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Regulations & Safety

Why Proper Maintenance of Aircraft Wheel Bearings Is Critical for Safety

Airbus technical data shows aircraft wheel bearing failures result mainly from maintenance errors. Proper torque, cleaning, and lubrication are essential for safety.

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This article is based on technical guidance and safety publications from Airbus and additional industry safety reports.

The Hidden Danger in the Gear: Why Wheel Bearing Maintenance Cannot Be Rushed

Aircraft wheel bearings are among the most stressed components in aviation. Despite supporting loads of up to 500 tons and enduring temperature shifts from sub-zero cruising altitudes to the intense heat of braking, they remain largely hidden from view. According to a technical safety publication by Airbus, the failure of these components is rarely due to design flaws but is almost exclusively the result of improper maintenance.

At AirPro News, we have reviewed the latest guidance from Airbus’s “Safety First” initiative, alongside broader industry data, to understand why these small components continue to pose significant risks to flight safety. The consensus across manufacturers and regulators is clear: strict adherence to maintenance protocols is the only barrier against catastrophic failure.

The Mechanics of Failure

The primary cause of bearing failure, as identified by Airbus and industry data, is maintenance error. Specifically, the issues revolve around incorrect torque application, contamination, and inadequate lubrication. Aircraft use “tapered roller bearings” designed to handle both the weight of the aircraft (radial loads) and side-to-side movement (axial loads). When these bearings are mistreated, the consequences are severe.

The “Double-Torque” Procedure

One of the most critical and frequently misunderstood aspects of wheel installation is the torque procedure. According to Airbus technical guidelines, a specific “double-torque” method is required to ensure the bearings are seated correctly without being overtightened.

The process generally involves three distinct steps:

  1. Initial Seating: A high torque is applied while rotating the wheel. This step is crucial to “seat” the rollers and eliminate free play.
  2. Back-off: The nut is loosened to relieve stress on the components.
  3. Final Torque: A specific, lower torque is applied to set the correct “preload.”

The risk lies in the details. If a technician skips rotating the wheel during the initial torque application, the rollers may not align, leading to a false torque reading. This can result in loose bearings that vibrate and wear prematurely, or tight bearings that overheat and seize.

Real-World Consequences

The failure of a wheel bearing is not merely a maintenance inconvenience; it is a direct threat to the structural integrity of the aircraft. When a bearing seizes, it can generate enough friction to weld components together or shear axles, leading to wheel separation.

Airbus and TSB Canada Data

In one notable case study highlighted by Airbus, an A330 aircraft lost a wheel during takeoff. The investigation revealed that a seized bearing destroyed the axle nut, allowing the wheel to eject from the landing gear. This is not an isolated event. Data from the Transportation Safety Board of Canada (TSB) underscores the prevalence of this issue.

“A study revealed 67 occurrences of nosewheel bearing failures on A319/A320/A321 aircraft worldwide between 1989 and 2004.”

— TSB Canada Data

Cross-Fleet Vulnerabilities

While the Airbus “Safety First” article focuses on their fleet, the physics of bearing failure applies universally. Reports from the UK Air Accidents Investigation Branch (AAIB) detail an incident involving a Boeing 737-800 where a seized bearing generated sufficient heat to compromise the chrome plating and base metal of the axle, causing it to fracture.

Similarly, an investigation into an Embraer EMB-145 (registration G-EMBP) found that moisture contamination due to improper seal installation led to severe overheating and subsequent axle failure. These incidents confirm that regardless of the airframe manufacturer, the root causes, contamination and torque errors, remain consistent.

Industry Best Practices

To mitigate these risks, manufacturers and technical organizations like Timken have established “gold standard” maintenance manuals. The following practices are considered non-negotiable for airworthiness:

  • Cleaning is Critical: Technicians must remove all old grease. Old lubricant can hide “spalling” (flaking metal) or heat discoloration (blue or straw-colored metal), which are early signs of fatigue and overheating.
  • Pressure Packing: Hand-packing grease is often insufficient. Industry standards recommend using pressure packing tools to ensure grease penetrates behind the cage where the rollers contact the race.
  • Grease Compatibility: Mixing clay-based and lithium-based greases can cause the mixture to break down, destroying its lubricating properties. Lithium-based grease is generally preferred for its water-repelling capabilities.
  • Wheel Rotation: As emphasized in the torque procedure, the wheel must be rotated while tightening the nut to align the rollers.

AirPro News Analysis

The Human Factor in Maintenance

While the technical steps are well-documented, we believe the persistence of these failures points to a human factors challenge. Wheel bearings are “hidden” components; unlike a tire that shows visible tread wear, a bearing often looks pristine until the moment it fails catastrophically. This lack of visual feedback places an immense burden on the maintenance process itself.

In high-pressure line maintenance environments, the requirement to rotate a wheel while torquing it, a process that relies on “feel” and patience, can be a trap for technicians rushing to clear an aircraft for departure. The data suggests that safety in this domain relies less on new technology and more on a disciplined adherence to the basics: cleaning, inspecting, and respecting the torque procedure.

Regulatory Context

Regulators continue to monitor these risks closely. The FAA has previously issued Airworthiness Directives, such as AD 2012-10-09 for Cessna 560XL aircraft, following reports of brake failure linked to loose bearing components. Furthermore, the FAA Safety Team (FAASTeam) frequently issues alerts reminding operators that “grease is not just grease,” warning that using unapproved substitutes constitutes a violation of FAR Part 43.

Whether operating a General Aviation aircraft or a commercial airliner, the message from the industry is uniform: take care of the wheel bearings, and they will carry the load.

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Photo Credit: Airbus

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Regulations & Safety

Bridger Aerospace Integrates TracPlus Data into IGNIS Platform

Bridger Aerospace partners with TracPlus to stream real-time wildfire aircraft data into its IGNIS incident management platform.

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Bridger Aerospace Group Holdings, Inc. has partnered with aviation data provider TracPlus to integrate real-time aircraft tracking and drop event data directly into Bridger’s IGNIS software platform. Announced on July 20, 2026, the collaboration aims to provide wildland firefighters and incident management teams with a unified operational picture of aerial suppression efforts.

In a press release issued from its Belgrade, Montana headquarters, Bridger Aerospace stated the integration is designed to break down information silos between disparate systems. The move directly responds to recent federal directives, specifically the June 2025 Executive Order 14308, which mandated the modernization of wildfire firefighting technology and improved data sharing across agencies.

Integrating aviation intelligence for ground crews

TracPlus currently manages approximately 2,500 wildfire suppression Commercial-Aircraft and processes 800,000 flight hours annually for over 700 customers in more than 40 countries. Under the new partnership, this extensive aviation intelligence, including real-time aircraft positioning and specific drop event data, will stream directly into the IGNIS platform.

The integration allows ground crews, aviation teams, and incident managers to view exact aircraft operating locations and suppression activity impacts within the broader incident environment. By connecting these specialized platforms, the companies intend to shift aerial firefighting response from a reactive model to a proactive one.

“Trying to do everything yourself isn’t the best way in modern wildfire response,” said Todd O’Hara, CEO of TracPlus. “Our industry moves forward when specialists each perform what they do best and connect their work. By delivering our expertise in bringing aviation data together from every source and streaming it directly into the IGNIS platform, we are empowering the people on the frontline with a more complete operational picture to do their jobs better and help keep their communities safe.”

Aligning with federal modernization directives

The Partnerships aligns with the federal government’s ongoing push for connected, interoperable wildfire technology. In 2025, the White House Office of Science and Technology Policy called for a national roadmap to modernize firefighting technology and improve data sharing between systems under Executive Order 14308.

Bridger Aerospace CEO Sam Davis noted that the combined solution will enhance situational awareness for both the company’s own aerial firefighting operations and incident management teams nationwide.

“Technology is the new frontier in our mission to protect lives, property, and the environment and we just got stronger with TracPlus as a strategic partner,” Davis said.

The announcement follows Bridger Aerospace’s recent expansion in federal contracting, including a Department of the Interior task order secured on July 16, 2026, for the deployment of its multi-mission wildfire aircraft.

AirPro News analysis

We view the Bridger-TracPlus integration as a direct commercial response to the interoperability mandates outlined in Executive Order 14308. Historically, aerial firefighting has suffered from fragmented data, with ground crews, dispatchers, and pilots relying on separate, non-communicating systems. By embedding TracPlus’s massive data feed into the IGNIS platform, Bridger Aerospace is positioning its Software not just as an internal operational tool, but as a comprehensive incident management solution. This strategic alignment with federal modernization goals likely strengthens Bridger’s competitive posture for future government Contracts as agencies prioritize unified operating pictures.

Sources: Bridger Aerospace

Photo Credit: TracPlus

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Regulations & Safety

AIAA Calls for Faster FAA Certification Path for AAM Aircraft

AIAA urges the FAA to adopt predictable AAM certification timelines as bipartisan legislation targets the 5-9 year type certificate process.

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This article summarizes reporting by Aerospace America by Ryan Cooperman, J.D.

The American Institute of Aeronautics and Astronautics (AIAA) is calling for the Federal Aviation Administration (FAA) to establish a more predictable certification pathway for Advanced Air Mobility (AAM) aircraft, warning that regulatory uncertainty threatens United States aerospace leadership.

In a July 2, 2026, policy article published in Aerospace America, the AIAA outlined the critical balance between maintaining rigorous safety standards and fostering innovation. The publication notes that while traditional amended type certifications typically require three to five years, certifying entirely new aircraft types like AAM platforms currently takes five to nine years under existing FAA processes.

Legislative push for regulatory predictability

To address these extended timelines, bipartisan lawmakers introduced the Aviation Innovation and Global Competitiveness Act on February 13, 2026. The legislation seeks to mandate standard expected timelines for the FAA type certification process regarding AAM aircraft. It also aims to clarify the specific conditions under which the agency must require an issue paper, a regulatory step that often introduces variability into the certification timeline.

The AIAA has formally endorsed the legislation, aligning the bill with the institute’s designation of AAM and autonomous flight integration as a 2026 Aviation Priority Issue. According to Aerospace America, securing a predictable regulatory framework is vital not only for engineering progress but also for maintaining the capital investment required to bring hybrid and electric vertical takeoff and landing (eVTOL) aircraft to market.

Overcoming historical bottlenecks and workforce gaps

The push for modernization follows years of documented regulatory friction. On June 21, 2023, the Department of Transportation Office of Inspector General (DOT OIG) released a report indicating that communication and management issues had hindered the FAA’s ability to certify AAM aircraft efficiently. Congress subsequently passed the FAA Reauthorization Act of 2024 on May 16, 2024, which included specific provisions targeting AAM integration.

Beyond statutory changes, Aerospace America highlights that certification modernization is fundamentally a workforce challenge. As aircraft designs incorporate more autonomous flight systems, the FAA must attract and retain technical specialists, software engineers, and flight-test experts capable of evaluating highly complex architectures.

“The challenge is ensuring that America’s certification system can efficiently evaluate increasingly novel aircraft and enabling technologies while preserving the world’s safest aviation system,” Cooperman wrote.

AirPro News analysis

We view the AIAA’s public policy push as a reflection of broader aerospace industry frustration with the ad-hoc nature of early eVTOL certification bases. While the FAA has made strides since the 2023 DOT OIG report, the five to nine year timeline for new type certificates remains a significant barrier for manufacturers relying on continuous venture capital funding. If the Aviation Innovation and Global Competitiveness Act passes, the mandated timelines could provide financial markets with the predictability they require. However, the FAA will still face the practical hurdle of staffing enough specialized engineers to meet those statutory deadlines without compromising its safety mandate.

Sources: Aerospace America

Photo Credit: Aerospace America

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Regulations & Safety

FAA Awards L3Harris Contract to Modernize US Airspace Through 2045

The FAA awarded L3Harris a contract to upgrade 700+ ground stations and operate the US aircraft tracking network through 2045.

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On July 1, 2026, the Federal Aviation Administration (FAA) awarded L3Harris Technologies a contract to upgrade and operate the United States aircraft tracking network through 2045. The modernization effort will overhaul ground infrastructure to support the integration of advanced air mobility (AAM) vehicles and drones into the National Airspace System.

In a press release issued on July 1, 2026, L3Harris announced the agreement, which mandates the upgrade of at least 700 ground stations across the country. The enhanced network will provide real-time, satellite-based flight positioning data while bolstering cybersecurity measures to protect air traffic management systems. The exact monetary value of the contract was not disclosed.

Expanding surveillance for next-generation airspace

The contract extends the role of L3Harris in managing the FAA surveillance infrastructure for nearly two more decades. The upgraded ground stations are designed to handle increased network capacity, a requirement as the airspace becomes more crowded with non-traditional aircraft.

Kathy Crandall, President of Mission Networks, Space & Mission Systems at L3Harris, emphasized the operational impact of the upgrades.

“L3Harris is propelling the FAA’s modernization vision forward by delivering an advanced surveillance infrastructure that will define the future of our airspace system and ensure increased safety for all air travelers.”

Crandall added that expanding network capacity ensures the United States maintains its position in global air traffic management.

Alignment with broader FAA modernization initiatives

This surveillance contract aligns with ongoing FAA efforts to replace aging infrastructure across the National Airspace System. The agency has been executing its Facility Replacement and Radar Modernization (FRRM) strategy, which targets the replacement of over 370 air traffic control facilities and 618 radars that average 36 years of age.

L3Harris is already involved in parallel infrastructure projects for the FAA. The company is currently executing the FAA Telecommunications Infrastructure (FTI) upgrade. That project replaces legacy copper wire connections with high-speed fiber optic networks across FAA facilities, providing the bandwidth necessary to support emerging aviation technologies like electric aviation vertical takeoff and landing (eVTOL) aircraft and uncrewed aerial systems.

AirPro News analysis

The extension of the L3Harris mandate through 2045 highlights the reliance of the FAA on established defense and aerospace contractors to execute its long-term modernization goals. As the National Airspace System transitions to accommodate AAM and widespread drone operations, the data bandwidth and latency requirements for air traffic control will increase exponentially. We view the concurrent execution of the surveillance network upgrade and the FTI fiber optic rollout as a necessary synchronization. Without high-speed ground data transmission, the benefits of satellite-based, real-time tracking for low-altitude and autonomous aircraft would be severely bottlenecked.

Sources: L3Harris Technologies

Photo Credit: L3Harris Technologies

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