Doman LZ-5

Doman Helicopters · United States · first flew 1953 · helicopter

The Doman LZ-5 was an American utility helicopter of the early 1950s notable for its patented gimbal rotor hub, which aimed to reduce vibration and simplify control by allowing the entire rotor disc to tilt as a unit.

Recognition (WEFT)

WEFT is AircraftIQ's four-point recognition method — how it works.

Spot it by:

• four-blade articulated rotor with unique gimbal hub
• conventional tail rotor on slender boom
• enclosed cabin seating up to eight

Medium-sized utility helicopter with a four-blade rotor featuring a distinctive low-profile gimbal hub rather than the articulated hinges typical of contemporaries. The square-section cabin and high-set tail boom are characteristic.

Specifications

• The Doman LZ-5 has a length of 14.4 m (47 ft).
• It has a wingspan of 14.6 m (48 ft).
• Its maximum speed is 167 km/h (104 mph).
• Typical crew: 1 pilot + up to 7 passengers.

Figures are for the representative variant described above; marks differ. See how AircraftIQ sources figures.

History

Glidden Doman developed his distinctive rotor concept in the late 1940s, arguing that the conventional flapping hinge arrangement introduced unnecessary complexity and vibration. The LZ-5 embodied these ideas in a practical utility airframe and attracted US Army interest; the Army evaluated it under the YH-31 designation. Despite a sound engineering argument, the design did not achieve production contracts, and Doman Helicopters eventually closed.

Variants

The US Army evaluated a version as the YH-31; no other distinct variants reached service.

Where you'll see it

Evaluated by the US Army in the mid-1950s but not adopted for service. A small number of aircraft were operated on commercial trials.

Related aircraft

• Bell HSL
• Brantly B-2
• Kaman HH-43 Huskie
• Kaman OH-43D Huskie

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