As the commercial airline industry continues to meet the demands for expected increased air traffic over the next two decades, fundamental advances are being made to reduce operating costs and gas emissions. The Hydraulic Systems Division (HSD) of Parker Aerospace is leading the way by supporting major commercial aircraft manufacturers with proven hydraulic systems and subsystems designed to perform at 5,000 psi, creating significant gains over the 3,000-psi systems traditionally used for commercial applications. Parker’s extensive experience in high-pressure fluid technology is providing real value and competitive advantage to aircraft manufacturers looking to maximize fuel economy and reduce maintenance, repair, and overhaul (MRO) costs.
The hydraulic system of an aircraft consists of a power generation system that provides fluid power, regulation of pressure, and distribution of the fluid power across the aircraft. The fluid power is used to actuate the primary flight controls (elevator, ailerons, and rudder) and secondary flight controls (flaps, slats, and spoilers), landing gear, thrust reversers, brakes, steering mechanisms, and cargo doors.
Increasing the pressure from 3,000 to 5,000 psi in a hydraulic system allows the fluid power to be transmitted through smaller hose and tubing with narrower diameters. The smaller piping saves weight in itself, but also allows the use of smaller components – including actuators, valves, and fittings – which further reduces the weight of the hydraulic system. Because the increased pressure achieves the same power requirements while operating at lower flow rates, the hydraulic fluid can be driven by pumps that are also smaller in size and weight. The system-wide integration of smaller, lighter components can reduce the overall weight of an aircraft by hundreds or thousands of pounds, depending on its size, resulting in fuel savings and additional efficiencies.
High-pressure hydraulic systems of 4,000 psi have been successfully powering military aircraft since the 1960s, with newer modern aircraft such as the V-22 Osprey and F/A-18E/F making a shift to 5,000 psi. The push for higher pressure systems resulted from space constraints and the need for military planes to achieve lighter weight. This demonstrated success was also apparent on the Aerospatiale/BAC Concorde supersonic passenger airliner that incorporated a 4,000-psi system until it ceased operations in 2003. The Airbus A380 four-engine airliner became the first commercial application of a 5,000-psi system when it entered service in 2007. The integration of the 5,000-psi system on the world’s largest passenger aircraft contributed significantly to critical component weight and volume reduction in overall system design.
Two commercial aircraft currently using 5,000-psi systems are the Airbus A350 XWB and the Boeing 787 Dreamliner. Parker Aerospace’s Hydraulic Systems Division helped elevate the performance of both twin-engine aircraft by working closely with each original equipment manufacturer in the design, development, integration, testing, and certification of the aircrafts’ hydraulic systems and components, including:
As a tier-one, leading provider of fully integrated hydraulic systems and advanced hydromechanical and electromechanical subsystems and components, Parker Aerospace offers the talent, expertise, and resources that aircraft customers count on for program success during all stages of development. Parker is uniquely qualified to design, build, test, and support 5,000-psi hydraulic systems for today’s high-performance commercial aircraft programs.
“When aircraft manufacturers select Parker as a hydraulic system supplier, they know their programs will succeed because of the partnership approach we take and the years of expertise we possess. Parker’s significant experience in developing 5,000-psi hydraulic systems for the Airbus A350 XWB and the Boeing 787 have solidified our position as a proven global leader, able to integrate more advanced, high-pressure solutions where complexity is never a barrier.”
– Dan Novak, engineering manager, Parker Aerospace Hydraulic Systems Division
Materials and some processes become increasingly important in a 5,000-psi system, including those used in pumps, accumulators, filters, and sealing systems throughout the hydraulic system. Parker develops and manufactures high-performance sealing materials and technologically advanced sealing devices that keep pace with aggressive chemicals, temperatures, and pressures.
In higher pressure systems, more exotic materials such as carbon fiber, Kevlar™, and titanium are used to accommodate higher level pressure loads, while minimizing overall component size and weight. In some cases, new proprietary processes had to be developed and used for the manufacture of 5,000-psi equipment, and many conventional processes used in the manufacture of lower pressure equipment either had to be revised and/or improved.
The testing and certification of 5,000-psi systems require extensive experience in developing, integrating, building, and certifying hydraulic systems. Parker starts with a comprehensive portfolio of analytical design tools to conduct advanced dynamic modeling, stress, vibration, and thermal simulations, as well as flow performance studies.
System function and performance at the hydraulic system level is often validated early in a program by using mini test rigs (like a hydraulic system integration rig), which replicates the actual aircraft layout and components of the power generation portion of a system. The systems are further validated with in-depth ground testing using fully automated iron bird rigs that include complete hydraulic systems integrated with landing gear, steering, brakes, flight controls, and thrust reverser systems, duplicating actual aircraft operational conditions as closely as possible. Parker Aerospace also provides aircraft flight test support to demonstrate system performance and compliance with airworthiness regulations.
Since 1993, 80 percent of the world’s major aerospace hydraulic systems have been awarded to Parker Aerospace. In fact, Parker has designed, developed, and qualified more hydraulic systems than any other provider, supporting such aircraft as:
Parker’s ability to provide fully integrated, turnkey systems are among the many reasons aircraft manufacturers look to Parker first for design and build solutions. As a risk-sharing partner on the Boeing 787 program, Parker took the lead to provide an innovative approach to modularization. Working with 787 partners, Parker pre-integrated 60 major components, plus hundreds of structural elements and fasteners, into a single deliverable aft fairing module. The aft strut unit was engineered to quickly interface with the wing for simplified installation, thereby reducing supply chain infrastructure.
Through Parker Aerospace’s Customer Support Operations – a centralized support organization that provides customer and product support, as well as customized service solutions to meet customers’ needs for spares, repairs, and overhaul services for all Parker Aerospace airframe and engine products – Parker is dedicated to providing its commercial and military customers with a premier service experience.
In addition to Parker’s North America-based facilities, its operations extend across 11 key countries, including Germany, France, Russia, Japan, China, Canada, and Brazil to support major aircraft centers through local service. As a joint venture between Parker Aerospace and SIA Engineering Company, Ltd. (a subsidiary of Singapore Airlines), the 30,000-square-foot Aerospace Component Engineering Service (ACE Services) facility in Singapore was the first aftermarket hydraulic service center in the world capable of 5,000-psi service.
Besides being a Parker Center of Excellence, ACE Services specializes in the repair and overhaul of aerospace hydraulic components including hydraulic pumps, flight control actuators, and thrust reverser actuators. The facility supports an expanding base of international airlines in the Asia Pacific region, capable of providing quick and accurate diagnostics, as well as innovative engineering solutions to repair equipment manufactured by Parker and other original equipment manufacturers (OEMs).
Through long-term relationships with key industry suppliers, Parker has assembled a global network of subcontractors that provide excellent quality at competitive costs. Parker’s multinational structure provides significant global supply chain synergies with an emphasis on process stability, continuous improvement, and lean manufacturing to consistently help customers meet the toughest performance expectations.
To learn more about Parker’s 5,000-psi hydraulic systems, please contact Ted Savard, business team leader, Hydraulic Systems Division, at email@example.com or (269) 384-3400. Follow this link to download Parker HSD’s capabilities brochure.
This article was contributed by engineering manager Dan Novak and senior principal engineer Don Bolton for Parker Aerospace’s Hydraulic Systems Division.