Reports about progress in jet engine design are generally eye-glazing in their detail, however, the most recent blurb from Rolls-Royce about its E3E program is important for reasons the UK engine maker doesn’t discuss.
And that is the “you-go-first, no-please-you-go-before-me” signalling that is going on between Boeing and Airbus over their ambitions to building ‘something completely different’ for the 150-250 seat sized medium range airliner market.
Read the RR press release if you must. But note the tiny passing reference to the corporate and narrow body market.
That market is huge. It is where the ageing, but repeatedly revised Boeing 737 and Airbus A320 families fit. It’s where most air travellers, those flying short distances between domestic cities, would welcome a change from uncomfortable, small seated, difficult to get out of single aisle jets that now frequently squeeze 180 seats into a space that used to take about 140 seats.
The trouble is, Airbus and Boeing are torn between slinging new types of engines under the wings of their existing torture tubes to exploit lower fuel burns and emissions, or, replacing them with designs than are much easier to board, and break away from tubular hell with cabins that might even have two aisles, or two decks, or bulge and taper in unexpected ways to fit more effectively into existing aerobridge and gate arrangements.
Airbus might do both. Boeing is dropping hints that it will go for all-new-design without pausing to re-engine its latest 737s. Both are circling each other, uncertain which way to lunge in what will be the biggest jet contest ever seen, given the continued growth in single-aisle short-to-medium markets, lead by China, Asia at large, and then the mature markets of North America and Europe.
What is unusual about the Rolls-Royce design?
Well, it looks like a stubby propeller engine for a start. Or what it calls an ‘unshrouded’ turbine. And which if it comes apart at a zillion rpm in flight could destroy the airliner. A minor but important point, which Rolls-Royce boffins are of course feverishly labouring to prevent happening.
The merits and demerits of previous attempts at building such engines are outlined in this report from a green skies conference in Sydney earlier this year, and were also discussed in the NASA N+3 studies into new subsonic designs for 2030 and beyond.