Improvement of European thin haul mobility: the role of small Green commuter aircraft
Authors: Romano Diego Giuseppe , Apuleo Gianvito 
Published: February 2022

Abstract
In the last years, transportation demand has grown up as consequence of the increase in leisure, and business for both heavily travelled routes (between major cities) and thin routes (between remote areas, and remote areas with major cities).
In parallel, aviation sustainability issues have become more and more important, being aviation pollution an important source of global environmental pollution. Moreover, several States, as well as private Companies travelling for business, have introduced bans and/or special taxes on short flights covering distances that could be travelled by train in less than 3 hours. These regulations have a major impact on short haul thin routes, which could be covered by small air transport (up to 19 seats). Thus, dedicated research and technology innovation effort has been put in place over the last years to develop eco-friendly, and economically viable, aircraft able to answer sustainability needs, market demand, and cost-effectiveness.
In particular, Clean Sky 2 Joint Undertaking, a public-private partnership between the European Commission and the European aeronautics industry, has co-financed the SAT (Small Air Transport) TA (Transverse Activity) initiative. SAT TA main goal is to address technology innovations to reduce environmental impact as well as operational cost of small commuters, ensuring improved levels of operational safety. SAT TA is a Project with an overall EU (European Union) funding of about 68 mln€, including small aircraft OEMs (Original Equipment Manufacturers), major aircraft suppliers, SMEs (Small and Medium Enterprises), research centres and academia (more than 80 Partners involved).
The research activity has focused on the following main technology streams:
•New generation turboprop engine with reduced fuel consumption, emissions, noise and maintenance costs for 19 seats aircraft.
• More electric digital systems including:
• Affordable fly-by-wire architecture for small aircraft (CS23 certification rules).
• More electric systems replacing pneumatic and hydraulic aircraft systems (hybrid de-ice system, landing gear and brakes, high voltage EPGDS –Electrical Power Generation and Distribution System –).
• Advanced avionics for small aircraft, to reduce pilot workload, paving single pilot operations for 19 seats.
• Affordable airframe structures including:
• Low cost composite wing box and nacelle using OoA (Out of Autoclave) technology, LRI (Liquid Resin Infusion) and automated deposition process.
• Affordable small aircraft manufacturing of metallic fuselage by means of FSW (Friction Stir Welding) and LMD (Laser Metal Deposition).
• Advanced cabin comfort with new materials and more comfortable seats.
To address the abovementioned technologies, two different platforms have been designed: a Reference and a Green aircraft. Reference aircraft is a virtual aircraft designed considering 2014 technologies with an existing engine assuring requested take-off power. Green aircraft is designed integrating the technologies developed within Clean Sky 2.
The present work describes designed aircraft, and preliminary mission analyses, showing the achievement of Project goals (20% CO2, 20% NOx reduction for the design mission).