AD/CESSNA 303/13 - Alternate Static Air Source Valve

The central concept is the alternate static air source selector valve, a component that allows the pilot to select an alternate source of static air pressure for the pitot-static instruments (altimeter, airspeed indicator, vertical speed indicator) if the primary static port becomes blocked. The specific valve at issue is P/N 2013142-18, which replaced earlier versions (P/Ns 2013142-9, -13 and -17). The AD focuses on a manufacturing defect: the part number identification placard was installed on the valve body in a location that physically covers the port on the forward end of the valve. That port is the entry point for static air into the valve. If the placard obstructs it, the flow of static air to the instruments is blocked or restricted, causing erroneous readings. The stated safety risk is that the pilot could react to incorrect flight information and lose control of the aeroplane. The AD therefore defines the condition as an unsafe condition that must be corrected before further flight. Another key concept is the compliance pathway: the operator may choose between two methods. The first is a records-based determination: check the aeroplane’s maintenance records to see if the affected valve was installed after 19 November 2007. This can be done by the aeroplane operator as long as they hold at least a private pilot’s licence. Note 2 permits this without requiring a licensed aircraft maintenance engineer (LAME). The second method is a direct physical inspection of the valve if records are inconclusive or if it is known the valve is present. The physical inspection is defined in Requirement 3: adjust both pilot and co-pilot seats fully aft, then use a flashlight and mirror to view the port on the forward end of the valve to confirm the placard is not covering it. The AD also introduces the concept of an airworthiness directive as a legally binding instrument. Compliance is mandatory under the Civil Aviation Regulations: an aircraft cannot be operated unless it complies with all applicable ADs. The directive’s scope is deliberately wide: it applies to all T303 aeroplanes because CASA acknowledges it cannot determine which ones have the defective valve without inspection. The manufacturing window is narrow (20 November 2007 to 18 February 2008), but the AD applies retrospectively to any valve installed after 19 November 2007 because replacement parts could have been fitted at any time, and the defect might not be limited to that window (though the background only refers to parts manufactured during that period). The concept of a placard as a part number identification label is also central: the placard is separate from the valve component itself, and its misplacement is the root cause. The correction is simple removal and disposal of the placard, not replacement of the valve. This means the economic cost is low per unit, but the search cost to identify affected valves is potentially high across a large fleet.

The directive directly affects operators of Cessna T303 series aeroplanes worldwide registered in Australia or operated under an Australian Certificate of Registration. Because the AD is issued by CASA, it applies to Australian-registered aircraft and may also apply to foreign-registered aircraft operating in Australia under certain conditions. However, the text does not limit geographical scope; ADs generally apply to aircraft on the Australian register. The class of affected persons includes private owners, flight schools, charter operators, and any entity that operates a T303. The applicability is not limited by serial number: all T303 serial numbers are included (Table 1). This means that even aircraft that never had the specific valve replaced, or that were manufactured after the defect was corrected, must check their records or physically inspect the valve if it is present. The AD does not differentiate between aircraft that have the valve and those that do not; the initial determination step sets the burden on every operator. The secondary group affected is maintenance personnel and licensed aircraft maintenance engineers who may be called upon to perform the physical inspection if the operator chooses not to rely on the records check or cannot perform it themselves. Note 2 allows a private pilot to do the records check, but the physical inspection (Requirement 3) does not specify who may perform it. It could be done by a pilot or an engineer, but in practice it may require someone qualified to access the valve area safely. The directive also affects parts suppliers and repair stations that hold inventory of P/N 2013142-18 valves, because Requirement 5 mandates that any such valve installed after the effective date must be inspected before installation. This imposes a quality-check obligation on installers even if the part is brand new from stock. The background notes that Cessna corrected all valves held in stock, but spares in the field may still be defective. Therefore, distributors, maintenance organisations, and any person who installs this part must ensure it is inspected before fitting. Finally, the AD indirectly affects insurers, lessors, and purchasers of used T303s, because compliance status becomes a factor in airworthiness and value. The compliance burden is concentrated on a relatively small fleet (T303 production was limited), so the aggregate economic impact is modest, but for individual operators the before-further-flight requirement means immediate grounding if compliance is not achieved before the next intended operation. The AD also imposes a record-keeping duty: the inspection results must be documented in the aircraft maintenance records to demonstrate compliance for future reference.

The primary duty under this AD is to ensure that before further flight after the effective date, the operator has either inspected the alternate static air source selector valve physically (Requirement 3) or inspected the maintenance records to determine whether the affected part (P/N 2013142-18) has been installed since 19 November 2007 (Requirement 1.b.). If the records check shows no such installation, no further action is needed. If the records check is inconclusive or shows installation of the part, the operator must physically inspect the valve using the prescribed method: adjust seats aft, use a flashlight and mirror to verify the port is not covered by the placard (Requirement 3). If the port is obstructed, the duty is to remove the placard from the valve body, discard it, and ensure the port is open (Requirement 4). This removal must be done before further flight after the inspection. Additionally, any person installing a P/N 2013142-18 valve as a replacement or modification part after the effective date must inspect that valve before installation (Requirement 5). The AD gives operators a right to choose which compliance path to take: records check or physical inspection. The records check can be performed by the operator provided they hold at least a private pilot’s licence (Note 2). This is a significant concession because it avoids the cost of hiring a licensed engineer for a simple records search. However, the physical inspection does not explicitly grant that right; in practice, the person doing the inspection should be competent to access and examine the valve, which may require removal of panels or seats. The AD does not require replacement of the valve; only removal of the placard. That preserves the operator’s ability to continue using the same valve after correction. The operator also has the right to delegate the inspection to a maintenance organisation. The AD does not prescribe the format of records; standard logbook entries are sufficient. The compliance timeline is strict: before further flight. That means the aircraft cannot be flown unless the inspection is complete. The operator has no right to defer the inspection to a later maintenance interval. This imposes an immediate operational impact. The AD also implies a duty to maintain records of the inspection results for future airworthiness reviews. There is no explicit obligation to report removal of the placard to CASA, but the maintenance record should show what was done. The operator’s rights under the AD are limited to the two compliance paths; there is no option to apply for an alternative means of compliance unless the AD itself provides for it (it does not). The background notes that CASA varied the inspection requirements from the FAA version, which presumably did not allow the records-check option. That variation is a concession that reduces the compliance burden for operators who never installed the affected part.

The AD itself does not specify a penalty amount or enforcement mechanism; it is a mandatory directive issued under the Civil Aviation Act 1988 and the Civil Aviation Regulations 1988 (CARs). Under the CARs, operating an aircraft that does not comply with an applicable airworthiness directive is an offence. The standard penalty for such an offence can include fines, suspension or cancellation of the operator’s certificate, and in serious cases, prosecution for endangering safety. The specific penalty ranges are not repeated in this AD, but practitioners will know that CAR 1998 (as applicable) imposes strict liability for operating an unairworthy aircraft. The compliance requirement is “before further flight”, which means any flight after the effective date without completing the required inspection would be a breach. Enforcement could arise from a routine airworthiness inspection, a ramp check, or an incident investigation where non-compliance is discovered. Because the AD is based on a foreign FAA AD, Australian operators cannot assume that FAA compliance alone satisfies CASA; the Australian AD must be followed explicitly. The AD does not include a provision for extensions or individual exemptions; any deviation would require a separate instrument from CASA. The practical enforcement risk is moderate: the affected fleet is small, so targeted enforcement through the normal airworthiness cycle is likely. However, the before-further-flight requirement means that an operator who flies without compliance is immediately exposed to enforcement action if detected. The AD also has a secondary enforcement dimension for maintenance organisations: installing a valve without inspection (Requirement 5) could lead to regulatory action against the engineer or organisation. The background narrative is factual and does not indicate any previous non-compliance; it is purely precautionary. Enforcement discretion rests with CASA, which may take a pragmatic view given the low-cost fix, but the legal exposure remains. The AD also creates a compliance record obligation: if an aircraft is sold without the AD being recorded as complied with, the new owner could be liable. The lack of a penalty table in the AD should not mislead operators into thinking the consequences are trivial; the underlying legislation carries significant penalties. In summary, the enforcement risk flows from the mandatory nature of ADs and the operator’s duty to ensure airworthiness before each flight.

This AD is issued under the Civil Aviation Act 1988 and the Civil Aviation Regulations 1988, specifically provisions relating to airworthiness directives. It sits within a hierarchy: it is subsidiary legislation that modifies the normal maintenance requirements of the aircraft. It does not override the design approval (type certificate) but imposes a continued airworthiness requirement. The AD specifically references FAA AD 2008-10-02 Amdt 39-15508. While not legally binding in Australia on its own, CASA has adopted it with modifications. The interaction with the FAA AD means that operators with aircraft also subject to US regulations must comply with both; the Australian AD may be satisfied by performing the FAA equivalent, but the Australian AD permits the records-check option which the FAA version may not. Operators holding dual registration must ensure compliance with both sets of rules. The AD also interacts with the Civil Aviation Safety Regulations (CASR) Part 43 (Maintenance) and Part 91 (General Operating and Flight Rules). Maintenance actions under the AD must be recorded in the aircraft maintenance records in accordance with normal record-keeping requirements (e.g. CAR 1998). The AD does not specify any specific log-book entry format, so standard engineering entries suffice. It also interacts with the rules on airworthiness reviews: during a periodic inspection, the reviewer will check that all applicable ADs are complied with. Non-compliance could prevent renewal of the Certificate of Airworthiness. The AD does not conflict with any other Australian legislation; it is a technical directive specific to the aeroplane model. There is potential interaction with safety management systems: operators with a CASR Part 119 or Part 121 certificate must incorporate this AD into their system as a mandatory directive. The AD also interacts with insurance contracts: operating non-compliant with an AD may void insurance coverage in the event of a claim, as it may be considered operation of an unairworthy aircraft. The broad applicability across all T303 serial numbers means that even aircraft used for private recreation are caught. There is no exemption for aircraft operated under experimental certificates or special permits, unless the AD specifically says otherwise (it does not). The interaction with the FAA AD is noteworthy because the Australian AD varies the inspection; an Australian operator who relies solely on the FAA AD must ensure they also fulfil the specific Australian requirement, including the records-check allowance. If an operator chooses to inspect per FAA AD without exercising the records-check option, they still comply with the Australian AD if the physical inspection is done. But the AD does not allow an operator to ignore the records-check option and rely on FAA AD only; the operator must comply with this instrument. The AD is also relevant to liability: an operator who fails to comply and has an accident may face both regulatory and civil liability.

The source text provides only the original issue of AD/CESSNA 303/13. There is no indication of any earlier amendments, corrections, or subsequent revisions within the document. The effective date is 13 May 2008, and the document is signed by James Coyne as delegate of CASA dated 6 May 2008. The directive number does not include a revision number or a series identifier beyond /13. This suggests it is the first and only version of this specific AD. However, the AD references FAA AD 2008-10-02, which may have its own amendment history in the United States, but that is not part of this Australian instrument. The Australian AD is a standalone instrument. The background states that CASA has varied the inspection requirements (compared to the FAA AD), which implies that the FAA version was the starting point and CASA made changes before issuing. That variation is part of the original issue, not an amendment. In the absence of any amendment history in the source, we must note that no amendments are recorded. It is possible that later ADs superceded this one or that revisions were issued after 2008, but the user provided only this text. Therefore, within the scope of this deep dive, the amendment history is null. The directive’s number format (AD/CESSNA 303/13) suggests it is part of a series for Cessna 303 models; earlier ADs exist (e.g., /12, /11) but they are not relevant. The compliance framework for ADs in Australia generally includes the possibility of amendments by CASA if new information arises, but none are documented here. Operators should check CASA’s current AD register for any later versions. The lack of amendment history in the source does not mean none exists elsewhere; it means that for the purpose of this analysis, the instrument is presented as originally enacted. The effective date is unambiguous: 13 May 2008. Anyone relying on this AD for historical or current compliance must verify that no subsequent AD has superseded or amended it. The source text also includes a note referencing FAA AD 2008-10-02 Amdt 39-15508, which is the FAA’s amendment number. That is not an amendment to the Australian AD but a reference to the US counterpart.

The source text for AD/CESSNA 303/13 contains no references to any litigation, court cases, or legal challenges. There is no mention of appeals, disputes, or administrative review regarding this directive. The AD was issued by a delegate of CASA under statutory authority, and in Australia, airworthiness directives are generally not challenged in court because they are technical safety instruments with a narrow scope. It is unlikely that this particular AD generated litigation, given its low cost and simple fix. The background does not describe any accidents or incidents that resulted from the defect; it refers only to reports of improper installation discovered during a quality control check. There is no indication that any operator suffered loss due to the defect or that any enforcement action led to a court case. The AD’s content is standard: it mandates an inspection and corrective action based on a manufacturing error. Without any case law cited in the source, we cannot speculate about litigation. The deep dive must remain grounded in the source; therefore, the litigation history is essentially absent. Practitioners should be aware that ADs are delegated legislation and may be subject to judicial review if they are ultra vires, procedurally flawed, or irrational, but there is no evidence that this one was challenged. The absence of litigation history is not unusual for low-profile ADs on a small fleet. The FAA counterpart may have been subject to petitions for reconsideration, but that is outside the source. The note that CASA varied the inspection requirements suggests that the original FAA AD may have been more burdensome, and CASA actively reduced the burden; that might have lessened the incentive for operators to challenge the Australian version. Overall, the litigation history is nil within the provided material.

Several aspects of this AD could catch operators by surprise. First, the applicability is not limited to aircraft with the affected valve; it applies to all T303 aeroplanes regardless of serial number. That means an operator who has never replaced the alternate static air source valve and has no knowledge of P/N 2013142-18 still must inspect the records to prove that the valve was not installed. If the records are incomplete or missing, the operator may be forced into a physical inspection. The before-further-flight compliance timeline is stringent: an aircraft parked for maintenance could not be flown until the AD action is completed, even if the valve is clearly not present. Note 2 permits the records check by a private pilot, but that check requires the operator to understand the maintenance log system and locate the relevant entries. If the aircraft has been through multiple owners with fragmented records, the check may be impossible without a physical inspection. Second, the physical inspection (Requirement 3) is not trivial: gaining access to the valve may require removing panels or seats, and using a flashlight and mirror to see a small port. The AD does not specify how to access the valve; it assumes that the valve is visible from the cockpit area after adjusting seats aft. On some T303 configurations, the valve may be behind trim panels or covered by carpet, requiring more extensive disassembly. The operator could be grounded while discovering that access is non-standard. Third, Requirement 5 applies to parts installed after the effective date. An operator who orders a new P/N 2013142-18 from a distributor, thinking it is now corrected, must still inspect it before installation. The AD does not provide a mechanism to verify that the part has been corrected at the factory; the installer bears the obligation. Fourth, the AD does not specify a deadline for the placard removal if the port is obstructed; it must be done before further flight after the inspection. That means if an operator finds the placard obstructing the port while on a remote airstrip, they cannot fly out until the placard is removed. Fifth, the AD references FAA AD 2008-10-02 but does not reproduce it. An operator may need to consult the FAA AD for full context, especially regarding the manufacturing window and the earlier part numbers. Sixth, the AD does not address what to do if the valve is the earlier P/N 2013142-9, -13, or -17; only the -18 is affected. But an operator might mistakenly inspect older valves. Seventh, the Note 1 states that P/N 2013142-18 replaced earlier P/Ns; this implies that -18 is the only variant with the placard problem, but earlier variants could have other defects not covered. Finally, the AD is from 2008; any aircraft still operating today should already have this AD recorded as complied, but a buyer of a T303 must verify the AD history. Missing compliance could delay registration or sale. The low-cost fix (placard removal) might have been overlooked in some aircraft if the placard was not actually obstructing, but the AD still required the inspection; a failure to document compliance could be a gotcha during an audit.

Compliance requires a systematic approach. Step 1: As soon as possible after the effective date (13 May 2008) but before the next flight, the operator must obtain the aircraft’s maintenance records and determine whether an alternate static air source selector valve P/N 2013142-18 has been installed at any time after 19 November 2007. This records check may be performed by the operator themselves if they hold at least a private pilot’s licence (Note 2). The operator should inspect logbook entries, component history cards, and any invoices or work orders for the relevant period. If no installation of P/N 2013142-18 is recorded, the operator must make a signed entry in the maintenance records stating that the records check showed no installation of the affected part, and the AD is satisfied for Requirements 1 and 2. No further action is needed. Step 2: If the records indicate that P/N 2013142-18 was installed after 19 November 2007, or if the records are missing or inconclusive, the operator must proceed to a physical inspection of the valve. The inspection procedure is described in Requirement 3: adjust both pilot and co-pilot seats as far aft as possible, then use a flashlight and mirror to inspect the alternate static air source selector valve on the forward end. The objective is to verify that the part number identification placard is not covering the port. The operator should ensure they have adequate lighting and a small mirror to see behind the valve. Step 3: If the placard is found covering the port, the operator must remove the placard from the valve body, discard it, and visually confirm that the port is open and unobstructed (Requirement 4). This may require a tool such as pliers or a screwdriver to detach the placard; care must be taken not to damage the valve. Step 4: Record the inspection result and any corrective action in the aircraft maintenance records. The entry should include the AD number, the date, a description of the action taken (e.g., records check showing no part, or inspection and placard removal), and the signature of the person performing the work (with licence number if applicable). Step 5: For any new P/N 2013142-18 valve installed as a replacement or modification on or after the effective date, the installer must perform the physical inspection (Requirement 3) before installation (Requirement 5). This means even a brand new valve from stock must have its placard checked before it is fitted. Step 6: Ensure that the compliance is maintained for future operations; if a placard is removed, the valve remains serviceable. The AD does not require reporting to CASA, but the records must be available for inspection. Operators should note that compliance with the FAA AD alone does not automatically satisfy the Australian AD because CASA varied the inspection procedure; the records-check option is unique to the Australian version. Therefore, an operator who followed the FAA AD by performing a physical inspection without first checking records is still compliant with the Australian AD, but the reverse may not hold. The entire compliance process, for an aircraft that does not have the affected part, is essentially a paperwork check and a logbook entry. For an aircraft that does have the part, the physical inspection and possible placard removal takes a few minutes. The main cost is the time needed to access the area and possibly ground the aircraft if records are not immediately available.