Rolls-Royce RB401

The RB401 was a business jet engine which Rolls-Royce started to develop in the mid-1970s.

RB401-06 prototype engines were already being manufactured when a decision to develop the higher thrust RB401-07 was taken.

Although the basic configurations of both engines were almost identical, the -07 variant had a larger fan diameter. The -06 version HP compressor was based on the 8 stage version of RC34B research compressor, unscaled, whereas the -07 was a scaled-up unit. A single stage fan, driven by 2 stage LP turbine, supercharged the HP compressor which was driven by the single stage transonic HP turbine. The combustor was annular and the co-annular exhaust featured a lightweight target type thrust reverser. Leading particulars for -07 variant were as follows:

Fan Diameter: 32.4 in

Take-off Thrust(Sea Level Static): 5,540 lbf, flat-rated to ISA+15C

Cruise Thrust: 1128lbf (Mach 0.7, 40,000 ft, ISA+10C)

Bypass Ratio: ~4

Overall Pressure Ratio: ~20:1

Although ground testing of both the -06 and -07 continued into the early 1980s, a lack of funds caused the project to be cancelled.