Market Dynamics
Introduction
Accessory drive trains represent critical power transmission systems within aircraft engines that mechanically transfer rotational energy from the main engine shaft to essential accessories required for aircraft operation. These sophisticated systems comprise precisely engineered gearboxes, shafts, couplings, bearings, and housings that power vital components such as hydraulic pumps, electrical generators, fuel and oil pumps, starter motors, and air conditioning compressors. The drive train must reliably convert high-speed engine rotation into appropriate speeds and torques for individual accessories while withstanding extreme operating conditions, including wide temperature variations, high rotational speeds, substantial loads, and continuous vibrations throughout flight operations.
The accessory drive train market encompasses the design, development, and supply of these complex mechanical systems used across commercial, military, and other platforms. Market growth is being driven by increasing aircraft production, demand for efficient and lightweight power transmission solutions, and continuous advancements in gearbox and material technologies. Furthermore, the emergence of hybrid-electric propulsion systems and the industry’s focus on improving fuel efficiency, reliability, and ease of maintenance are fostering innovation in accessory drive train architectures. As aircraft manufacturers and engine OEMs emphasize performance optimization and lifecycle cost reduction, accessory drive train systems continue to evolve as a vital element of modern aeroengine design and integration.
Recent Market JVs and Acquisitions:
A moderate number of strategic alliances, including M&As, JVs, etc., have been performed over the past few years:
- In November 2022, The Timken Company completed the sale of its Aerospace Drive Systems (ADS) business to PCX Aerostructures, LLC, a supplier of drive-system components and sub-assemblies for military and civil rotorcraft applications.
- In January 2023, Airbus Helicopters completed the acquisition of ZF Luftfahrttechnik GmbH (formerly a subsidiary of ZF Friedrichshafen AG), a specialist in gearboxes and dynamic systems for helicopters, including more than 10,000 gearboxes delivered globally.
- In June 2025, GE Aerospace acquired Northstar Aerospace, a manufacturer of gears, transmissions, and accessory gearbox assemblies for fixed-wing and rotorcraft platforms.
Market Segments' Analysis
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Segmentations
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List of Sub-Segments
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Dominant and Fastest-Growing Segments
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Aircraft-Type Analysis
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Commercial Aircraft, Regional Aircraft, General Aviation, Military Aircraft, and Helicopter
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Commercial aircraft is projected to record the highest growth among aircraft types during the forecast period.
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Component-Type Analysis
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Accessory Gearbox, PGB, Actuator Gearbox, APU Gearbox, and Others
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Accessory gearboxes are expected to continue as the most widely used gearbox throughout the forecast period.
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Engine-Type Analysis
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Turbofan Engine, Turboprop Engine, and Others
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Turbofan engines are forecasted to grow at the fastest rate among all engine types.
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Application-Type Analysis
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Airframe and Engine
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The engine is expected to remain the dominant application throughout the forecast period.
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End-User-Type Analysis
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Linefit and Retrofit
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Linefit is projected to maintain its position as the leading end-user in the accessory drive train market.
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Regional Analysis
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North America, Europe, Asia-Pacific, and The Rest of the World
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Asia-Pacific is anticipated to be the fastest-growing market for accessory drive trains over the forecast period.
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By Aircraft Type
“Commercial aircraft is projected to remain the dominant and fastest growing aircraft type during the forecast period.”
The accessory drive train market is segmented by aircraft type into narrow-body aircraft, wide-body aircraft, regional aircraft, military aircraft, and general aviation.
Commercial aircraft remains the dominant aircraft type in the accessory drive train market because of its unmatched production scale and the continuous ramp-up of global commercial fleets. By mid-2025, Airbus held a backlog of 8,653 aircraft, including about 7,590 narrow-body jets from the A220/A320neo family, whereas Boeing recorded 6,576 unfilled orders, with roughly 4,800 of them being 737 MAX. These exceptionally large order books keep narrow-body production rates far higher than any other segment, driving sustained demand for accessory-drive-train systems that power electrical, hydraulic, lubrication, and fuel-pumping functions. The commercial aircraft also operates on stringent dispatch reliability standards, making robust accessory drive trains critical for minimizing aircraft-on-ground (AOG) incidents. This creates a cycle of consistent replacements and aftermarket demand, further solidifying the commercial aircraft’s lead.
Commercial aircraft is also the fastest-growing category, driven by long-term air travel recovery, fleet modernization, and airlines' shift toward more fuel-efficient models. Modern turbofan engines with higher bypass ratios place more functional load on accessory gearboxes, and next-generation architectures integrate more electrically driven accessories. This increases unit value and technological intensity of drive train systems per aircraft.
By Gearbox Type
“Accessory gearboxes are projected to remain the most widely used and the fastest-growing gearbox type throughout the forecast period.”
Based on gearbox type, the accessory drive train market is segmented into accessory gearbox, PGB, actuator gearbox, APU gearbox, and others.
Accessory gearboxes retain the largest market share because they are embedded in nearly every major propulsion system, including turbofan, turboshaft, and APUs, making them indispensable across commercial aircraft, military aircraft, helicopter, and general aviation fleets. They act as the power distribution center for crucial systems such as fuel pumps, oil pumps, hydraulic pumps, electrical generators, and FADEC drives, giving them a universal presence that no other gearbox type can match. As airlines aim for longer time-on-wing and OEMs move towards more integrated engine-module designs, accessory gearboxes are being crafted as long-lasting, highly reliable units with better thermal management and lubrication pathways, solidifying their leading position.
The growth is further fueled by engine modernization initiatives like CFM RISE, PW1000G family block upgrades, and military rotorcraft turboshaft refresh cycles, all of which require accessory gearboxes that can handle higher power density and lower mechanical losses. Electrification trends also work in their favor; rather than eliminating gearboxes, hybrid-electric and more-electric aircraft architectures increase the electrical and hydraulic load on the accessory drive train, requiring more capable and sometimes additional gearbox stages.
By Engine Type
“Turbofan engines are expected to lead the market and are also forecast to record the fastest growth over the coming years.”
The market is segmented into the turbofan engine, turboprop engine, and others.
Turbofan engines are likely to continue leading the accessory drive train market due to their overwhelming use in commercial aviation, which accounts for the majority of new aircraft deliveries and in-service fleet expansions. Manufacturers continue to rely on turbofan engines because they offer flexibility in fabrication and require lower upfront investment. Modern high-bypass turbofan architectures rely on increasingly complex accessory drive systems to support advanced FADEC units, fuel pumps, oil pumps, generators, and thermal management modules, creating a greater demand for high-performance accessory drive train components.
The rapid growth of this segment is also fueled by the industry’s shift towards next-generation turbofans, such as geared turbofan (GTF) and ultra-high bypass ratio engines. These new platforms need more efficient and lightweight accessory gearboxes to handle higher rotational speeds and tighter thermal conditions. With major programs such as the LEAP, GEnx, PW1000G, and the upcoming RISE (Revolutionary Innovation for Sustainable Engines) technology maintaining strong multi-year production rates, turbofan engines are poised to remain the largest and fastest-growing contributor to ADT demand throughout the forecast period.
By Application Type
“Engines are projected to remain the leading and also the faster-growing application by 2034.”
The market is segmented into airframe and engine. Engine applications are set to retain their leading position in the accessory drive train market due to their high integration intensity and the critical role of accessory gearboxes in engine operation. Modern aircraft engines require increasingly complex power extraction systems to drive essential accessories, such as fuel pumps, oil pumps, hydraulic pumps, generators, and FADEC units, which makes the accessory drive train indispensable within the engine module. With the continued shift towards high-bypass turbofan engines, stricter emissions regulations, and a growing demand for electrified onboard systems, the functional load on engine-mounted gearboxes is increasing. Each new engine program, ranging from next-gen single-aisle platforms to cutting-edge business jets, features more efficient, higher-torque accessory gearboxes, further solidifying this segment’s leadership.
Engine applications are also experiencing the fastest growth rate, supported by long-term fleet replacement cycles, sustained production of major engine families such as the LEAP, PW1000G, and Trent series, and steady recovery in global aircraft deliveries. A clear sign of this growth is the trend in engine deliveries, as after peaking at 4,018 units in 2019, deliveries dropped sharply to 1,982 units in 2020, but they have since recovered to 2,802 units in 2024. This renewed upward momentum places higher demand on engine-mounted accessory drive trains, especially as OEMs integrate improved thermal management, advanced lubrication architectures, and higher-strength gearbox materials into next-generation propulsion systems.
By End-User Type
“Linefit is projected to retain its leading position while also emerging as the faster-growing end-user.”
The market is segmented into linefit and retrofit.
Linefit installations are set to remain the dominant end-user category in the accessory drive train market, primarily because every new commercial and military aircraft delivered requires a fully integrated ADT system certified directly at the OEM level. Since ADTs connect with essential engine-mounted accessories, like generators, hydraulic pumps, starters, and lubrication systems, OEMs prefer to have these units installed at the factory. This approach ensures everything works together smoothly, optimizes weight, and meets the ever-changing demands of propulsion system designs.
Linefit is also expected to grow at the fastest pace as global aircraft production accelerates. Rising deliveries of next-generation engines and the industry’s shift toward more-electric architectures are increasing both the number and complexity of engine-mounted accessories. As OEMs push for higher efficiency, tighter tolerances, and longer service life, demand for advanced, low-maintenance ADT systems is surging, supporting linefit as the most robust and rapidly advancing segment in the market.
Regional Analysis
“North America is likely to remain the leading market for accessory drive trains, whereas Asia-Pacific is projected to experience the fastest growth during the forecast period.”
North America is set to maintain its leading position in the accessory drive train market, supported by its large fleet of commercial and military aircraft, continuous deliveries of next-generation platforms, and strong presence of engine OEMs and tier-1 gearbox manufacturers. The region’s ongoing investments in engine modernization programs, particularly for narrow-body aircraft and advanced fighter jets, ensure steady demand for accessory gearboxes and drive-train components.
Meanwhile, the Asia-Pacific is forecast to experience the most rapid expansion. This growth is driven by aggressive fleet growth plans from emerging airlines, increasing indigenous engine development programs in China, India, and Japan, and rising outsourcing of precision gearbox components to regional suppliers. The region’s accelerating shift toward local manufacturing of propulsion systems also contributes to its strong projected growth in accessory drive train consumption.
