectively extend the scope of enforceable duties once incorporated by reference, but the AD excerpt itself does not reproduce those clauses. Users must therefore consult the Goodrich SB and the referenced FAA AD to determine whether those texts add enforced reporting or certification steps.

In short, the AD sets binding technical obligations with specified time windows and a categorical installation prohibition for failed units. The supplied text does not state the mechanisms CASA will use to enforce compliance nor the specific penalties for contravention. Practitioners or compliance officers should therefore consult CASA guidance, the full AD record, and the referenced FAA AD and Goodrich SB to locate the enforcement and reporting provisions that operate in practice.

The AD explicitly cross‑references FAA regulatory material and a manufacturer service bulletin, creating interfaces with both foreign regulator outputs and with private technical standards. The AD refers to Goodrich Pump & Engine Control Systems, Inc. Service Bulletin No. 73‑42, Revision 1, dated 12 August 2004, or later FAA‑approved revisions (Requirement). It also notes FAA AD 2006‑11‑16 Amdt 39‑14620 dated 23 May 2006 (Note 2). By incorporating the SB and recognising FAA AD material, the AD creates a textual bridge between CASA’s regulatory instrument and both manufacturer documentation and FAA regulatory action.

Because the AD makes the SB mandatory "in accordance with paragraphs 2.A. through 2.D.(7) and 2.E. through 2.F.(2) of the Accomplishment Instructions of Goodrich ... Service Bulletin No. 73‑42" (Requirement), compliance requires operators and maintainers to implement procedures contained in a private sector technical document. That constitutes incorporation by reference: the AD does not reproduce the SB paragraphs but makes them mandatory. Any legal questions about conformity, measurement limits, or acceptance criteria will therefore depend on the SB text as much as the AD.

The citation of FAA AD 2006‑11‑16 indicates coordination or parallel action with a foreign authority. The AD includes Note 2: "FAA AD 2006‑11‑16 Amdt 39‑14620 dated 23 May 2006 refers." The operator subject to CASA jurisdiction may therefore be required to comply with CASA’s AD and may also need to consider FAA requirements, particularly for operators or maintenance organisations that operate across jurisdictions, import parts, or maintain records used by FAA oversight. The AD does not elaborate on how conflicts between CASA and FAA requirements would be reconciled; only the cross‑references are given.

The AD’s non‑installation prohibition (“Do not install any engine fuel control regulator assembly that fails inspection”) interacts with procurement, spares management and parts certification rules. Operators who must discard or quarantine failed assemblies may need to follow disposal, traceability and parts‑sourcing rules established elsewhere in aviation safety regulation and industry practice. Those procedural and recordkeeping interactions are not reproduced in this AD text.

The AD does not refer to international conventions or other Australian statutes, nor does it include transitional or saving clauses relating to other legal obligations. It operates as a standalone directive that imports technical detail by reference to a manufacturer SB and mentions a related FAA AD. Practitioners should therefore treat the AD as part of a web of regulatory and technical instruments: the CASA AD sets the mandatory action, the Goodrich SB supplies the technical steps, and the FAA AD is a parallel or related regulatory action. Any legal or operational conflicts or overlaps will need to be resolved by consulting the full texts of those referenced instruments and by reference to CASA administrative practice and aviation law.

The AD document itself contains a small but concrete amendment history and cross‑reference trail. It cites Goodrich Pump & Engine Control Systems, Inc. Service Bulletin No. 73‑42, Revision 1, dated 12 August 2004, or “later FAA approved revision” as the procedural source for the inspections (Requirement). That indicates the AD incorporates a specific version of the SB as the minimum acceptable baseline and leaves open later FAA‑approved revisions as acceptable alternatives. The AD therefore anticipates that the manufacturer or FAA might update inspection instructions and that such later FAA approvals will be acceptable for compliance.

The AD also references FAA AD 2006‑11‑16 Amendment 39‑14620 dated 23 May 2006 (Note 2). That FAA AD’s date is earlier than the AD’s effective date of 3 August 2006, indicating that CASA’s action is contemporaneous with or follows the FAA action. The AD does not include an internal amendment log beyond those state dates, nor does it include successive CASA amendments or revocations within the supplied text.

The titular metadata in the top table shows the AD identifier AD/T53/22, subject "Engine Fuel Pump Spline Failure", and a date code "8/2006". The signature block shows James Coyne signed on 21 June 2006 and the AD becomes effective on 3 August 2006 (header, signature and effective date). Those dates record issuance and commencement. The AD also contains a pair of duplicated headings and metadata lines at the end (multiple instances of "AD/T53/22" and "Engine Fuel Pump Spline Failure" and "8/2006") that appear to be formatting repeats rather than substantive amendments.

No further amendments, extended compliance windows, or revised inspection intervals are recorded in the provided text. If operators require an amendment to the AD or relief by alternative methods of compliance, the AD as provided does not state the process; practitioners must look to CASA rulemaking and administrative processes outside this document to pursue amendments or alternative compliance determinations.

The provided AD text contains no litigation history. It does not name any cases, appeals, or judicial or administrative reviews relating to this AD. There is no record of challenges, stays, or injunctions in the excerpt supplied. The AD notes and references (Goodrich SB and FAA AD) are technical and regulatory, not judicial (Note 2; Requirement).

Because the AD makes mandatory actions contingent on a manufacturer SB and references a related FAA AD, potential disputes would likely arise in contexts not documented here: for example, disputes over whether an operator complied with the SB paragraphs as incorporated, whether pre‑existing inspections "previously accomplished" meet the AD’s requirements, or whether a failed assembly was correctly judged. None of those disputes are present in the document as supplied.

Practitioners seeking precedential or litigated interpretations should therefore note that no litigation material is included in the AD text. Any authoritative legal interpretation would require consulting CASA administrative decisions, judicial records, or appeal processes beyond this AD excerpt.

There are several practical and legal pitfalls in this AD that arise from its structure and the way it incorporates external materials. First, the AD does not reproduce the inspection criteria in the body of the directive. Instead, it requires operators to perform inspections "in accordance with paragraphs 2.A. through 2.D.(7) and 2.E. through 2.F.(2) of the Accomplishment Instructions" of Goodrich SB No. 73‑42 Revision 1, dated 12 August 2004, or later FAA‑approved revision (Requirement). The gotcha is that compliance requires precise reference to those SB paragraphs; an incomplete reading of the SB or use of the wrong SB revision may leave an operator non‑compliant even if a thorough inspection was otherwise performed.

Second, the AD specifies an initial compliance interval "within 150 flight hours after the effective date of this AD, unless previously accomplished." That creates an evidence problem: operators who claim work was "previously accomplished" must be able to show records demonstrating that the prior inspections matched the exact SB paragraphs and criteria now mandated. Without matching records it will be difficult to rely on the "unless previously accomplished" clause.

Third, the AD mandates both visual and dimensional inspections of main and secondary drive shaft and pump gear splines for wear (Requirement). Dimensional inspections require calibrated measurement tools, technical skill, and possibly removal to a workshop environment. Operators must ensure maintenance personnel are competent to carry out the specific dimensional checks prescribed in the SB. Assuming a casual visual only inspection will likely be non‑compliant.

Fourth, the non‑installation prohibition is categorical: "Do not install any engine fuel control regulator assembly that fails inspection" (Requirement). That means that a failed assembly cannot be returned to service under any circumstances under this AD. The AD does not state permissible corrective actions for a failed assembly within its own text. Operators must therefore plan for replacement parts and immediate spare availability, otherwise aircraft may be grounded awaiting compliant parts.

Fifth, the AD references FAA AD 2006‑11‑16 (Note 2) and allows "later FAA approved revision" of the Goodrich SB. Operators must therefore track FAA approvals; a later FAA‑approved revision may change inspection limits or methods and will be acceptable under the CASA AD, but only if FAA approval exists. Failure to confirm approval status of a revised SB could result in using a revision that is not FAA‑approved and hence not accepted under the AD.

Sixth, the applicability language lists engines and regulator models, but then states those engines are installed on, "but not limited to", several helicopter types (Applicability). The gotcha here is that operators should not rely on the listed aircraft types as a safe screen; other installations of the listed engines are captured.

Seventh, the AD does not reproduce enforcement or penalty language. That is a procedural gap: operators should not assume leniency; rather they should consult CASA enforcement policy and any guidance accompanying the AD to understand reporting, recordkeeping and consequences, because those elements are absent from the AD itself.

Finally, the AD’s reliance on a manufacturer SB introduces a dependency on the manufacturer’s supply of replacement parts, recommended tooling and instructions. Shortages in parts or delays in SB publication or FAA approval of SB revisions could affect an operator’s ability to comply within the specified windows.

Compliance requires a sequence of concrete steps that track the AD’s text. Operators and maintenance organisations should take the following actions, matching the AD’s requirements.

1. Confirm applicability. Identify whether the installed engine/regulator combination is within the AD’s applicability: AlliedSignal/Textron Lycoming T5311A, T5311B, T5313B, T5317A, T5317A‑1, T5317B, or Lycoming T53‑L‑11B/11D/13B/13B/D/703 series engines using Goodrich TA‑series regulator assemblies TA‑2S, TA‑2G, TA‑2F, TA‑7 or TA‑10 (Applicability). Do not rely solely on aircraft type listings; the AD states those are not exhaustive.

2. Obtain the referenced SB and FAA approvals. Acquire Goodrich Pump & Engine Control Systems, Inc. Service Bulletin No. 73‑42, Revision 1 dated 12 August 2004, and check for any later FAA‑approved revisions. The AD makes inspection procedures mandatory only if they correspond to the specified SB paragraphs and to “later FAA approved revision” where applicable (Requirement).

3. Schedule the initial inspection within the AD window. The AD requires the initial removal and inspection "within 150 flight hours after the effective date of this AD, unless previously accomplished" (Compliance). If prior work has been done, retain and verify records that demonstrate the previous inspection matched the SB paragraphs cited.

4. Remove the fuel control regulator assembly. The AD mandates removal of the assembly from the engine to perform the inspection (Requirement). Plan for hangar or shop time, task cards, and qualified personnel.

5. Perform visual and dimensional inspections as prescribed. Follow paragraphs 2.A through 2.D(7) and 2.E through 2.F(2) of the SB’s Accomplishment Instructions. That includes both visual checks and dimensional measurements of the main and secondary drive shaft and pump gear splines for wear (Requirement). Use calibrated measuring instruments, document readings and acceptance criteria.

6. Decide on disposition of the unit. If the assembly passes the inspection, log the inspection and return the unit to service. If it fails, do not install it; the AD is categorical on non‑installation (Requirement). Establish quarantine, removal from inventory and replacement sourcing procedures for failed units.

7. Implement recurring inspection tracking. Record flight hours meticulously and schedule repetitive inspections every 1,250 flight hours since the last inspection (Compliance). Ensure maintenance records show the date, flight hours, SB revision used, inspector identity and inspection results.

8. Coordinate parts and spares. Because the AD forbids installation of failed assemblies, operators should maintain a procurement plan for replacement regulator assemblies and any spline components identified in the SB. Confirm lead times with suppliers so inspections do not cause undue aircraft downtime.

9. Maintain records and traceability. Document all removals, inspections, measurements, pass/fail determinations, and actions taken. While the AD excerpt does not specify reporting for CASA, good practice is to preserve inspection records in the aircraft’s maintenance records and to be prepared to show compliance if requested by the regulator or during audits.

10. Monitor for SB revisions and related ADs. The AD allows later FAA‑approved revisions of the Goodrich SB; maintain a compliance process that checks for new FAA approvals or related ADs such as FAA AD 2006‑11‑16 to ensure inspection criteria remain current (Requirement; Note 2).

11. Consult CASA for uncertainties. If there is doubt about whether a prior inspection satisfies the AD, whether a replacement action is acceptable, or whether an alternative method of compliance is appropriate, seek CASA guidance. The AD text supplied does not specify alternative method procedures or enforcement mechanics.

By following the steps above operators will satisfy the AD’s expressed requirements: removal and inspection of the fuel control regulator assembly in accordance with the specified SB paragraphs, initial compliance within 150 flight hours unless previously done, repetitive inspections every 1,250 flight hours thereafter, and prohibition on installing failed assemblies (Requirement; Compliance).