AD/CESSNA 650/7 - Actuator Control Unit

The directive revolves around several key concepts that an operator or maintenance organisation must understand. The actuator control unit (ACU) is the electronic component that controls the movement of the horizontal stabiliser. The directive refers to specific part numbers (P/N) : the original units susceptible to the defect are P/N 9914197-3 and P/N 9914197-4; the corrected unit is P/N 9914197-7. The directive draws a bright line: if you have the corrected unit, you are done with the ACU requirement; if you have one of the earlier part numbers, you must replace it.

The accomplishment instructions reference Cessna Service Bulletin SB 650-27-53, dated 11 March 2004. A service bulletin is a manufacturer-issued document that provides detailed instructions for inspection, replacement or repair. The directive does not reproduce those instructions; it makes them mandatory by reference. The directive also notes that later revisions of that service bulletin, if approved by the FAA as an Alternate Method of Compliance (AMOC) to FAA AD 2005-13-21, are considered acceptable for compliance with the equivalent requirements of this directive. This creates a mechanism for ongoing updates without requiring CASA to issue a new AD each time.

The aircraft flight manual (AFM) is the official document for that specific aeroplane, containing limitations, normal procedures, emergency procedures and performance data. The directive requires operators to revise the Limitations and Normal Procedures sections by inserting one or more Cessna temporary revisions (TRs). A temporary revision is an interim change to the AFM that takes effect until superseded by a general revision. The table in the directive lists which TR applies to each subset of Model 650 aeroplanes: Citation III (serials 0001-0199 and 0203-0206) with or without the SPZ-8000 system; Citation VI (serials 0200-0202 and 0207 and subsequent); and Citation VII (serials 7001 and subsequent) with or without SPZ-8000. The TR dates are specified: 12 May 2004 for most, and 11 August 2004 for some subsequent AFM versions.

The compliance times create a hierarchy. For requirements 1 and 2 (inspection and replacement), the deadline is within 12 months after the effective date of the directive. For requirement 3 (AFM revision), the deadline is within 1 month after the effective date, or concurrently with the replacement required by requirement 2, whichever occurs first. This means that even if no ACU replacement is needed, the AFM revision must still be done within the first month. The effective date is 1 September 2005.

This directive directly affects three groups in the Australian aviation industry. The first group is the registered operator of any Cessna 650 series aeroplane on the Australian register. Under the Civil Aviation Act 1988, the operator is ultimately responsible for maintaining the aircraft in an airworthy condition and for ensuring compliance with all airworthiness directives. The operator must arrange for the inspection and, if required, the replacement of the ACU, and must ensure that the AFM is revised. The cost of parts, labour, and downtime falls on the operator, as does the risk of non-compliance penalties. The directive does not provide any government subsidy or compensation for these costs.

The second group is licensed aircraft maintenance engineers (LAMEs) and approved maintenance organisations (AMOs). These are the persons who will physically perform the inspection in accordance with the service bulletin, obtain and install the replacement ACU if needed, and update the AFM. They must have access to the current version of SB 650-27-53 and to the relevant temporary revisions. They also need to ensure that any replacement ACU is correctly identified and that the maintenance release and logbook entries accurately record compliance with the directive. Maintenance organisations that service Citation aeroplanes will need to stock or source the P/N 9914197-7 ACU, which may involve supply chain delays and increased inventory costs.

The third group is owners and prospective purchasers of these aeroplanes. An owner who does not comply with the directive before selling the aircraft may pass on a non-conforming aircraft, which could affect the sale price or even prevent the transfer of the aircraft’s airworthiness certificate. A purchaser’s due diligence should include checking that AD/CESSNA 650/7 has been complied with, especially verification that the ACU is P/N 9914197-7 and that the correct AFM revisions have been inserted. The directive also affects insurance underwriters: many policies require strict compliance with all applicable airworthiness directives; failure to comply could void coverage in the event of an incident related to horizontal stabiliser movement.

The directive applies to all Model 650 aeroplanes, which includes the Cessna Citation III, Citation VI and Citation VII variants, regardless of how they are used - private, charter, corporate or other. The specific serial numbers listed in the AFM revision table cover the entire production range up to the directive’s issue date. Later serial numbers may be covered by other directives, but this AD does not exclude them.

The principal duties on the operator are clear. First, the duty to inspect within 12 months of 1 September 2005: determine the part number of the installed ACU in accordance with the accomplishment instructions of Cessna Service Bulletin SB 650-27-53. Second, the duty to replace if the inspection reveals P/N 9914197-3 or 9914197-4: replace the ACU with a new unit P/N 9914197-7, again following the service bulletin. Third, the duty to revise the AFM within 1 month (or concurrently with replacement, whichever sooner): insert a copy of the appropriate temporary revision into the Limitations and Normal Procedures sections of the AFM. The table in the directive lists the exact TR numbers and dates for each subset of aircraft. Note 1 to the AFM revision requirement allows an operator to later remove the TR if a general revision of the AFM includes identical statements; at that point the general revision may be inserted and the TR may be removed. This is a right: the operator can eventually clean up the AFM without losing compliance.

The operator also has a right to rely on later FAA-approved revisions of the service bulletin. Paragraph 2 of the requirement states: “Later revisions of the above SB, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2005-13-21, are considered acceptable for compliance with the equivalent Requirements of this Directive.” This means that if the manufacturer issues a revision to SB 650-27-53 after the AD’s effective date, and the FAA approves that later version as a method of complying with its own AD, then CASA will treat that later revision as acceptable for compliance here. This reduces the compliance burden if the manufacturer improves the service procedure, and it avoids the need for CASA to issue a formal amendment or new AD.

There is no duty in the directive to submit a compliance report to CASA, though the operator must still maintain records of the inspection, replacement and AFM revision for audit purposes. The directive also does not create a duty to inspect for any other ACU part number; if the unit is an earlier part number not in the list (e.g., 9914197-5 or -6), those are not mentioned and presumably do not fall within the scope of the directive, but a cautious operator would check with the manufacturer or CASA. The duty is limited to the listed part numbers.

The directive does not itself prescribe penalties, but it forms part of the regulatory framework enforced under the Civil Aviation Act 1988 and the Civil Aviation Safety Regulations 1998 (CASR). An airworthiness directive issued by CASA is a legislative instrument, and operating an aircraft contrary to an applicable AD is an offence. Under the Civil Aviation Act, the maximum penalty for a breach of a safety regulation can be substantial: for an individual, fines of up to several thousand penalty units (a penalty unit at the time was $110, so up to $110,000 or more depending on the specific provision) and imprisonment for serious offences. For a body corporate, the fines can be five times those amounts. In addition, CASA may issue civil penalty notices, suspend or cancel the aircraft’s certificate of airworthiness, or ground the aircraft until compliance is demonstrated.

The practical enforcement mechanism is typically through routine maintenance audits and airworthiness reviews. When an aircraft undergoes its annual or periodic airworthiness inspection, a CASA-authorized person will check that all applicable ADs are listed in the aircraft’s continuing airworthiness records and that the actions required by each AD have been completed. If non-compliance is detected, the authorised person may refuse to issue a certificate of release to service or may ground the aircraft. That grounding has immediate operational and financial consequences for the operator.

Enforcement can also occur after an incident or accident. If an uncommanded horizontal stabiliser movement occurs and it is found that the ACU was not replaced in compliance with this directive, the operator could face enforcement action, and potentially criminal charges if the breach is judged to be reckless or intentional. Insurance policies typically exclude cover for losses caused by non-compliance with mandatory airworthiness directives, so the operator may bear the full cost of any subsequent accident.

The directive is silent on any defence or exemption. Operators cannot simply decide that the risk is low and ignore the AD. The only flexibility built into the text is the ability to use later FAA-approved revisions of the service bulletin. There is no provision for obtaining an individual AMOC from CASA; the directive only references an FAA AMOC for service bulletin revisions, not for the AD itself. An operator seeking a different method of compliance would need to apply to CASA separately under the general provisions of the Civil Aviation Safety Regulations, which can be a time-consuming and uncertain process.

This directive sits within a hierarchy of aviation safety law. At the top is the Civil Aviation Act 1988 (Cth), which empowers CASA to issue airworthiness directives. Below the Act are the Civil Aviation Safety Regulations 1998 (CASR), particularly Part 39 (which deals with airworthiness directives) and Part 42 (continuing airworthiness). The directive itself is a specific legislative instrument made under those regulations. An operator must comply with this AD in addition to all other applicable ADs and regulatory requirements.

The directive explicitly references and relies on the equivalent FAA airworthiness directive, FAA AD 2005-13-21 Amdt 39-14158. By adopting the FAA’s safety analysis and allowing later FAA-approved revisions of the service bulletin, CASA is effectively harmonising its requirement with the US regulation. This is common for type-certificated aircraft manufactured in the United States. However, the directive is a separate Australian legal instrument; an operator cannot simply point to FAA compliance alone. The operator must ensure that the specific actions are performed on the Australian aircraft and that the AFM revisions listed in the CASA directive are inserted, not just the FAA-required revisions. The benefit is that if a later version of the Cessna service bulletin is approved by the FAA as an AMOC, it can be used for Australian compliance as well.

The directive also interacts with the Continuing Airworthiness Management requirements under CASR Part 42. The operator’s maintenance control manual (MCM) should include a process for tracking and complying with ADs. This directive must be added to the aircraft’s AD status list, and the compliance action must be recorded in the aircraft logbook. The timing of the directive (effective 1 September 2005) means it would have been a new AD that operators had to schedule into their existing maintenance cycles. The 12 month compliance period for the ACU inspection and replacement allows operators to incorporate the work into a planned maintenance check, but the 1 month AFM revision deadline is very tight.

Under the Civil Aviation (Carriers’ Liability) Act and general tort law, an operator who does not comply with this directive could be found negligent in a civil claim if the defect leads to injury or damage, even if no criminal penalty is imposed. The AD gives a clear standard of care: a reasonable operator would comply. Similarly, insurance policies often exclude cover for breaches of mandatory ADs, as a contractual condition.

The source document is the original directive, effective 1 September 2005. The document itself does not show any subsequent amendments, and the text bears no amendment note or history. As a standalone instrument, AD/CESSNA 650/7 (reference 9/2005) is the version that operators must have complied with. However, standard practice for airworthiness directives is that CASA may later issue a superseding directive that either extends the compliance time, adds additional requirements, or removes the requirement if the defect is found not to exist. CASA may also issue an amendment to correct typographical errors or to adjust the applicability. Without access to a current AD register, we cannot confirm whether this AD has been superseded or amended since 2005. The reference to “AD/CESSNA 650/7” suggests this is the seventh AD for the Cessna 650 series; later ADs may have incorporated or replaced this one. Operators must always check the current CASA AD listing to see if a newer directive (e.g., AD/CESSNA 650/10 or similar) supersedes this one.

The directive itself contains a mechanism for “later revisions of the above SB” to be accepted if approved by the FAA. That is not an amendment of the AD itself, but a flexibility that allows the AD to remain current even when the underlying service bulletin is updated. The AFM revision table lists specific temporary revision numbers; those TRs have their own revision status. Note 1 says that if a general revision of the AFM incorporates the same statements, the TR can be removed. That is a housekeeping update, not an amendment to the AD.

The source does not mention any litigation history, and it is unlikely that this specific airworthiness directive has been the subject of reported court proceedings. Airworthiness directives are routinely complied with, and challenges to ADs are rare in Australia. The most common form of legal interaction would be an administrative review under the Administrative Appeals Tribunal Act 1975 if CASA takes enforcement action and the operator disputes the factual basis. The Civil Aviation Act allows for merits review of certain decisions, but the AD itself, as a legislative instrument, is not reviewable on its merits; a person may apply for a variation or an exemption.

In the United States, the parallel FAA AD (2005-13-21) may have been challenged or commented upon, but there is no indication of that from this source. The absence of litigation does not mean the AD is uncontroversial; many operators of ageing Citation aircraft face significant cost for parts and labour, and the replacement ACU (P/N 9914197-7) may have been expensive or difficult to source. However, the safety justification - preventing loss of controllability - is powerful, and operators likely complied rather than risk enforcement.

A notable point: the directive states it is issued by David Villiers, Delegate of the Civil Aviation Safety Authority, on 21 July 2005. That lends it the full force of CASA’s authority. Any legal challenge would need to show that the decision to issue the directive was ultra vires or procedurally defective, which would be difficult given the reliance on the FAA’s safety determination.

Several points in the directive can easily trap an unwary operator or maintainer.

Trap 1: The AFM revision deadline is independent of the ACU replacement. Requirement 3 must be complied with within 1 month after the effective date (1 September 2005) or concurrently with the ACU replacement if that replacement is done earlier. If the aircraft already has P/N 9914197-7, no ACU replacement is needed, but the AFM revision still must be done within the first month. A busy operator might think “no ACU action needed, so I’m done,” and miss the AFM deadline.

Trap 2: The AFM revision table is tightly crafted. The table splits aircraft by model, serial number range, and avionics configuration (with or without Honeywell SPZ-8000). Using the wrong temporary revision, or not inserting all the TRs listed for a given aircraft, would be non-compliance. For example, Citation VII serials 7001 and subsequent need TR 65C7FM TC-R10-01, but if equipped with SPZ-8000 they also need TR 65C7FM TC-R10-07. An operator who inserts only the first TR may be in breach.

Trap 3: The directive does not provide a free pass for P/N 9914197-5 or other variants. The text only says if an ACU having P/N 9914197-7 is installed, no further action is required under requirement 1 and 2. It does not address what happens if a unit has P/N 9914197-5 or any part number not listed. The operator might think that because the part number is not mentioned, it is automatically acceptable. However, the directive is focused on the specific model numbers; other part numbers may still be suspect or unknown. The prudent approach would be to treat any ACU that is not P/N 9914197-7 as needing replacement unless the manufacturer confirms otherwise.

Trap 4: The allowance for later FAA-approved SB revisions is not a free pass to ignore the original. The directive says only later revisions of the above SB that are approved by the FAA as AMOC to FAA AD 2005-13-21 are acceptable. If the manufacturer issues a later revision that the FAA does not formally approve as an AMOC, that revision cannot be used for Australian compliance unless CASA separately approves. Also, the AMOC only applies to the SB, not to the AFM revision requirement.

Trap 5: Record-keeping. The directive does not specify what records must be kept, but the aircraft maintenance records must show each AD number, the date of compliance, and the details of the action taken. If the inspector signs off without noting the AD number and the part number of the installed ACU, a later auditor may deem the compliance incomplete.

**Trap 6: The directive references FAA AD 2005-13-21 Amdt 39-14158 in Note 2, but that note does not create an obligation; it is just a cross-reference. However, if an operator mistakenly relies on the FAA AD’s compliance deadline (which may differ), they could be late for the Australian deadline.

Compliance with AD/CESSNA 650/7 requires a systematic approach. The following steps are grounded in the source.

Step 1: Identify the aircraft. Determine the make, model and serial number. Confirm it is within the applicability: all Model 650 aeroplanes. Also note the avionics fit (Honeywell SPZ-8000 or not) from the equipment list or AFM.

Step 2: Obtain documents. Acquire Cessna Service Bulletin SB 650-27-53, dated 11 March 2004 (or a later FAA-approved revision). Also obtain the appropriate Cessna temporary revisions from the table: for example, for a Citation III (S/N 0120 without SPZ-8000), get TR 65C3FM TC-R02-01 dated 12 May 2004 and TR 65C3FM TC-R02-07 dated 11 August 2004. These TRs can be obtained from Cessna or the CASA website.

Step 3: Perform the ACU inspection. Within 12 months after 1 September 2005 (i.e., by 1 September 2006), inspect the ACU per the SB to determine its part number. Record the part number in the maintenance log. If it is P/N 9914197-7, proceed to Step 5 (AFM revision only). If it is P/N 9914197-3 or 9914197-4, proceed to Step 4.

Step 4: Replace the ACU. If P/N 9914197-3 or -4, replace it with a new unit P/N 9914197-7 in accordance with the same service bulletin. The replacement must be done within the same 12 month compliance period. After replacement, the aircraft may have the corrected part.

Step 5: Revise the AFM. This must be done within 1 month after 1 September 2005 (i.e., by 1 October 2005), or concurrently with the ACU replacement if that is earlier. Insert a copy of the applicable temporary revision(s) into the Limitations and Normal Procedures sections of the AFM. The TRs should be placed in the correct sections, and the AFM should be marked with the date of insertion. Record this action in the logbook. Note 1 allows later removal of the TR if a general revision incorporates the same statement, but only after that general revision is actually published and inserted.

Step 6: Record compliance. Enter the AD number, a brief description of actions taken (e.g., “ACU inspected P/N 9914197-7, no replacement required; AFM revised per TR 65C3FM TC-R02-01 and TC-R02-07 dated …”), the date, and the signature and license number of the person who performed the maintenance and the person who authorised the return to service. Ensure that the aircraft’s continuing airworthiness records now show AD/CESSNA 650/7 as “complied” with the date and details.

Step 7: Monitor for later revisions. If the operator later becomes aware of an FAA-approved revision to SB 650-27-53, they may use that revision for future maintenance, but only if they previously performed the replacement under the original SB. For example, if the original replacement was done using the original SB, and a later revision changes the inspection or installation procedure, it is not required unless a new AD or amended AD mandates it.

Step 8: During subsequent maintenance. If the ACU is ever removed and replaced in the future, the operator must ensure that only P/N 9914197-7 (or an equivalent approved by CASA or the exemption) is fitted. A unit with P/N 9914197-3 or -4 must not be reinstalled.

The direct financial compliance burden includes the cost of the ACU itself (likely several thousand dollars), labour for inspection and replacement, and cost of obtaining the service bulletin and temporary revisions (if not free). There may also be aircraft downtime. For an aircraft that already has the corrected part, the burden is only the AFM revision and the cost of an inspection that may only be a visual check of the part number plate. However, the directive does not allow an assumption; the inspection must still be performed within the 12 month window, even if the operator is confident the part is correct.