The Advanced Jet Trainer (AJT) project originated in the work of Tristan Crawford during the early 2010s. In 2018, Aeralis sought £1 million ($1.32 million) via
crowdfunding to fund the design of a concept fuselage demonstrator to be presented at trade shows. During September 2019, it was announced that Aeralis had partnered with engineering and design consultancy firm
Atkins to work on two out of three planned variants of the aircraft: the advanced jet trainer and the basic jet trainer. During February 2021, Aeralis was awarded a three-year contract with the RAF's Rapid Capabilities Office for the further development of the aircraft. Additional external funding was also actively being sought to accelerate the programme; according to a spokesperson, the company aimed to reach the preproduction stage prior to the middle of the decade. In March 2021, the company signed a teaming agreement with
Thales UK for the latter to support development of training and simulation systems. In September 2021, Aeralis showcased a number of potential future variants of the type, including an uncrewed combat model and an uncrewed
refuelling aircraft. which it stated was an indication that the AJT was gaining international interest. Atkins and
Siemens also agreed to collaborate with Aeralis on Aerside, the aircraft's digital system. Also in September 2021, Aeralis stated that it was scheduled to perform the first flight of the AJT some time during 2024. Two months later, Aeralis received another significant investment from the RAF, initiating Phase 2 of the programme which evaluated the potential of PYRAMID, the UK
Ministry of Defence's (MOD) open mission architecture. Aeralis also engaged with the MOD and its procurement arm,
Defence Equipment and Support (DE&S) to explore the potential of Aeralis within the framework of the RAF's
Future Combat Air System (FCAS) initiative. During July 2022, the company signed a MoU with
Ascent Flight Training to develop a future flying training system and explore collaboration opportunities in the provision of military flying training. During October 2022,
wind tunnel testing of a scale model of the AJT was performed by
Airbus UK at
Filton. Two months later, Aeralis was awarded a £9 million (US$11 million) contract from the MOD to provide digital engineering services. During June 2023, Aeralis signed a MoU with
International Turbine Engine Company (ITEC), a
joint venture between
Honeywell and
Aerospace Industrial Development Corporation (AIDC), to develop powerplant solutions for the AJT; the agreement also covers collaboration on the designing of electrical and thermal management systems. ==Design==