In 1964, when the XV-4A proved unsatisfactory, the remaining Hummingbird was modified with four General Electric J85-GE-19 lift engines (3,000 lb thrust) for hover. Two additional J85 engines provided thrust during horizontal flight. During hover, large diverter valves directed the cruise engine exhaust on each side through the fuselage to a nozzle between the lift engines for additional vertical thrust. In transition, one lift/cruise engine was diverted, while the other provided forward thrust. Pitch and yaw jets at the nose and tail provided control in hover. Maximum vertical take-off weight was 12,600 lb. The Hummingbird II had a fly-by-wire dual channel autostabilization system.

It was rolled out on 4 June 1968 but was destroyed in a crash during a conventional flight on 14 March 1969, without ever making a hover.

Source: AHS V/STOL Wheel

Overview

Data on design, manufacture and status

Design authority: Lockheed Aircraft Corporation

Primary manufacturer: Lockheed Aircraft Corporation

Parent type: Lockheed XV-4

Aircraft status: No longer flying

Configuration

Primary flight and mechanical characteristics

VTOL type: Jet lift VTOL

Compound type: N/A

Lift configuration: Combined lift devices (x6)

Dedicated control device: Thruster (x4)

Crew required: 1

Crew seating: Single seater

Landing gear: Wheels (all retractable)

Overall Dimensions

Data on aircraft size

Engine Details

Aircraft powerplant (lift and/or propulsion)

Total number of engines: 6

Weights and Performance

Data on aircraft weight and flight characteristics

Related VFS Resources

Resources related to the XV-4B Hummingbird, provided by the Vertical Flight Society.
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Related Public Resources

Resources related to the XV-4B Hummingbird, provided by public sources across the internet.

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