AD/CL-600/96 - Stick Pusher Capstan Shaft

The central concept is the stick pusher, a stall protection device that automatically pushes the control column forward to reduce the angle of attack when an impending stall is detected. The capstan shaft is the rotating component within the stick pusher mechanism around which the cable wraps. If the capstan shaft fractures or degrades, the stick pusher function may be lost or severely impaired. Because this loss can occur without any cockpit indication, the AD describes it as a dormant failure. The AD addresses two detection layers. The first is a procedural check: the first flight of the day check is revised to detect any degradation of stick pusher function. The second is a physical inspection: a new periodic task in the maintenance schedule to directly check the structural integrity of the capstan shaft. The Aircraft Flight Manual (AFM) is the primary document containing operating limitations, procedures, and performance data for the aircraft. A Temporary Revision (TR) is an interim change to the AFM pending a permanent update to the manual. The TRs are identified by part numbers and dates, e.g. PSP 600 DOT TR 600/24 dated Jan 30/07. Each aircraft model and variant has its own specific TR. The maintenance schedule is the approved plan of periodic inspections and tasks that must be performed to maintain the aircraft in an airworthy condition. The AD specifies which chapter and task number to incorporate for each model. For example, for the CL-604, the new task is Chapter 5, section 5-10-40, task number 27-35-10-101, introduced via Temporary Revision TR 5-2-32 to the maintenance schedule. The concept of an Airworthiness Directive itself is a mandatory instruction issued by a civil aviation authority to correct an unsafe condition. ADs are regulatory instruments with legal force. The AD operates by cross-referencing another jurisdiction's directive (Transport Canada) but is issued by CASA as the Australian regulator. Operators must ensure compliance with the Australian AD regardless of any other jurisdiction's requirements. The concept of effectiveness date (8 May 2008) is critical: the 30-day compliance period runs from this date, not from the date of issuance (6 March 2008). The AD includes a note referencing Transport Canada AD CF-2008-12, informing operators that this is the underlying directive. However, compliance with the CASA AD is the legal requirement in Australia.

The AD applies to operators of Bombardier Inc. CL-600 aircraft in Australia, specifically four model variants within specified serial number ranges. For the CL-600-1A11 (CL-600), serial numbers 1004 through 1085. For the CL-600-2A12 (CL-601), serial numbers 3001 through 3066. For the CL-600-2B16 (CL-601-3A/3R), serial numbers 5001 through 5194. For the CL-600-2B16 (CL-604), serial numbers 5301 through 5665. Any Australian operator, whether a commercial air transport operator, charter company, private owner, or corporate flight department, who holds an aircraft within those serial numbers must comply. The AD also affects flight crew who must be briefed on the AFM revisions and who will perform the revised first flight of the day check. Maintenance personnel are affected because they must carry out the new periodic inspection task on the capstan shaft and ensure the maintenance schedule is updated. Design organisations and repair stations that maintain these aircraft for Australian operators need to be aware of the new task. Bombardier Aerospace is referenced indirectly as the source to consult if the operator has an AFM not listed in the AD. Engineers and planners within operator organisations must update the approved maintenance schedule and ensure the task cards reflect the new requirement. Insurance underwriters may take an interest, as non-compliance with an AD can affect coverage. Passengers and crew are indirectly affected, as the AD aims to restore the reliability of the stick pusher function, thereby maintaining the aircraft's stall protection envelope. The AD does not apply to aircraft outside the listed serial number ranges, but the background does not explain why those ranges were chosen. Other operators of similar models not captured may still face the same underlying risk but are not legally compelled to act by this AD. The AD does not affect manufacturers or regulators directly, though Transport Canada issued the original directive. Within Australia, the most directly affected party is the CASA office that will monitor compliance. Suppliers of spare parts for the capstan shaft may see increased demand if the inspections reveal failures that require replacement.

The primary duty is on the operator to accomplish two tasks within 30 days after 8 May 2008, unless previously accomplished. Duty one: amend all copies of the AFM by incorporating the applicable TR listed for the specific model. Additionally, the operator must advise all flight crews on the changes introduced through the AFM TR. This is an active briefing duty, not merely a notification; the operator must ensure crew are informed and understand the revised check. Duty two: amend the Transport Canada approved maintenance schedule by incorporating the new inspection task as introduced by the specified Temporary Revision for that model. The AD does not specify who must perform the physical inspection but it logically falls to the maintenance organisation. The operator may contract this out but remains ultimately responsible. The operator also has the right to consult Bombardier Aerospace if the AFM it holds is not listed in the AD. This implies that some AFM configurations may exist that are not covered by the specified TRs, and Bombardier can advise on the appropriate amendment. The AD does not create a right to an extension or exemption. The compliance period is fixed. The operator has no right to choose an alternative method of compliance unless CASA grants one under its general powers, which the AD does not address. The operator has the right to rely on the TRs as published by Bombardier. There is no duty to develop original solutions. The AD does not impose a duty on the pilot in command beyond the normal obligation to operate an airworthy aircraft and follow the AFM. However, once the AFM is amended, the pilot must comply with the revised procedures. The AD does not explicitly require that the inspection be performed before further flight; it only requires incorporation of the task within 30 days and presumably the task will then be performed at its next interval. The operator has the duty to ensure that the inspection is completed on schedule after incorporation. The AD does not specify the interval of the new task; that is defined in the TR to the maintenance schedule. The operator must rely on the TR for the exact detail. The AD imposes a duty of record keeping: evidence of AFM amendment, crew briefing, and schedule amendment must be retained for compliance verification.

The AD is issued under delegation from CASA, which derives its authority from the Civil Aviation Act 1988 (Cth). Non-compliance with an Airworthiness Directive is a breach of the Civil Aviation Safety Regulations 1998 (CASR), specifically Part 39 (Airworthiness Directives). The operator who fails to comply commits an offence. The Civil Aviation Act provides for penalties including fines and imprisonment for contraventions that create a risk to safety, but the typical enforcement action for AD non-compliance is a direction to ground the aircraft, revocation of the Certificate of Airworthiness, and/or civil penalty proceedings. The AD itself does not specify the penalty amount, but under CASR Part 39, a breach is generally a strict liability offence, meaning no fault needs to be proved. The operator cannot defend on the basis of ignorance or impracticality. The AD carries a fixed compliance date, so delay beyond 30 days from 8 May 2008 is a continuing breach. Each day of non-compliance may be treated as a separate offence. The AD does not list the specific penalty, but reference to CASA's enforcement policy indicates that fines can be up to several hundred thousand dollars for corporations, plus daily penalties. CASA can issue a written direction to ground the aircraft until the AD is complied with. If an operator operates an aircraft that does not comply with the AD, the Certificate of Airworthiness may be suspended or revoked. In serious cases, CASA may prosecute under the Act, leading to criminal convictions and potentially imprisonment for individuals under section 20A of the Act for reckless conduct. The absence of a prior accident does not mitigate the breach. CASA has a policy of zero tolerance for AD non-compliance because of the safety imperative. The AD is enforced by CASA inspectors who may audit operator records and spot-check aircraft. The operator must be able to produce evidence of compliance on demand. The AD does not specify the consequences of failing to brief flight crews, but that is part of the overall duty. The penalty for failing to brief may be considered a separate breach.

This AD is issued under the Australian Civil Aviation Act and the Civil Aviation Safety Regulations. It operates within the framework of the International Civil Aviation Organization (ICAO) Annex 8 (Airworthiness of Aircraft) which requires member states to ensure continued airworthiness through ADs. The AD specifically references Transport Canada AD CF-2008-12 dated 8 February 2008. This indicates that the Canadian directive is the originating safety action, and CASA has adopted it as a national AD. Therefore, operators who have already complied with the Transport Canada AD before 8 May 2008 are deemed to have complied with the Australian AD, as the compliance wording says unless previously accomplished. The AD does not require duplication of effort if the Canadian requirements were already met. However, the operator must ensure that the Australian AD's specific TR numbers and dates are satisfied, which should be identical to the Canadian TRs if properly adopted. The AD interacts with the operator's own maintenance control manual and approved maintenance schedule, which must be amended to include the new task. It also interacts with the continuing airworthiness management system; the task must be entered into the operator's airworthiness program and tracked for repeat intervals. The AD may interact with other ADs affecting the same aircraft, such as those for the stick pusher system or related components. The operator must ensure compatibility of revision numbers and avoid conflicts. The AD does not override any other legislation; it is additive. It does not interact with trade practices law or contract law directly, but an operator who fails to comply may breach lease agreements or insurance policies that require compliance with all ADs. If the aircraft is leased or chartered, the lessee and lessor must coordinate compliance. The AD may also interact with workplace health and safety laws, as the inspection task introduces occupational risks for maintenance staff (e.g., working around flight controls). The AD does not address these. The AD does not interact with environmental laws. It does not purport to amend tax, customs, or immigration law. It is a narrow, technical regulatory instrument.

The AD as presented is the original and only version published by CASA. There is no preceding amendment history shown in the source. The AD was issued on 6 March 2008 and became effective on 8 May 2008. The TRs referenced in the AD are dated 30 January 2007, indicating that Bombardier's engineering action occurred over a year before the CASA directive. The AD has no listed supersedure or amendment record. It does not state that it replaces any earlier AD. The number AD/CL-600/96 suggests that CASA has issued previous ADs on CL-600 models; this is number 96. The stick pusher capstan shaft issue may have been addressed by earlier ADs on other aircraft types, but not on this series. The AD itself may later be superseded by a more comprehensive directive if Bombardier develops a terminating action, such as a design change to the capstan shaft. As of the source text, no amendment exists. The AD is current as at its effective date. Operators should check whether CASA has later superseded, revised, or withdrawn this AD. The AD's amendment history must be tracked through CASA's online AD database. The absence of amendment history in the source is not unusual; ADs are often issued as fresh directives without a long amendment chain. If a terminating action (a one-time fix) is later developed, CASA will typically issue a new AD that supersedes this one, removing the need for periodic inspections. The source does not indicate any such supersedure.

The source text includes no litigation history. This is common for Airworthiness Directives because they are rarely challenged in court. The narrow technical nature, the safety imperative, and the fact that ADs are founded on engineering evidence make judicial review difficult. Operators typically comply rather than litigate. If an operator were to challenge AD/CL-600/96, the grounds would likely be procedural, such as alleging that CASA failed to follow proper consultation or that the AD is disproportionate to the risk. However, in Australia, ADs are issued by a delegate under delegated legislation and are generally immune from merits review. Judicial review under the Administrative Decisions (Judicial Review) Act 1977 (Cth) is theoretically available but very rare. No published Australian court or tribunal decision specifically concerns this AD number. A search of the Australasian Legal Information Institute database would yield no results. Internationally, ADs for similar capstan shaft issues on other aircraft types have not led to reported litigation. If an incident occurred that was linked to non-compliance with this AD, litigation might arise in tort or contract against the operator rather than against CASA. The AD itself would then be evidence of the standard of care. The absence of litigation history does not mean the AD is unimportant; it reflects that the regime is accepted. The AD's enforceability has not been tested. The most likely legal proceedings involving this AD would be CASA enforcement actions against a non-compliant operator, which rarely generate published decisions. Any such action would be a prosecution in the Federal Court or the Local Court, which may not be publicly reported. In summary, there is no known case law interpreting or applying AD/CL-600/96.

Several aspects of this AD can catch an unwary operator. First, the compliance period is 30 days after the effective date of 8 May 2008. If a new entrant acquires an aircraft after that date, the AD must still be complied with before operation; the 30-day period does not restart. The phrase unless previously accomplished means the operator must verify whether the AD was complied with by a previous operator. Many operators assume that when buying an aircraft the ADs are current, but the TRs and inspection may not have been transferred if the aircraft was operated under a different jurisdiction. Second, the AD requires amendment of all copies of the AFM. Many operators have multiple copies at various bases. If any copy is missed, the operator is non-compliant. The flight crew briefing is a separate duty; it is not enough to amend the manual. The AD says advise all flight crews, which implies a positive communication requirement. An electronic briefing bulletin may be insufficient if not all crew acknowledge receipt. Third, the AD applies only to specific serial number ranges. Operators must double-check their serial numbers. A one-digit error in the serial number can cause an operator to miss applicability or incorrectly assume it applies. The serial numbers for the CL-600-1A11 start at 1004; if serial number 1003 is operated, the AD does not apply, but the underlying risk may still exist. Fourth, the maintenance schedule amendment requires incorporation of the new inspection task as introduced by the applicable TR. The TR numbers differ across models. Using the wrong TR can result in an incorrect task being added. The operator must ensure the task matches the exact model and serial number. Fifth, the AD does not specify the inspection interval for the new task. That information is contained within the TR. Operators must look up the TR to determine whether the inspection is required before further flight or on a repetitive cycle. If the interval is missed, the operator may be out of compliance without realising it. Sixth, the AD notes that if the operator has an AFM not listed, they must consult Bombardier. This is an open-ended obligation; the operator cannot simply ignore the AD on the basis that their AFM is not listed. They must proactively seek guidance from Bombardier. Seventh, the AD refers to Transport Canada AD CF-2008-12. An operator who complies only with the Canadian AD may think they are done, but must ensure the Australian AD's specific TR incorporation dates are satisfied. Eighth, the AD requires compliance within 30 days, but the inspection itself might take longer if parts are unavailable. The AD does not grant relief for parts availability. The operator must plan accordingly. Ninth, the AD does not require a return to service inspection; the aircraft can continue operating as long as the AFM and schedule are amended and the first flight check is revised. However, the new periodic inspection must be performed at its first due interval. Operators must integrate the new task into their maintenance program promptly.

Compliance with AD/CL-600/96 involves a structured, documented process. Step one: confirm applicability. Check the aircraft's model and serial number against the ranges listed in the AD. For each affected aircraft, record the specific model and serial. Step two: locate the correct AFM Temporary Revision (TR) for that model. The AD provides the part number and date for each variant. For a CL-604, the TR is PSP 604-1 DOT TR 604/22 dated Jan 30/07. Obtain a copy of this TR from Bombardier Aerospace or from the aircraft's maintenance data provider. Step three: amend all copies of the Aircraft Flight Manual. Insert the TR into each AFM binder or electronic document system. Follow the TR's instructions for insertion, which typically require removing superseded pages and inserting new ones. Verify that the revision is visible and that a record of the amendment date is logged. Step four: brief all flight crew. This can be done via a crew bulletin, a sign off sheet, or a briefing at the next available crew meeting. The briefing must cover the changes introduced by the TR to the first flight of the day check of the stall protection system. Document the date and content of the briefing and ensure each crew member signs to acknowledge receipt. Retain these records indefinitely. Step five: amend the Transport Canada approved maintenance schedule. For each model, find the applicable TR to the maintenance schedule. For example, CL-604 uses TR 5-2-32. This TR introduces a new task at Chapter 5, section 5-10-40, task number 27-35-10-101. Insert the TR into the operator's approved maintenance schedule as per the TR instructions. Step six: determine the initial compliance time for the new inspection task. The TR should specify whether the task must be done immediately, within a certain flight hours or cycles, or by a calendar date. If the TR does not specify an initial threshold, contact Bombardier for clarification. Schedule the inspection accordingly. Step seven: perform the inspection task on the stick pusher capstan shaft. The task is to check the structural integrity, likely by visual inspection or non destructive testing. Use the manufacturer's instructions. If cracks or defects are found, follow the repair instructions or contact Bombardier. Record the inspection results in the aircraft maintenance log. Step eight: update the operator's Continuing Airworthiness Management Exposition (CAME) or equivalent to reflect the new task and its repeat interval. Ensure the task is entered into the maintenance tracking system and will be repeated at the correct interval. Step nine: maintain a compliance file containing copies of the AFM TR, evidence of crew briefing, the maintenance schedule TR, and records of the inspection. This file must be available for CASA inspection. Step ten: verify that all actions are completed within 30 calendar days after 8 May 2008, i.e., by 7 June 2008. If the aircraft was already in compliance before the effective date, confirm by documentary evidence. If the aircraft is acquired later, comply before further flight. If any step is unclear, consult Bombardier Aerospace as directed in the AD. Do not rely on oral advice alone; obtain written confirmation. Consider engaging a CASA authorized maintenance organisation to oversee the process. After compliance, schedule a periodic review to ensure the AFM and maintenance schedule remain current with any subsequent Bombardier revisions. The AD itself does not require a return to service by CASA; the operator can close the compliance action internally. However, a logbook entry referencing compliance with AD/CL-600/96 should be made.