THE ROLLS-ROYCE Dart engine made Sir George Edward's Viscount (a name politically changed from "Viceroy") a front-runner in propeller turbine-powered airliners.
The Dart is a comparatively simple engine, with a two-stage centrifugal compressor (the geometry of which was derived from that of the supercharger of the mighty vee-12 Griffon piston engine) and a two-stage (three in later variants) axial-flow power turbine. It began an initially troubled life with an output of 745kW (1,000shp); the most-powerful 540 variant produced 1,820kW, with a further 3kN (670lb)-thrust from the exhaust. The Mk510 flown here delivers 1,190kW to the propeller, with the remaining 65% of the power-turbine's output being absorbed by the centrifugal compressor. Power is maintained at temperatures above 15°C by water methanol injection, to cool the compressor air.
Handley Page, Hawker Siddeley and Fokker (with the Herald, 748 and F27) exploited the Dart in twin-engine short-haul airliners, as did Grumman with the executive Gulfstream 1. Vickers' sister company Armstrong Whitworth produced the four-engine Argosy freighter, which served with British European Airways and the Royal Air Force.
Source: Flight International