Tumansky R-21

The Tumansky R-21 was a Soviet turbojet engine of the 1960s. Used for development only, the project was canceled.

The Tumansky R-21 was developed at Tushino motor plant (part of OKB-300), headed by Nikolai Georgievich Metskhvarishvili, as a twin-spool axial-flow afterburning turbojet. It was based on the Tumansky R-11 with the goal of increasing thrust and airflow, using a new six-stage compressor with a larger diameter and different rotor blades than its predecessor as well as a new afterburner chamber and variable exhaust nozzle. The increased pressure ratio and turbine inlet temperature required components to be fabricated from advanced alloys.^[1] Several contemporary Soviet aircraft were planned to use the R-21, including the Sukhoi T-58, Sukhoi T-6 and the Mikoyan-Gurevich Ye-8. On September 11, 1962 an R-21, fitted to a Ye-8, exploded in mid-air after compressor failure; test pilot Georgy Mosolov survived the ejection at Mach 1.78, but he never fully recovered.^[2] Shortly afterward the Ye-8 program was cancelled along with R-21 development in favour of heavier fighter planes such as the Mikoyan-Gurevich MiG-23, which required more powerful engines.

• R-21F-300 – the only version built.

• Type: Afterburning turbojet
• Length:
• Diameter: 987 mm (38.9 in)
• Dry weight: 1,250 kg (2,755 lb)

• Compressor: Six-stage axial compressor

• Maximum thrust:
  
• 46.1 kN (10,361 lbf) military power
• 80.6 kN (15,873 lbf) with afterburner
• Thrust-to-weight ratio: 3.76; 5.76 with afterburner.

Related development

• Tumansky R-11

Related lists

• List of aircraft engines