AD/CESSNA 180/93 - Alternate Static Air Source Valve

An airworthiness directive is a legally enforceable order issued by the national aviation safety regulator (CASA) under the Civil Aviation Act 1988 and the Civil Aviation Safety Regulations 1998 (CASR). It requires the owner or operator of a specified type of aircraft to perform a particular inspection, modification, or maintenance action within a stated time frame, often before further flight. Non compliance can result in the aircraft losing its certificate of airworthiness, grounding it, and exposing the responsible person to enforcement action, including civil penalties or prosecution.

The central component at issue is the alternate static air source selector valve, which is a pilot operated valve that provides an alternative source of static air pressure to the flight instruments if the primary static port becomes blocked (for example, by ice or debris). The valve has an inlet port through which ambient static pressure enters. The part number identification placard is a label affixed to the valve body showing the manufacturer’s part number. In this case, the placard was installed in a location that physically covers the inlet port. That obstruction means the alternate static source may not deliver accurate ambient pressure, and more importantly, if the placard obstructs the port even when the valve is in the normal (closed) position, it could create a leak or blockage affecting primary static pressure as well. The consequence is that the altimeter, airspeed indicator, and vertical speed indicator may display erroneous readings. The AD’s risk assessment is that a pilot relying on these instruments in instrument meteorological conditions (IMC) could lose control.

The directive introduces two categories of aircraft based on how the valve came to be installed. Table 1 captures aircraft that had the valve installed during manufacture; these are four specific Cessna 182T and T182T serial numbers. Table 2 covers a much larger population of models where the valve could have been installed as a replacement part or from spares held in stock, after 19 November 2007. The distinction is important because Table 1 aircraft cannot rely on records; they must physically inspect. Table 2 aircraft may opt for a records check provided the operator holds at least a private pilot licence (Note 3). This is a notable delegation: the regulator permits a pilot, not necessarily a licensed aircraft maintenance engineer (LAME), to perform the records determination and certify it. However, if the records show the -18 valve was installed, the physical inspection must then be done by a person qualified to perform maintenance (likely a LAME, though the AD does not expressly require one for the physical inspection; it only says “inspect”). The AD also cross references that P/N 2013142-18 replaced earlier parts P/Ns 2013142-9, -13, and -17, so aircraft with those older parts already fitted are not affected unless the older part was subsequently replaced with the -18 version.

The directive directly affects owners, operators, and maintainers of any Cessna 180, 182, or related model aeroplane listed in Table 1 or Table 2 with the specified serial numbers. For Table 1, that is an extremely narrow population: only two 182T serial numbers (18282062 and 18282065) and two T182T serial numbers (T18208822 and T18208828). For Table 2, the population is very broad, covering all serial numbers of eleven models: 180, 182, R182, T182, TR182, F182P, F182Q, FR182 (all serial numbers), plus 182S serial numbers 18280001 through 18280944, 182T serial numbers 18280945 through 18282061 (note these are separate from the Table 1 serial numbers), and T182T serial numbers T18208001 through T18208821. The number of individual aircraft potentially affected runs into the thousands in Australia, particularly the popular 182 Skylane and 180 models.

The directive also affects any person or entity holding spare P/N 2013142-18 valves that were manufactured between 20 November 2007 and 18 February 2008. Those spares must be inspected before being installed on any aircraft. This includes maintenance organisations, parts distributors, and flying schools that hold such valves.

The compliance obligation falls primarily on the registered operator of the aircraft, who must ensure the inspection or records check is done before further flight. The operator may delegate the physical inspection to a LAME or the records check to a private pilot (provided they hold a private licence or higher). The AD does not require a specific certification by a LAME for the records check; it allows the operator (if a private pilot) to make the determination and presumably endorse the maintenance records accordingly. This reduces compliance cost but introduces a risk of incorrect determination.

Beyond the direct population, the directive indirectly affects the broader aviation compliance ecosystem. Insurers may require evidence of AD compliance before covering an aircraft. Aircraft sellers or buyers will need to verify compliance during pre purchase inspections. Maintenance organisations must ensure their staff are aware of the precise inspection procedure and the placard removal action. The Federal Aviation Administration (FAA) issued an equivalent AD (2008-10-02), so the directive also affects Australian operators who may have imported aircraft from the US or who have aircraft maintained under FAA oversight.

Importantly, the directive only applies if the specific P/N 2013142-18 valve is installed. Aircraft that still have the earlier part numbers (-9, -13, -17) are not covered, even if they fall within the serial number ranges. This means the compliance burden is not uniform across the fleet; it depends on the replacement history of the valve. That creates an incentive for operators to check their records carefully to avoid unnecessary physical inspection costs, and for those who have never replaced the valve to simply document that fact and move on.

The primary duty is on the aircraft operator: before further flight after 13 May 2008, the operator must ensure compliance with one of the two pathways for their aircraft. For Table 1 aircraft, the duty is absolute: perform the physical inspection described in Requirement 1. For Table 2 aircraft, the operator has a duty to decide between two options and execute that option correctly. If the operator chooses the records check (Requirement 2.b), the duty includes accurately reviewing the aircraft’s maintenance records to determine whether the valve has been replaced since 19 November 2007 with P/N 2013142-18. The operator must be competent to do this; Note 3 clarifies that a holder of at least a private pilot licence may perform and certify that determination. That is a right of delegation not typically found in maintenance directives, which usually require a LAME. However, if the operator is not a private pilot (e.g., a corporate operator without a pilot on staff), the records check would still need to be performed by someone who meets the licensing requirement, or the operator must opt for the physical inspection instead.

If the records check reveals that a -18 valve was installed, then the operator is duty bound to perform the physical inspection before further flight. Similarly, if the physical inspection reveals the placard obstructing the port, the operator must remove the placard, discard it, and confirm the port is open. The AD does not specify how to confirm the port is open; presumably visual inspection or using a small probe would suffice, but the operator risks non compliance if the port remains partially blocked.

A further duty arises for any person installing a P/N 2013142-18 valve as a modification or replacement part on or after the effective date. That valve must be inspected under Requirement 1 before installation. This places a duty on maintenance organisations and installers to either pre inspect each valve or ensure that the valves they hold have already been corrected (which the background says Cessna did for stock, but the AD does not provide a method to verify correction other than physical inspection). The right to rely on a supplier’s representation is not expressly granted; the duty is personal.

The AD does not expressly confer any right of appeal, refund, or compensation. It is a regulatory order; an operator who believes their aircraft is incorrectly included (e.g., because the valve was never installed despite the serial number range) can rely on the records check to avoid the physical inspection, but must still make a determination. There is no right to delay compliance pending a CASA ruling; the compliance deadline is “before further flight after the effective date”, which is immediate. The only explicit right is the ability of a private pilot to perform the records check, which reduces the need to hire a LAME for that step.

A subtle right exists for those who performed the records check and found no -18 valve: they bear no further duty under this AD for that aircraft until the valve is replaced in the future. That saves the cost of a physical inspection, which would involve repositioning seats and using a mirror and flashlight, potentially requiring a hangar visit. However, the records check itself imposes a time cost and requires the operator to know what to look for; improper documentation could lead to later enforcement if a subsequent inspector finds a -18 valve that was missed.

The AD itself does not specify penalties, but it is issued under the Civil Aviation Act 1988 and the Civil Aviation Safety Regulations 1998. Failure to comply with an airworthiness directive is a breach of regulation 42ZC (or similar provision under the CASR) and can lead to a range of enforcement actions. The most immediate consequence is that the aircraft’s certificate of airworthiness becomes invalid until compliance is achieved; flying the aircraft without a valid certificate of airworthiness is a separate and more serious offence. CASA can issue a notice of suspension of the certificate of airworthiness, and the aircraft cannot be flown without specific permission.

For an operator who flies the aircraft without complying with the AD, CASA may take enforcement action including issuing a written direction, imposing a civil penalty (currently up to 1,000 penalty units for an individual and 5,000 penalty units for a body corporate, with one penalty unit currently around $313), or prosecuting the offence in court. In serious cases involving deliberate non compliance or endangering safety, CASA can suspend or revoke the operator’s aviation licence or the aircraft’s registration.

The Australian Transport Safety Bureau (ATSB) may also investigate any incident where non compliance contributed to an accident or serious incident, and the regulator may use evidence of non compliance to ground the aircraft or initiate enforcement.

Although the AD has a narrow scope and a straightforward corrective action (removing a placard), the enforcement risk is real for operators who ignore the directive. The compliance deadline is before further flight, meaning an operator who becomes aware of the AD on 13 May 2008 and flies that day without inspecting or checking records is technically in breach. Given the AD was published and made available, ignorance is unlikely to be accepted as a defence. The records check option is a low cost way to comply for many operators, making the penalty for non compliance disproportionate to the effort required.

For maintenance organisations that install a -18 valve without pre installation inspection as required by Requirement 5, they face similar enforcement: a breach of the AD may be treated as a maintenance error, potentially leading to suspension or revocation of the organisation’s approval under CASR Part 145. In practice, CASA may treat minor breaches with a warning letter or directive to rectify, but the possibility of escalation exists.

This AD operates as a standalone regulatory instrument under the Civil Aviation Act. It is one small node in a network of Australian airworthiness management. It coexists with the manufacturer’s service instructions, the FAA’s equivalent AD (2008-10-02), and CASA’s own maintenance and airworthiness framework under CASR Parts 21, 42, 43, and 91 (depending on the aircraft type and operation).

The AD specifically cross references FAA AD 2008-10-02 Amdt 39-15508, which became effective on 12 May 2008. Australia adopted the FAA AD with a variation: the records check option (Requirement 2.b) is not necessarily present in the FAA AD, which may have required a physical inspection for all aircraft regardless of replacement history. CASA’s variation reflects a cost benefit judgment: allowing a records check reduces the compliance burden on operators who likely never installed the faulty part. The relationship between the Australian AD and the FAA AD is not one of substitution; an Australian operator could rely on this AD alone, but if the aircraft is also registered with the FAA (e.g., US registered aircraft operating in Australia), the FAA AD would also apply. For Australian registered aircraft, this AD is the governing instrument, but CASA may accept compliance with the FAA AD equivalently if it meets the requirements; the AD notes are careful to state “FAA AD 2008-10-02 … refers”.

The AD also interacts with the general maintenance recordkeeping obligations under CASR 42.200 (if the aircraft is operated under Part 42) or equivalent. The records check under Requirement 2.b must be documented; the CASR requires that maintenance records accurately reflect the fitment of parts. If an operator checks records and finds no evidence of a -18 valve, they should retain that determination in the aircraft logbook or maintenance record. The physical inspection under Requirement 1 likewise requires a logbook entry certifying compliance.

Because the AD is an airworthiness directive, it overrides any contrary manufacturer’s instructions or operator maintenance manual that might suggest a different inspection interval or method. The AD is mandatory; manuals are advisory. If a manufacturer later issues a service bulletin that conflicts with the AD, the AD prevails until modified or withdrawn by CASA.

Finally, the AD has implications for the import and export of aircraft. An Australian operator importing a Cessna 182 from the US must ensure compliance with the FAA AD before flying in Australia; if the FAA AD was complied with in the US, the Australian AD may be considered satisfied because the corrective action is the same. However, the Australian AD’s records check option may not be available if the aircraft falls under Table 1. Operators should check the specific serial number and maintenance history carefully.

The source document is the original issue of AD/CESSNA 180/93, published as TX 7/2008. It is effective 13 May 2008. The AD number “93” suggests it is the 93rd AD issued for Cessna 180 series, indicating a long history of airworthiness directives for these aircraft families. The TX suffix implies a text based issuance. There is no amendment history included in the source. No subsequent amendments are noted. Given this is a product of 2008 and concerns a specific manufacturing defect that was resolved by Cessna correcting stock, it is unlikely that later amendments were necessary. However, the AD does not expire; it remains in effect unless explicitly superseded or withdrawn by CASA. If a future revision occurs (e.g., to change the compliance method or add models), it would be issued as a new AD or an amendment to this one with a new number. There is no mention of supersedure or cancellation in the source.

The source does not mention any litigation arising from this AD. No court cases are cited. Given the limited scope and the fix (removing a placard), litigation is improbable. The AD is a routine safety directive. The most likely legal friction would occur if an operator disputed CASA’s authority to ground an aircraft over a placard, but such a challenge would face the regulator’s broad statutory power to issue ADs. No known Australian litigation involves this specific AD. The absence of litigation does not mean the AD was uncontroversial; it may reflect that operators complied quickly due to the minimal cost (checking records or removing a placard) compared to the cost of legal challenge. The FAA AD was also uncontested. The directive’s background notes that the problem was discovered during a quality control check at Cessna, so there was no accident or crash that triggered the AD; the regulator acted preventively. In a free market perspective, such a proactive mandate imposes costs on private aircraft owners who had no control over the manufacturing error, but the regulator judged the safety risk sufficient to require action. The lack of litigation suggests the market accepted this trade off without legal contest.

Several aspects of this AD can catch an unsuspecting operator. First, the applicability is not uniform. An aircraft may fall within the broad serial number ranges of Table 2 but never have had the valve replaced with the -18 part. The operator who assumes a physical inspection is required and pays a LAME to inspect wastes money if a simple records check would have sufficed. Conversely, an operator who skips the records check and does no inspection risks being non compliant if the valve is in fact the -18. The AD requires an active determination; passive ignorance is not compliance.

Second, Note 2 states that P/N 2013142-18 replaced earlier parts -9, -13, and -17. If an aircraft has one of those earlier parts, it is not affected, but if the aircraft is later sold and the new owner sees the AD, they might panic and order an unneeded inspection. The records check should reveal the earlier part number if the records are accurate.

Third, the physical inspection (Requirement 1) requires moving seats full aft and using a mirror and flashlight. That sounds simple, but many aircraft have seat tracks that may not slide all the way, or the valve may be in a cramped location requiring removal of kick panels. The AD does not specify any tools beyond a mirror and flashlight. An operator who cannot complete the inspection because of poor access may be tempted to rely on the records check even if the aircraft is in Table 1. But Table 1 aircraft cannot use the records check; they must physically inspect. That is a trap for owners who think they can substitute the easier option.

Fourth, the compliance deadline is “before further flight after the effective date”. The effective date is 13 May 2008. If the AD was published on 6 May 2008 but the operator did not read it until after a flight on 13 May, they may have already flown without compliance. The AD is effective from the date stamped; there is no grace period for notification. Operators who do not subscribe to AD updates risk inadvertent non compliance.

Fifth, Requirement 5 applies to valves “installed as modification or replacement parts on or after the effective date”. If a valve had already been installed before 13 May 2008 but was not inspected at time of installation, the operator must still comply with Requirements 1-4. The AD does not retroactively invalidate a prior installation; it only requires that the current installation be inspected. So a valve installed in March 2008 that was never inspected before installation must now be inspected. An operator who replaced the valve before the effective date but never checked for placard obstruction still has a duty to inspect.

Sixth, the records check under Note 3 can be performed by a private pilot, but the pilot must “certify” the determination. The AD does not specify the form of certification. A pilot who simply notes “no -18 valve found” without signing or dating the logbook may not have adequately complied. The regulator may require a formal entry signed with the pilot’s licence number. Without that, the determination may be considered incomplete.

Seventh, the placard removal under Requirement 4 says “discard the placard”. It does not say to replace it with a correctly placed placard. If the placard was the only source of part number identification, the valve will now lack a placard. That could cause confusion later. The operator should consider marking the part number elsewhere or keeping a record of the part number.

Eighth, the AD applies to aircraft “that have an alternate static air source selector valve, P/N 2013142-18, installed after 19 November 2007.” That date is the start of the manufacturing period of the faulty parts. But the valve may have been manufactured earlier and held as stock before 19 November 2007 and installed later. The AD’s language “installed after 19 November 2007” catches any installation after that date, regardless of when the valve was manufactured. So a valve made in 2005 but installed on 1 December 2007 is captured. The focus is on installation date, not manufacture date.

Finally, the AD is specific to Cessna 180, 182, and Wren 460 series, but the background mentions many other Cessna models (172, 175, 185, 206, 207, 208, 210, 303) that had similar issues. Those models have their own ADs. An operator with a Cessna 172 must not rely on this AD; they must check the corresponding AD for their model.

Compliance with this AD can be broken into a step by step process that minimises cost and risk.

First, determine which table applies to the aircraft. Check the aircraft’s registration certificate, logbook, or type data sheet to identify the exact model and serial number. Compare against Table 1 and Table 2 in the AD. If the aircraft is one of the four specific serial numbers in Table 1 (182T: 18282062, 18282065; T182T: T18208822, T18208828), the pathway is mandatory: immediately arrange for a physical inspection of the alternate static air source selector valve before the next flight. The inspection must be performed by a person competent to carry out maintenance (typically a LAME), though the AD does not explicitly require a LAME for the physical inspection. If the aircraft falls within the broader Table 2 list, the operator has a choice.

Second, for Table 2 aircraft, review the aircraft’s maintenance records to determine whether the alternate static air source selector valve has ever been replaced since 19 November 2007 with P/N 2013142-18. This records check can be done by the aircraft operator provided they hold at least a private pilot licence. If the records show a replacement with that part number, or if the records are inconclusive, perform the same physical inspection as for Table 1. If the records clearly show that only earlier parts (-9, -13, -17) are fitted and no -18 valve was ever installed, note the determination in the aircraft logbook or other maintenance record, signed and dated. No further action is required for this AD (unless the valve is later replaced).

Third, for aircraft requiring a physical inspection, gather a flashlight and a mirror small enough to reach behind the valve. Move the pilot and copilot seats as far aft as possible. Locate the alternate static air source selector valve, which is typically near the cockpit floor or behind a panel near the pilot’s left side. Ensure the port on the forward end of the valve is clearly visible and not covered by the part number identification placard. If the placard obstructs the port, remove the placard from the valve body and discard it. Confirm that the port is open and unobstructed.

Fourth, document the compliance action. For a physical inspection, the person performing it should make an entry in the aircraft maintenance records stating: “Compliance with AD/CESSNA 180/93. Inspected alternate static air source selector valve P/N 2013142-18. Port found clear/unobstructed” or “Port obstructed - placard removed and port cleared”. The entry should include the date, the aircraft registration, the person’s name, and their qualification (e.g., LAME license number or private pilot licence number if the entry is for the records check). If placard removal was performed, note that the placard was discarded and the port is clear.

Fifth, for any future installation of a P/N 2013142-18 valve as a modification or replacement, inspect that valve under Requirement 1 before installation, regardless of whether it is new or from stock. Do not install a -18 valve that has not been checked for placard obstruction.

Sixth, maintain awareness of any subsequent amendments or supersedures. This AD does not expire, but if CASA issues a later AD that either supersedes or revokes this one, the operator must follow the new directive. Since this AD covers a specific manufacturing defect now corrected at the source, no further changes are likely, but vigilance is prudent.

Finally, consider the cost benefit. For a Table 2 aircraft with a clean record, the compliance cost is the time to review the maintenance records (perhaps 15 minutes) and make a logbook entry. For a Table 1 aircraft or a Table 2 aircraft that has had the -18 valve installed, the cost is the time to perform the physical inspection (30 minutes to an hour) plus any disassembly required to access the valve. The corrective action (placard removal) is trivial. The risk of non compliance - grounding or enforcement - far exceeds these costs, so prompt action is wise.