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)

Layout and Dimensions

Data on aircraft size

Overall Dimensions
Overall Height:  
Overall Length:  
Overall Width:  
Airframe Dimensions
Airframe Length:  
Airframe Width:  
Airframe Height:  
Landing Gear Dimensions
Landing Gear Base:  
Landing Gear Track:  
Cabin Dimensions
Cabin Internal Height:  
Cabin Internal Length:  
Cabin Internal Width:  

Weights and Performance

Data on aircraft weight and flight characteristics

Weights
Max Gross Weight (ground):  
Max Gross Weight (airborne):  
Max Take-off Weight:  
Empty Weight:  
Useful Load:  
Empty Weight Fraction:  
Climb Performance
Max Rate of Climb:  
Hover Performance
Hover Ceiling IGE:  
Hover Ceiling OGE:  
Limitations
Max Level Flight Speed:  
Never Exceed Speed:  
Service Ceiling:  
Range and Endurance
Max Range:  
Max Endurance:  

Engine Details

Aircraft powerplant (lift and/or propulsion)

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

Powerplant
Number of engines: 6
Normal Ratings
Max continuous:  
Take-off / rated:  
Intermediate:  
Maximum:  
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:  
RPM:  
Direction of Rotation: Unknown
Hub Type:  
Main Rotor Blade Characteristics
Blade Construction:  
Blade Chord:  
Blade Tip Geometry:  
Blade Twist:  
Number of Blades:  
Main Rotor Derived Characteristics
Disc Area:  
Disc Loading:  
Solidity:  
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
Diameter:  
Configuration: Unknown
Direction of Rotation: Unknown
RPM:  
Tail Rotor Blade Characteristics
Number of Blades:  
Blade Construction: N/A
Blade Chord:  
Blade Twist:  
Tail Rotor Derived Characteristics
Disc Area:  
Solidity:  
Tail Rotor Blade Derived Characteristics
Tip Speed:  
Blade Area (per blade):  

Related VFS Resources

Resources related to the XV-4B Hummingbird, provided by the Vertical Flight Society.
Forum Proceedings
 
Vertiflite articles
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Web files from vtol.org
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Related Public Resources

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

Images