AD/BEECH 55/94 - Propeller Accumulator Oil Tube

The instrument rests on a small set of interlocking technical and regulatory concepts drawn from the source text. Applicability narrows the scope by model, serial-number range, and by equipment option: it applies only to Beechcraft Baron 58 and G58 aeroplanes (Raytheon/Beechcraft) with serial numbers TH-2097 through TH-2150 inclusive and only when optional propeller unfeathering accumulators are installed (Applicability). The narrow applicability confines the operational and cost consequences to a specific fleet slice.

The AD defines three discrete remedial actions. Requirement 1 is an inspection (visual and/or other procedure as specified in the Raytheon MSB) of the left propeller accumulator oil tube assembly for chafing. Requirement 2 is conditional on finding chafing during that inspection and requires replacement of the propeller accumulator oil tube assembly. Requirement 3 requires repositioning and securing with clamps the left manifold pressure hose and its metal identification tags to ensure clearance from adjacent systems. All three actions are to be performed "in accordance with" RAC MSB No. SB 61-3806 original issue (August 2006) or later FAA-approved revisions, which imports Raytheon’s procedural detail and any FAA refinements without restating them in the AD text (Requirements 1-3).

Timing (Compliance) introduces a short-window compliance schedule keyed to recent maintenance history: aircraft without the 100-hour TIS inspection or the Raytheon Safety Communiqué No. 271 inspection must be inspected within 25 hours TIS of the effective date; aircraft that have had either of those inspections must be inspected within 50 hours TIS of the effective date. The AD imposes a "before further flight" standard for replacement and for the repositioning/clamping corrective steps after the inspection or replacement (Compliance 2-3). The AD thus sets two temporal layers: an imposed short inspection window, and an immediate grounding risk for any aircraft where chafing is found (since replacement is required before further flight).

The AD cross-references external documents and authorities. It requires adherence to a Raytheon Mandatory Service Bulletin (MSB SB 61-3806) and accepts "later FAA approved revisions" of that MSB. It also explicitly references FAA AD 2007-06-07 (Amendment 39-14988) as a related instrument (Requirement note and Background). The practical effect is that the AD delegates technical procedures to an OEM MSB and links Australian regulatory action to FAA action and FAA-approved MSB revisions.

The stated safety hazard is loss of engine oil from the left engine caused by chafing of the left propeller accumulator oil tube assembly. The AD lists plausible failure modes stemming from loss of oil: fire or smoke in the engine compartment, inability to unfeather the propeller, engine damage, or loss of engine power (Background). The AD converts detection and correction of the identified chafing into mandatory maintenance tasks targeted at that left-side assembly and at ensuring clearance of the left manifold pressure hose and its identification tags.

The only persons and organisations explicitly affected by this AD are operators, owners, and maintenance providers for Raytheon (Beechcraft) Baron models 58 and G58 bearing serial numbers TH-2097 through TH-2150 inclusive, when those aeroplanes are equipped with optional propeller unfeathering accumulators (Applicability). The instrument does not apply to other models, serial numbers outside that range, or aircraft without the optional accumulators installed; those exclusions are explicit in the Applicability box.

Roles implicated by the AD’s text include the aircraft operator (who must ensure the inspection and corrective actions are performed within the stated TIS windows), maintenance personnel or organisations implementing the inspection and any replacement (who must carry out the actions "in accordance with" Raytheon MSB SB 61-3806 original issue or later FAA-approved revisions), and the regulator’s delegate (the AD is issued by CASA and signed by Charles Lenarcic as "Delegate of the Civil Aviation Safety Authority", which establishes who issued the instrument). The AD’s procedural reference to the Raytheon MSB directs maintenance providers to follow the OEM-prescribed steps and to any FAA-approved MSB revisions that may be in force.

The AD places a temporal obligation on operators: a mandatory inspection within a short hours window (25 or 50 hours TIS depending on prior inspections), and potentially immediate replacement and repositioning "before further flight" if the inspection reveals chafing or following replacement (Compliance). Thus operators who own or operate the identified aeroplanes must schedule maintenance, potentially ground aircraft until corrective action is complete, and use the Raytheon MSB as the procedural specification. The AD does not list exemptions, alternative methods of compliance, or an approval process within its text; it permits use of "later FAA approved revisions" of the referenced MSB, which provides an avenue for updated procedures but does not itself create a bespoke Australian alternative. The AD also cross-references FAA AD 2007-06-07, which may be of interest to internationally operating operators.

No other classes of persons (for example passengers, lessors, manufacturers other than Raytheon, or unrelated operators) are directly regulated by this AD as written. The AD’s actions, however, carry indirect operational effects: operators will bear the direct costs of inspections and any replacements and may experience aircraft downtime while actions are undertaken. The AD does not specify who pays; by standard demarcations in the text, the operators and their maintenance providers are the practical payers of compliance work because the AD imposes the technical tasks on the aircraft when within the applicability and compliance windows.

Key duties are narrowly specified and sourced to the three numbered Requirements and the Compliance block. Duty 1: carry out an inspection of the left propeller accumulator oil tube assembly for chafing "in accordance with the provisions of Raytheon Aircraft Company (RAC) Mandatory Service Bulletin (MSB) No. SB 61-3806 original issue dated August 2006 or later FAA approved revisions" (Requirement 1). Duty 2: if chafing is found during that inspection, replace the propeller accumulator oil tube assembly "in accordance with MSB 61-3806 original issue or later FAA approved revisions" (Requirement 2). Duty 3: reposition and secure with clamps the left manifold pressure hose and its metal identification tags to ensure clearance from adjacent systems, again in accordance with MSB 61-3806 original issue or later FAA approved revisions (Requirement 3).

Timing duties are explicit in the Compliance section: the initial inspection must occur within 25 hours TIS after the effective date for aeroplanes that have not had a 100‑hour TIS inspection or the Raytheon Safety Communiqué No. 271 inspection; and within 50 hours TIS after the effective date for aeroplanes that have had either the 100‑hour inspection or the Communiqué inspection. Replacement (if required) and repositioning/clamping are required "before further flight" after the inspection or replacement as applicable (Compliance 1-3). The AD therefore imposes both a short-term scheduling duty and, conditional on findings, a grounding-until-corrected duty.

A key procedural duty is the obligation to use the Raytheon MSB SB 61-3806 or later FAA-approved revisions for how to perform the inspection, replacement, and repositioning. The AD does not restate the MSB’s procedures; instead it compels adherence to them. That creates de facto reliance on the OEM’s procedural detail and any FAA-approved subsequent changes to that MSB.

Rights or options spelled out in the AD are limited. The AD allows reliance on "later FAA approved revisions" of the RAC MSB as the procedural standard; this permits use of updates that the FAA approves subsequent to the MSB’s original issue. The AD also cross‑references FAA AD 2007-06-07, which may provide parallel or supplementary obligations; the AD itself notes that FAA AD 2007-06-07 "refers" (note in Requirement). The AD does not provide in-text alternative methods of compliance, nor does it specify an administrative process in the AD text for seeking exemptions or approvals of alternative procedures. The AD likewise does not specify recordkeeping obligations, penalties, or appeal routes within its body.

Who decides which procedures to follow is functionally split: the AD’s issuer (a CASA delegate) prescribes the mandatory actions and timing, while the Raytheon MSB (and any FAA-approved revisions) provides the technical procedures for compliance. Maintenance providers therefore must implement the steps set out in the MSB; the regulator enforces the AD’s applicability, timing and the "before further flight" condition. The AD thus creates a duty for operators to schedule and oversee compliance, a duty for maintenance organisations to carry out the MSB steps, and a right to use updated FAA-approved MSB revisions when available.

The AD itself sets out mandatory technical actions and timing, but it does not state explicit penalties or enforcement mechanisms within the text provided. The document records that it "becomes effective on 10 May 2007" and is issued by a CASA delegate (Charles Lenarcic, 27 March 2007). The AD mandates actions "before further flight" for replacement and repositioning and fixes a short compliance window for inspections, which operationally creates the risk of grounding an aircraft that fails to meet those mandatory actions. However, the text does not include statutory penalty clauses, civil penalty amounts, criminal penalties, or the procedural steps the regulator will take to enforce non-compliance.

Enforcement in practice is implied rather than specified in the text: mandatory ADs create obligations that operators must meet; because the AD prescribes "before further flight" corrective action for defects found, failure to carry out such corrective work could render the aircraft non-compliant with the AD and therefore unairworthy. The AD’s reference to FAA AD 2007-06-07 and to FAA-approved MSB revisions indicates a cross-jurisdictional regulatory alignment but does not supply additional enforcement provisions within the instrument.

Because the AD relies on an external MSB for procedural detail (RAC MSB SB 61-3806), enforcement of correct procedure would logically examine whether inspections and replacements followed the MSB. The AD’s requirement that actions be "in accordance with" that MSB creates a standard against which compliance can be judged. The AD does not describe whether the regulator will audit records, inspect completed work, or what evidentiary standards would prove compliance. It also does not state an explicit process for documenting compliance or for obtaining relief or alternative methods of compliance. There is no text in the AD itself describing the sanctions for non‑compliance, nor any administrative enforcement steps.

Finally, the AD notes that the subject matter arose from reports of chafing that led to in‑flight oil leaks; the AD frames the corrective measures as intended "to detect, correct, and prevent any chafing damage" because such chafing "could result in loss of engine oil" and enumerates the operational hazards of oil loss (Background). The AD thereby creates an operational imperative to act promptly, but the instrument does not specify enforcement modalities or penalties in its body.

Within the text of the AD, the primary cross-references are to Raytheon Aircraft Company (RAC) Mandatory Service Bulletin No. SB 61-3806 (original issue dated August 2006) and to FAA AD 2007-06-07 (Amendment 39-14988). The AD requires that the inspection, replacement, and repositioning actions be performed "in accordance with the provisions of" that RAC MSB or "later FAA approved revisions" (Requirements 1-3). That mechanism imports the technical content of the OEM MSB and any FAA-approved updates into the AD’s compliance duties without reproducing them, effectively creating an operational link between the Australian AD and FAA-authorised procedural standards.

The AD also explicitly states in a note that "FAA Airworthiness Directive (AD) 2007-06-07 Amendment 39-14988 refers." That indicates the CASA AD is aligned with or related to the FAA’s AD on the same subject. The CASA AD therefore functions in tandem with FAA regulatory activity: it references FAA material and accepts FAA-approved MSB revisions as authoritative for procedural compliance. The text, however, contains no references to any other Australian statutory or regulatory provisions, and it does not include cross-references to civil aviation regulations, enforcement statutes, or administrative procedure rules within the body of the AD as provided.

Because the AD specifies that compliance shall be "in accordance with" an RAC MSB or later FAA-approved revisions, the AD creates a practical dependency between Australian compliance obligations and the content of the MSB and FAA approvals. Changes to the FAA-approved MSB after the AD’s issuance are explicitly accepted by the AD if they are FAA-approved. The AD thus allows the operative technical standard to be updated consistent with FAA approvals without amendment to the CASA AD text itself.

No other statutory interplay, such as exemptions under other laws, alternative compliance pathways, recordkeeping cross-obligations, or supervisory arrangements, is described in the AD as provided. The AD does not expressly create or describe appeals, approvals for alternative methods of compliance, or any interaction with contractual arrangements between operators and maintenance providers. The only cross‑instrument cross‑reference the AD makes is to the RAC MSB and the FAA AD noted above.

The AD identifies itself by a code and date (AD/BEECH 55/94, 5/2007) and states an effective date of 10 May 2007. The signature block shows it was issued by Charles Lenarcic, "Delegate of the Civil Aviation Safety Authority", with a date of 27 March 2007. The AD also includes a referential note that "FAA Airworthiness Directive (AD) 2007-06-07 Amendment 39-14988 refers" and requires compliance with Raytheon MSB SB 61-3806 "original issue dated August 2006 or later FAA approved revisions." Those references together indicate the AD’s temporal relationship to the OEM MSB (August 2006) and to an FAA AD issued in 2007.

Within the AD text there is no line-item record of subsequent amendments to the CASA AD itself, nor does the provided text show any later CASA amendments or revocations. The AD expressly permits reliance on "later FAA approved revisions" of the Raytheon MSB for procedural compliance, which allows the operative technical requirements to evolve via FAA approvals without a CASA-specific amendment for each procedural update. The presence of "original issue or later FAA approved revisions" signals that the AD’s technical standard is designed to track future FAA-approved MSB changes.

The AD’s own metadata shows the identifier AD/BEECH 55/94 and the date block "5/2007", implying issuance in the May 2007 AD cycle. The effective date is specified (10 May 2007), and the issuer and signature date are recorded (Charles Lenarcic, 27 March 2007). No further amendment history, multiple issues, superseding AD numbers, or revocation text is present in the document provided. Therefore, based solely on this source text, the AD’s amendment history comprises the original issuance and effective date and an express allowance for FAA-approved future MSB revisions to govern procedural detail.

The provided AD contains no references to any litigation, judicial review, appeals, or dispute resolution concerning the AD, its validity, its interpretation, or its enforcement. The text includes a background statement describing the safety incidents that motivated the AD, operational requirements, and cross-references to Raytheon MSB SB 61-3806 and FAA AD 2007-06-07, but it does not document any court proceedings, challenges to the AD, or legal outcomes. The signature block shows the AD was issued by a CASA delegate, which records administrative issuance rather than any adjudicative or judicial event.

Because the source text does not include any litigation-related material, no cases are named or summarised. The AD does not reference prior CASA determinations, tribunal decisions, or judicial interpretations. Accordingly, within the confines of the supplied text, there is no litigation history to report. Any judicial or administrative litigation relating to this AD, the underlying MSB, or the FAA AD is not documented in this instrument and must not be inferred from it.

Several operational and interpretive details in the AD are easily overlooked but can materially affect compliance planning.

1. Narrow applicability is essential. The AD applies only to Baron model 58 and G58 aeroplanes with serial numbers TH-2097 through TH-2150 inclusive and only when "optional propeller unfeathering accumulators" are installed (Applicability). Aircraft outside that serial-number block or without the optional accumulators are not covered by this AD. That limits the population affected but means that operators must verify serial numbers and equipment fitment carefully before treating the AD as applicable.

2. The AD requires adherence to an external OEM document. All three mandatory actions are to be performed "in accordance with the provisions of Raytheon Aircraft Company (RAC) Mandatory Service Bulletin (MSB) No. SB 61-3806 original issue dated August 2006 or later FAA approved revisions" (Requirements 1-3). The AD does not reproduce the MSB’s procedures, so compliance requires access to and reliance on the MSB text or any later FAA-approved revisions. Failure to follow the MSB steps could be judged non-compliant even if an inspector visually checked for chafing.

3. Two-tiered time window based on prior inspections. The initial inspection deadline depends on whether the aeroplane has had a 100‑hour TIS inspection or the inspection following Raytheon Safety Communiqué No. 271 dated May 2006. If not, the inspection is due within 25 hours TIS; if yes, within 50 hours TIS (Compliance 1). Operators must confirm past maintenance actions and document that confirmation to select the correct compliance window.

4. "Before further flight" is consequential. Both replacement following a finding of chafing and the repositioning/clamping of the left manifold pressure hose and metal identification tags are required "before further flight" (Compliance 2-3). The practical effect is that an aircraft with chafing discovered cannot be flown again until replacement (and repositioning/clamping) is completed. Operators should plan for potential grounding and required parts and access to the MSB for the replacement process.

5. Repositioning requirement is not conditional on chafing. Requirement 3 mandates repositioning and securing the left manifold pressure hose and its metal identification tags to ensure clearance, in accordance with the MSB. The Compliance block ties this repositioning to the inspection or replacement (Compliance 3), meaning the repositioning must be completed before further flight regardless of whether chafing was detected. That is, repositioning is an independent corrective task that must be done after inspection or replacement.

6. Reference to FAA material. The AD permits "later FAA approved revisions" of the RAC MSB and references FAA AD 2007-06-07. Operators who are internationally mobile or who coordinate with US-based maintenance shops should ensure they are using the latest FAA-approved revision adopted under the AD’s allowance. The AD does not itself list which later revisions qualify, so operators must confirm that a given MSB revision has FAA approval.

7. No explicit penalty language or administrative relief in the AD. The AD does not state consequences, recordkeeping requirements, or alternative compliance procedures within its text. That absence means operational implementers must not assume the AD is aspirational; rather it creates mandatory duties with a "before further flight" trigger, even though the AD does not specify enforcement modalities or administrative appeal processes in the document itself.

8. Timing of the AD’s effective date and signature block. The AD lists an effective date of 10 May 2007 while the delegate’s signature is dated 27 March 2007, which requires operators to observe the stated effective date when computing compliance windows (Compliance 1). Operators must count TIS hours from the AD’s effective date, not the signature date.

Operators and maintenance providers should therefore verify serial numbers and equipment fitment, obtain and follow the RAC MSB (or FAA-approved revisions), confirm which compliance time window applies, plan for potential grounding and parts/work, and ensure the repositioning/clamping step is completed before returning the aircraft to service.

The AD prescribes a short, concrete compliance pathway that references Raytheon MSB SB 61-3806 for procedural detail. The following steps, grounded in the AD text, set out the minimum actions required:

1. Confirm applicability. Verify the aircraft is a Raytheon (Beechcraft) Baron model 58 or G58 and that its serial number is within TH-2097 through TH-2150 inclusive. Also confirm that the aeroplane has the optional propeller unfeathering accumulators installed. The AD applies only when all three of these conditions are met (Applicability).

2. Determine applicable inspection window. Check whether the aircraft has had a 100‑hour TIS inspection or the inspection following Raytheon Safety Communiqué No. 271 (May 2006). If it has not had either, the initial inspection required by Requirement 1 must be completed within the next 25 hours TIS after the AD’s effective date (10 May 2007). If it has had either of those inspections, the initial inspection must be completed within the next 50 hours TIS after the effective date (Compliance 1).

3. Obtain the technical procedure. Acquire Raytheon Aircraft Company Mandatory Service Bulletin No. SB 61-3806 original issue dated August 2006. Alternatively, if there are later FAA-approved revisions of that SB, obtain the FAA-approved revision that applies. The AD requires that the inspection, any replacement, and the repositioning/clamping be carried out "in accordance with" the MSB or later FAA-approved revisions (Requirements 1-3).

4. Perform the inspection per the MSB. Inspect the left propeller accumulator oil tube assembly for chafing using the procedures in SB 61-3806 (Requirement 1). Record the inspection findings per the maintenance organisation’s usual standards; while the AD itself does not specify recordkeeping, documentation will be required for operational and regulatory audit purposes.

5. Respond to findings. If the inspection reveals any chafing, replace the left propeller accumulator oil tube assembly "in accordance with MSB 61-3806 original issue or later FAA approved revisions" (Requirement 2). The AD requires that replacement be completed "before further flight" after the inspection (Compliance 2), so do not return the aircraft to service until the replacement is effected.

6. Reposition and secure manifold pressure hose and tags. Regardless of whether chafing was found, reposition and secure with clamps the left manifold pressure hose and its metal identification tags to ensure clearance between it and all tubes, hoses, electrical wires, parts, components, and structure, following SB 61-3806 (Requirement 3). The AD requires this repositioning and securing "before further flight" after the inspection or replacement (Compliance 3).

7. Use FAA-approved MSB revisions if applicable. If a later FAA-approved revision of SB 61-3806 is available, that revision may be used for the inspection, replacement, and repositioning steps because the AD expressly permits reliance on "later FAA approved revisions" of the MSB (Requirements 1-3). Confirm that the revision used carries FAA approval.

8. Plan for grounding and parts. Because replacement is required "before further flight" when chafing is found, plan maintenance scheduling, spare parts procurement, and any necessary aircraft downtime accordingly. The AD does not provide parts lists or lead times; these will come from the MSB and from Raytheon supply chains.

9. Confirm compliance date calculations. Calculate the TIS hours from the AD’s stated effective date (10 May 2007) and apply the correct 25‑hour or 50‑hour inspection window as determined in step 2. Do not count from the signature date in the AD but from its effective date when computing TIS deadlines (Compliance 1).

10. Cross-reference the FAA AD where necessary. The AD notes that FAA AD 2007-06-07 (Amendment 39-14988) refers. Operators working across jurisdictions or using FAA guidance should review the FAA AD and any FAA-accepted MSB revisions for any procedural differences or clarifications that have FAA approval and are accepted under the CASA AD.

The AD’s text does not specify any alternative method of compliance, formal administrative approvals for relief, or recordkeeping format. Compliance therefore requires strict adherence to the MSB procedures and timely completion of the inspection and any mandated corrective steps within the prescribed TIS windows, with replacement and repositioning completed before further flight if required.