LONDON — British companies involved in the trinational program to develop the Tempest sixth-generation combat jet have lifted the lid on a fraction of the technologies being employed to fly a demonstrator aircraft within the next four years. A new power plant manufacturing process, a bespoke simulator and auto-coding software all got a name check in a progress statement due for release by BAE Systems June 14. BAE Systems, Rolls-Royce, Leonardo UK, MBDA, the Ministry of Defence and a number of