The TP400 power-plant developed for the A400M by EuroProp International (EPI) took to the air for the first time on Dec. 17, 2008 on a C-130K flight test bed. The TP400 is installed on the inner left engine mount of the C-130K which is otherwise powered by three of the usually four Allison T56 turbopropellers. The aircraft took off at 10:44 a.m. local time from Cambridge airfield in the United Kingdom where Marshall Aerospace, which is conducting the flight test-bed trials, is based, and touched down at 11:59 a.m. local time. The flight lasted one hour and 15 minutes.
During the flight, various flight characteristics such as aircraft basic handling and TP400 response at a thrust equivalent to the maximum power generated by each of the other T56 engines were tested to satisfaction in several aircraft configurations up to a speed of 165 knots and an altitude of 8,000 feet.