2 were purchased (known by the designation YH-31) for U.S. Army evaluation and test. A third ship was subsequently built in Canada.  Resembling the LZ-4, the helicopter was equipped with an 8-cylinder supercharged engine.

The aircraft was capable of talking 6 passengers or 4 litters.


Data on design, manufacture and status

Design authority: Doman Helicopters Inc.

Primary manufacturer: Doman Helicopters Inc.

Parent type: No type defined

Aircraft status: No longer flying


Primary flight and mechanical characteristics

VTOL type: Helicopter

Lift configuration: Single main rotor

Dedicated control device: Tail rotor

Crew required: 2

Crew seating: Side-by-side

Landing gear: Wheels (non-retractable)

Layout and Dimensions

Data on aircraft size

Overall Dimensions
Overall Height:  
Overall Length:  
Overall Width: 14.63 m 48.0 ft
Airframe Dimensions
Airframe Length: 11.58 m 38.0 ft
Airframe Width:  
Airframe Height: 3.12 m 10.2 ft
Landing Gear Dimensions
Landing Gear Base:  
Landing Gear Track:  
Cabin Dimensions
Cabin Internal Height:  
Cabin Internal Length:  
Cabin Internal Width: 1.52 m 5.0 ft

Weights and Performance

Data on aircraft weight and flight characteristics

Cruise Speed: 86 mph (138 km/h)

Max Gross Weight (ground): 2,359 kg 5,200 lb
Max Gross Weight (airborne):  
Max Take-off Weight: 2,359 kg 5,200 lb
Empty Weight: 1,297 kg 2,860 lb
Useful Load: 1,061 kg 2,340 lb
Empty Weight Fraction: 0.550
Climb Performance
Max Rate of Climb: 7 m/s 1,300 fpm
Hover Performance
Hover Ceiling IGE:  
Hover Ceiling OGE:  
Max Level Flight Speed: 170 km/h 92 kts
Never Exceed Speed:  
Service Ceiling: 5,486 m 18,000 ft
Range and Endurance
Max Range: 394 km 213 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: Lycoming 580-D reciprocating
Manufacturer: Lycoming Engines
Normal Ratings
Max continuous:  
Take-off / rated:  
OEI Ratings
OEI contingency:  
OEI continuous:  
OEI 30-second:  
OEI intermediate:  

Primary Lift Device

Data on primary lift devices such as main rotors

Main Rotor Characteristics
Diameter: 14.63 m 48.00 ft
Direction of Rotation: Clockwise
Hub Type:
Main Rotor Blade Characteristics
Blade Construction:
Blade Chord:  
Blade Tip Geometry: Conventional
Blade Twist:  
Number of Blades: 4
Main Rotor Derived Characteristics
Disc Area: 168.10 m² 1809.5 ft²
Disc Loading: 14.03 kg/m² 2.874 lb/ft²
Main Rotor Blade Derived Characteristics
Blade area per blade:  
Tip Speed:  

Primary Control Device

Data on primary control devices such as tail rotors

Tail Rotor Characteristics
Configuration: Tractor
Direction of Rotation: Top blade aft
Tail Rotor Blade Characteristics
Number of Blades: 3
Blade Construction:  
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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