EADS biofuel airliner could fly four times speed of sound

EADS has unveiled plans for a biofuel-powered commercial airliner that the company claims could travel at over four times the speed of sound.

The plane could fly from Tokyo to Paris or Los Angeles under 2 hours 30 minutes, the aerospace firm announced this week at the Paris Air Show.

Named ZEHST (Zero Emission High Supersonic Transport), the high-speed concept draws on technology from Astrium’s suborbital spaceplane project and could reach speeds of Mach 4 (5,000 kph or 3,107 mph).

ZEHST demonstrators are planned for the end of the decade, to be followed by development of an operational vehicle, with the final commercial craft scheduled to be ready by 2050.

The thrust required for the ZEHST’s initial flight phase ­– beginning with a takeoff, a climb to 5km altitude and acceleration to Mach 0.8 – would be provided by two high-power, low-bypass turbojet engines without afterburners that operate on biofuel.

Two small liquid hydrogen/liquid oxygen-powered booster rocket engines would then be fired, followed by the ignition of a larger one, accelerating the aircraft to a speed of Mach 2.5 up to a cruising altitude of 23km.

Once the altitude had been reached, two airbreathing hydrogen-fuelled ramjets would then be employed to push the speed of the aircraft beyond Mach 4 up to an altitude of about 32km.

When approaching its destination, a gliding descent and deceleration to subsonic speed would be performed, followed by the re-ignition of the aircraft’s turbojets at an altitude of 10km for the approach to landing.

The ZEHST programme is in part a product of a French-Japanese cooperation between the Groupement des Industries Françaises Aéronautiques et Spatiales (GIFAS) and the Society of Japanese Aerospace Companies (SJAC), who signed a supersonic tchnologies co-operation agreement during the 2005 Paris Air Show.