New engine for supersonic AS2

Dal Kikin
October 22, 2018

The American company GE Aviation introduced the Affinity turbofan jet engine, which is supposed to be installed on the promising supersonic passenger aircraft AS2. The developer of the engine is a start-up Aerion. The new power plant constructively combines the features of jet engines with a small degree of bypass ratio for combat aircraft and power plants with a high degree of bypass ratio for passenger aircraft. At the same time, there are no new and breakthrough technologies in Affinity.

The development of the AS2 passenger aircraft has been conducted by Aerion since 2014. According to preliminary calculations, the length of the aircraft will be 51.8 meters, height - 6.7 meters, and wingspan - 18.6 meters. The maximum take-off mass of a supersonic aircraft will be 54.8 tons. AS2 will be equipped with three engines, each of which, according to developers, must be at least 69 kilonewtons. The aircraft will be designed to carry up to 12 passengers.

AS2 will fly above water at a cruising speed of 1.4-1.6 Mach numbers, slowing to 1.2 over land. A slightly lower flight speed over land, coupled with the special aerodynamic design of the airframe, will allow, as developers expect, to almost completely avoid the formation of shock waves. The range of the aircraft at a speed of 1.4 Mach number will be 7.8 thousand kilometers and 10 thousand kilometers at a speed of 0.95 Mach number. At present, international rules prohibit flights of supersonic aircraft over populated land areas.

For supersonic flights, conventional turbofan engines of modern passenger aircraft are not suitable. Due to the large fan area, the fan and compressor operation peculiarities, and many other reasons, conventional engines are mostly either unable to operate reliably at supersonic flight speeds, or they cannot even disperse the aircraft before it. At the same time, such power plants consume less fuel than special engines for combat aircraft, designed for flights, including supersonic.

GE Aviation refers Its new Affinity engine to power plants with an average degree of bypass. The basis of the engine is a modified gas generator of the CFM56 turbofan engine, which, in turn, is structurally based on the gas generator from F101, the power plant for supersonic B-1B Lancer bomber. According to a record in the corporate blog of GE Aviation, the power plant will receive an upgraded electronic digital engine management system with full responsibility.

The new Affinity power unit will be able to provide passenger flight at altitudes up to 18.3 thousand meters. The developer claims that the new engine will work effectively at supersonic and subsonic flight speeds. Presumably, the new engine will be fully ready by 2023.

Aerion plans to conduct the first flight of the AS2 supersonic passenger aircraft in June 2023. In October of the same year, AS2 should have already completed the first transatlantic flight. It is timed to the 20th anniversary of the last flight of the French supersonic aircraft Concorde.

Previously, Aerion announced that the outline design of AS2 is scheduled to be completed by mid-2020, and the technical design will be defended in early 2022. The developers plan that certification of the new aircraft will be completed by the end of 2025, and from 2026 new supersonic aircraft will begin to perform regular flights. For the first year of serial production, Aerion plans to assemble 12 AS2, for 2027, 23 aircraft should be assembled, and for 2028, 36 already. In the future, the company will produce 36 AS2 each year until 2035.