The CAFE Green Flight Challenge Program (CGFCP) Brien A. Seeley M.D.* CAFE Foundation, Santa Rosa, California, 95404 The consensus aviation future predicted by the expert faculty at NASA’s 2010 Aviation Unleashed Conference, i.e., ubiquitous, fast, on-demand, point-to-point distributed transporting of people and goods by autonomous aircraft, will demand specialized new small aircraft capabilities. To be sustainable, these capabilities will necessarily include emission- free, ultra-quiet electric propulsion, autonomous flight, and extremely short take off and landing (ESTOL). The Comparative Aircraft Flight Efficiency Foundation (“CAFE”), host of the 2011 Green Flight Challenge, has adopted the name “Sky Taxi” to describe electric- powered aircraft that combine these capabilities. The CAFE Green Flight Challenge Program (CGFCP) is a concerted, five-year technology prize matrix to efficiently bring forth such Sky Taxis. This paper describes the background, feasibility and metrics for each of the CGFCP prize competitions, CAFE’s rationale for point-to-point Sky Taxi operations at pocket airports, and the potential economic and societal benefits of such operations. The CGFCP aligns with the goals of the DOE, OSTP, NASA, FAA, EPA, NSF, and IPCC. Nomenclature 4D = a three dimensional path along which each point has a defined specific clock time 6’ = 6 feet, with apostrophe indicating feet Ad = flat plate drag area at zero lift AFS = autonomous flight system AGL = height above ground level ATC = air traffic control BHP = brake horsepower BMS = battery management system CAFE = CAFE Foundation, Inc., an all volunteer, 501c3 non-profit educational foundation CAS = calibrated airspeed Cdo = zero lift drag coefficient CCW = circulation controlled wing CGFCP = CAFE Green Flight Challenge Program CGFC = CAFE Green Flight Challenge II, III, IV, V or VI CLmax = maximum lift coefficient CNEL = community noise equivalent level CO2 = carbon dioxide CTOL = conventional take off and landing dBA = decibel noise level, A-weighted scale EAA = Experimental Aircraft Association EMAS = engineered materials arresting system EMI = electro-magnetic interference ESTOL = extremely short take off and landing eta = propeller efficiency G = the force of gravity at sea level on Earth GA = general aviation GFC I = the 2011 Green Flight Challenge sponsored by Google and prize-funded by NASA GPS = global positioning system kg = kilogram kWh = kilowatt hour kW = kilowatt __________________________________ *President, CAFE Foundation, 4370 Raymonde Way, [email protected], Senior Member AIAA. 1 American Institute of Aeronautics and Astronautics lb = pound m = meter mic = microphone MMW = millimeter wave MPG = miles per gallon, typically referenced to 87 unleaded auto fuel mph = miles per hour MSL = above mean sea level, describing elevation or altitude on a standard day NAS = National Airspace System NFL = National Football League NOTAM = notice to airmen NTSB = National Transportation Safety Board OSTP = Office of Science and Technology Policy PAS = propeller acoustics simulator pKmPG = passenger kilometers per gallon PSI = pounds per square inch RAS = runway acceleration simulator RITS = runway-in-the-sky, a virtual airport runway situated in the airspace ROI = return on investment RPM = revolutions per minute STEM = science, technology, engineering and mathematics education STS = Charles M. Schulz Sonoma County Airport STZ = simulated traffic zone TFR = temporary flight restriction UPS = United Parcel Service, a leading freight hauling company UV = ultra-violet V = volt VMT = vehicle miles traveled VTOL = vertical take off and landing Vmax = maximum velocity Vso = minimum velocity at 1 G at which an aircraft in landing configuration stalls I. Introduction The Obama Administration’s new “COMPETES” Program and its Center of Excellence for Collaborative Innovation, as announced by the President’s OSTP report in March 2012, authorizes all federal agencies to use the technology prize mechanism as a legitimate alternative to research grants and procurement contracts to fulfill agency goals and needs.1 The authorizing report cites the all-volunteer CAFE Foundation’s conduct of the 2011 Green Flight Challenge (GFC I) as exemplary and recognizes the foremost advantage of such prizes as their leveraged stimulus to substantial private investments in diverse, concurrent, sophisticated, innovative approaches to goals that can benefit society. NASA officials labeled the achievements of the electric powered aircraft in the September 2011 GFC I as a “Lindbergh Moment” because it inaugurated the age of quiet, emission-free flight in practical electric aircraft. In January 2010, CAFE realized from its Electric Aircraft Symposia and from the electric aircraft designs that it had registered to compete in the upcoming GFC I, that electric propulsion could enable a new class of aircraft. That new aircraft could uniquely combine ultra-quiet propulsion with ESTOL performance and autonomous flight capabilities to enable operations at pocket airports as small as 1 hectare. In May 2010, CAFE presented a formal colloquium at NASA Langley Research Center describing how such an aircraft, which CAFE has named the Sky Taxi, could transform transportation and substantially reduce greenhouse gas emissions. In October, 2010, the assembled expert faculty of NASA engineers, scientists and respected industry futurists at NASA’s Aviation Unleashed Conference jointly concluded that aviation’s future would be one of ubiquitous, fast, on-demand, point-to-point distributed transporting of people and goods by autonomous aircraft.2 In November 2011, CAFE designed the CGFCP as five stepwise, inter-dependent technology prizes (“missions”) necessary to bring forth the Sky Taxi. All missions of the CGFCP can be completed in 68 months from its announcement date. The core CGFCP missions are: 2 American Institute of Aeronautics and Astronautics MISSION: SPECIFIC FLIGHT CAPABILITY: GFC I: Speed and MPG: Electric aircraft (“Lindbergh Moment of 2011”) CGFC II: 2013, Wheel Motors for Extremely Short Take Off and Landing (ESTOL) CGFC III: 2014, Ultra-Quiet Propulsion CGFC IV: 2015, Autonomous Personal Flight (with Safety pilot) CGFC V: 2016, Fast ESTOL (Vmax with ESTOL) CGFC VI: 2017, The Sky Taxi: Quiet, Autonomous Personal Flight with Fast ESTOL The competition rules for all CGFCP missions are to be published at the outset in order to launch concurrent progress toward their goals and to maximize the time available for teams to prepare. Each mission brings forth one or more of the breakthrough air vehicle capabilities necessary for Sky Taxis to transform aviation and transportation. Those essential capabilities and thresholds to be demonstrated are as follows: 1. take off distances of less than 128 meters (420 feet) over a 38.1 meter (125 foot) obstacle (i.e., ESTOL); 2. take off noise emissions of less than 65 dBA at a 38.1 meter (125 feet) sideline distance; 3. directed, autonomous flight with 4D navigation and ATOL (automatic take off/landing); 4. cruise speed of at least 193.12+ kph (120+ mph) combined with ESTOL capability; 5. energy efficiency better than 321.8 pKmPG (200 pMPG); 6. electric propulsion; 7. range of at least 200 statute miles; 8. at least two seats with 200 lb per seat payload capability; 9. all of the above combined into a Sky Taxi whose reliability can rival that of the airlines. The CGFCP matrix of technology prize competitions can achieve its ultimate goals: • in ideal conjunction with NASA’s mission to bring forth innovations “for the good of all”; • in ideal conjunction with FAA’s priorities for green, quiet, sustainable advances that enhance airspace capacity and safety; • for much less cost than a conventional procurement contract mechanism; • with a guaranteed, multi-fold return on invested public dollars; • with shorter lead-times than other contracting strategies; • with more transparency and publicity than other private contracting strategies; • while harnessing a maximally diverse pool of innovation talent; • with a natural stimulus to science, technology, engineering, and mathematics (STEM) education Each future CGFC mission is designed to assure that its practical performance breakthroughs are safely demonstrated in fair, accurately measured competitions without loopholes. The CGFCP has been called a ‘moonshot for aviation’ that, like NASA’s Apollo Program, needs assured funding at its outset for all of its concerted, inter- dependent missions because no single mission alone is sufficient to produce the ultimate goal. The CGFCP encompasses a ‘technological feast’ because it demands that teams excel in all of these technology areas: • electric motors—quiet, reliable, lightweight, regenerative and vibration-free; • precise and reliable motor control technology; • energy storage density, management systems, cycle life and burst power capability; • solar energy capture, photovoltaics; • ideal traction—tire pressure, compounding, profile, and grip; • advanced structures including nano-technologies; • ultra-quiet propulsion including ANR and synchro-phasing; • high lift devices including powered lift, vectored thrust and CCW; • high L/D and high pMPG sailplane technology; • CFD guided drag reduction, laminar flow, and Goldschmied propulsion; • vehicle parachutes; • motor-in-wheel acceleration, braking, steering, and navigating; 3 American Institute of Aeronautics and Astronautics • computerized flight decks with machine intelligence; • advanced sensor systems and wireless communication/navigation;