One of the replacements for the L-39 Albatros was the Aero L-159 Alca, a modernised version of the L-39. Originally, Aero Vodochody had intended to develop the L-159 in partnership with Elbit, but the Czech Ministry of Defense instead selected Rockwell Collins to partner on the program. The limited success of the L-159 led Aero to announce at the 2014 Farnborough Airshow that it was developing an upgraded version of the L-39, designated L-39NG, to compete with the Alenia Aermacchi M-346 and British Aerospace Hawk. The L-39NG replaces the AI-25 turbofan with a Williams FJ44 engine; the airframe is modified, the wingtip fuel tanks being eliminated, and a new suite of avionics will be provided. First flight of the L-39NG was in September 2015, with deliveries starting in 2020.