A description of the aircraft and its characteristics can be found in the following references,

The Cierva W-11 "Air Horse", J. Gordon Leishman, VERTIFLITE Spring 2003, Page 52

Discussing the Helicopter, FLIGHT Staff, FLIGHT, December 2nd 1948, Pages 665-668


Data on design, manufacture and status

Design authority: Cierva Autogiro Company Ltd.

Primary manufacturer: Cierva Autogiro Company Ltd.

Parent type: Cierva Air Horse

Aircraft status: No longer flying


Primary flight and mechanical characteristics

VTOL type: Helicopter

Lift configuration: Multi-rotor (x3)

Crew required: 2

Crew seating: Side-by-side

Landing gear: Wheels (non-retractable)

Layout and Dimensions

Data on aircraft size

Overall Dimensions
Overall Height: 5.41 m 17.8 ft
Overall Length: 30.05 m 98.6 ft
Overall Width: 28.96 m 95.0 ft
Airframe Dimensions
Airframe Length:  
Airframe Width:  
Airframe Height:  
Landing Gear Dimensions
Landing Gear Base: 6.36 m 20.9 ft
Landing Gear Track: 9.42 m 30.9 ft
Cabin Dimensions
Cabin Internal Height: 1.83 m 6.0 ft
Cabin Internal Length: 5.79 m 19.0 ft
Cabin Internal Width: 2.29 m 7.5 ft

Weights and Performance

Data on aircraft weight and flight characteristics

Max Gross Weight (ground): 7,938 kg 17,500 lb
Max Gross Weight (airborne):  
Max Take-off Weight: 7,938 kg 17,500 lb
Empty Weight: 5,384 kg 11,870 lb
Useful Load: 2,554 kg 5,630 lb
Empty Weight Fraction: 0.678
Climb Performance
Max Rate of Climb: 7 m/s 1,320 fpm
Hover Performance
Hover Ceiling IGE:  
Hover Ceiling OGE:  
Max Level Flight Speed: 222 km/h 120 kts
Never Exceed Speed:  
Service Ceiling: 7,620 m 25,000 ft
Range and Endurance
Max Range: 556 km 300 nm
Max Endurance:  

Engine Details

Aircraft powerplant (lift and/or propulsion)

Provided powerplant data is for uninstalled, sea level, static operations.

Number of engines: 1
Designation: RR Merlin 24 reciprocating
Manufacturer: Rolls-Royce
Normal Ratings
Max continuous:  
Take-off / rated: 1209 kW 1620 hp
OEI Ratings
OEI contingency:  
OEI continuous:  
OEI 30-second:  
OEI intermediate:  

Primary Lift Device

Data on primary lift devices such as main rotors

The torque from the 3 rotors was reacted by a moment due to side force from the 3 rotors (front rotor/side-force to port, rear rotors, side-force to stbd)

Main Rotor Characteristics
Diameter: 14.33 m 47.00 ft
RPM: 219.5 rpm 219.5 rpm
Direction of Rotation: Counterclockwise
Hub Type:
Main Rotor Blade Characteristics
Blade Construction:
Blade Chord:  
Blade Tip Geometry:
Blade Twist: -0.205 rad -11.750 deg
Number of Blades: 3
Main Rotor Derived Characteristics
Disc Area: 161.18 m² 1735.0 ft²
Disc Loading: 16.42 kg/m² 3.362 lb/ft²
Main Rotor Blade Derived Characteristics
Blade area per blade:  
Tip Speed: 164.64 m/s 540.2 fps

Primary Control Device

Data on primary control devices such as tail rotors

Tail Rotor Characteristics
Configuration: Unknown
Direction of Rotation: Unknown
Tail Rotor Blade Characteristics
Number of Blades:  
Blade Construction: N/A
Blade Chord:  
Blade Twist:  
Tail Rotor Derived Characteristics
Disc Area:  
Tail Rotor Blade Derived Characteristics
Tip Speed:  
Blade Area (per blade):  

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