Safran Completes First Ground Test of Distributed Hybrid Electric Propulsion System

Image copyright: Remy Bertrand

Safran engineers completed the first ground test of the company’s distributed hybrid electric propulsion  system at a Safran Helicopter Engines test facility near Pau-Pyrenees Airport in France. Several operating modes were tested and validated during this first series of tests, with the electric motors powered only by batteries or by a combination of batteries and turbo-generator. The system generated 100 kilowatts (kW) of electrical power.

In a distributed hybrid electric propulsion system for aircraft, a turbo-generator (a gas turbine driving an electrical generator) is coupled to a bank of batteries. This system powers multiple electric motors turning propellers to provide propulsion. The power is efficiently distributed by a new-generation power management system, and the motors are controlled by a fully-integrated smart power electronics assembly

Safran Helicopter Engines, Safran Electrical & Power, and Safran Power Units in conjunction with Safran Tech, the group's research and technology center, conducted the test run. It was carried out according to Safran's roadmap for the development of hybrid propulsion solutions.

“This test marks a major step forward in demonstrating our ability to offer hybrid propulsive solutions for tomorrow's aircraft,” says Jean-Baptiste Jarin, Safran Helicopter Engines vice president, hybrid propulsion system program. “We are on track to meet our goal of testing a more powerful system in the near future.”

Hybrid propulsion systems should contribute to the emergence of new vertical takeoff and landing (VTOL) and short takeoff and landing (STOL) aircraft, by enhancing their flight capabilities and expanding their range of missions, officials say. Safran's hybrid electric propulsion roadmap is focused on bringing these technologies to the market by 2025.

“Following the recent announcement of our partnership with Bell concerning ‘mobility on demand', this latest milestone clearly reflects Safran's determination to invest in the development of hybrid electric propulsion systems, which will be the foundation of future propulsion solutions,” says Stéphane Cueille, senior executive vice president for R&T and Innovation at Safran.

Bell Helicopter, a Textron Inc. (NYSE:TXT) company, and Safran are collaborating on the development of innovative hybrid electric power system solutions to support Bell's VTOL aircraft concept, company officials announced in June 2018. The focus is on-demand mobility, ushering a new era of flight where the benefits of aviation are accessible to more people in more places, according to Scott Drennan, Bell's director of innovation. Drennan stresses the company’s commitment to providing transportation of people and logistics in new, innovative, and more efficient ways. “Our work with Safran is a historical milestone for future transport solutions," he adds.

Safran innovation teams have been actively exploring the potential of hybrid solutions for future propulsion systems for years, officials say. Bell and Safran's shared vision for electric and hybrid electric aircraft is to strive for the successful deployment of Bell Air Taxis and new on-demand mobility systems in the future.

In this collaboration, Bell will lead the design, development, and production of VTOL systems, and Safran will bring its technical expertise to bear in the development of a disruptive propulsion system.

Safran also contributes to the new Airbus BelugaXL extra-large cargo plane, which will enter service in 2019 and will be operated by Airbus Transport International (ATI).

Safran Electrical and Power supplies most of the wiring and electrical cabinets that handle electrical power distribution to the flight controls. Safran Electronics & Defense supplies several flight control systems, a data loading system and a backup electric flight control module. Safran Landing Systems supplies the landing gear, along with the wheels and carbon brakes. The wheels and carbon brakes, a dual source arrangement on this airplane, were developed by Goodrich-Messier, a joint venture between Safran Landing Systems and UTC Aerospace Systems.

The 10 thrust reversers on the Rolls-Royce Trent 700 engines powering the BelugaXL were developed by Safran Nacelles, while the power transmission systems come from Safran Transmission Systems.

Zodiac Aerospace also contributes, as supplier of fuel supply and oxygen distribution systems. Safran Filtration Systems provides hydraulic filters.

Safran is an international high-technology group operating in the aircraft propulsion and equipment, space, and defense markets. Safran has a global presence, with more than 58,000 employees and sales of 16.5 billion euros in 2017. Safran undertakes Research & Development programs to meet fast-changing market requirements, with total R&D expenditures of around 1.4 billion euros in 2017.

Safran took control of Zodiac Aerospace in February 2018, significantly expanding its aircraft equipment activities. Together with Zodiac Aerospace, Safran has more than 91,000 employees and would have around €21 billion in adjusted revenue (pro forma 2016).

Safran Helicopter Engines manufactures helicopter engines, having produced more than 72,000 since being founded, with a wide range of helicopter turboshafts and more than 2,500 customers in 155 countries.

Courtney E. Howard  is editorial director and content strategist at SAE International, Aerospace Products Group. Contact her by e-mail at This email address is being protected from spambots. You need JavaScript enabled to view it..