AD/B737/349 - Windshield Wiper Motors

The core concept of an Airworthiness Directive is that it is a mandatory instrument issued by the Civil Aviation Safety Authority to require inspection, modification, or other action to address an unsafe condition in an aircraft type. AD/B737/349 operates within that framework. The directive introduces two main conceptual elements: the distinction between “affected” and “unaffected” wiper motors, and the phased compliance dates.

“Affected” wiper motors are those identified in the service bulletins as being of a certain part number and serial number range. The directive does not itself list the serial numbers; it incorporates by reference the Boeing bulletins and, through them, the Rosemount Aerospace Service Bulletin 2313M-347/2313M-348-30-01. An operator must consult that chain of documents to know exactly which motors require action. The concept of “records review” is important: the directive permits a maintenance records check instead of a physical inspection, but only if the part number and serial number can be “conclusively determined” from the records. This is a legal standard that places evidentiary weight on documentation. If records are ambiguous, a physical inspection is required.

Another key concept is the use of Alternate Methods of Compliance (AMOC). The directive states that later revisions of the Boeing service bulletins, approved by the FAA as an AMOC to FAA AD 2008-24-05, are acceptable for compliance with the equivalent requirements. This creates a dynamic reference: the regulatory requirement is not frozen at the issue date. If the FAA later approves a revised service bulletin that changes the inspection criteria or corrective actions, that revision becomes automatically acceptable under the CASA directive, provided it is an AMOC to the FAA AD. This reduces the need for CASA to issue separate amendments but places an onus on operators to monitor FAA AMOC decisions.

The concept of “corrective actions” is left to the service bulletins, but the directive gives a specific cross-reference to AD/B737/218. For 737-400, -500, -600, -700 and -800 series, accomplishing the wiring modification required by that earlier AD is acceptable for compliance with Requirement 1, provided that no Rosemount motor of the prohibited part numbers has been installed. This shows how multiple ADs can interact: compliance with one AD can discharge requirements of another, but only under certain conditions.

The directive also introduces a note correcting a typographical error in the Rosemount service bulletin: serial number M252 should be M0252. This is an administrative clarification but serves as a warning that the external references may contain errors. Operators relying on the Rosemount bulletins must use the correct serial number.

The concept of “part marking” is addressed in Note 3. The Rosemount bulletin specifies marking affected parts with BAC5307, Class RO, with an approved opaque permanent marking material. However, the CASA directive relaxes that requirement: any permanent method of part marking is acceptable. This gives operators flexibility to use their own approved marking procedures.

The directive applies to the operator (or registered operator) of any Boeing 737 aircraft that falls within the applicability paragraphs. Specifically, it covers Model 737-400, -500, -600, -700, -700C, -800 and -900 series aeroplanes, identified by the listed service bulletins. In practice, this means airlines, charter operators, freight operators, and any entity that holds a Certificate of Air Registration for one of those aircraft types. The directive does not apply to earlier 737 models (e.g., -100, -200, -300) because the unsafe condition (windshield wiper motor failure) is not addressed for those types in the referenced bulletins. Owners of aircraft not listed have no obligations under this AD, though they should verify whether other ADs apply.

Maintenance organisations that perform work for these operators are directly affected. They must have access to the service bulletins and be able to correctly identify part numbers, serial numbers, and any corrective actions. The notes about Rosemount SB serial number errors and marking requirements mean maintenance personnel must read the documents carefully. The 60-month compliance window means that heavy maintenance checks (C-checks, D-checks) will be the typical opportunity to accomplish the inspection, but the prohibition on installing prohibited part numbers as spares takes effect immediately, impacting parts supply chains and stores departments.

Parts suppliers and distributors are also affected. From 15 January 2009, they may not sell or supply a Rosemount Aerospace windshield wiper motor with part number 2313M-347-3 or 2313M-348-3 for installation as a replacement spare on any of the affected 737 models. This prohibition extends to any operator, not just those with aircraft currently in service. A supplier that sells such a part after the effective date exposes the installing operator to non-compliance. However, the directive does not prohibit the installation of those part numbers if they were already fitted before the effective date, provided the inspection requirement is met and the motor is not found to be defective.

From a regulatory perspective, the Civil Aviation Safety Authority (CASA) is the issuing body, but the directive is a one-time rulemaking. CASA is not directly affected operationally, but its compliance monitoring and enforcement personnel will check for adherence during audits. The Federal Aviation Administration (FAA) is also relevant because the directive relies on FAA AMOC decisions for later revisions of the service bulletins. This cross-border interaction means that changes in US regulatory action can affect Australian compliance obligations without a separate CASA decision.

Smaller operators - for example, a regional airline with a single 737-400 - will bear a disproportionate compliance burden compared to a large fleet operator. The fixed costs of understanding the directive, locating the service bulletins, and organising the inspection may be similar regardless of fleet size, but the benefit in terms of safety improvement may be the same per aircraft. The free-market lens suggests that the regulatory burden could disadvantage smaller players who lack in-house engineering departments to manage these cross-referencing tasks efficiently.

The primary duty is on the operator to ensure compliance with the two requirements. Requirement 1 imposes a duty to inspect (or review records) and to accomplish all applicable corrective actions in accordance with the referenced service bulletins within 60 months of 15 January 2009. This is a proactive obligation: the operator must schedule and perform the work within the deadline. It is not triggered by a defect report; it is a prescriptive routine inspection. The second duty is a negative obligation: from the effective date, “Rosemount Aerospace windshield wiper motors having P/N 2313M-347-3 or P/N 2313M-348-3 (P/N 2313M347-3 or P/N 2313M348-3) may not be installed on any aeroplane as a replacement spare.” This prohibition applies to all affected models, even if the aircraft is not yet due for the Requirement 1 inspection.

The rights of the operator include the right to rely on maintenance records in lieu of physical inspection if the records are conclusive. This right is valuable because it can save the cost of physical access to the wiper motor, which may require removing interior panels or cowlings. However, the operator must be able to demonstrate that the records establish the part number and serial number to a conclusive standard - if there is any ambiguity, the right is lost and physical inspection becomes mandatory.

Another right is the ability to use compliance with AD/B737/218 (the wiring modification) as an alternative to the actions specified in Requirement 1, provided no prohibited Rosemount motor is installed. This allows operators who have already done the earlier wiring mod to avoid duplicative work. However, the right is conditional: the operator must verify that no prohibited part number is fitted. If a prohibited motor was installed after the earlier modification, the wiring mod does not suffice.

Operators also have the right to use later revisions of the service bulletins that have been approved by the FAA as an AMOC. This is a right to follow a different procedure than the one originally specified in the bulletin, provided the FAA has approved it and the revision covers the equivalent requirements. But note: the directive does not say that any AMOC from the FAA is automatically an AMOC from CASA. It only says that later revisions of the Boeing SBs approved by the FAA as an AMOC to FAA AD 2008-24-05 are “considered acceptable for compliance with the equivalent Requirements of this Directive.” If an operator wants to use an AMOC that is not a revision of the SB (e.g., a different method), it would likely need to seek a specific AMOC from CASA. This right is therefore narrow.

Operators have no explicit right to an extension of the compliance time. The 60-month period is absolute; if an operator fails to comply, it is in breach. There is no provision for applying for an alternative compliance time. However, because the directive is issued under the Civil Aviation Act, CASA has general powers to grant exemptions or AMOCs, but that is not mentioned in the source.

From a free-market perspective, the operator has the right to choose any method of undertaking the inspection (in-house or contracted), and to choose any permanent marking method for parts that need re-identification. However, the prohibition on installing certain part numbers as spares removes the right to use those specific parts in the supply chain, potentially limiting competition among parts suppliers.

The AD itself does not specify penalties. However, as a CASA-issued Airworthiness Directive, it is a legislative instrument made under the Civil Aviation Act 1988 and the Civil Aviation Regulations 1988 (CAR 1988). Non-compliance with an AD is an offence under the Act and Regulations. The typical enforcement framework: a person who operates an Australian aircraft that does not comply with an applicable AD may face civil penalty proceedings, criminal prosecution, or administrative action such as suspension or cancellation of the aircraft’s Certificate of Airworthiness or the operator’s Air Operator Certificate. Under the relevant provisions, penalties can include fines (for individuals and companies) and, for serious breaches, imprisonment. The maximum fines are substantial - under the current Act, penalties can reach hundreds of thousands of dollars per offence. However, the source does not quantify these.

Enforcement is the responsibility of CASA’s enforcement branch. CASA may also issue a direction to ground the aircraft until compliance is achieved. For a non-compliant aircraft, the operator may be prohibited from flying until the AD is accomplished. This grounding power is a significant economic sanction because it directly removes the aircraft from revenue service.

The directive does not create a private right of action. Passengers or other third parties cannot sue for breach of the AD per se; but non-compliance could be used as evidence of negligence in a common law claim for damages if an accident occurs.

The background states that two in-flight failures of wipers prompted the directive. If an operator had a failure after the effective date and was found not to have complied with the AD, that failure could be evidence of a reckless or knowing breach, increasing the severity of enforcement action. Conversely, if an operator complied and a failure still occurred, that may point to a latent defect the AD did not address.

From an economic incentives perspective, the penalty structure creates a deterrent, but the 60-month compliance window reduces the immediate urgency. An operator might defer the inspection to the last moment, hoping to spread costs. However, the immediate ban on installing prohibited spares means that even a compliant operator could inadvertently breach Requirement 2 if procurement staff are not aware. CASA enforcement would likely treat such a breach as a technical violation, but if it leads to an aircraft being operated with a prohibited motor, more serious consequences follow.

The directive itself does not mention record-keeping requirements, but general regulations require operators to retain records of compliance with ADs. Failure to produce those records during an audit can itself be an offence.

This directive does not operate in isolation. It explicitly references FAA AD 2008-24-05 (Amdt 39-15745) and CASA AD/B737/218. The interaction is layered. For Australian-registered aircraft, AD/B737/349 is the governing regulatory requirement, but compliance with the equivalent foreign AD may be accepted as compliance with the Australian AD, provided the correct conditions are met. That condition, for the wiring modification, is that no prohibited Rosemount motor is installed.

The directive also interacts with the broader regulatory regime under the Civil Aviation Act and the Civil Aviation Safety Regulations 1998 (CASR). Airworthiness Directives are a subset of airworthiness requirements. An aircraft’s maintenance program must incorporate all applicable ADs, and the operator’s continuing airworthiness management system must ensure compliance. The directive imposes a one-time action, but the prohibition on installing certain parts as spares is an ongoing obligation that affects procurement and inventory management.

The reference to Rosemount Aerospace SB 2313M-347/2313M-348-30-01 as an additional source of service information means that the Rosemount bulletin is not itself mandatory but provides detail on part identification. That bulletin is a manufacturer’s document, not a regulatory instrument. However, because the directive requires compliance with the Accomplishment Instructions of the Boeing SBs, and those SBs incorporate the Rosemount bulletin by reference, the Rosemount bulletin effectively gains regulatory force for the purpose of this AD.

There is interaction with standards for part marking: Note 3 allows any permanent marking method instead of the BAC5307 specification. This overrides the Rosemount bulletin’s requirement for a specific opaque material. The directive thus liberalises the marking requirement, reducing compliance cost.

The interaction with FAA AMOC decisions creates a dynamic regulatory interface. An operator cannot simply assume that any FAA-approved AMOC is automatically acceptable for the CASA directive. The directive only accepts later revisions of the Boeing service bulletins that are FAA-approved as AMOC. If a different AMOC is developed (e.g., a custom modification approved by FAA under a specific operator’s design change), it requires separate CASA approval. This asymmetry could increase compliance costs for operators that want to use an alternative method not covered by a revised SB.

There is also interaction with AD/B737/218, which required modification of wiring to windshield wiper motors. AD/B737/349 acknowledges that complying with that earlier AD (specifically paragraph (b) of FAA AD 2003-20-13) meets Requirement 1, provided no prohibited Rosemount motor is installed. This means an operator that already did the wiring mod may not need to re-inspect the motors but must still verify the part numbers are not prohibited. That verification may be a records check.

From a competition perspective, the requirement creates a de facto ban on certain Rosemount part numbers in the Australian aftermarket. Suppliers of those specific parts lose a market, while alternative part suppliers may benefit. The directive does not itself mandate a new part design; operators must source either approved existing parts (non-prohibited numbers) or ones that have been modified per the service bulletins.

The source does not show any amendments to AD/B737/349. The document is signed on 27 November 2008 and takes effect 15 January 2009. There is no notation of subsequent revisions, such as “Issue 2” or “Amended by AD/B737/349A”. It appears to be a single, standalone directive. However, the text references later revisions of the service bulletins (ASB 737-30A1059 and SB 737-30A1057) as being acceptable for compliance if approved by the FAA as AMOC. That means the bulletins themselves may have been revised after the AD’s issue date, but the AD remains unchanged. Operators must track bulletin revisions.

The directive notes: “Later revisions of the above SB(s), approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2008-24-05, are considered acceptable for compliance with the equivalent Requirements of this Directive.” This effectively allows the AD’s requirement to be updated via the service bulletin reference without a formal CASA amendment. That is a cost-saving feature for the regulator but imposes a monitoring obligation on operators.

The history of the underlying FAA AD is referenced: FAA AD 2008-24-05 Amdt 39-15745. That AD likely has its own amendment history, but that is not relevant to the Australian directive except for the AMOC chain.

Given the age (2009) and the fact that no amendment history is provided, it is likely that this AD is still current unless superseded by a more recent AD. But the source does not indicate supersession. For a legal analyst, the absence of amendment history means that the text as published is the only version to rely on. However, practitioners should check CASA’s AD register for any later amendments or cancellations.

The practical implication: if an operator finds that the service bulletins have been revised multiple times, they must ensure they are using the version that meets the criteria - i.e., approved by FAA as AMOC to the FAA AD. If a revision is merely a minor editorial change not approved as AMOC, it may not satisfy the directive. This requires due diligence into FAA’s AMOC decisions.

The source does not mention any litigation involving this directive. Given the technical, prescriptive nature of the AD, it is unlikely to have been directly challenged in court. Airworthiness Directives are generally accepted by the aviation industry as part of routine compliance. Judicial review of CASA decisions is possible, but there is no record in the source of any proceedings.

To the extent that AD/B737/349 is based on Boeing and Rosemount service bulletins, any challenge would likely focus on whether the unsafe condition was correctly identified or whether the compliance method was reasonable. But the source offers no such challenge. The background states two reports of wipers stopping in flight - a factual basis that would be hard to contest.

From a litigation risk perspective, an operator who fails to comply and suffers an incident may face civil liability, and the AD would be a standard of care. A plaintiff could argue that non-compliance is negligence per se. However, no case law is cited.

The absence of litigation history may also indicate that the AD has been effective in preventing the stated risk, or that the compliance burden has not been high enough to provoke legal action. The 60-month window and the flexibility with marking and records review likely reduced friction.

Practitioners should not assume that no litigation means no legal risk. The directive has been in force for over fifteen years, and it is possible that enforcement actions have been taken but not publicly litigated. The source gives no information.

From a free-market perspective, the lack of litigation suggests that the regulatory intervention did not impose costs that exceeded the benefits for operators - or that operators found it cheaper to comply than to challenge. The narrow scope of the AD (one inspection) limits the incentive to litigate compared to a major structural modification requirement.

Several points in the directive could trap an unwary operator. First, the records review in lieu of inspection is only allowed if the part number and serial number can be “conclusively determined” from maintenance records. If the records are ambiguous, or if there is any possibility that a motor was replaced without updating the records, the operator must physically inspect. The standard is high. An operator relying on a records review should document the basis for conclusiveness.

Second, the prohibition on installing P/N 2313M-347-3 or 2313M-348-3 as replacement spares applies immediately from the effective date. Operators who have these parts in stock must not use them as replacement spares for any of the affected aircraft models. However, the prohibition does not apply to parts already fitted. An operator could strip a used motor of that part number from a scrapped aircraft and install it as a replacement - that would be a new installation and would be prohibited. The definition of “replacement spare” is not further clarified, but any part not originally fitted at the time of manufacture or previously installed is likely a spare.

Third, Note 2 warns that the Rosemount service bulletin Appendix A lists an incorrect serial number. If an operator relies solely on that appendix without cross-checking the correct list in the bulletin’s body (if any), they might misidentify an affected motor. The directive corrects it: M252 should be M0252, but it does not mention other possible errors. Operators should use the corrected value and treat the Rosemount bulletin with caution.

Fourth, Note 3 states that for part marking, any permanent method is acceptable, overriding the Rosemount bulletin’s requirement for BAC5307 Class RO opaque material. An operator may mistakenly believe they must follow the Rosemount marking specification strictly, incurring unnecessary cost. Conversely, an operator might choose an inadequate marking method that is not truly permanent. The directive does not define “permanent”, so the operator must use judgment or refer to accepted standards.

Fifth, the interaction with AD/B737/218: complying with that earlier AD does not automatically discharge Requirement 1. The operator must ensure that no prohibited Rosemount motor is installed. If the wiring modification was done but the motor was later replaced with a prohibited part number, the operator still needs to take corrective action. This is a trap for operators who assume that previous compliance is sufficient.

Sixth, the acceptance of later revisions of the service bulletins as AMOC is conditional on the revision being approved by the FAA as an AMOC to FAA AD 2008-24-05. If the FAA approves an AMOC that is not a “later revision of the SB” (e.g., a one-off alternative method for a specific operator), it may not be acceptable under this directive. The directive only mentions “later revisions of the above SB(s)”. An operator seeking to use a non-standard method must request an AMOC from CASA.

Seventh, the 60-month compliance period is from the effective date. Operators who acquire an affected aircraft after that date must determine compliance based on the date of acquisition. If the previous operator had not accomplished the inspection, the new operator inherits the compliance obligation and must comply within the remaining time (or immediately if the 60 months have already passed). This could be a problem for aircraft imported or transferred close to the deadline.

Eighth, the directive does not require re-identification of wiper motor part numbers if the motor is found not to be affected. That is stated explicitly. However, an operator might still want to mark it for future identification, but the directive does not mandate it.

Finally, the directive does not specify how to handle a wiper motor that fails the operational test specified in Work Packages 2 and 3 of the service bulletins. It says corrective actions must be accomplished per the bulletin, but the operator must ensure those actions are done before the compliance deadline.

Compliance with AD/B737/349 requires a structured process that begins with determining applicability to each aircraft in the operator’s fleet. For every Boeing 737-400, -500, -600, -700, -700C, -800 or -900 series aeroplane, the operator must establish which service bulletin applies: ASB 737-30A1059 for -400 and -500 models, or SB 737-30A1057 Revision 1 for the later models. The operator must obtain the correct issue of those bulletins - they may be available from Boeing or through the FAA website. It is critical to use the revision specified (Revision 1 for the second bulletin) unless a later revision has been approved by the FAA as an AMOC. If a later revision is used, the operator must confirm that it is an FAA-approved AMOC to FAA AD 2008-24-05.

Step one: inspect or review records to identify the part number and serial number of the windshield wiper motor for both pilot and first officer positions. A physical inspection may require removing panels to access the motor nameplate. If the operator chooses a records review, the maintenance records must be sufficient to establish the part number and serial number beyond doubt. The operator should document the basis for conclusiveness. If records are incomplete, physical inspection is required.

Step two: compare the identified part numbers and serial numbers against the lists in the service bulletins (and the Rosemount bulletin referenced therein). If the motor is found to be one of the affected part numbers (i.e., 2313M-347-3 or 2313M-348-3) and within a certain serial number range (specified in the bulletins), corrective actions are required. The service bulletins detail the corrective actions - typically a re-identification of the part number to show it has been inspected, and possibly a wiring modification or motor replacement. For aircraft that have already been modified per AD/B737/218, that wiring modification may be accepted as corrective action, but only if no prohibited Rosemount motor is installed.

Step three: accomplish the corrective actions within 60 months of 15 January 2009. For aircraft that were not modified under the earlier AD, the corrective actions will involve following the Accomplishment Instructions of the applicable service bulletin. Those instructions include an operational test of the wiper motor. The operator must also ensure that any parts that are to be re-identified are marked with a permanent method. The directive specifies that any permanent marking is acceptable, so the operator may use stamping, engraving, or a permanent label as long as it is durable.

Step four: from the effective date, the operator must not install any Rosemount Aerospace windshield wiper motor having part number 2313M-347-3 or 2313M-348-3 as a replacement spare on any of the affected models. This prohibition is ongoing and applies regardless of the inspection compliance. Therefore, the operator’s parts procurement and inventory system must be updated to flag those part numbers as prohibited for installation as spares. If the operator has such motors in stock, they may not be used as replacements on any affected aircraft; they might be disposed of or returned to the supplier.

Step five: document compliance. The operator must maintain records of the inspection (or records review), the determination of part numbers, any corrective actions undertaken, and the marking applied. These records must be kept for the life of the aircraft and produced on request by CASA. If using an FAA-approved later revision of the service bulletin, the operator should retain evidence of the FAA’s AMOC approval.

Step six: if the operator wishes to use an alternative method of compliance not covered by a later revision of the SB, they must apply to CASA for an AMOC before the compliance deadline. The directive does not provide a procedure, but general CASA practice requires a written application with supporting engineering analysis.

Step seven: for aircraft acquired after the effective date, the operator must determine compliance status as part of the acceptance inspection. If the previous operator’s records are available and conclusive, the new operator may rely on them. If not, the inspection must be performed. The 60-month clock started on 15 January 2009, so for any aircraft that was already five years past that date at the time of acquisition, the requirement is overdue, and the operator must accomplish the inspection immediately before operation.

For multi-aircraft operators, the compliance can be scheduled during regular maintenance events, but the prohibition on installation is immediate and requires action regardless of the inspection schedule. The most efficient approach is to perform the inspection as soon as practical within the 60-month period, especially for aircraft that may be sold or transferred, to avoid creating a compliance issue for the next operator.

From a cost perspective, the records review option is cheaper if the records are clear. For a large fleet with robust record-keeping, this may be the quickest compliance path. For smaller operators with less detailed records, physical inspection is inevitable. The corrective actions, if needed, may involve additional labour and parts cost, but the service bulletins provide prescriptive instructions, and most maintenance organisations are familiar with such tasks.

The operator should also watch for any amendments to this directive by CASA, or any new ADs that supersede or modify it. The source version is from 2009, and it is the operator’s responsibility to monitor the official AD register for updates.