AIRCRAFT SYSTEM INCLUDING A CRYOGENIC FLUID OPERATED AUXILIARY POWER UNIT (APU)

An aircraft system includes a turbine engine (32, 34) having a compressor (44), a combustor (48) having an inlet (105) and an outlet (107), and a turbine (46) having an inlet portion (110) and an outlet portion (112). An auxiliary power unit (37), APU, is operatively connected to the turbine engine (32, 24). The APU (77) includes a compressor portion (70), a generator (74), and a turbine portion (72). The compressor portion (70) is operatively connected to the turbine portion (72) through the generator (74). A source of cryogenic fluid (62) is operatively connected to the turbine engine (32, 34) and the APU (37). A heat exchange member (84) includes an inlet section (116) operatively connected to the source of cryogenic fluid (62), a first outlet section (120) operatively connected to the turbine engine (32, 34) and a second outlet section (122) operatively connected to the compressor portion (70).