The Dart didn’t just power aircraft—it created the regional airline market. By delivering turbine smoothness and reliability at a cost piston engines couldn’t match, it made short-haul scheduled service economically viable. The Mk 520 variant represented a mature development of the Dart line, which ultimately produced over 7,100 engines before production ended in 1987.
Dart Mk 520 Engineering Details
The primary subject of this technical guide focuses on the Rolls-Royce Dart Mk 520 engine, engineered specifically for Turboprop applications. Below is an essential digest of this powertrain configuration.
• Classic British turboprop
• 1,815 ehp output
• Centrifugal compressor design
• 7,100+ Darts produced
Rolls-Royce Dart Mk 520 Specifications
Two-stage centrifugal compressor, seven straight-flow combustion chambers, three-stage axial turbine; 1,353 kW (1,815 ehp) at 15,000 rpm; weight 534 kg.
The Dart’s centrifugal compressor design was a deliberate choice for robustness. Unlike axial compressors, centrifugal stages are less sensitive to foreign object damage and easier to manufacture with the tolerances of the 1940s and 1950s. That ruggedness made the Dart ideal for the unpaved runways and variable maintenance environments of early regional aviation. The Mk 520 powered later Vickers Viscount models and other regional airliners.
| Type | Turboprop |
|---|---|
| Compressor | 2-stage centrifugal |
| Combustor | 7 chambers |
| Turbine | 3-stage axial |
| Power | 1,815 ehp @ 15,000 rpm |
| Weight | 534 kg (1,177 lb) |
| Fuel | Jet A / Jet A-1 |
Aircraft Powered by the Dart Mk 520
This engine model is deployed across various operational frameworks. Here is a breakdown of the typical machine or vehicle applications using this unit:
Vickers Viscount (later models), Fokker F-27 Friendship, Hawker Siddeley HS 748
Pros & Advantages
Exceptional reliability in harsh environments; centrifugal compressor resistant to FOD; smooth turbine operation.
Cons & Disadvantages
Lower cruise speed than jets; higher specific fuel consumption than modern turboprops; obsolete by 1980s.
Frequently Asked Questions (FAQs)
Q1: What aircraft used the Rolls-Royce Dart Mk 520?
A1: The Dart Mk 520 powered later Vickers Viscount models and was used across the Dart-powered regional fleet including Fokker F-27 and HS 748 variants.
Q2: How many Rolls-Royce Dart engines were built?
A2: Production totaled approximately 7,100 engines before the line ended in 1987.
Q3: Why did the Dart use a centrifugal compressor?
A3: Centrifugal compressors were more robust and tolerant of manufacturing tolerances and foreign object damage than early axial designs, making them ideal for regional operations.
Later Dart developments reached over 2,237 kW (3,000 shp), though the Mk 520 was rated at 1,815 ehp.