Lockheed R6O / R6V Constitution — Technical Documentation Archive

The Lockheed R6O Constitution (redesignated R6V Constitution in 1950) stands as one of the most ambitious and technically singular aircraft programmes of the immediate post-war era — the largest fixed-wing type ever operated by the United States Navy. Only two airframes were ever completed (BuAer Serial Nos. 85163 and 85164), making primary-source documentation of this programme exceptionally rare.

This archival collection brings together the surviving technical publications issued by Lockheed Aircraft Corporation, Burbank, California, and published under the authority of the Chief of the Bureau of Aeronautics, covering the full engineering and operational lifecycle of both prototypes.

Documents in This Collection

• Erection and Maintenance Instructions — Navy Model XR60-1 Airplane (BuAer Serials 85163 & 85164) · Lockheed Aircraft Corporation · 1 June 1948, Revised 15 May 1949
• Pilot's Handbook — Navy Model R60-1 Airplanes · NAVAER 01-75CLA-501 · Published by Direction of the Chief of the Bureau of Aeronautics · 1 July 1949, Revised 1 May 1950

1. Aerodynamic & Structural Layout

• Fuselage geometry: Engineered with a unique double-bubble (figure-eight) cross-section to maximise structural efficiency under full cabin pressurisation.
• Wing profiles: Exceptionally thick, high-aspect-ratio wings incorporating structural internal tunnels — permitting flight engineers to access and service the powerplants while airborne.
• Configuration: Conventional four-engine mid-wing layout with a massive single vertical stabiliser sized to offset asymmetric thrust conditions.

2. Engine Technical Notes

• Powerplants: Four Pratt & Whitney R-4360-22W Wasp Major 28-cylinder, four-row radial engines.
• Output: 3,000 hp (2,237 kW) per engine; large four-blade propellers.
• Cooling & access: Advanced internal duct system within the thick wing profile for engine cooling and in-flight accessory servicing.
• Power limitation: Testing definitively established the aircraft was chronically underpowered on piston engines. Planned upgrade to 5,500 hp Wright Typhoon turboprops was abandoned when that programme was cancelled.

3. Handling & Stability Studies

• Landing gear: Specialised electric motors inside the struts pre-spun all eight main wheels to match ground speed prior to touchdown, eliminating friction stress and producing exceptionally gentle landings.
• Cockpit indicator: Touchdowns were so smooth that pilots could not feel them — an AIRPLANE ON GROUND indicator light was added to the instrument panel.
• Control response: Flight testing characterised handling as stable but heavy, requiring substantial pilot input across the vast control surface areas prior to hydraulic boost optimisation.

4. Performance Data

5. Programme Fate

• Production: Two prototypes only — BuNo 85163 and BuNo 85164.
• Civil rejection: Pan American World Airways determined the type lacked the power-to-weight efficiency required for profitable commercial routes.
• Retirement: Both airframes decommissioned by the U.S. Navy in 1953 due to high maintenance footprint and the cost of bespoke hangar infrastructure.

This is an archival, static-copy edition fixed at its original publication date. Intended for historical reference, flight simulation, museum restoration, and educational use only. Not approved for active airworthiness maintenance under FAA 14 CFR § 43.13, EASA Part-M, or equivalent international regulations. Operators of active aircraft must use current, revision-controlled publications from the Type Certificate holder or an authorised distributor.

⚠️ Regulatory Notice: Under FAA 14 CFR § 43.13 and EASA Part-M, any mechanic performing maintenance on an active aircraft must use current, manufacturer-approved revision-controlled data. This archival document does not satisfy that requirement.

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