A safety concern involving fuel lines on Canadian-designed Airbus A220 aircraft is receiving renewed attention from American aviation regulators. The Federal Aviation Administration is proposing to expand an existing inspection requirement after discovering that four additional aircraft may have been exposed to an installation problem capable of damaging fuel hoses and potentially creating a fire hazard.
The proposal, published September 2, 2026, would extend safety checks already required under a 2021 directive. It follows action taken by Transport Canada in 2025 and would bring the estimated number of affected U.S.-registered aircraft to 13.
Although the potential consequences are serious, the FAA has not announced a fleetwide grounding. The issue concerns particular aircraft and a specific fuel-line configuration, highlighting how manufacturing procedures and routine inspections remain essential to aviation safety.
The FAA Wants to Expand an Existing Safety Requirement
The Federal Aviation Administration is seeking to replace its August 2021 airworthiness directive covering certain Airbus Canada A220 aircraft. The earlier rule required operators to inspect flexible fuel-line assemblies on both sides of affected airplanes and replace damaged components. The proposed replacement would preserve those requirements while expanding the number of aircraft covered. According to the FAA, four additional jets may have been exposed to the same unsafe condition because previous corrective procedures were not properly implemented on those aircraft.
The expansion is relatively small but significant. The FAA estimates that its revised directive would affect 13 U.S.-registered airplanes, including nine covered by the previous requirement and four newly identified aircraft. That does not mean all 13 have damaged fuel lines. Instead, regulators want operators to examine the specified components and correct any defects that could compromise safety. The proposal was published in the Federal Register on September 2, with October 19 established as the public-comment deadline. Until a replacement directive is finalized, the existing American requirements remain in effect.
A Twisted Fuel Hose Could Create a Potential Fire Hazard
The safety concern involves the aircraft’s motive-flow fuel system, which helps move fuel through the airplane’s fuel-distribution network. According to the FAA, a flexible fuel hose installed between the engine pylon and wing could become twisted because of an improper installation procedure. Such a twist can restrict fuel movement and contribute to an imbalance between fuel quantities. It may also place unwanted pressure on the surrounding protective shroud, allowing components to rub against one another.
Over time, that contact could damage the protective covering and eventually abrade the fuel line itself. Regulators warn that a resulting leak would be particularly concerning because electrical harness connectors are located nearby. Under certain circumstances, those connectors could provide an ignition source and create a fire risk. The FAA describes this as a potential unsafe condition rather than reporting that the affected aircraft have experienced fires. The purpose of the proposed inspections is to identify twisting, deformation or wear before those problems develop into something more serious.
The Problem Dates Back to an Earlier Manufacturing Change
Transport Canada’s investigation traces the issue to a production change involving the flexible fuel-line assembly between the engine pylon and wing. A new configuration was introduced without a corresponding revision to the installation procedure. That mismatch created the possibility that the flexible hose could be fitted with an unintended twist. Canadian regulators originally addressed the concern through airworthiness directive CF-2021-09, issued in March 2021, which required inspection and corrective action on specified aircraft.
Airbus Canada subsequently introduced a revised installation procedure to address the problem. However, Transport Canada later determined that the earlier directive had not been correctly implemented on four additional A220-300 airplanes. That discovery prompted the issuance of an expanded Canadian directive in September 2025. The sequence illustrates a persistent challenge in aircraft manufacturing: correcting a technical process is only part of the solution. Manufacturers and operators must also verify that every aircraft requiring attention has been identified and properly addressed. A small number of omissions can keep a safety issue active years after its initial discovery.
Four Additional A220-300 Aircraft Are Specifically Identified
The proposed American directive covers the Airbus A220-100 and A220-300, formally designated BD-500-1A10 and BD-500-1A11. However, the newly added group consists entirely of A220-300 aircraft. Transport Canada’s expanded directive identifies four specific serial numbers: 55239, 55241, 55257 and 55271. These aircraft form a separate group from the airplanes identified under the original Canadian directive. Using individual serial numbers is important because the affected aircraft are defined by their production history, not simply by belonging to the A220 family.
The A220 has deep Canadian roots, having originated as Bombardier’s C Series before becoming part of Airbus in 2018. Its principal production facility remains in Mirabel, Quebec, while Airbus also assembles A220 aircraft in Mobile, Alabama. Consequently, the broader A220 program includes aircraft assembled in both countries, despite its Canadian design heritage. The FAA’s proposal should not be interpreted as evidence that every Canadian-built A220 or every A220-300 has the same problem. The expanded directive addresses a narrowly defined group of aircraft with potentially affected fuel-line installations.
Inspectors Would Examine Fuel Lines on Both Sides of the Aircraft
Under the proposed requirements, maintenance personnel would perform general visual inspections of the left and right motive-flow fuel-line assemblies. The inspections would examine the flexible hoses and their protective shrouds for damage, including permanent deformation. Mechanics would be looking for indications that the installation has placed stress on a hose or allowed components to contact one another in a potentially damaging way. The work follows procedures established through Airbus Canada’s technical service information and referenced by Transport Canada’s directive.
If inspectors discover damage, the affected assembly must be replaced before the aircraft is permitted to fly again. The FAA’s proposal also describes replacement procedures involving cleaning the flexible-hose ends, applying grease at specified locations and correctly tightening the assembly. These details may appear minor, but proper installation is central to preventing the condition from recurring. The applicable manufacturer service bulletin, BD500-282011, was updated in March 2025. Importantly, the proposed directive does not automatically require replacing every inspected fuel line. Replacement depends on the condition of the particular components, allowing undamaged assemblies to remain in service when they meet the specified requirements.
Transport Canada Already Introduced Broader Checks in 2025
Canadian aviation authorities acted before the latest American proposal. Transport Canada issued airworthiness directive CF-2025-47 in September 2025, replacing its original 2021 requirement and adding the four newly identified airplanes. The expanded Canadian directive became effective on September 25, 2025. For the four additional A220-300 aircraft, it required inspection and any necessary replacement within four months of that date. Aircraft covered by the original directive remained subject to the earlier compliance timetable.
The FAA’s September 2026 proposal seeks to align American requirements with this expanded Canadian action. Because the aircraft were originally certified under Canadian aviation oversight, Transport Canada’s findings provide the technical basis for the American rulemaking. The proposed U.S. directive would incorporate the Canadian requirements while making adjustments to applicable compliance dates and certain procedures. For example, the FAA specifies that damaged assemblies must be replaced before further flight and does not adopt the Canadian provision requiring removed parts to be returned to the manufacturer. This regulatory coordination allows authorities in different countries to address the same underlying aircraft design concern.
The FAA Estimates Limited Inspection Costs but Higher Repair Expenses
The FAA estimates that the required inspection work would involve approximately 10 labour-hours per aircraft. Using a standard labour rate of US$85 per hour, regulators calculate a direct inspection cost of US$850 per airplane, excluding replacement parts. For the nine aircraft already covered by the existing American directive, that represents approximately US$7,650 in previously required inspection work. Extending the requirement to four additional aircraft would add an estimated US$3,400 in inspection costs for U.S. operators.
Repair expenses could be considerably higher if damage is discovered. The FAA estimates that replacing an affected assembly would cost approximately US$10,005 per pylon, including US$9,920 in parts and US$85 in labour. The agency cannot determine how many aircraft might require that additional work, making the total potential repair bill uncertain. Some expenses could also be covered under manufacturer warranties, although coverage is not guaranteed. The financial estimates help distinguish a relatively inexpensive inspection from a more involved repair. For airlines, the practical impact may also depend on maintenance scheduling, component availability and whether an aircraft requires additional time out of service.
Airlines Are Not Facing an Immediate Fleetwide Grounding
The FAA’s proposed action does not order all Airbus A220 aircraft out of service. It targets particular airplanes and a potential installation defect that can be addressed through inspection and replacement where needed. That distinction matters for airlines and passengers because an airworthiness directive is not necessarily equivalent to a widespread operational disruption. The FAA has proposed a conventional rulemaking process rather than issuing an emergency directive requiring immediate action across the entire fleet.
Airlines operating aircraft within the affected production group would need to ensure compliance with the applicable inspection and repair procedures. Maintenance departments could potentially coordinate required checks with planned servicing, subject to the deadlines established by the regulators. Any aircraft found to have a damaged assembly would require corrective work before returning to flight. The regulatory documents do not establish that the proposal has caused widespread cancellations or passenger disruptions. They identify a potential safety hazard and specify how operators should address it. For passengers, this is an example of preventive oversight working to reduce the likelihood of a more serious event.
The Issue Highlights the Importance of Canada’s A220 Manufacturing Industry
The Airbus A220 remains an important part of Canada’s aerospace manufacturing sector. Developed originally by Bombardier, the aircraft retained its main assembly operation and program headquarters in Mirabel after Airbus became the majority partner in 2018. The program subsequently expanded into the United States, with Airbus opening a dedicated A220 final assembly facility in Mobile, Alabama, in 2020. The production relationship illustrates how Canadian engineering and American manufacturing contribute to a shared international aerospace program.
The A220’s commercial importance has continued growing. In May 2026, Airbus announced that Malaysia’s AirAsia had placed an order for 150 A220-300 aircraft, the largest single firm order in the program’s history. The agreement pushed total firm orders beyond 1,000 aircraft and reinforced the importance of Mirabel’s manufacturing operation. Against that backdrop, reliable safety oversight remains essential to protecting customer confidence. The fuel-line proposal does not establish a broader manufacturing failure across the program. Instead, it demonstrates why highly specific production issues must be followed through, particularly as aircraft are delivered to operators in multiple countries with different regulatory authorities.
The Next Step Depends on the FAA’s Final Decision
The FAA established October 19, 2026, as the deadline for public comments on the proposed expanded directive. Under the standard American rulemaking process, the agency reviews relevant submissions before deciding whether to issue a final regulation and whether the proposed language needs modification. The September notice identifies docket FAA-2026-8794 and project identifier MCAI-2025-01464-T. Any finalized directive would establish the legally enforceable requirements and applicable American compliance dates.
The immediate objective is straightforward: ensure every aircraft exposed to the identified installation concern has received the appropriate attention. Canadian regulators have already expanded their directive, while the FAA is seeking to bring its own requirements into alignment. Airlines, maintenance organizations and Airbus Canada will remain responsible for following the applicable approved procedures and documenting corrective work. For Canada’s aerospace industry, the situation is also a reminder that aircraft safety depends on more than sophisticated engineering. Accurate manufacturing instructions, consistent inspections and effective international communication are just as important to keeping aircraft operating safely over decades of service.
