Fiat 4700

The Fiat 4700 was an Italian turbo-generator developed by Fiat Aviazione under contract to the Italian Defence Ministry and used to power the experimental Fiat 7002 tip jet helicopter.[1]

National origin Italy
Manufacturer Fiat Aviazione
First run 1960
Major applications Fiat 7002
Developed from Fiat 4002

Design and development

The Fiat 4700 was developed to provide power in cold-jet driven helicopters.[1] The 4700 was a turbo-driven air compressor driven by the primary engine, a turbojet engine based on the Fiat 4002.[1] The compressor and primary engine are mechanically independent.[1] The engine is mounted vertically to reduce the length of the compressed-air ducts to the rotor.[1] The engine was used on the Fiat 7002 helicopter which first flew on 26 January 1961 where the Fiat 4700 was used to power the cold tip-jets on the two-blade rotor.[2]



Data from Jane's All the World's Aircraft 1962-63.[3]

General characteristics

  • Type: Gas generator
  • Length: 1,300 mm (51.2 in) (height)
  • Diameter: 612 mm (24.1 in)
  • Dry weight: 152 kg (335 lb)


  • Compressor: Single-sided centrifugal flow plus gas generator single-sided centrifugal flow compressor driven by the free power turbine
  • Combustors: Annular with 16 burners
  • Turbine: 1-stage axial flow (gas turbine power) + 1-stage axial flow free power turbine (Gas generator power)
  • Fuel type: Aviation kerosene to MIL-F-5624 (JP-4)
  • Oil system: Re-circulating pressure system with one pressure pump and three scavenge pumps, oil grade DERD 2479.


  • Maximum power output: 450 kW (610 hp) (gas hp for take-off), 377 kW (505 hp) (ghp max continuous)
  • Overall pressure ratio: 4:1
  • Air mass flow: 5.1 kg/s (11.2 lb/s) at 25,000 rpm at sea level, 3.34 kg/s (7.36 lb/s) (max continuous)
  • Specific fuel consumption: 0.758 kg/kW/h (1.246 lb/hp/h)
  • Power-to-weight ratio: 2.99 kW/kg (1.82 hp/lb)

See also

Comparable engines

Related lists



  1. "Fiat's New Helicopter - Notes on the 7002 and its powerplant". Flight International: 110. 24 January 1958.
  2. "Fiat 7002 flies". Flight International: 138. 3 February 1961.
  3. Taylor, John W.R. FRHistS. ARAeS (1962). Jane's All the World's Aircraft 1962-63. London: Sampson, Low, Marston & Co Ltd.
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