Bryan R. Swopes grew up in Southern California in the 1950s–60s, near the center of America's aerospace industry. He has had a life-long interest in aviation and space flight. Bryan is a retired commercial helicopter pilot and flight instructor.
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Spirit of St. Louis over San Diego, May 1927. (San Diego Air and Space Museum)
4 May 1927: Charles A. Lindbergh completes his last series of flight tests of the Ryan NYP, N-X-211, Spirit of St. Louis. Flying at 50 feet (15.2 meters) over San Diego Bay, he times the Spirit‘s flight from marker to marker with a stop watch. The airspeed indicator jumps past 130 miles per hour (209.2 kilometers per hour). He records indicated air speed and engine r.p.m. at various power settings. At 1,500 r.p.m. the Spirit can fly at 96 miles per hour (154.5 kilometers per hour). He makes three runs in each direction to come up with averages.
After the speed runs, Lindbergh flies back to Camp Kearney for load tests. Take-off distances are measured while increasing the fuel load in 50 gallon (189.3 liter) increments.
“Twilight is thickening. We stake the Spirit of St. Louis down and leave it under guard. . . When I get back to the city, I telegraph my partners that the tests are satisfactorily completed. . . .”
—The Spirit of St. Louis, by Charles A. Lindbergh, Charles Scribner’s Sons, 1953, Chapter 37 at Page 128.
4 May 1924: At 7:30 a.m., Étienne Edmond Oehmichen (1884–1955), an engineer for Société Anonyme des Automobiles et Cycles Peugeot, flew his four-rotor L’Hélicoptère Nº2 around a triangular closed circuit of approximately 1 kilometer (0.62 mile) at Valentigney, France. The flight took 7 minutes, 40 seconds. It was observed by the public, members of the press and officials of the Service Technique de l’ Aéronautique (S.T.Aé, the French air ministry). For his accomplishment, Oehmichen was awarded a prize of ₣90,000 by the government of France.
FLIGHT reported:
A Fresh Helicopter Record
M. Oemichen has been continuing his experiments at Valentigny with his helicopter, and on Sunday, May 4, established a record for helicopters by accomplished a flight of more than one kilometre—1,100 yards—in a closed circuit. The flight lasted 7 mins. 40 secs. and during most of the time the machine maintained a height of about 3 feet, but sometimes rose to 10 feet. The flight was officially observed by a representative of the Department of Military Aeronautics. By this performance M. Oemichen wins an award of 90,000 francs given by the French Government.
FLIGHT, The Aircraft Engineer & Airships, No. 802 (No. 19, Vol. XVI.) May 8, 1924, Page 267, Column 1
The previous month, Oehmichen had set two FAI world rotorcraft records for distance in a straight line. On 14 April 1924, he flew 360 meters (1,181 feet)¹, and on 17 April, 525 meters (1,722 feet).²
On 14 September 1924, he would set two records for altitude, 1 meter (3.28 feet) with a 100 kilogram (220 pounds) and a 200 kilogram (441 pounds) payload.³
One of the configurations of Oemichen’s helicopter.
Oehmichen’s helicopter (also referred to by some sources as the Peugeot Nº2) was a cross-shaped structure built of metal tubing. Lift was generated by four two-bladed, counter-rotating, main rotors. Two rotors had a diameter of 6.5 meters (21 feet, 4 inches), and the other two, 7.5 meters (24 feet, 7 inches). They all turned at 145 r.p.m. Blade pitch was controlled by warping.
The helicopter had another five rotors positioned in the horizontal plane. Three had a diameter of 1.45 meters (4 feet, 9 inches), and two, 1.55 meters (5 feet, 1 inch). These had reversible pitch were used to provide lateral control. Two variable-pitch pusher propellers with a diameter of 1.40 meters (4 feet, 7 inches) were positioned on each side of the lateral structure, and were driven by belts. The helicopter was steered by another small rotor at the front.
“Ensemble perspectif sçhématique des sustentateurs, propulseurs et évoluers de l’hélicoptère Oemichen-Peogeot Nº 2.” (L’Aéronautique, 6me Année. Nº 61, Juin 1924, at Page 138)
With the helicopter having an operating weight of approximately 1,000 kilograms (2,205 pounds), the rotors had a load factor of 33 kilograms per square meter (6.8 pounds per square foot).
L’hélicoptère Nº2 was powered by a single Société des Moteurs Gnome et Rhône Type R nine-cylinder rotary engine placed vertically near the center of the structure.
The Le Rhône Type R, introduced in 1917, was an air-cooled, normally-aspirated, 15.892 liter (969.786 cubic inches) nine-cylinder overhead valve rotary engine with two valves per cylinder. The Type R produced 170 cheval vapeur (167.7 horsepower) at 1,360 r.p.m. The engine was 0.990 meters (3 feet, 2.9 inches) long, 0.995 meters (3 feet, 3.2 inches) in diameter, and weighed 166 kilograms (366 pounds).
Étienne Oehmichen’s Helicopter No. 2, 4 May 1924.
¹ FAI Record File Number 13093
² FAI Record File Number 13095
³ FAI Record Files 13091 (100 kilograms) and 13092 (200 kilograms)
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)
LCOL William P. Benedict and LCOL Joseph O. Fletcher in cockpit of C-47 enroute the North Pole, 3 May 1952.
3 May 1952: A ski-equipped United States Air Force Douglas C-47A Skytrain, piloted by Lieutenant Colonels William P. Benedict and Joseph O. Fletcher, USAF, was the first airplane to land at the North Pole.¹ The navigator was 1st Lieutenant Herbert Thompson. Staff Sergeant Harold Turner was the flight engineer and Airman 1st Class Robert L. Wishard, the radio operator.
Also on board was Arctic research scientist Dr. Albert P. Crary and his assistant, Robert Cotell. Additional personnel were Fritza Ahl, Master Sergeant Edison T. Blair and Airman 2nd Class David R. Dobson.
Colonel Fletcher was commanding officer of the 58th Strategic Reconnaissance Squadron, Eielson Air Force Base, Fairbanks, Alaska. He was responsible for establishing Drift Ice Stations within the polar ice cap for remote weather observation bases. Ice Island T-3 was renamed Fletcher’s Ice Island in his honor. He became a world authority on Arctic weather and climate. Various geographic features, such as the Fletcher Abyssal Plain in the Arctic Ocean, and the Fletcher Ice Rise in the Antarctic are also named for him.
Crew and passengers of the C-47A Skytrain, 43-15665, at The North Pole, 3 May 1952. (A2C David R. Dobson, United States Air Force)
The airplane flown on this expedition was Douglas C-47A-90-DL Skytrain 43-15665.
The Douglas C-47 in the photograph below is similar to the Skytrain that Benedict and Fletcher landed at the North Pole, however it is a screen image from the RKO/Winchester Pictures Corporation motion picture, “The Thing from Another World,” which was released just one year earlier, 29 April 1951. Howard Hawks’ classic science fiction film involves an Air Force C-47 Skytrain crew that flies in support of a remote Arctic research station.
Screen Image of a ski-equipped Douglas C-47 Skytrain, “Tropical Tilly.” (RKO Pictures)
The Douglas C-47A Skytrain is an all-metal twin-engine, low wing monoplane transport with retractable landing gear. It was operated by a minimum flight crew of two pilots, a navigator and a radio operator. The wing is fully cantilevered and the fuselage is of semi-monocoque construction. Control surfaces are fabric-covered.
The C-47 is 64 feet, 5½ inches (19.647 meters) long with a wingspan of 95 feet (28.956 meters) and height of 17 feet (5.182 meters). Empty weight of the C-47A is 17,257 pounds (7,828 kilograms) and the maximum takeoff weight is 29,300 pounds (13,290 kilograms).²
The C-47A is powered by two 1,829.4-cubic-inch-displacement (29.978 liter) air-cooled, supercharged R-1830-92 (Pratt & Whitney Twin Wasp S1C3-G) two-row 14-cylinder radial engines. These were rated at 1,200 horsepower at 2,700 r.p.m. at Sea Level for takeoff. The maximum continuous rating for normal operation was 1,060 horsepower at 2,550 r.pm., up to 7,500 feet (2,286 meters). Each engine drives a three-bladed Hamilton Standard Hydromatic constant-speed full-feathering propeller with a diameter of 11 feet, 6 inches (3.505 meters) through a 16:9 gear reduction. The R-1830-92 is 48.19 inches (1.224 meters) long, 61.67 inches (1.566 meters) in diameter, and weighs 1,465 pounds (665 kilograms).
The C-47 has a cruising speed of 185 miles per hour (298 kilometers per hour) at 10,000 feet (3,048 meters) and service ceiling of 24,100 feet (7,346 meters).
The C-47-DL could carry 6,000 pounds (2,722 kilograms) of cargo, or 28 fully-equipped paratroopers. Alternatively, 14 patients on stretchers could be carried, along with three attendants.
43-15665 crashed on Fletcher’s Ice island 3 November 1952. It has since sunk to the floor of the Arctic Ocean.
Derelict C-47A 43-15665 at T-3, Fletcher’s Ice Island.
¹ At least one source states that a Soviet expedition aboard three Lisunov Li-2 transports (a license-built Douglas DC-3) landed near the North Pole on 23 April 1948.
² Data from AAF Manual 51-129-2, Pilot Training Manual for the C-47 Skytrain
Viking 1 launch (Chicago Tribune)Viking 1 launch (AP Wirephoto/Baltimore Sun)
3 May 1949: at 9:14 a.m., Mountain Daylight Saving Time (15:14 UTC), the Viking 1 rocket was launched from the White Sands Proving Grounds in southern New Mexico. The rocket carried a 460 pound (210 kilogram) instrumentation payload.
This was the first launch of a U.S.-designed and -built rocket capable of carrying a payload to space.¹
Viking 1 surrounded by the service gantry. The rocket is angled to the north by 3°. (Drew Ex Machina)
Although the planned engine run time was 65 seconds, Viking 1’s engine shut down after 54.5 seconds. At that time, the rocket had reached a speed of 2,350 miles per hour (3,780 kilometers per hour). After the engine shut down, Viking 1 continued to climb on a ballistic trajectory to an altitude of 50 miles (81 kilometers). As it fell back to Earth, 291 seconds after launch, the rocket broke up and was scattered across many miles of the Proving Grounds.
Viking 1 was a single-stage liquid-fueled rocket. It was built by the Glenn L. Martin Company for the Naval Research Laboratory. It was constructed primarily of aluminum. The skin was rolled into a cylinder and welded. It was 47 feet, 7.5 inches (14.516 meters) long, 2 feet, 8 inches (0.813 meters) in diameter, with a fin span of 9 feet, 2.5 inches (2.807 meters). Each fin had an area of 15 square feet (1.39 square meters). The rocket had a gross weight of 10,824 pounds (4,910 kilograms).
A Reaction Motors XLR10-RM-2 rocket engine. (Reddit)
Viking 1 was powered by a Reaction Motors Inc. XLR10-RM-2 engine. It’s propellant was a mixture of ethanol and water, mixed at a ratio of 95:5. The oxidizer was liquid oxygen. The engine produced 20,800 pounds of thrust (92.523 kilonewtons) at Sea Level, and 24,800 pounds (110.316 kilonewtons) in vacuum. Fuel was fed to the engine by a turbopump driven by high-pressure hydrogen peroxide steam. Turning at 10,000 r.p.m., the turbopump provided propellant at a rate of 110 pounds (50 kilograms) per second.
Static test firing of the Viking 1 rocket engine. (Drew Ex Machina)
The engine was mounted on gymbals which were controlled by gyroscopes. By rapidly angling the engine exhaust away from the rocket’s centerline, the engine was able to stabilize the rocket. A British Pathé news film (available on YouTube) showing the launch of Viking 2 illustrates this:
¹ “Space” is defined as being above the von Kármán Line, the boundary between the Earth’s atmosphrere and outer space, at an altitude of 100 kilometers (62.14 miles)