Although these two planes went into service with the Navy, the Constitution design ultimately proved underpowered and too large for practical airline use at the time.

Although the Martin JRM Mars flying boat had a slightly longer wingspan, the Constitution remains the largest fixed-wing aircraft type ever operated by the U.S. Navy.

This transport would carry 17,500 lb (7,900 kg) pounds of cargo 5,000 miles (8,000 km) at a cruising altitude of 25,000 feet (7,600 m) and a speed greater than 250 mph (400 km/h).

The aircraft would be fully pressurized and large enough so that most major components could be accessed and possibly repaired in flight.

Due to the aircraft's large size—the tail towered 50 feet (15 m)—Lockheed had to build a special hangar for final assembly.

[2] Joe Towle and Tony LeVier flew the aircraft on a leisurely course to Muroc Air Force Base.

Four days later, the ship was formally christened by Mrs. John L. Sullivan, wife of the Secretary of the Navy, at Washington National Airport.

1 was delivered to Navy Transport Squadron 44 (VR-44), based at Naval Air Station Alameda, on 2 February 1949.

On the rear of the forward bulkhead, in front of the spiral staircase leading to the lower deck, there was a permanent display case containing a scale model of the original USS Constitution sailing ship.

On 3 February 1949, the aircraft flew 74 members of the press from Moffett Field to Washington National Airport.

While this could be compensated for by flying with engine cowl flaps partially open, it increased drag and decreased range.

[6] The first Constitution was brought to Las Vegas, where it served as an enormous billboard for Alamo Airways,[7] before being scrapped by Howard Hughes when he acquired the property.

[6] The second Constitution was flown to Opa-Locka Airport, Florida, where it was damaged by an internal fire, suspected by the authorities to be arson, while the aircraft was being prepared for a ferry flight to Barcelona.