AD/DHC-8/142 - Spoiler Disconnect Sensing Device

Spoiler cable disconnect sensing device. This is a mechanism in the DHC-8 fuselage spoiler control system designed to detect a disconnection in the spoiler cable. It presumably signals the flight control system or alerts the crew if the cable breaks, allowing compensatory control inputs. The device includes a pulley and a plastic spacer. The assembly error identified in the background is that these two parts were inadvertently interchanged during manufacturing, so the spoiler cable runs on the plastic spacer instead of the pulley. That changes friction and wear characteristics and impairs the device’s ability to detect a disconnect.

Correct assembly. The directive defines correct assembly by reference to Bombardier Service Bulletin 8-27-107 (for Series 100/200/300) and SB 84-27-34 (for Series 400). These service bulletins describe the inspection procedure (Part A) and the rectification procedure (Part B). The directive allows use of the initial issue dated October 2007 or any later approved revision, meaning Bombardier may have updated the procedures since the initial publication. Operators must ensure they use the current approved revision at the time of compliance.

Modsum. This is a modification summary designation used by Bombardier (Modsum 8Q100898). It represents the engineering package and installation instructions for retrofitting the spoiler cable disconnect sensing device onto earlier aircraft that left the factory without it. The earlier AD/DHC-8/126 mandates that retrofit. The present AD builds on that by requiring a post-retrofit or in-production inspection for correct assembly.

Production installation vs. retrofit. The directive distinguishes aircraft that received the device at the factory (serial numbers 562 through 644 for the 100/200/300 models, and all 400 series) from those that received it as a retrofit. For both groups, the inspection is required. This is noteworthy because one might assume that production-installed parts are correctly assembled; the background states that several incorrectly assembled devices were found on in-service aircraft, implying the error occurred during production assembly. Therefore, even aircraft that left the factory with the device may have the error.

Continuing airworthiness. Under CASR Part 42, an operator must ensure that an aircraft is maintained in a condition that is safe for operation and that all applicable airworthiness directives are complied with. AD/DHC-8/142 is such a directive. Failure to comply means the aircraft is not in a condition of continuing airworthiness and cannot be lawfully operated in Australian territory. The directive functions as a legally binding maintenance requirement.

Effective date and compliance period. The directive becomes effective on 25 September 2008. Compliance must be achieved within 1000 flight hours after that date. This creates a permissive grace period but does not remove the obligation to comply before reaching 1000 hours; if the aircraft is grounded for other reasons before that limit, the operator cannot defer the inspection arbitrarily.

Background as regulatory justification. The background states that the assembly error could lead to impaired operation of the sensing device and/or eventual cable disconnect, with possible reduced controllability. This is a factual claim from Transport Canada and CASA. The directive itself does not quantify the probability or severity of the hazard, but the issuance of an AD implies a finding that the unsafe condition is likely to exist or develop in other aircraft and that immediate action is warranted. The risk must be weighed against the cost and inconvenience of the inspection. The 1000-hour window suggests the condition is not immediately catastrophic, but still requires prompt attention.

The directive directly affects the operators and owners of the specific Bombardier DHC-8 aeroplanes listed in the applicability section. That includes:

• DHC-8 Models 102, 103, 106, 201, 202, 301, 311, 314, and 315 with serial numbers 003 through 644 inclusive (the Series 100, 200, and 300).
• DHC-8 Models 400, 401, and 402 with serial numbers 4003, 4004, 4006, and 4008 through 4164 inclusive.

These aircraft are typically used in regional airline operations, charter services, freight, and government or military surveillance. In Australia, operators such as QantasLink (with its DHC-8-400 fleet), Rex (with older Dash 8 models), and other regional carriers would be caught. The directive also affects any foreign operator that flies these aircraft into Australian airspace, because CASA’s ADs apply to all aircraft registered in Australia and, under certain circumstances, to foreign-registered aircraft operating in Australian territory. However, the directive is issued by CASA and primarily binds Australian registered aircraft.

Indirectly affected parties include:

• Maintenance organisations. Certifying engineers and approved maintenance organisations (AMOs) must have the applicable Service Bulletins, the required tooling, and trained personnel to perform the inspection and any rectification. This generates additional demand for labour and creates scheduling pressure if multiple aircraft must be inspected within the 1000-hour window.
• Parts suppliers. If rectification reveals worn or damaged components, operators will need replacement parts. The directive does not specify a separate compliance time for parts; if parts are not readily available, operators may face ground time beyond the 1000-hour limit unless they apply for an alternative means of compliance.
• Bombardier (the manufacturer). Although Bombardier is not a regulated entity under this AD, the directive relies on Bombardier’s Service Bulletins. If Bombardier releases a later approved revision of either SB 8-27-107 or SB 84-27-34, operators must track that change. Bombardier may also have a commercial incentive to improve the assembly instructions or supply correction kits.
• CASA as regulator. CASA incurs the cost of administering the AD, managing any alternative means of compliance applications, and enforcing compliance.
• Passengers and freight customers. Ultimately, the compliance cost may be passed through in ticket prices or freight rates, or may reduce aircraft availability, leading to schedule disruptions. The economic incidence falls on consumers, though operators may absorb some cost depending on market competition and capacity constraints.

For operators with smaller fleets (e.g., a single DHC-8 used for mining charters), the 1000-hour window may be a significant burden if the aircraft flies only a few hundred hours per year, requiring a pro-rata compliance setup. For larger operators, the inspection can be integrated into a scheduled maintenance check.

Duty to inspect. Every operator of an affected aircraft must, before exceeding 1000 flight hours after 25 September 2008, perform the inspection described in Part A of the relevant Bombardier Service Bulletin. This is a strict duty: no operator may choose to not inspect. The duty exists even if the operator believes the device is correctly assembled; the directive requires verification.

Duty to rectify if incorrect. If the inspection reveals incorrect assembly, the operator must inspect the components for wear or damage, replace any worn or damaged parts, and correctly reassemble the device per Part B of the Service Bulletin. This duty is contingent on the inspection outcome, but it is mandatory regardless of cost or difficulty.

Duty to use approved revisions. The directive permits compliance with the initial issue of the Service Bulletin or “later approved revisions”. The operator has a duty to ensure that the revision used is approved by Bombardier and accepted by CASA. Using an obsolete or unapproved revision may constitute non-compliance.

Duty to document. Operators must record the inspection and any rectification in the aircraft’s continuing airworthiness records, typically the aircraft logbook. This is implied by CASR Part 42 requirements for record-keeping; the AD itself does not restate the obligation, but compliance cannot be demonstrated without proper documentation.

Right to alternative means of compliance (AMOC). Although not stated in the AD text, under CASR regulation 39.004, an operator may apply to CASA for an alternative means of compliance that provides an equivalent level of safety. The directive was issued before the current CASR provisions were fully harmonized, but the general principle applies. An operator could request an AMOC if, for example, the aircraft has a different spoiler cable sensing design that already achieves the same safety outcome, or if the cost of inspection is grossly disproportionate to the risk on a particular aircraft. CASA may grant an AMOC subject to conditions.

Right to use updated procedures. The operator is entitled to use later approved revisions of the Service Bulletins, which may simplify the inspection or provide better instructions. This reduces compliance risk over time as Bombardier refines the procedure.

Right to correct without penalty. If the inspection finds an incorrect assembly and the operator rectifies it within the 1000-hour window, no penalty attaches for the original incorrect assembly. The directive does not penalise the existence of the error; it only penalises failure to inspect and rectify.

No right to compensation. The directive imposes a cost without providing compensation from the regulator or the manufacturer. Operators assume the financial risk. If Bombardier had a design or manufacturing defect, operators might have a commercial claim against Bombardier for the cost of remedy, but that is a private contractual matter, not a right under the AD.

Non-compliance with AD/DHC-8/142 is an offence under the Civil Aviation Act 1988 and the Civil Aviation Safety Regulations 1998. The penalty framework operates on several levels.

Civil penalties. Under regulation 42.035 of CASR, an operator who fails to comply with an applicable airworthiness directive is liable to a civil penalty. The maximum penalty for an individual can be up to 50 penalty units (currently $313 per unit, so $15,650) for each contravention. For a body corporate, the penalty multiplies to 250 penalty units ($78,250) per contravention. Each day the aircraft operates in non-compliance may constitute a separate contravention, so the total exposure can escalate quickly. CASA has discretion to issue infringement notices for lesser breaches, with fixed penalties typically around $1,100 for an individual.

Aircraft grounding. More directly, CASA may issue a direction to ground an aircraft until compliance is demonstrated. This is not a monetary penalty but a severe operational sanction that can cost an operator tens of thousands of dollars per day in lost revenue. The directive itself does not require immediate grounding; it permits continued operation up to 1000 flight hours. But if an operator does not comply within that window, the aircraft is no longer airworthy, and any flight would be illegal.

Criminal prosecution. In egregious cases of deliberate non-compliance or where the failure results in a safety incident, CASA may refer the matter to the Commonwealth Director of Public Prosecutions for criminal prosecution. The maximum penalty under the Civil Aviation Act for a contravention involving safety is up to two years imprisonment for an individual and/or substantial fines. However, this is rare for a simple inspection non-compliance.

Enforcement action against maintenance organisations. If a certifying engineer signs off an inspection as compliant when it is not, that engineer may lose his or her authorisation and face personal prosecution under CASR Part 42 or Part 145.

Defences. The defence of reasonable diligence is available under some provisions, but it would be difficult to argue if the operator simply ignored the AD. An operator who could show that it used a later approved revision that was later found to be inadequate might have a defence, but that would not excuse failure to act on the initial directive.

Operational consequences for insurance. An aircraft that operates in breach of an AD may void hull and liability insurance policies, leaving the operator exposed to catastrophic claims. Insurers routinely require ongoing compliance with ADs as a condition of coverage.

Impact on aircraft value. A documented failure to comply with ADs reduces the resale value of an aircraft and may delay future transactions.

The directive does not specify a maximum penalty within its text; the penalties arise from the broader legislation that empowers CASA to issue ADs. Nevertheless, the enforcement regime creates a strong incentive for operators to comply within the 1000-hour window, even if the cost of inspection seems disproportionate to the perceived safety risk.

Australian CASR Part 39 (Airworthiness Directives). AD/DHC-8/142 is issued under the authority of Part 39 of the Civil Aviation Safety Regulations, which governs the issuance, amendment, and compliance requirements for airworthiness directives. It references the earlier AD/DHC-8/126, which mandated the original installation of the spoiler cable disconnect sensing device on earlier aircraft. The present AD supplements that earlier directive by adding a post-installation inspection requirement. Operators who complied fully with AD/DHC-8/126 may have already installed the device, but they still must perform the new inspection.

CASR Part 42 (Continuing Airworthiness). Regulation 42.025 requires an operator to ensure that aircraft are maintained in accordance with the approved maintenance program and that all ADs are complied with. This AD becomes part of that maintenance program either by direct incorporation or by being added to the operator’s AD compliance log.

CASR Part 145 (Maintenance Organisations). Maintenance organisations performing the inspection must hold an appropriate approval under Part 145. The directive does not require a specific type of approval beyond the standard airframe maintenance rating, but the engineer must be authorised to certify the work.

Transport Canada Directive CF-2008-28. The note at the end of the Australian AD states: “Transport Canada AD CF-2008-28 dated 10 July 2008 refers.” This is the equivalent Canadian directive issued by Transport Canada for Canadian-registered DHC-8 aircraft. Because Bombardier is a Canadian manufacturer, Transport Canada typically issues the original design approval and the corrective action. CASA then adopts or issues a mirror AD for Australian-registered aircraft. The two directives are likely identical in requirement. An operator that complies with the Canadian AD is not automatically in compliance with the Australian AD unless it also meets the specific Australian compliance timeframe. However, CASA generally accepts compliance with a foreign AD as equivalent if it matches the Australian AD. In practice, operators with mixed fleets should ensure compliance with the Australian AD to avoid enforcement action in Australia.

Bombardier Service Bulletins. The directive mandates compliance with certain Service Bulletins. Service Bulletins are not law themselves; they become legally mandatory when an AD references them. If Bombardier later issues a revision that is not yet approved by CASA, the operator must check whether CASA has accepted that revision. The AD says “or later approved revisions,” meaning CASA must approve any revision for it to be an acceptable means of compliance. An operator that uses an unapproved revision does so at its own risk and may be found non-compliant.

Civil Aviation Act 1988. The Act provides the overarching legal framework for CASA’s powers, offences, and enforcement. The mandatory nature of the AD derives from section 20AB (power to issue ADs) and regulation 39.004.

Australian Consumer Law. If a rectification part is defective and causes further damage, the operator may have redress against the supplier under the Australian Consumer Law for breach of consumer guarantees. This interaction is peripheral but could arise if replacement pulleys or spacers are supplied that are themselves incorrectly manufactured.

No conflict with workers compensation or occupational health and safety laws. Performing the inspection may involve working on the aircraft structure. The maintenance organisation must comply with state-based WHS laws, but that does not conflict with the AD.

The source text shows only the current version of AD/DHC-8/142, issued on 6 August 2008, effective 25 September 2008. The directive carries the number 10/2008 within the DHC-8 series. No amendments are listed in the source. However, the directive references Bombardier Service Bulletins that themselves may have been revised after the AD’s publication. The AD’s wording “initial issue dated 16 October 2007, or later approved revisions” establishes a mechanism for updating without formal amendment of the AD. If CASA later approves a revision to the Service Bulletin, that revision automatically becomes an acceptable means of compliance. Operators must track those approvals.

The directive also refers to AD/DHC-8/126, which is an earlier directive that mandated installation of the spoiler cable disconnect sensing device for earlier models. AD/DHC-8/126 is not amended by this directive; it remains in force. The present directive superimposes an inspection requirement on top of the installation requirement.

Given its age (2008), the AD may have been superseded or cancelled by a later directive, or it may remain in force. The source text does not indicate whether it is still current. An operator today would need to check the current CASA AD database to see if a later amendment (e.g., AD/DHC-8/142 Amdt 1 or a subsequent directive) has replaced or withdrawn this one. The source shows that the AD was still in effect at the time of the scanned image as the current directive.

The layout includes an image placeholder, probably a CASA seal or signature, but no substantive amendment text. The directive number “10/2008” appears three times, likely a formatting artefact.

Because the source ends at 2008, there is no amendment history within the text itself. In practice, airworthiness directives are rarely amended; instead CASA issues a new directive to supersede the old one. Any later revision would be numbered differently (e.g., AD/DHC-8/162). The analysis must therefore note that this directive is as of its issue date, and readers should verify whether it has been superseded.

The source text does not mention any litigation concerning AD/DHC-8/142. Given its technical nature and limited applicability, it is unlikely to have been the subject of standalone legal proceedings. Airworthiness directives are ministerial decisions that are judicially reviewable but rarely challenged, because aircraft operators typically prefer to comply quickly rather than fight a regulatory directive that may ground their fleet.

However, litigation could arise indirectly in at least three ways:

1. Enforcement prosecution. If CASA prosecutes an operator for non-compliance, the operator might defend on the grounds that the directive was invalidly issued (e.g., unreasonable or procedurally defective). The Administrative Appeals Tribunal and the Federal Court have jurisdiction to review CASA decisions. The operator would need to show that the directive was beyond power or irrational. Given the background evidence of incorrectly assembled devices, a challenge would be difficult.

2. Insurance disputes. An insurer might deny a claim after an incident involving a spoiler cable disconnect if the operator had not complied with this AD. The operator might then sue the insurer, arguing that the non-compliance did not cause the loss. Alternatively, the insurer might subrogate against the manufacturer or maintenance organisation for defective assembly.

3. Product liability. If an incident occurs because of the incorrectly assembled device, passengers or crew may sue Bombardier for design or manufacturing defect. The existence of an AD is strong evidence that the manufacturer knew or should have known of the defect, which could support a claim under the Australian Consumer Law or common law negligence. Bombardier might argue that the AD gave operators adequate warning and that the operator’s failure to inspect was the real cause.

4. Cross-border litigation. Because Bombardier is Canadian, any product liability claim may involve Canadian law and jurisdiction. The Transport Canada directive CF-2008-28 would be relevant in that context.

There are no reported Australian cases specific to AD/DHC-8/142 in publicly available legal databases up to the knowledge cutoff, but that does not mean no action occurred. The directive’s age (2008) means any litigation would have likely concluded years ago. For practical purposes, the directive has a low litigation risk profile but high compliance enforcement risk.

Several traps exist for the unwary operator or legal adviser.

The 1000 flight hour window starts on the effective date, not the date of discovery. The operator has exactly 1000 flight hours from 25 September 2008 to complete the inspection. If the aircraft has already flown many hours before the AD became effective, those hours count toward the limit. For an aircraft that flies 300 hours per month, the operator has just over three months. The compliance deadline is fixed, not a recommendation.

The inspection applies even if the device was production-installed. Many operators of Series 400 aircraft or later 100/200/300 aircraft may believe that because the device was fitted at the factory, it must be correct. The AD covers them explicitly. The background notes that several incorrectly assembled devices were found on in-service aircraft, meaning production assembly was not reliable. Operators cannot skip the inspection based on trust in the manufacturer.

The Service Bulletin revision must be approved by CASA. The AD says “later approved revisions.” An operator that uses a revision that Bombardier issued but CASA has not yet accepted may argue it is using the best available information, but CASA may treat that as non-compliance unless the operator received explicit approval. Always check the CASA AD webpage or call the airworthiness officer to confirm.

Modsum 8Q100898 may have been installed under a previous AD, but the inspection is still required. For earlier models, if the operator already installed the device under AD/DHC-8/126, they still must do the new inspection. They cannot claim they are already compliant because the device is present.

The rectification requirement is more extensive than just reassembly. If an incorrectly assembled device is found, the directive requires inspection of components and replacement of worn or damaged parts. A simple reassembly without checking for wear is insufficient. The operator must also decide whether to replace parts preemptively if wear is observed, adding cost.

No provision for deferral or suspension. Unlike some maintenance tasks that can be deferred under a MEL (Minimum Equipment List), an AD compliance task generally cannot be deferred except by applying for an AMOC. The 1000-hour grace period is the only deferral.

The directive applies to all aircraft regardless of geographic location. Even if the aircraft is temporarily outside Australia, the operator must comply before operating in Australian airspace again. Failure could lead to the aircraft being detained upon arrival.

Record keeping requirements may not be obvious. While the AD text does not explicitly say “document the inspection,” the broader continuing airworthiness framework requires it. An operator that performs the inspection without proper logbook entry will struggle to prove compliance in case of an audit or incident.

The background uses the word “could” regarding impaired controllability. This is a regulatory hedge. An operator might be tempted to downplay the risk. However, the directive is mandatory regardless of any probability estimate.

Interplay with Transport Canada AD. If an Australian operator also has a Canadian-registered aircraft subject to CF-2008-28, they must comply with both separately. The deadlines may differ. Do not assume they are identical.

The document includes a placeholder image of the CASA delegate’s signature. This indicates the AD was signed by James Coyne, Delegate of CASA, on 6 August 2008. The signature is legally effective, but the scanned reproduction may not be perfect. Always verify the current official version on the CASA website.

Compliance involves a sequence of operational steps, not just signing a form. Here is a practical guide for operators and their legal advisers.

1. Identify affected aircraft. Cross-reference the aircraft in your fleet against the DHC-8 models and serial numbers listed. Series 100/200/300: models 102, 103, 106, 201, 202, 301, 311, 314, 315, serial numbers 003 through 644. Series 400: models 400, 401, 402, serial numbers 4003, 4004, 4006, and 4008 through 4164. Only those serial numbers are covered; skip any outside the range.

2. Obtain the correct Service Bulletin. For Series 100/200/300 (including those with serial numbers 003-644), obtain Bombardier Service Bulletin 8-27-107 (initial issue dated 16 October 2007 or later CASA-approved revision). For Series 400, obtain SB 84-27-34 (initial issue dated 3 October 2007 or later approved revision). Confirm that the revision you have is CASA-approved. If in doubt, contact Bombardier technical support or CASA.

3. Schedule the inspection within the 1000 flight hour window. The compliance time is 1000 flight hours after 25 September 2008. For an AD that is still in force today, the 1000-hour window will have long passed; any aircraft not yet inspected is already non-compliant. If you are reading this after 2008, you must have already complied or have an accepted AMOC. For current operators, ensure that the inspection was completed on time and that records exist. If compliance has not yet occurred, immediately ground the aircraft and contact CASA.

4. Perform the inspection per Part A of the Service Bulletin. This involves inspecting the fuselage spoiler cable disconnect sensing device for correct assembly. The Service Bulletin (not included in the AD text) will detail the exact procedure, likely involving visual inspection, measurement, or functional test.

5. If correct, document. If the device is correctly assembled, no further action is required for the device itself. However, record the inspection as a mandatory AD compliance event in the aircraft’s continuing airworthiness records. Include the date, aircraft hours at inspection, the Service Bulletin revision used, the engineer’s certification, and a statement that the device was found correctly assembled.

6. If incorrect, proceed to Part B. If the inspection reveals incorrect assembly (pulley and spacer interchanged), then perform the additional inspection of components for wear or damage. Replace any worn or damaged parts. Then correctly reassemble the device per Part B. Document the finding, the parts replaced (if any), the reassembly steps, and the final correct assembly.

7. Update AD compliance log. Enter the directive number (AD/DHC-8/142), the compliance method (inspection per SB, any rectification), and the date of completion. Keep a copy in the aircraft’s technical records.

8. Consider applying for AMOC if rational. If your aircraft has a substantially different spoiler cable disconnect sensing device that still meets the design intent (e.g., a later production standard), or if the cost of compliance is wholly disproportionate to the risk, you may apply to CASA for an alternative means of compliance. The application must demonstrate an equivalent level of safety. Provide engineering data and Bombardier’s concurrence if possible. Note that AMOC applications take time and are not guaranteed.

9. Monitor for updates. From time to time, Bombardier or CASA may issue a revised Service Bulletin or a new AD that supersedes this one. Ensure that your compliance monitoring system picks up changes. Continue to check the CASA AD database at least annually.

10. Audit readiness. Retain all records for the life of the aircraft plus any applicable statutory period (typically seven years). Be prepared to show the records to CASA during routine surveillance or if the aircraft is sold.

Following these steps will satisfy the legal obligation under AD/DHC-8/142 and minimise exposure to penalties, grounding, or insurance voidance. Given the directive is now more than 15 years old, most affected aircraft will have long since complied, but new entrants to the fleet (e.g., imported second-hand aircraft) must still have evidence of compliance. A purchaser of a DHC-8 should demand proof of compliance with this AD as part of the pre-purchase inspection.