Paris Innovation Review – The aviation sector is at a crossroads. Many airlines are struggling to stay afloat while others seem insatiable in their demand for ever more aircraft. In the midst of this seeming paradox is it even possible to imagine the aircraft future?
Jean-Paul Herteman – Over roughly 40 years, air traffic has increased ten-fold despite three significant oil shocks. It would be imprudent to over-extrapolate from past experience, but it pays to have some familiarity with previous trends. The origins of commercial aviation date back to the late-1960s and early-1970s. Since this time, traffic has increased at double the rate of GDP. This growth model is typical of industries that have yet to reach maturity, and demand shows no signs of letting up in the foreseeable future.
To make a comparison, in the automotive sector elasticity hovers slightly above one while the aviation sector still enjoys the potential for significant growth margins, much of which will be derived from expansion in the so-called BRICs (Brazil, Russia, India, China). Whereas two-thirds of the current fleet is based in Europe and North America, two-thirds of our order books emanate from the emerging economies.
Is this scale of growth sustainable?
Without question as the demand for air transportation is far from being satisfied. At home we have witnessed the phenomenal success of the low-cost segment of the sector, but the real driver for future growth will be the emerging economies. In 2011, the average Chinese flew once every ten years whereas for Americans the figure was twice a year. Now imagine for a moment a China in which the numbers reach parity with those found in the United States. This would require us to fully double the current global fleet.
The scale may seem enormous, frightening even when considered in terms of climate change, yet the past is instructive in this regard and gives rise to optimism. The very reason supply has been able to keep pace with demand over the last 40 years is because of increases in energy efficiency. For every kilometer flown, the fuel consumption per passenger is a mere quarter of what it once was. How? Engine makers would like to claim the credit, and aircraft manufacturers are willing to concede that they deserve at least half of the praise for this positive outcome. Still, there is no question that the design of ultra-modern aircraft such as the A380 has driven down fuel consumption to a mere three liters per passenger for every 100 km travelled, better than an automobile.
Constraints imposed by more stringent environmental regulations have led numerous studies to suggest that rising demand will remain unsatisfied unless a reduction to two liters per 100 km is achieved by 2020? Is this a realistic goal?
The real goal is a stable, or even reduced, carbon footprint to accompany the increase in air traffic, and an economic model that renders air travel accessible to an ever wider public. This is not a pipe dream. European working groups set the two liter target and were swiftly followed by their French counterparts. Over the next 20 years air traffic is expected to double and we would like to see carbon emissions cut in half over the corresponding period. Here the equation gets rather complicated. More efficient and less fossil-fuel dependent technologies have become a necessity. Major progress will also have to be made regarding noise pollution (50% reduction) and nitrogen-oxide emissions (80%). We are diving head first into the solution.
In short- and medium-haul aircraft, primarily the Airbus A320 and Boeing’s B737, a new generation of engines are being introduced that consume 15% less fuel. For example, we are currently working on a hybrid engine that would allow aircraft to taxi using auxiliary power generators placed in the tail. This is just one small step toward a greener future. In partnership with Honeywell, Safran has developed a new electric engine, to be integrated with the primary landing gear. The result: for a flight from Paris to Nice (roughly equivalent to Boston-Washington D.C.) this technology could lead to consumption efficiency gains of up to 5%.
A promising start but the target is 50% …
Yes, and this goal should be achieved by the years 2020-2025, but the horizons actually stretch much farther. In any case, we cannot change the laws of physics. Eventually an asymptote will be reached, and the laws of diminishing returns suggest additional cuts in carbon emissions will depend on factors other than simple reductions in fuel consumption. Development must focus on new sources of fuel, intelligent biofuels if you will, with a negative carbon footprint. The feed stock must not interfere or compete with existing food crops and should require a minimum of energy to produce. Promising sources have already been identified in the form of algae and succulent plants, both of which can be cultivated in unused tropical zones currently occupied by desert. Irrigation systems would rely on sea water. Aviation is expected to continue to rely on liquid fuel, and biofuels could provide the perfect solution as long as no undue strain is placed on increasingly precious water resources.
Hydrotreated vegetable oils (HVO) is another option as the process can utilize biomass to produce biofuels much like kerosene that are of a quality equal to the same product produced using fossil-fuels. The technology has the potential to reduce greenhouse gas emissions by as much as 70% to 80%. It is particularly promising as a drop-in solution as the new biofuel can be used alongside, and as a compliment to, traditional kerosene with no change to existing aircraft fuel handling systems. This is not a fantasy. The role played by biofuels over the next 20 years may well be the key to resolving many of our current dilemmas. Test flights have already been conducted in aircraft making use of these new sources of fuel.
Reaching your goals will require more than new sources of fuel.
In terms of performance, economic, and environmental concerns we continue to be blessed with substantial room to maneuver, and any asymptote is far off on the horizon. Development of new sources of fuel is merely the final stop on the long road toward achieving our goals. We are also concentrating our efforts on mass, materials, hydraulic fluids, and propulsion.
The key to increased performance in jet engines—operating on a Carnot cycle with expansion, combustion, compression—is more efficient propulsion, which roughly translates into more efficient transformation of thermodynamic energy into kinetic energy. Currently, the ratio of overall propulsive energy is relatively modest when compared to some other forms of transportation. To use the example of trains, the rolling resistance between the wheels and the rails is negligible which means 98% of energy expended translates directly into propulsion. The figure for automobiles is more modest considering their need for transmission, universal joints, gear boxes, and tires but still climbs to 80%. As of 2011, the figure for jet engines is less than 50%. Clearly the margin for progress is enormous.
How can this margin be exploited?
By increasing air velocity as it passes through the engine we can increase thrust, but this gain will come at the expense of larger engines. Complications arise as we must also take into account the size of the landing apparatus. Further difficulties are created by the need to reduce air velocity as it passes from fan blades to the turbines. The race toward larger engines also introduces a new set of safety concerns, notably jet engine bird ingestion, and air velocity is enormous. Of the drag created by wing units, 30% is attributable to these larger engines.
The dilution ratio, which defines the level of air flow that is simply driven then released through the exhaust, thus avoiding a complete Carnot cycle (bypass flow), and the flow that actually passes through the combustion chamber (core flow) is on a vertiginous upward path. At the dawn of the aviation industry the dilution ratio was roughly one to one (i.e. the ratio of the mass of air that flows in both flows). For engines such as the CFM56 the ratio has now passed to five or more (i.e. five times more air in the bypass flow than the core flow), leading to better thrust specific fuel consumption. Next generation engines are being introduced with ratios climbing to ten and by 2020, we should be at 30! Ensuring safety has become mission critical. We are currently conducting tests to measure the impact of events such as bird ingestion using computational fluid dynamics in much the same way as we measure the possible consequences of an aircraft colliding with a nuclear power reactor.
How would you define the oft-discussed notion of “intelligent” aircraft?
Any answer depends on our definition of “intelligence” and opinions are divided. First and foremost we must look at the capacity of a given aircraft to interact with air traffic control systems and 4D trajectory control. Satellite navigation systems are an essential component, and we are working toward the creation of two or three independent satellite positioning systems (e.g. Galileo) to compliment current GPS technology. This will provide the required redundancy to ensure a constant stream of reliable data. Once this goal is achieved we could see efficiency gains of up to 10% based on better optimization of flight path trajectories.
Moreover, as aircraft become more and more electricity powered, or in fact completely electric, we will reduce our dependence on hydraulic systems which rely on extremely heavy mechanisms to drive moving parts (force could be increased but at the price of reliability). We are therefore moving toward replacing current systems with electrically powered actuators. The objective: harmonize next generation electricity powered systems to sequence and optimize the various stages of air transportation. Returning to our comparison with trains, braking systems are left idle during departures leading to lower fuel consumption overall.
Are we in danger of increasing risk by making aircraft more “intelligent”?
The interaction between man and machine remains a major focal point of our sector. Whether discussing the current generation’s reliance on avionics or the more rustic interfaces of the past, the link between pilots and the overall systems has always been an obsession in the aviation industry.
Does the Chinese aviation industry have the potential fulfill its fantastic promise?
Spectacular Chinese economic growth is moving hand in hand with increasingly technological sophistication. The country is among the world leaders in numbers of patent applications and possesses an army of engineers that is, per capita, equal to France. There is no point in trying to bury our heads in the sand over this new reality. The country’s commercial aviation was launched in the latter half of the 1980s and has since experienced rapid growth. Infrastructure has kept pace with the boom and the Chinese have demonstrated their ability to develop infrastructure such as airports and air traffic control while Asia’s other emerging giant, India, has come up remarkably short in this regard.
We took our first steps into China at the dawn of the 1990s when we made the decision to open the doors of an educational facility near Chengdu dedicated to training individuals in engine maintenance. When the decision was made air traffic was fairly modest, but we have since seen annual increases of between 15% and 20% (double the rate of GDP growth). Every year, between 20% and 25% of Safran’s business comes from China. While the country is far from being our most significant client, we operate a maintenance facility in joint venture with Chinese carriers.
In the civil sector at least, is the Chinese helicopter industry virgin territory?
The potential for this market cannot be understated. In addition to our other activities we have sealed our first partnership for the development of helicopter turbines. As it stands, helicopters are virtually non-existent due to Chinese regulations that restrict airspace below 1500m to military use. Following recent crises and natural catastrophes policymakers have come to recognize the need for more helicopters. Whereas the United States’ fleet numbers 10,000 in China the figure is only 600, all restricted to military use. One component of the recently approved 12th Five-Year Plan was a decision to remove numerous airspace restrictions. China is an enormous country with over 5000 islands as well as an immense and widely distributed coastline. Increasing the fleet has become critical to ensure the country can meet its commitments and will serve multiple functions: securing borders, fighting drug traffic, maintaining high voltage electricity networks, and supporting oil and gas exploration and extraction.
The Chinese market has become an integral component of the industrial strategy for groups such as Safran. How do you work with your Chinese counterparts?
Success depends on trust and deep personal ties. Chinese business culture revolves less around contracts and more around building durable relationships.
Transfers of technology are quite rare in our business and when it occurs we ensure that we receive maximum value in return. Safran is no stranger to international cooperation and we can draw from a rich history of success in this area. Following an accord between Presidents Nixon and Pompidou we partnered with GE on the CFM 56. Nixon was heard to say: “Let’s give this a shot but there will be no transfer of technology to France.” We were willing to play the game, and in retrospect the project remains one of our most inspiring tales of transatlantic cooperation.The key driver for success was the personal bond that developed between former Snecma President, René Ravaud, and his counterpart at GE Aviation, Gerhard Neumann.
The aerospace industry is multipolar and global by design. Never forget that Safran sells twice as many engines to Boeing as it does to Airbus, and that 40% of the components and materials that make up an Airbus are manufactured in the United States.
Do you envision a day when aircraft manufacturers in emerging economies are capable of competing with the current Boeing and Airbus duopoly?
As of 2011, the world’s third leading aircraft constructor is Brazil’s Embraer. In China it is not a matter of if but when aircraft manufacturing reaches a critical mass. The country’s current production relies on a mixture of traditional state-owned enterprises working from outdated models imported from the former-Soviet Union, but rapid advances are being made.
What should not be forgotten is that it took Airbus some 35 years to reach parity with Boeing. The aerospace industry is somewhat unique: elaboration and development of the alloys and composites necessary for construction of aircraft and engines requires about 20 years. No real shortcuts exist. Because of the deep scientific insight and experience required to bring a project to fruition planning must be long-term. Project management demands mastery of extremely complex science, the ability to synthesize numerous strands of the development process, and open channels of communication to allow for a multi-disciplinary approach in which specialists in various domains can share knowledge freely. Aircraft construction is truly a team effort and individuals, no matter how capable they may be, cannot operate in isolation. Deep scientific knowledge does not invent itself and it cannot be bought, it is priceless.
An additional reason for the long-term lens through which the industry must be viewed is that security and safety, as in the nuclear industry, are of paramount importance. The regulatory regime is extremely rigorous and follows specific protocols leading to international certification. It goes without saying that developed countries enjoy an advantage in this domain as the two agencies responsible for the process are European (EASA) and American (FAA).
The C919 is the Chinese response to the A320. What is their exact role in overall construction?
We are responsible for the engines but there has been no transfer of technology. The Chinese are more or less responsible for the rest, in other words the “body” of the aircraft such as the fuselage, the wings; to put it simply the structure as well as some aspects of integration. On closer inspection it becomes quickly evident that most of the components are Western in origin and have been bought in: navigation and flight control systems, electricity generation, engines, landing gear, thrust reversers, etc. In the aerospace industry, the various components are at least as important as the actual aircraft. The Chinese are in all truthfulness still only taking their first tentative steps so it is imperative that they continue to push forward. As for the construction of a truly Chinese aircraft it is really only a matter of time.
------Note from the editors: Safran is a patron of Paris Innovation Review