First flight, Boeing Model 377 Stratocruiser NX90700, c/n 15922. After the flight test program was completed, this airplane was upgraded to the 377-10-26 standard and placed in service with Pan American World Airways as Clipper Nightingale, N1022V
8 July 1947: First flight, Boeing Model 377-10-19 Stratocruiser, Project Test Pilot John Bernard Fornasero. (Fornasero had been the co-pilot on the first flight of the XC-97 Stratofreighter, nearly three years earlier.)
Flight deck of the Boeing Model 377 Stratocruiser. (Boeing)
The Model 377 was a large, four-engine civil transport which had been developed, along with the military C-97 Stratofreighter, from the World War II B-29 Superfortress long-range heavy bomber. It utilized the wings and engines of the improved B-50 Superfortress. The airplane was operated by a flight crew of four. It was a double-deck aircraft, with the flight deck, passenger cabin and galley on the upper deck and a lounge and cargo compartments on the lower. The airliner was pressurized, and could maintain Sea Level atmospheric pressure while flying at 15,500 feet (4,724 meters). The Model 377 could be configured to carry up to 100 passengers, or 28 in sleeping births.
Airline stewardesses examine a cutaway model of the Boeing 377 Stratocruiser. (Museum of History & Industry, Seattle)
The Stratocruiser was 110 feet, 4 inches (33.630 meters) long with a wingspan of 141 feet, 3 inches (43.053 meters) and overall height of 38 feet, 3 inches (11.659 meters). The airliner had an empty weight of 83,500 pounds (37,875 kilograms) and its maximum takeoff weight was 148,000 pounds (67,132 kilograms).
Boeing Model 377-10-19 Stratocruiser NX90700. (Boeing)
The 377-10-19 prototype was powered by four 4,362.49-cubic-inch-displacement (71.49 liter) air-cooled, supercharged Pratt & Whitney Wasp Major B5 four-row, 28-cylinder radial engines. This engine had a compression ratio of 6.375:1 and required 100/130 aviation gasoline. It had a Normal and Maximum Continuous Power rating of 2,650 horsepower at 2,550 r.p.m., and Take Off Power rating of 3,250 horsepower at 2,700 r.p.m. with water/alcohol injection. The Wasp Major B5 was 4 feet, 6.00 inches in diameter and 8 feet, 0.75 inches long. The engine weighed 3,490 pounds (1,583 kilograms).
The following production Stratocruisers were equipped with Pratt & Whitney Wasp Major B6 engines rated at 3,500 horsepower at 2,700 r.p.m. (with water/alcohol injection) for takeoff, and a Normal Power of 2,650 horsepower at 2,550 r.p.m., at 5,500 feet (1,676 meters). The Maximum Continuous Power rating for the B6 was 2,800 horsepower at 2,550 r.p.m. at 3,500 feet (1,067 meters). The Wasp Major B6 was 4 feet, 7.00 inches (1.397 meters) in diameter and 8 feet, 0.50 inches (2.451 meters) long. It weighed 3,584 pounds (1,626 kilograms), dry.
Pan American World Airways’ Boeing Model 377-10-26 Stratocruiser, Clipper Nightingale, N1022V, c/n 15922. (Boeing)
The engines drove four-bladed Hamilton Standard Hydromatic constant-speed propellers with a diameter of 17 feet (5.182 meters) through a 0.375:1 gear reduction. The propeller assembly weighed 761 pounds (345 kilograms).
The 377 had a cruise speed of 301 miles per hour (484 kilometers per hour) and a maximum speed of 375 miles per hour (604 kilometers per hour). During testing by Boeing, a 377 reached 409 miles per hour (658 kilometers per hour). Its service ceiling was 32,000 feet (9,754 meters) and the range was 4,200 miles (6,759 kilometers).
Lower deck passenger lounge of a Boeing 377 Stratoliner. (Boeing)
Boeing built 56 Model 377 Stratocruisers, with Pan American as the primary user, and another 888 military C-97 Stratofreighter and KC-97 Stratotankers.
Following the flight testing program, NX90700 was brought up to the 377-10-26 standard and placed in service with Pan American World Airways, 24 October 1950. It was named Clipper Nightingale and registered N1022V. The airliner remained in Pan Am service until 1960, when it was sold back to Boeing.
N1022V was next sold to Rutas Aéreas Nacionales, S.A. (RANSA) and converted to a freighter. The new owners named it Carlos. It was re-registered YV-C-ERI. The Stratocruiser was finally retired in 1969 and scrapped.
The prototype Boeing 377 Stratocruiser was sold to RANSA and converted to a freighter. It was named “Carlos” and registered YV-C-ERI.
Captain Charles F. Blair, Jr., standing in the cockpit of Pan American World Airways’ North American Aviation P-51C Mustang, Excalibur III, Bardufoss, Norway, 29 May 1951. (National Air and Space Museum, Smithsonian Institution.)
29 May 1951: Pan American World Airways Captain Charles F. Blair, Jr., flew a modified North American Aviation P-51C-10-NT Mustang, NX12012, Excalibur III, from Bardufoss, Norway to Fairbanks, Alaska, via the North Pole. He flew the 3,260 miles (5,246.5 kilometers) non-stop in 10 hours, 27 minutes.
After departing Bardufoss at 3:58 p.m., Captain Blair flew north along the E. 20° meridian until crossing the North Pole at an altitude of 22,000 feet (6,706 meters), then south along the W. 160° meridian until reaching N. 70° latitude, and then southeast to Fairbanks.
During the transpolar flight, the Mustang was subjected to air temperatures as low as -25 °F. (-31.6 °C.).
Captain Charles F. Blair, Jr., checks his astrocompass shortly before beginning his transpolar flight, 29 May 1951. ( National Air and Space Museum, Smithsonian Institution)
Captain Blair navigated by using a system of pre-plotted sun lines calculated by Captain Phillip Van Horns Weems, U.S. Navy (Ret.), as a magnetic compass was useless near the Pole and there were no radio navigation aids available.
Charles Blair used this Astrocompass Mark II on his transpolar flight. It is in the collection of the Smithsonian Institution National Air and Space Museum. (NASM2012-02107)
Blair was presented the Harmon International Trophy by President Harry S. Truman, in a ceremony at the White House, 18 November 1952. The Harmon awards are for “the most outstanding international achievements in the art and/or science of aeronautics for the previous year, with the art of flying receiving first consideration.”
Excalibur III being fueled at Bardufoss, Norway, May 1951. (Arkivverkets digitale fotoarkiv)
Charles Blair was commissioned in the United States Naval Reserve in 1931. He was promoted to lieutenant, junior grade, in 1937. During World War II, Blair served as a transport pilot in the U.S. Navy and rose to the rank of captain.
Blair resigned from the Navy in 1952 and the following year accepted a commission in the U.S. Air Force Reserve with the rank of colonel. In 1959 he was promoted to brigadier general.
While serving as a reserve officer, Charlie Blair continued his civilian career as an airline pilot for United Airlines, American Overseas Airlines, and then with Pan American.
Captain Blair was married to actress Maureen O’Hara, whom he had met during one of his 1,575 transatlantic crossings.
Excalibur III is a Dallas, Texas-built North American Aviation P-51C-10-NT Mustang, one of a group of 400 fighters which had been contracted on 5 March 1943. Its North American Aviation serial number is 111-29080, and the U.S. Army Air Forces assigned it serial number 44-10947.
After World War II, 44-10947 was purchased by Paul Mantz, and the Civil Aeronautics Administration registered it as NX1202. Mantz had it painted red and named it Blaze of Noon. Paul Mantz flew NX1202 to win the 1946 and 1947 Bendix Trophy Races. Flown by Linton Carney and renamed The Houstonian, NX1202 placed second in the 1948 Bendix race, and with “Fish” Salmon in the cockpit, it took third place in 1949. Paul Mantz had set several speed records with the Mustang before selling it to Pan American World Airways, Inc., Blair’s employer. Blair named the Mustang Stormy Petrel, but later changed it to Excalibur III.
To increase the Mustang’s range for these long-distance flights, Mantz had removed the standard 90-gallon pressure-molded Firestone self-sealing tanks from each wing and converted the entire wing to a fuel tank (what is known as a “wet wing”).
Test pilot Herman “Fish” Salmon awaits the starter’s signal at the beginning of the 1949 Bendix Trophy Race on Rosamond Dry Lake, California. Paul Mantz had won the 1946 and 1947 races with this P-51C, NX1202, “Blaze of Noon.” (San Diego Air and Space Museum Archive)
The P-51B and P-51C Mustang are virtually Identical. The P-51Bs were built by North American Aviation, Inc, at Inglewood, California. P-51Cs were built at North American’s Dallas, Texas plant. They were 32 feet, 2.97 inches (9.829 meters) long, with a wingspan of 37 feet, 0.31-inch (11.282 meters) and overall height of 13 feet, 8 inches (4.167 meters) high. The fighter had an empty weight of 6,985 pounds (3,168 kilograms) and a maximum gross weight of 11,800 pounds (5,352 kilograms).
North American Aviation P-51C-10-NT 44-10947, “Excalibur III,” at the Steven F. Udvar-Hazy Center, National Air and Space Museum.
P-51Bs and Cs were powered by a right-hand tractor, 1,649-cubic-inch-displacement (27.04-liter) liquid-cooled, supercharged, Packard V-1650-3 or -7 Merlin single overhead cam (SOHC) 60° V-12 engine which produced 1,380 horsepower at Sea Level, at 3,000 r.p.m and 60 inches of manifold pressure (V-1650-3) or 1,490 horsepower at Sea Level, turning 3,000 r.p.m. with 61 inches of manifold pressure (V-1650-7). (Military Power rating, 15 minute limit.) These engines were license-built versions of the Rolls-Royce Merlin 63 and 66. The engine drove a four-bladed Hamilton Standard Hydromatic constant-speed propeller with a diameter of 11 feet, 2 inches (3.404 meters) through a 0.479:1 gear reduction.
The P-51B/C had a cruise speed of 362 miles per hour (583 kilometers per hour) and the maximum speed was 439 miles per hour (707 kilometers per hour) at 25,000 feet (7,620 meters), slightly faster than the more numerous P-51D Mustang. The service ceiling was 41,900 feet (12,771 meters). With internal fuel the combat range was 755 miles (1,215 kilometers).
Identical to the Inglewood, California-built North American Aviation P-51B Mustang, this is a Dallas, Texas-built P-51C-1-NT, 42-103023. (North American Aviation, Inc.)
In military service, armament consisted of four Browning AN/M2 .50-caliber machine guns, mounted two in each wing, with 350 rounds per gun for the inboard guns and 280 rounds per gun for the outboard.
1,988 P-51B Mustangs were built at North American’s Inglewood, California plant and another 1,750 P-51Cs were produced at Dallas, Texas. This was nearly 23% of the total P-51 production.
Though the P-51D with its bubble canopy was built in far greater numbers during World War II, the earlier P-51B and P-51C Mustangs were actually faster, so many surplus airplanes were used for racing and record attempts after the war.
In 1952, Pan American World Airways donated Excalibur III to the Smithsonian Institution. Today, completely restored, it is on display at the Steven F. Udvar-Hazy Center in Chantilly, Virginia.
North American Aviation P-51C-10-NT Mustang, Excalibur III, at the Steven F. Udvar-Hazy Center, National Air and Space Museum. (NASM)
Pan American World Airways’ Boeing 747SP-21 N533PA, s/n 21025, renamed Clipper New Horizons in 1977, with the “Flight 50” insignia. (CNN.com)
1–3 May 1976: Pan American World Airways’ Boeing 747SP–21 Clipper Liberty Bell, N533PA, departed New York’s John F. Kennedy International Airport, on a record-setting around the world flight. Under the command of Captain Walter H. Mullikan, the airline’s chief pilot, the flight crew included co-pilots Albert A. Frink, Lyman G. Watt, and flight engineers Frank Cassaniti and Edwards Shields. The airliner carried 98 passengers. The flight set a new speed record for a flight around the world, eastbound, and three speed records for commercial airline routes.
Clipper Liberty Bell flew eastward from New York JFK to Indira Ghandi International Airport (DEL), New Delhi, India, a distance of 8,081 miles (13,005.1 kilometers), at an average speed of 869.63 kilometers per hour (540.363 miles per hour).¹ After servicing the 747, it continued on its journey. The next destination was Tokyo International Airport (HND), Tokyo, Japan. This stage covered 7,539 miles (12,132.8 kilometers). The airliner’s average speed was 421.20 kilometers per hour (261.722 miles per hour).² Striking Pan Am workers at Tokyo delayed preparing the airliner for the next leg of the journey. After refueling, the Pan American flight continued on to its starting point, John F. Kennedy International Airport, New York, New York. This final leg was 7,517 miles (12,097.4 kilometers). The average speed was 912.50 kilometers per hour (567.001 miles per hour).³
The total duration of the flight was 46 hours, 1 second. The actual flight time was 39 hours, 25 minutes, 53 seconds. Total distance flown was 23,137 miles (37,235.4 kilometers). The average speed for the entire flight was 809.24 kilometers per hour (502.838 miles per hour).⁴
Clipper Liberty Bell had been christened in a ceremony at Indianapolis on 30 April 1976 by Betty Ford, First Lady of the United States of America.
In 1977, Captain Mullikin flew the same 747SP on another circumnavigation, 29–31 October 1977, but this time it crossed both the North and South Poles. Renamed Clipper New Horizons, 21025 set 7 world records on that flight, with a total flight time of 54 hours, 7 minutes, 12 seconds. This trip was called “Flight 50.”
Pan American’s Boeing 747SP, Clipper Liberty Bell, N533PA. (Pan Am)
The Boeing 747SP (“Special Performance”) is a very long range variant of the 747–100 series airliners. The airplane is 48 feet, 5 inches (14.757 meters) shorter than the –100, the vertical fin is 5 feet (1.5 meters) taller and the span of horizontal stabilizer has been increased. The weight savings allows it to carry more fuel for longer flights, and it is also faster. The maximum number of passengers that could be carried was 400, with a maximum of 45 on the upper deck. Boeing built 45 747SPs.
The 747SP is 184 feet, 9 inches (56.312 meters) long, with a wingspan of 195 feet, 8 inches (59.639 meters). It has an overall height of 65 feet, 1 inch, at maximum gross weight and 65 feet, 10 inches (19.837–20.066 meters), empty. It has an operating empty weight of 337,100 pounds (152,906 kilograms), and a maximum takeoff weight of 700,000 pounds (317,515 kilograms).
Boeing 747SP three-view illustration with dimensions
The 747SP could be ordered with Pratt & Whitney JT9D- or Rolls-Royce RB211-series engines. These engines had a range of thrust of 43,500–51,980 pounds (193.50–231.22 kilonewtons) for takeoff (5-minute limit), and resulted in variations of the airliner’s empty weight and fuel capacity.
The airliner had a design cruising speed (VC) of 0.86 Mach, and a maximum operating speed (VMO/MMO) of 375 knots KEAS, or 0.92 Mach. The service ceiling is 45,100 feet (13,746 meters) and the design range is 5,830 nautical miles (6,709 statute miles/10,797 kilometers). The fuel capacity is 48,780 U.S. gallons (184,652 liters), and it carries 600 gallons (2,271 liters) of water for engine injection.
Boeing 747SP–21 N40135, c/n 21025, 1 January 1975. (747SP.com)
The record-setting Boeing 747SP-21, serial number 21025, was the fourth Special Performance 747 built, and one of 10 that had been ordered by Pan American World Airways. It first flew 8 October 1975, in Boeing’s corporate paint scheme. It was then retained for use in the test fleet. When flight testing was completed, the airliner was refurbished and repainted in the Pan Am livery. It was delivered to the airline 5 March 1976 and registered N533PA.
While in the Pan Am fleet, N533PA also carried the names Clipper New Horizons, Clipper Young America and Clipper San Francisco.
Pan Am Boeing 747SP–21, N533PA, c/n 21025, renamed Clipper Young America, circa 1985. It still carries the “Flight 50” insignia. (747SP.com)Compare this standard Boeing 747–121, Pan American’s Clipper Sea Serpent, N655PA, to the 747SP in the photograph above. (Detail from image by Bruno Geiger)
Pan American sold its fleet of Boeing 747SPs to United Airlines in 1986. 21025 was re-registered N143UA to reflect its new ownership. Twenty years after its first flight, 21025 was removed from service in 1995 and placed in storage at Ardmore, Oklahoma. It was scrapped in December 1997. The airliner had accumulated 78,941 total flight hours on its airframe (TTAF) with 10,733 cycles.
United Air Lines’ Boeing 747SP–21 N143UA, c/n 21025. (747SP.com)
