It is easy to belittle Soviet aviation's efforts to keep up with the West, to accuse it of mindlessly following Western trends-many of which, like most fashions, prove short-lived.

News that Yakovlev is flight-testing a propfan engine will no doubt amuse - or bemuse - those who recall the flurry of activity just a few years ago when Western engine and airframe manufacturers believed they were on the brink of a propulsion revolution.

Propfans were built and flown, only to be shelved in the face of an acute lack of airline interest-fuel was cheap, propfan airliners were expensive and existing airliners remained acceptably efficient.

That remains true today - for Western airlines. Aeroflot airliners are nowhere near as fuel-efficient as most of those flown by Western carriers. In the first quarter of this year, fuel burned by the Soviet airline exceeded the planned amount by tens of thousands of tonnes...