Abstract The aviation industry has deployed a wide set of broadband networks and services to offer high-speed connectivity to passengers and crews. The aircraft terminal antenna is a critical item with a high impact on the total cost of ownership for the airline connectivity services. Electronically Steered Antennas (ESAs) are expected to disrupt the market thanks to their unique capacity to track two or more satellites simultaneously due to the multi-beam capability. The advantages of the ESAs over traditional mechanically steered antennas are especially valued by aviation sector customers because of their reduced size (less additional fuel burn costs due to the less additional drag) and improved reliability. The objective of LESAF project is to propose low-profile and highly efficient ESA solution for the next generation of In-Flight Connectivity services. This will be achieved through the requirements definition, system analysis, technology assessment, prototyping and validation of this type of new generation directional antennas. It will be demonstrated that this type of antennas can meet the stringest requirements impose by the aviation market while bringing superior benefits over their alternative technological solutions. Two electronically steered antenna prototypes will be produced and tested (TRL 6) in order WP1.4.4 partners to perform testing in a representative test environment representative of an aircraft installation (installation on real aircrafts is not envisaged). The main characteristics and innovations of LESAR are: 1) Separated Tx and Rx apertures based on a multilevel modular concept 2) Innovative vertical assembly model maximizing the efficiency and reducing the size, number of elements, power consumption and heat dissipation 3) End-fire contactless radiating elements 4) Broadband Analogue beamforming with phase delay compensation 5) Multibeam steering and signal processing.