EasyJet plane solution and it is no secret that their plane proposal shares many of the characteristics of the US propfan
efforts in the late eighties and early nineties.
This lower tip speed may permit the application of lightweight composite material and a spar/shell construction similar to the swept, counterrotating, variable-pitch blades used on the open rotor propfan
Thus was invented the propfan
, an "ultra-high" bypass engine that is a throwback in two ways.
Green sky thinking - carbon credits and the propfan
Designed for the new Propfan
jet engine, this seal has a stainless steel housing
It first flew in 1994, but its advanced propfan
propulsion system has proved difficult to develop.
There is an argument in favour of the Russian Air Force having both the IRTA and the much larger Tu-330 (or the Ukraine's propfan
An-70), but for the time being that service may have to settle for one or the other.
In combination with ducted propfans
and a swept wing, this was thought to provide potential for speeds up to 740 km/hr.
The sole direct competitor for the A400M is the 145-tonne Antonov An-70, which is powered by 10,350-kW Progress D-27 engines turning 14-blade contra-rotating propfans
. It has 22% more power and is claimed to have a shorter take-off and faster cruise than the A400M.
Older physically thanthe A400M, having first flown in 1994, but arguably more advanced technologically, having propfans
rather than turboprops, the Antonov An-70 is a long-running on-again, off-again saga that might (if launched earlier) have become one of the aerospace success stories of the Soviet Union.
The An-70 is powered by four 10,300-kW Ivchenko-Progress D-27 engines (25% more powerful than the TP400), turning 14-blade (eight at front, six at rear) contra-rotating SV-27 propfans
. Its cabin is somewhat larger than that of the A400M, and it has a ten-tonne margin in terms of maximum payload (47 tonnes).
The A-42 could be a development of the 86-tonne A-40 of 1986, since the company website refers to a 96-tonne Be-42PE with Progress D-27A propfans
replacing the A-40's Soloviev D-30KPV turbofans.