Safran and aviation's electric future
A long road to all-electric aircraft
What's on the horizon for more and all-electric aircraft?
The actual timetable for the entry into service of electric aircraft depends on multiple factors. Safran is planning ahead for these long-term step changes in the market, starting with shorter-range and more limited solutions, while awaiting technologies that are mature enough to store and deliver the electrical power needed for propulsion.
Technologies within our reach
While all-electric aircraft remain a tantalizing but distant prospect, "more electric" aircraft are increasingly a reality. This progress is in part due to the systems and equipment developed by Safran to make upcoming aircraft even more reliable and economical, while improving their performance. Safran is a pioneer in the trend towards "more electric" aircraft, and one of the most innovative players in the industry. It now offers a wide range of electric systems to replace conventional pneumatic and hydraulic systems, including deicing, flight control actuators, thrust reversers and brakes. The aim is of course to electrify aircraft systems, which in turn simplifies the overall energy system, facilitates maintenance and enhances control. Safran will continue to devise innovative solutions for these strategic technologies and support a smooth transition to even more electric airplanes and helicopters.
- Electric taxiing on track for production
Safran has generated real industry buzz by offering the first electric taxiing solution, with an electric motor in the landing gear, powered by the APU, so that pilots no longer have to use their jet engines for taxiing. This innovative solution is now being developed with Airbus for the A320neo/ceo. The target date for entry into service is 2022. According to a study carried out with airlines, this system makes a lot of sense at busy airports with long taxiing times, as well as for carriers that operate a number of daily shuttle flights. With this new technology, they can reduce not only their operating costs, but also their environmental footprint.
- PODS: power just where you need it
One of the main research thrusts at Safran is how to can change the role of auxiliary power units (APU) to optimize energy management and engine performance. Looking at propulsive and non-propulsive power management as a whole, APUs could take on a growing role by handling more functions during the different flight phases. Safran has already taken a first step in this direction with the eAPU for "more electric" aircraft. Today, the company is working on an even more advanced concept, namely PODS (power on demand system), a smart secondary generator that will be activated automatically when it's more advantageous for the aircraft to tap power from the APU instead of the jet engines.
A number of hurdles ahead
The electrification of aircraft propulsion would seem to be an inevitable trend. However, given the current state-of-the-art, all-electric propulsion of a large commercial airplane is impossible in either the short or medium term. The main reason is that the power equation just doesn't compute! If we want to generate the dozens of megawatts needed to power a large airplane for flights of at least several hours, we will have to improve current battery technology at least 10-fold. Even with energy density five times greater than what current electric vehicles can offer, a long-distance flight (3,000 nm) would require 170 metric tons of batteries (374,000 lb), compared with the 80 metric tons (176,000 lb) maximum takeoff weight (MTOW) of an Airbus A320 or Boeing 737 class jetliner.
Over and above these technology obstacles, there are also a number of unknowns in terms of aviation regulations. No current legislation governs urban VTOL operations, for instance, and the whole certification process will have to be revamped to cover future distributed propulsion layouts.
There's a final roadblock to electric aircraft: will they be accepted by society in general? From the geopolitical standpoint, these technologies use large quantities of rare earths (especially for batteries), which raises ethical issues, as well sustainability issues for supply chains. From the environmental standpoint, the energy budget is undoubtedly better than current designs, but perhaps not everywhere and at all times: we can well imagine regions where electric VTOL aircraft would be a welcome alternative to congestion in big cities, but in others perhaps they would only extend noise and visual pollution vertically.