It’s been a while since an airplane maker has rekindled the age old dream of New York to Tokyo flights in a few hours. But taking advantage of having the aerospace world currently camped out on its home turf, EADS, the parent company of Airbus, used the Paris airshow as the venue announce an idea it’s pondering for the latest Mach 4+ airliner.

Aimed at travelers who may need to travel half way around the world and back in a day, the concept being developed by EADS is called the Zero Emission Hypersonic Transport, or ZEHST. We’re not quite sure how the three different propulsion systems add up to zero emissions, but it is an interesting idea.

The 50-100 passenger airplane would take off from a runway using turbo fan jet engines like a normal airliner. Shortly after take off the sleek fuselage would be pulled into a steep climb where rocket engines would then push it along to Mach 2 and more than 100,000 feet. Once up to the proper speed and altitude, ramjet engines would then be used propel the ZEHST to over Mach 4 (~3,000 mph) allowing it to link any two cities in just a few hours or less.

Upon arriving near the destination, the ramjet engines would be shut down and the airplane would glide until it is flying slow enough and low enough to start up the turbo fan engines. It would then make an approach and land like a typical airliner.

If all this sounds like a dream, EADS acknowledges some of the technology is still in the development phase. But like any good dreamy idea, it is not promising anything soon. The company says such an airliner would not enter service until 2040.

Photos/Video: EADS