Boeing 520 / T60

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)