Rolls-Royce set to power Boeing

British engines could be used to power Boeing’s Sonic Cruiser – its proposed rival to Airbus’s A380 superjumbo.

Following the announcement last month of Boeing’s intention to develop its Sonic Cruiser, a high-altitude 200-seat plane capable of Mach 0.98 to be launched onto the market by 2008, The Engineer has learned that Rolls-Royce is in discussions with Boeing to supply the engines.

A Rolls-Royce spokesman said: ‘We are participating fully in Boeing’s concept studies. We submitted alternatives to them some weeks ago. The most advanced technology would be ready for the plane’s introduction in 2007 or 2008.’

The engines will be a variant on the existing Trent family used on a wide range of Boeing and Airbus aircraft.

Boeing stresses that the new engine design will include environmentally friendly features. John Roundhill, vice-president of the US manufacturer’s commercial airplanes marketing division, recently outlined the engine’s environmental claims in the Royal Aeronautical Society’s annual Sopwith lecture.

The company is aiming for lower noise output and lower emissions of nitrogen oxides, he said. Boeing expects the Sonic Cruiser’s fuel efficiency to be similar to a two-engined aircraft and better than a four-engined one, aided by the reduced drag at high altitude.

Economical class

The Rolls-Royce spokesman confirmed it had studied the new Trent engine variant to see if it could achieve Boeing’s goals. ‘Five, 10 years down the line, the answers are there,’ he said. ‘Who knows what new materials will be available in five years’ time?’Converging technologies and changes in the airline market will make the aircraft profitable, argues Roundhill.

As well as having the advantage of more efficient engines, the aircraft would benefit from an improved body shape, while better air-traffic management could reduce fuel consumption by cutting down circling before landing.

The Sonic Cruiser will be smaller than the A380 and as comfortable as a Boeing 777, but with a range of 7,000 miles and top speed 10-15% faster than existing airliners, says Boeing. The company claims this extra speed will make the aircraft economical. Calculations by Boeing’s rival, Airbus, suggest a 225-seat cruiser would have a seat-mile cost 20-25% greater than a conventional 300-seat Boeing 777 or its own A340. And seat-mile costs will be 50% higher than the 555-seat A380, it estimates.Boeing counters that the higher speed will mean airlines can run three aircraft where they previously ran two.

This will match market changes, Roundhill believes, as airlines try to meet demands for quicker, more direct and frequent flights. For example, Trans-World Airlines ran one daily flight from Chicago to London in 1987. Last year it operated 22 flights from Chicago to 11 destinations in Europe.

Increased flight frequency has also led to the creation of global-route hub airports such as Narita in Tokyo, where intermediate-sized aircraft are used to expand flight numbers.

A closer shave

Boeing says the Sonic Cruiser is another stage in that development, and that it could shave two hours off the journey time on long-haul routes such as Los Angeles to Sydney.

With aircraft traffic growing at 5% a year, Roundhill expects existing airline fleets to carry on expanding, with the Sonic Cruiser filling niches in a plane market that is increasingly segmented.

Alan Mullaly, Boeing’s commercial airplanes president, said at the Sonic Cruiser’s launch: ‘One customer said it would take the first 300 aircraft we build. We think demand could total several thousand – maybe more.