Autonomous flying: a must for the future
The IATA Roadmap 2013 has shown that most of the technologies currently being researched will have a marginal effect on fuel consumption of aircraft and thus CO2 emissions. The technologies currently being developed in industry and EC programs like Clean Sky will not enable the industry to reach the IATA target of 50% CO2 (Fuel) reduction by 2050. IATA identified 4 technologies that will bring substantial benefits: The Hybrid Wing Body configuration, active flow control, new engine core concepts and flying without undercarriage thanks to take-off and landing with ground power. The EC sponsored research project Gabriel in which AD Cuenta was a partner demonstrated the technical feasibility of using ground power to launch and recover aircraft. The most challenging part may be the fully autonomous landing on a sledge mounted on the MagLev ramp in cross wind conditions and heavy turbulence. But future aviation is not just about emissions. The attractiveness of aviation to serve society is also based on low cost of transportation. Cost of flying has been reduced constantly despite increases in fuel prices. This is partly due to the high load factors in civil aviation. Today a load factor of 85% is common, which is at least 40% higher than in other transport modes. Direct operating cost have been reduced over time thanks to improvements in technology. Better engines, less drag and reduced weight have contributed to a constant reduction of fuel burn. The reduction in fuel overcompensated the increase cost for assets depreciation and maintenance. Indirect operating cost have gone down as well mainly thanks to internet bookings. In general productivity in aviation has reached limits as the A-380 is about the biggest still economically feasible aircraft ( also due to airport restrictions), speed cannot be increased at reasonable cost and aircraft utilization is high thanks to short turnaround times of 25 minutes. Perhaps there are possibilities to reduce turnaround time even more thanks to different procedures and technologies. But one aspect is not considered in the IATA analysis and that is unmanned flying. Cost savings can be substantial if no pilots would be needed and ATM could be fully automated. Passengers can be served by robots on board so no cabin crew is needed in future. (With adaptation of safety requirements). Today we can see already some examples of unpiloted vehicles especially in the RPAS domain. Unmanned vehicles are remotely piloted via a line of sight data-link (up to 150 nm), via line of sight via satellite/ airborne relay, or these vehicles are programmed to fly a particular pattern. None of these solutions seem to work for civil commercial aviation in non-segregated airspace. Recent tests in the UK showed a 4 seconds delay between sending and receiving instructions. Far too long to apply in civil aviation. Autonomous flying is the only option available. If there is no need for a pilot it will not only save substantial cost but would also prevent the pilot shortage that is predicted by Boeing and others. This is particularly relevant when air taxi operations and regional flying of both passengers and cargo will be feasible at affordable prices and substituting surface transport. Experience with autonomous flight is limited thus far. The technological approach is missing although a number of elements of autonomous flight are already available. By autonomous flight we mean a flight executed by a device able to perform complete complex flying missions safely and very efficiently without human interference. What do we need to accomplish this. What is the technological challenge? First we need to have much more reliable guidance and control equipment. Current equipment makes a pilot needed to correct the automation. If the pilot does not respond in a proper way it may lead to a crash, as demonstrated recently ( Loss of control). Although these accidents are contributed to pilot error often the root course of accidents is in inadequate information provided by or functioning of equipment. Second we need reliable sense and avoid systems. Data links need to be secure, hack proof and cheaper. Via ADS-B the position of aircraft should be known to other aircraft that fly direct routes from origin to destination. If automation allows aircraft to interact in a safe way, there is no need for air traffic control. That can be automated as well. This will save substantial cost. As part of the Single Sky initiative of the European Commission aiming at a single non segregated airspace in Europe the mission of the RTD program SESAR was to reduce ATM cost with at least 50%. Current estimates suggest that only a marginal cost reduction can be achieved. Full automation will bring cost benefits beyond the 50% aimed for. We also need to look into certification and regulation. With current regulation autonomous flying is not feasible. Like FAA in the USA, EASA should be part of a technology development program to enable autonomous flight in 2050. Another issue is public acceptance. It so expected that by 2050 cars will be able to drive autonomously so the public should be acquainted with autonomous vehicles. However there may be resistance to fly with fully autonomous aircraft. Therefore it is expected that cargo aircraft will be the first application of this technology, which should be feasible in 2040. Also small aircraft may be flown autonomously. There is a need to start research in the area today in order to be prepared for 2040. Changes in aviation are taking a long time. SESAR tries to implement a modification in the ATM system that was already demonstrated in 1990, but may see the first application in 2030. So we need to be prepared. Still there is no reason to accept the idea of autonomous flight and start working towards its introduction.