The Model 520 (military designation Boeing T60) was a family of small turboshaft / turboprop engines produced by Boeing, based on Boeing's earlier Model 500 gas generator and Model 502 turboshaft engines.
Variants:
YT60-BO-2A Military turboshaft verion for testing.
520-2 (YT60-BO-2A) Free power turbine turboshaft rated at 475 hp (354.21 kW)
520-4 Turboprop rated at 475 hp (354.21 kW)
520-6 Direct drive turboshaft rated at 550 hp (410.13 kW) military power
520-8 Turboprop rated at 550 hp (410.13 kW)
Specifications:
520-6 Type: Turboshaft Length: 54.1 in (1,374 mm) Diameter: 25.14 in (639 mm) maximum height Dry weight: 250 lb (113 kg) Compressor: Single-stage centrifugal flow Combustors: 2 reverse flow can combustors Turbine: 1x radial gas generator power turbine stage Fuel type: Aviation kerosene Oil system: pressure spray/splash, oil specification: MIL-L-7808 Maximum power output: 550 hp (410.13 kW) military rating at 6,000 output shaft rpm Overall pressure ratio: 6:1 Turbine inlet temperature: Jet pipe Temperature: 1,025 °F (552 °C) Specific fuel consumption: 0.67 lb/hp-hr (0.41 kg/kW-hr) Power-to-weight ratio: 2.2 hp/lb (3.616 kW/kg)