AD/CESSNA 337/30 - Pitot Tube Installation

The AD contains a small set of core legal and technical concepts. Each concept appears in the Directive text and establishes the scope, remedy, timeframe, accepted evidence of compliance, and provenance of the modification authority.

• Applicability by modification and serial number. The AD does not apply to all Cessna 337s. It applies only to Model 337 series aircraft modified under FAA STC SA1627WE and then only to the serial numbers listed. The AD’s opening line under "Applicability" identifies both the STC and the serial-number list. That makes applicability a conjunctive test: require both the modification per the STC and membership of the serial-number set.

• Prescribed corrective action. Under "Requirement" the AD specifies the technical fix: installation of Robertson Kit No. 14-118-100 using Robertson modification instructions No. 14-118-10 dated 23 January 1975. The AD therefore prescribes both a parts kit and a specific set of instructions as the method of compliance.

• Acceptable prior compliance. Note 2 provides that prior accomplishment of FAA AD 75-09-05 is acceptable evidence of compliance for these aircraft, if maintenance records show this, including work done before arrival in Australia. Note 3 explicitly refers readers to FAA AD 75-09-05 Amdt 39-2177. This concept links the Australian AD to the FAA action as a source of acceptable prior remediation.

• Compliance timeframe. The AD establishes a single timeframe: compliance is required within 100 hours time in service after the AD’s effective date, which is stated as 5 June 2008.

• Origin and procedural background. The AD includes a short background which states CASA’s internal review triggered issuance, explains why an Australian AD had not previously been issued (no aircraft in serial range in Australia at that time), and records CASA’s formal obligation to publish State of design ADs which may affect Australian aircraft. The background also explains the FAA AD’s original safety rationale: to prevent the possibility of unreliable airspeed indications due to ice formation in the pitot system.

• Administrative signatory and date. The AD was issued by a CASA delegate, James Coyne, on 21 April 2008. The effective date for compliance is 5 June 2008.

These main concepts define a narrow regulatory intervention that converts an FAA safety prescription into a domestic AD for a precisely enumerated set of aircraft and permits prior foreign compliance evidence to discharge the obligation.

The AD affects a tightly defined population of actors. The primary affected parties identified in the Directive are:

• Owners and operators of Model Cessna 337 series aeroplanes that have been modified in accordance with FAA STC SA1627WE and whose airframes appear in the serial-number list in the AD. The AD lists a sequence of serial numbers; only those aircraft are in scope. The AD states only one of the affected aeroplanes was on the Australian register at the time of issuance, which indicates the domestic population affected was minimal as at this document.

• Maintenance organisations and engineers who perform modification work on the listed aeroplanes. The AD requires installation of Robertson Kit No. 14-118-100 in accordance with Robertson modification instructions No. 14-118-10 dated 23 January 1975. That requires a person or organisation with the capability to perform that kit installation under appropriate aviation maintenance approvals.

• Record-keeping entities. Because Note 2 accepts prior compliance recorded as adherence to FAA AD 75-09-05, the AD affects whoever controls, creates, or authenticates maintenance records for the relevant aircraft. Those records are the documentary evidence that can discharge the AD without further physical work in Australia.

• The STC holder. Note 1 identifies that STC SA1627WE was originally held by Robertson Aircraft Corporation and is now held by Sierra Industries Ltd. The STC holder is a relevant point of contact for modification instructions and kit supply, and is acknowledged in the AD as the rights-holder for the modification approval.

• CASA as regulator. The AD is an instrument issued by a CASA delegate, so CASA is the issuer and custodian of the requirement and, implicitly, the body that will record compliance on the Australian register where appropriate.

Who does not appear to be affected. The AD does not apply to Cessna 337s that lack STC SA1627WE modification, nor to other types of aircraft. The AD also does not identify any broader class of manufacturers, parts suppliers, or aftermarket companies beyond the STC holder and Robertson kit reference.

Distribution of burden. The AD suggests concentrated burdens: a small number of aircraft and their owners are the ones who will bear the direct compliance cost, while CASA bears administrative burden to publish the State-of-design AD despite few domestic aircraft being affected. The background recognises that only one affected aeroplane was on the Australian register at the time, which narrows the domestic impact.

The Directive sets a single express duty and a set of linked evidentiary rights relating to acceptance of prior compliance.

Express duty

• Rework the extended pitot tube by installation of Robertson Kit No. 14-118-100 in accordance with Robertson modification instructions No. 14-118-10 dated 23 January 1975, if not previously accomplished. This is the operative command under the "Requirement" heading. The duty is defined by the parts kit and the instruction document referenced; there is no alternative method of compliance specified in the text.

Timebound duty

• This duty must be completed within 100 hours time in service after the effective date of the Directive. The AD’s "Compliance" paragraph fixes both the deadline and the temporal metric (aircraft time in service).

Evidentiary right to rely on prior work

• Note 2 grants an evidentiary right: if the rework was already accomplished before the aircraft arrived in Australia and the maintenance records indicate compliance with FAA AD 75-09-05, this is considered acceptable for compliance with the Australian Directive. That creates a documentary path to discharge the duty rather than a mandatory physical rework in Australia.

Cross-reference to foreign requirement

• Note 3 explicitly refers to FAA AD 75-09-05 Amdt 39-2177 as the relevant FAA action. The AD therefore recognises the FAA action as a source of acceptable prior compliance evidence.

Specification of STC holder

• Note 1 identifies the STC and the holder history: the STC SA1627WE was originally held by Robertson Aircraft Corporation and the STC is now held by Sierra Industries Ltd. While not phrased as a duty, this identifies the party that holds the modification approval and therefore is the appropriate source for kit supply and technical documentation.

Administrative rights and record-keeping

• The Directive gives no explicit list of rights of appeal, exemption, or alternative compliance routes. It does not indicate a process to apply to CASA for alternative means of compliance (AMOC) or for an extension. The text simply records the mandatory requirement, acceptable prior compliance evidence, and the compliance window.

Implications of the duty structure

• The duty is prescriptive and specific to kit and instructions: compliance requires adoption of the named parts and procedures unless prior FAA-compliant work is evidenced. The AD does not describe who must carry out the installation, the certification standard for the work, or the process for CASA to accept and record compliance. The only administrative trace in the text is the statement that the AD becomes effective on 5 June 2008 and the signing by the CASA delegate.

The AD text does not state penalties, enforcement mechanisms, or administrative sanctions. The instrument sets an obligation and a compliance timeframe but contains no express penalty clause, no enforcement procedure, and no description of surveillance, inspection, or consequences for non-compliance in the text provided.

What the Directive does provide that interacts with enforcement

• A clear mandatory requirement and a specific compliance deadline. The presence of a specific time-in-service window for compliance (100 hours after effective date) creates a measurable standard for compliance or non-compliance. That standard is the sort of fact an inspector or regulator could use to determine whether the AD has been complied with.

• Recognition of prior compliance through maintenance records. Note 2 creates an accepted method of establishing compliance without further physical work, by relying on existing maintenance documentation showing FAA AD 75-09-05 compliance. This affects enforcement practice by defining acceptable documentary evidence.

What the Directive does not provide

• The AD omits any mention of civil penalties, criminal offences, enforcement notices, grounding powers, or directions to operators to cease flight. The text contains no instructions on how CASA will verify or record compliance, nor any appeals mechanism or alternative means of compliance. The AD also does not set out whether documentation must be lodged with CASA to evidence compliance.

Implications

• Because the AD itself contains no enforcement provisions, any enforcement or sanctioning would have to rely on CASA’s general regulatory powers and processes external to the text. The Directive, however, constrains what constitutes compliance by specifying the required modification and the acceptability of prior FAA AD compliance documented in maintenance records. In practice, the Directive thereby defines the compliance criteria that enforcement agents would apply, even though the instrument does not itself define sanctioning measures.

Note on source limitations

• All observations in this section are limited to the content of the Directive text. The AD’s silence on penalties and enforcement is a textual fact; the document does not authorise or describe how CASA will enforce compliance or what penalties, if any, will follow non-compliance.

The Directive explicitly cross-references and incorporates by reference actions taken by the FAA and a FAA Supplemental Type Certificate framework. The text establishes interaction with foreign-certification material and domestic administrative obligations.

Interaction with FAA AD 75-09-05

• The AD explicitly references FAA AD 75-09-05 in Notes 2 and 3. Note 3 says "FAA AD 75-09-05 Amdt 39-2177 refers." Note 2 states that compliance with FAA AD 75-09-05, documented in maintenance records and undertaken before arrival in Australia, is acceptable for compliance with this Directive. That creates a direct evidentiary bridge between the foreign AD and this Australian AD. In operational terms, maintenance work done to satisfy FAA AD 75-09-05 can discharge the Australian AD where records show that work.

Interaction with FAA STC SA1627WE

• The AD applies only to aircraft modified in accordance with FAA STC SA1627WE. The AD identifies the STC by number and explicitly names the STC holder history in Note 1, noting original ownership by Robertson Aircraft Corporation and current holding by Sierra Industries Ltd. That situates the required modification inside the STC framework and associates parts and instructions (Robertson Kit No. 14-118-100 and instructions No. 14-118-10) with the STC.

State-of-design obligations and domestic regulatory practice

• The background states CASA is required to publish State-of-design ADs which may affect Australian aircraft. That indicates the Directive is part of CASA’s obligation to transpose or publish ADs that originate with a State of design, here the United States (FAA). The AD thus functions as a domestic manifestation of State-of-design safety action, though the Directive’s text does not reproduce FAA rulemaking as law but rather imposes a domestic requirement consistent with the foreign AD.

Record-keeping and acceptance across jurisdictions

• Note 2 creates an acceptance mechanism for foreign compliance performed prior to arrival in Australia. That recognises cross-border maintenance records as valid evidence for compliance with domestic ADs, where those records show compliance with the referenced FAA AD.

What the Directive does not specify

• The AD does not reference any Australian primary legislation, CASA enforcement provisions, or civil aviation regulations that would govern enforcement or recording of the AD on the Australian register. The Directive provides the requirement but does not identify the legal instrument or process by which CASA will record compliance or what statutory power underpins the AD.

Implication for operators and maintenance providers

• Operators who have complied with FAA AD 75-09-05 prior to entry into Australia have a document-based route to compliance without repeating work. The AD therefore reduces duplication where the FAA AD has already been followed and documented. Conversely, operators of affected aircraft who do not have maintenance records evidencing FAA AD compliance must perform the discrete modification as specified.

The Directive text as provided does not record any amendments to the AD itself. The document contains:

• A single effective date for this AD: "This Airworthiness Directive becomes effective on 5 June 2008."

• The date of signature, 21 April 2008, and the name of the signing delegate, James Coyne.

• Notes that refer to FAA documents and identify the STC holder history (Note 1), but no later amendments, revisions, supersessions, or cancellations of the AD are recorded in the text provided.

Interpretive implications of the absence of an amendment record

• The AD reads as a standalone instrument issued on the dates above. Because no subsequent amendments or revisions are shown in the material provided, a reader must treat the text as the operative content of AD/CESSNA 337/30 as at the effective date. The lack of internal amendment entries means the reader cannot identify from this document whether CASA later changed the applicability, compliance timeframe, or the required method of compliance.

• The AD’s references to FAA AD 75-09-05 and to the STC holder history are static references within the body text. There is no indication in the AD itself that subsequent FAA action, changes to the STC holder, or later CASA practice will automatically alter compliance obligations under this AD.

Practical consequence

• For an operator or maintenance provider seeking to determine current obligations, the absence of amendment history in this text is a signal to consult current CASA records or registers for any superseding ADs or updates. The AD itself does not provide a mechanism for discovering amendments; the document as supplied simply does not contain amendments.

Limitations on statements here

• All statements in this section are grounded in the Directive text. The Directive itself contains no amendment history, and the paragraph above explains the practical implications of that silence. The AD does not say whether CASA has a separate public register of amendments or how to check for supersession.

The AD contains no litigation history, judicial references, or mention of legal proceedings. The document does not cite any cases, decisions, or disputes relating to the AD or to the underlying FAA action. The only foreign instrument referenced is FAA AD 75-09-05 Amdt 39-2177, and no litigation concerning that instrument is mentioned in the text.

Implications of absence of litigation record

• There are no court decisions or tribunal determinations referenced that interpret or test the AD’s terms in the text supplied. Therefore, the Directive’s interpretation and practical enforceability as expressed here do not have adjudicated clarification contained in the instrument.

• The AD’s silence on litigation also means there are no precedential holdings recorded in this document concerning the acceptance of maintenance records, the sufficiency of particular installation work, or the scope of the applicability test (STC plus serial number). Those matters would therefore require resolution in external dispute or administrative processes if contested.

What to do if legal clarification is needed

• Because the AD contains neither litigation history nor internal appeal procedures, affected parties requiring legal certainty about the AD’s meaning, enforcement, or the sufficiency of specific documentation should seek clarification from CASA or obtain legal advice. The Directive itself does not provide a forum, process, or adjudicative history for resolving disputes.

Scope of this section

• All observations here are limited to the content of the AD text provided. No external cases, statistics, or later administrative actions are referenced or assumed.

The AD’s concise form leaves several practical traps for owners, operators and maintenance providers that are identifiable from the text.

Narrow applicability confusion

• The AD applies only to aircraft modified in accordance with FAA STC SA1627WE and only to the serial numbers listed. Failing to check the aircraft’s modification status and serial number precisely could result in mistakenly treating an aircraft as in-scope or out-of-scope. The AD is explicit: both the modification and the serial-number list are prerequisites for applicability under the "Applicability" paragraph. An aircraft that has the STC but a serial number not listed, or vice versa, is outside the AD’s scope per the text.

Reliance on maintenance records

• Note 2 permits acceptance of prior compliance where maintenance records show compliance with FAA AD 75-09-05. Two practical issues arise. First, the form and sufficiency of records are not described in the AD. The AD says maintenance records indicating compliance are "considered acceptable", but it does not specify whether operator logbooks, stampings, certificates of release to service, or other documentation is required. Second, if records do not explicitly reference FAA AD 75-09-05 or are ambiguous, an owner may be required to undertake the physical work even where the work may have been done, or to seek administrative confirmation from CASA.

STC holder change and parts availability

• Note 1 indicates the STC was originally held by Robertson Aircraft Corporation and is now held by Sierra Industries Ltd. This raises practical questions about availability of Robertson Kit No. 14-118-100 and of Robertson modification instructions No. 14-118-10 dated 23 January 1975. The AD names the kit and instruction by number and date, but the document does not provide contact details for kit supply, nor does it indicate whether Sierra Industries supplies the kit or documentation. Operators must be alert to potential supply-chain issues and to confirming whether the named kit and instruction remain available from the current STC holder or other authorised sources.

Lack of method of recording compliance in Australia

• The AD mandates the modification and an acceptance route for prior FAA compliance, but the document does not describe the administrative steps by which compliance should be recorded on the Australian register or submitted to CASA. Owners and maintenance organisations must therefore determine the correct administrative route to satisfy domestic recording and audit expectations.

No alternative means of compliance or extension process specified

• The AD prescribes a specific kit and instruction and sets a 100-hour window. It does not provide a process to seek an alternative means of compliance or to request an extension. If the specified kit is unavailable or if operational reasons make compliance within 100 hours impractical, the AD does not itself state how to secure an exemption. Operators will need to consult CASA or relevant regulatory guidance outside the text for those processes.

Temporal interplay and effective date

• The AD is signed on 21 April 2008 and states the directive becomes effective on 5 June 2008. The compliance clock is measured in hours time in service after the effective date. Operators must ensure their metric for “time in service” is consistent with the AD’s meaning and compute the 100-hour window from the effective date, 5 June 2008. Miscomputing the start of the compliance window is a potential procedural mistake.

Limited domestic population but unchanged obligation

• The background records that only one affected aeroplane was on the Australian register at the time of issuance. That limited domestic population can create false comfort, but the AD applies equally to any listed aircraft operated into Australia later. Operators importing affected aircraft into Australia must review the AD and present compliant maintenance records or undertake the modification.

Ambiguity on who may perform the work

• The AD specifies the kit and instructions but does not state the qualification of the person or organisation authorised to perform the installation. Determining the correct certification level for the engineer or organisation to perform the work is a practical issue left unaddressed in the text.

The AD sets a simple, documentable compliance path. To comply with the Directive based on its text, follow these steps.

1. Determine applicability precisely

• Confirm the aircraft is a Model 337 series. Confirm the aircraft has been modified under FAA STC SA1627WE. Confirm the aircraft’s serial number matches one of the serial numbers listed in the AD. The AD’s "Applicability" paragraph requires both the STC modification and inclusion in the serial-number list.

2. Check maintenance records for prior FAA AD compliance

• If the aircraft has a maintenance history entry that evidences compliance with FAA AD 75-09-05 Amdt 39-2177, then Note 2 states this is acceptable for compliance with the Australian Directive. Ensure such records are clear, legible and specifically reference FAA AD 75-09-05. While the AD does not prescribe the form of record, operators should compile and retain the original documentation demonstrating the FAA AD compliance, including certificates of release to service, work orders, or other appropriate documentation.

3. If prior FAA AD compliance is not documented, perform the prescribed modification

• The AD requires, "If not previously accomplished, rework the extended pitot tube by installation of Robertson Kit No. 14-118-100 in accordance with Robertson modification instructions No 14-118-10 dated 23 January 1975." Obtain Robertson Kit No. 14-118-100 and Robertson modification instructions No. 14-118-10 dated 23 January 1975. Note 1 identifies that the STC is now held by Sierra Industries Ltd; operators should identify the current source for the kit and the approved instruction set, or contact the STC holder for authorisation and supply.

4. Use appropriately authorised maintenance personnel

• The AD prescribes a technical installation. The Directive text does not specify who is authorised to carry out the work. Ensure the installation is undertaken by maintenance personnel or an organisation authorised under applicable aviation maintenance rules to perform structural and pitot system modifications, and that the work is documented in the aircraft’s maintenance records.

5. Complete the modification within the AD timeframe

• The AD requires compliance within 100 hours time in service after the effective date (the AD becomes effective on 5 June 2008). Calculate the 100-hour window using the aircraft’s time in service metric and ensure work is completed within that window if the AD is triggered.

6. Document the work for acceptance

• Record the installation and certification in the aircraft’s maintenance records. If relying on prior FAA AD compliance (Note 2), assemble the FAA compliance documentation and ensure it is available as proof. The AD states that maintenance records indicating compliance with FAA AD 75-09-05 are "considered acceptable for compliance with this Directive."

7. Verify administrative recording with CASA

• The AD does not specify the administrative mechanism to notify CASA of compliance. As this Directive becomes effective in Australia, operators should confirm with CASA’s current practice for recording AD compliance on the Australian register to ensure compliance is properly recorded for regulatory audit.

8. Retain documentary evidence

• Keep all work orders, modification instructions, kit serial numbers (if any), certificates of release to service, and any correspondence with an STC holder or CASA. Note 2’s acceptability of FAA compliance is evidence-based; therefore, retain the documents that support the claimed prior compliance.

9. For imported aircraft, check prior actions before arrival in Australia

• The AD expressly contemplates that the required work may have been done before the aircraft arrived in Australia and that those records suffice. If importing an aircraft, assemble and provide maintenance records that explicitly reference FAA AD 75-09-05 to avoid having to perform the same work in Australia.

10. If any ambiguity arises, contact CASA or the STC holder

• The AD identifies the STC holder history in Note 1 and is silent on administrative procedures. For any uncertainty on parts availability, approval of modification methods, or how to record compliance on the Australian register, contact Sierra Industries Ltd (current STC holder as stated in Note 1) or CASA for procedural guidance. The AD itself does not state the contact route.

All steps above follow the explicit prescriptions and acceptable alternatives contained in the AD text: the specified kit and instructions under "Requirement," the 100-hour compliance window and effective date under "Compliance" and the effective date line, and the allowance for prior FAA AD compliance under Note 2.