US airforce in $500m push for better jet turbines

Minority Report hovership consolation prize for ramjet fanciers

The US air force's push to produce revolutionary new jet engines is now fully underway, with the announcement of substantial demonstrator contracts.

Back in March, the Air Force Research Laboratory (AFRL) announced that it would mount a five-year programme called ADaptive Versatile ENgine Technology, or ADVENT*, to overcome the limitations of current turbine engines.

At the moment, in essence, an aircraft jet engine can be set up for maximum speed or maximum fuel economy. Fat, high-bypass turbofans of the sort seen on airliners get (relatively) good fuel economy but aren't capable of pushing through the sound barrier. Skinny low-bypass engines (or simple turbojets, in former times) can go faster but get worse endurance.

"ADVENT ... incorporates the best characteristics of high performance and fuel efficient jet engines into a single adaptable engine," according to Jeff Stricker of AFRL.

This could result in fighters or bombers which could go supersonic easily, but also be able to cruise economically or patrol an area for long periods. It might also deliver transport planes that could get airborne from short runways using massive takeoff thrust, but still haul cargoes a long way without refuelling.

AFRL also wants the ability to extract large amounts of electrical energy from its future engines, to power the amazing sensors, comms, and possible energy weapons carried by future military aircraft.

Two contractors will build competing initial designs, and then one will be selected in 2009 to take the tech forward alone. The idea is to have test units ready for operational environment trials in 2012.

The lucky two firms were awarded cost-sharing contracts yesterday. Rolls-Royce Inc, based in Indianapolis (what was Allison, until it was bought by the British firm), gets $296,254,318. General Electric gets $231,215,100, and Pratt & Whitney - the other big engine firm operating in the States - gets diddly.

The two winning firms will "develop and demonstrate inlet, engine, exhaust nozzle, and integrated thermal management technologies that enable optimized propulsion system performance".

The ADVENT programme, sadly for those who like their ramjets, scramjets, and spaceplanes, doesn't seem likely to get really radical and hypersonic. Still, there's hope for some sexy new kit other than relatively boring fuel-efficient fighters and short takeoff cargo planes etc.

Take massive liftoff poke combined with cruise economy from new ADVENT jets: add vectored thrust and stub wings (or something) and maybe - just maybe - our frikkin' flying cars might be on the drawing board for real at last. Or at least some kind of groovy urban-assault flying troop carrier, or Minority Report-esque police hovership, anyway.

Got to find your sci-fi hope where you can these days. ®

*We'd have gone for the Goal-Relevant Optimised Options for Velocity versus Economy jet, or GROOVEjet.