Napier Eland

Design and development

The Eland was first tested in 1953 in a Vickers Varsity aircraft. Further flight proving was carried out from 1955 using the first production Airspeed Ambassador 2. The Eland was dropped from production when Napiers was acquired by Rolls-Royce Limited in 1961.

The Eland was used to power various aircraft including the Westland Westminster heavy-lift helicopter, the Canadair CL-66; a turbine-powered version of the Convair CV-340 for the Canadian military(later converted to Allison T-56 propjets after a number of engine failures), and the Fairey Rotodyne gyrodyne. In the Rotodyne, the Eland powered the tractor propellors for forward flight and a compressor, via a clutch and shaft arrangement, to feed the rotor tip-jets with compressed air for vertical flight.

Variants

Eland N.El.1

2,690 hp (2,010 kW) + 825 lbf (3.67 kN) residual thrust, static at sea level ICAN conditions.

Eland N.El.3

Powerplant for the Fairey Rotodyne driving the propeller and an auxiliary compressor to feed the rotor tip jets 2,805 hp (2,092 kW) + 500 lbf (2.22 kN) residual thrust, static at sea level ICAN conditions.

Eland N.El.4

3,765 hp (2,808 kW) + 610 lbf (2.71 kN) residual thrust, static at sea level ICAN conditions.

Eland N.El.6

Turboshaft

Westland Westminster

Turboprop

Airspeed Ambassador

Canadair CC-109 Cosmopolitan (CL-66)

Convair CV-540

Fairey Rotodyne

Vickers Varsity (one aircraft as an engine test bed in 1954)

Engines on display

A turboshaft Eland is on display at the The Helicopter Museum, Weston-super-Mare.

Specifications (Eland N.El.6)

Data from Flight

General characteristics

Type: Single-shaft turboprop

Length: 120 in (3,048 mm)

Diameter: 36 in (914 mm)

Dry weight: 1,735 lb (787 kg)

Components

Compressor: 10-stage axial flow

Combustors: 6 chambers

Turbine: 3-stage

Fuel type: Jet fuel

Performance

Maximum power output: 3,500 eshp (2,610 kW)

Overall pressure ratio: 7:1

Air mass flow: 31 lb/s (14 kg/s)

Specific fuel consumption: 0.595 lb/(h eshp)

Thrust-to-weight ratio: 2.0 eshp/lb (3.3 kW/kg)