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)
Boeing Model 307 Stratoliner NX19901 taking of at Boeing Field, Seattle, Washington. (San Diego Air & Space Museum Archives)
18 March 1939: At 12:57 p.m., Pacific Standard Time (19:47 G.M.T.), the Boeing Model S-307 Stratoliner, NX19901, took off from Boeing Field, Seattle, Washington, on Test Flight No. 19. Julius Augustus Barr was the pilot in command.
The S-307, Boeing serial number 1994, was a prototype four-engine, pressurized commercial airliner. It had first flown on 31 December 1938, with Boeing’s Chief of Flight Test, Edmund Turney (“Eddie”) Allen, as first pilot (the Pilot in Command), and Julius Barr as his copilot. Allen had flown the first eighteen flights. “The performance of aircraft NX 19901 on flights prior to Test Flight No. 19 had either met or exceeded the manufacturer’s estimates.”
Julius Barr was employed by Boeing as a test pilot, 16 November 1938. Following Flight Test No. 15, Allen approved Barr to act as first pilot on the Model 307. He first served as the pilot in command of NX19901 on 21 January 1939. This was a taxi test, with the Stratoliner never leaving the ground. Barr first flew the airplane nearly two months later, 16 March 1939, with copilot Earl Alvin Ferguson. Barr made two more flights on 17 March. Harlan Hull, Chief Pilot of Transcontinental and Western Air, Inc., flew as copilot.
At takeoff on 18 March 1939, Barr had only 2 hours, 6 minutes as pilot in command of the Boeing 307; and 17 hours, 55 minutes as second in command. He had flown as an observer aboard NX19901 for 1 hour, 52 minutes.
There were ten persons on board the Stratoliner for Test Flight No. 19. In addition to Julius Barr as P.I.C., the designated copilot was Earl Ferguson. There were two alternate copilots, Harlan Hull and Benjamin J. Pearson, an assistant sales manager for Boeing. Ralph LaVenture Cram was first aerodynamcist, assisted by John Kylstra. William C. Doyle served as oscillograph operator, and Harry T. West, Jr., was the engineering officer. These were all Boeing employees. Pieter Guillonard, technical director of Koninklijke Luchtvaart Maatschappij N.V. (KLM Royal Dutch Airlines), acted as recorder and photographer, while Albert Gillis von Baumhauer, an engineer with the Luchtvaartdienst (the Dutch Aviation Authority), acted as an assistant aerodynamicist.
Albert G. von Baumhauer
Specialized test equipment had been installed at the copilot’s position. For this reason, Von Baumhauer, rather than the designated copilot, Ferguson, was in the copilot’s seat during this test flight. (Von Baumgartner held a Dutch private pilot certificate, issued 28 November 1931. Since that time, he had flown only 116 hours, and had no experience flying multi-engine aircraft. He was not qualified to act as copilot.)
Guillonard and Von Baumhauer had recommended a series of tests to be conducted on Test Flight No. 19, including observing the airplane’s behavior following an engine cut on takeoff with no rudder input; a series of side slips and stall tests. Von Baumhauer had emphasized “complete stalls” rather than initiating recovery when stall was detected.
After takeoff, NX19901 climbed to 10,000 feet (3,048 meters) and at 140 miles per hour (225 kilometers per hour) a series of static longitudinal stability tests were performed. According to the test flight plan, side slips were to be investigated next.
Boeing 307 Stratoliner NX19901 with both propellers on right wing feathered. Note the rudder deflection. (Boeing)
At 1:12 P.M. (PST) a radio message was transmitted from NX 19901 to the Boeing Aircraft Company radio station located at Seattle, Washington, which message gave the position of the aircraft as being between Tacoma Washington and Mount Rainier at an altitude of 11,000 feet. Some two or three minutes later, while flying at a comparatively slow rate of speed in the vicinity of Alder, Washington, the aircraft stalled and began to spin in a nose down attitude. After completing two or three turns in the spin, during which power was applied, it recovered from the spin and began to dive. The aircraft partially recovered from the dive at an altitude of approximately 3,000 feet above sea level, during which recovery it began to disintegrate. Outboard sections of the left and right wings failed upward and broke entirely loose from the aircraft. Major portions of the vertical fin and portions of the rudder were carried away by wing wreckage. The outboard section of the left elevator separated from the stabilizer and both fell to the ground detached. The right horizontal tail surface, being held on by the fairing long the top surface and also by the elevator trim tab cables, remained with the fuselage. The No. 1 engine nacelle also broke loose from the aircraft and fell to the ground separately. The main body of the aircraft settled vertically and struck the ground in an almost level attitude both longitudinally and laterally at a point approximately 1,200 feet above sea level. Watches and clocks aboard the aircraft, which were broken by the force of the impact, indicated the time of the accident at approximately 1:17 p.m. (PST).
—AIR SAFETY BOARD REPORT, at Pages 34–35.
Diagram of probable flight path of NX19901 from Air Safety Board report.
All ten persons aboard were killed in the crash. The Stratoliner was destroyed. Because of the water ballast in the main fuel tanks, there was no post crash fire.
Wreckage of Boeing Model 307 Stratoliner NX19901, right rear quarter.Wreckage of Boeing Model 307 Stratoliner NX19901, right front quarter.Wreckage of Boeing Model 307 Stratoliner NX19901 near Alder, WashingtonWreckage of Boeing Model 307 Stratoliner NX19901 near Alder, Washington. (SDASM)Wreckage of Boeing Model 307 Stratoliner NX19901, left front quarter.
During the crash investigation it was found that two B-17s had previously been spun. The first,
. . . while flying with a gross load of about 42,000 pounds at an altitude of 14,000 feet, went into an inadvertent spin and made two complete turns before recovery was effected. During the pull-out from the ensuing dive, permanent distortion occurred in the structure of both wings, necessitating the installation of new wings on the aircraft.
In the second of these experiences, a similar ship was intentionally permitted to enter a spin following a complete stall. The controls were immediately reversed and the aircraft responded promptly, enabling the pilot to effect recovery after three-fourths of a turn in—
Evidence indicated that power was used in recovery from the spin in the case of NX 19901. It should be noted that in the two instances above described recovery from spin in similar aircraft was accomplished without the employment of power. In one of these cases, permanent distortion occurred in both wings.
—AIR SAFETY BOARD REPORT, at Pages 48 and 49.
Diagram of wing failure under load. (Air Safety Board Report)
PROBABLE CAUSE
Structural failure of the wings and horizontal tail surfaces due to the imposition of loads thereon in excess of those for which they were designed, the failure occurring in an abrupt pull-out from a dive following recovery from an inadvertent spin.
—AIR SAFETY BOARD REPORT, at Page 56
Crash site diagram. (Air Safety Board Report)Boeing Model 307 Stratoliner NX19901. The engine cowlings have been removed. The inboard right engine is running. The arrangement of passenger windows differs on the right and left side of the fuselage. (San Diego Air & Space Museum Archives)
The Boeing Model 307 was operated by a crew of five and could carry up to 33 passengers. It was the first pressurized airliner and, because of its complexity, it was also the first airplane to include a flight engineer as a crew member. It could maintain a cabin pressure equivalent to 12,000 feet (3,650 meters) to a pressure altitude of 19,000 feet (5,791 meters).
The Model 307 used the wings, tail surfaces, engines and landing gear of the production B-17B Flying Fortress heavy bomber. The vertical fin and rudder were of the same design as the B-17B’s, though somewhat larger. The fuselage was circular in cross section to allow for pressurization. It was 74 feet, 4 inches (22.657 meters) long with a wingspan of 107 feet, 3 inches (32.690 meters) and overall height of 20 feet, 9½ inches (6.337 meters). The wings had 4½° dihedral and 3½° angle of incidence. The empty weight was 29,900 pounds (13,562.4 kilograms) and loaded weight was 45,000 pounds (20,411.7 kilograms).
The airliner was powered by four air-cooled, geared and supercharged, 1,823.129-cubic-inch-displacement (29.875 liter) Wright Cyclone 9 GR-1820-G102 9-cylinder radial engines with a compression ratio of 6.7:1, rated at 900 horsepower at 2,200 r.p.m., and 1,100 horsepower at 2,200 r.p.m. for takeoff. These drove three-bladed Hamilton-Standard Hydromatic propellers through a 0.6875:1 gear reduction in order to match the engine’s effective power range with the propellers. The GR-1820-G102 was 4 feet, 0.12 inches (1.222 meters) long, 4 feet, 7.10 inches (1.400 meters) in diameter, and weighed 1,275 pounds (578 kilograms).
The maximum speed of the Model 307 was 241 miles per hour (388 kilometers per hour) at 6,000 feet (1,828.8 meters). Cruise speed was 215 miles per hour (346 kilometers per hour) at 10,000 feet (3,048 meters). The service ceiling was 23,300 feet (7,101.8 meters).
Boeing Model 307 Stratoliner NX19901 with all engines running. (San Diego Air & Space Museum Archives)
As a result of the crash of NX19901, production Stratoliners were fitted with a vertical fin similar to that of the B-17E Flying Fortress.
Pan American Airways’ Boeing 307 Stratoliner NC19903, photographed 18 March 1940. Note the new vertical fin. (Boeing)
Julius Augustus Barr was born at Normal, Illinois, 6 December 1905. He was the son of Oren Augustus Barr, a teacher and school superintendent, and Margaret M. Wallace Barr. He grew up in Pittsburg, Kansas. He attended the Kansas State Teachers College at Pittsburg in 1925. He was a member of the Alpha Gamma Tau (ΑΓΤ) fraternity, of which he was the treasurer.
Julius Augustus Barr
Barr enlisted in the Air Corps, United States Army, and was trained as a pilot at Brooks and Kelly Fields, San Antonio, Texas.
On 1 July 1928, Julius Barr married Miss Effie Hortense Roberson at Pittsburg, Kansas. They would have two children, Jo Anne Barr, and Gene Edward Barr.
In 1930, Barr and his family lived in Cheyenne, Wyoming. He flew as an air mail pilot, and was employed by Boeing Air Transport.
During the mid 1930s, the Barr family traveled to China, where he acted as manager of the airport at Hankow, and conducted flight training. He then flew as the personal pilot of Zhang Xueliang (also known as Chang Hseuh-Liang), (“The Young Marshal”). Zhang and another of other communist generals arrested Chiang Kai-Shek in the Xi’an Incident, December 1936. Chiang was released after two weeks, and Zhang placed under house arrest for the remainder of his life. (The others were executed.) Julius Barr then served as the personal pilot for Soong Mei-ling (“Madame Chiang”), and helped General Chang with the air defense of Shanghai during the Second Sino-Japanese War.
Barr and his family departed Hong Kong aboard S.S. Empress of Russia, which arrived at Victoria, British Columbia, Canada, 14 November 1938. He then went to work as a test pilot for Boeing two days later.
Julius Barr had flown a total of approximately 5,000 hours. Of these, 2,030 hours were in single-engine airplanes, 2,240 hours in twin-engine, and 765 hours in 3 engine.
Julius Augustus Barr was buried at the Mount Olive Cemetery, Pittsburg, Kansas.
The first Boeing B-47A Stratojet, 49-1900. (U.S. Air Force)
1 March 1950: The first production Boeing B-47 Stratojet, B-47A 49-1900 (Boeing serial number 450001), was rolled off the assembly line at Boeing’s Wichita, Kansas, Plant II.
The Wichita Eagle reported:
“FIRST B-47A PRODUCTION MODEL SHOWN—First production model of the B-47A Stratojet bomber is shown above, surrounded by Boeing-Wichita officials as it rolled from the assembly line at the local plant Wednesday. (Other pictures on Page 4.)”
First Stratojet Rolls Off B-47 Assembly Line Here
Boeing-Wichita Puts New Model Into Production
Six-Jet Speed Bomber Even More Powerful Than Its Predecessor
Boeing-Wichita’s first B-47 Stratojet bomber rolled off final assembly Wednesday at the local plant, less than 18 months after the Air Force gave the go-ahead signal to build the big, six-jet, swept-wing bomber here.
The airplane was given to an Air Force aircraft engineering inspection board. The board will examine it for a week, alterations will be made in the shops, if any are needed, and it will be ready to fly.
The first production model of the already-famous bomber has been designated the B-47A. It is almost identical in appearance to the experimental XB-47s, which were built in the Seattle, Wash., plant of the Boeing Aircraft Company, but the resemblance ends there.
More Powerful than XB-47
This is a more powerful airplane, Boeing officials say. Instead of the six jet engines of 4,000 pounds thrust each which powered the first experimental Stratojet, this first production model is powered by six jet engines of 5,200 pounds thrust each.
Additional internal improvements have been made based on experience gained in the XB-47 flight test program, which was moved from Moses Lake, Wash., with the arrival here of the first XB-47. The second “X” came here in October.
Recently one of the experimental models got a test of rocket assisted takeoff at Municipal Airport where an expansion program costing nearly $1,000,000 has been started to accommodate the B-47 flight testing program.
Holds Speed Record
The first production model climaxes more than six years of jet bomber design study and development by Boeing. The first experimental flight was made at Moses Lake Dec. 17, 1947, more than 26 months ago.
In February, 1949, an XB-47 was piloted to an unofficial, all-time, all-type transcontinental speed record. It flew 2,289 miles from Moses lake to Andrews Air Force Base, in three hours, 46 minutes. The average speed was 607.8 miles per hour. The record-breaking airplane was equipped with the smaller jet engines.
At Boeing-Wichita, closed down following World War II when 1,644 B-29 Superforts were built there, the first production model climaxes a reactivation begun in March, 1948.
Six months later came the Air Force “letter of intent” and B-47 Stratojet production got underway in Wichita.
“ASSEMBLY LINE IS SHOWN—Part of the assembly line which produced Boeing-Wichita’s first Stratojet six engine bomber is shown above. Three more Stratojets, designated B-47A, are shown being assembled.”“CLOSE-UP OF B-47A SHOWN—Here’s a close-up of the first production model of the B-47A Stratojet bomber which rolled from the Boeing-Wichita assembly line Wednesday. In the center of the crowd, above, J. Earl Schaefer, vice president and general manager of Boeing, happily makes the rounds congratulating workers and officials who built the bomber.”
—The Wichita Eagle, Vol. 24, Number 50, Wednesday 1 March 1950, Page 1, Column 7, and Page 4, Columns 5–8
Boeing B-47A Stratojet 49-1900. (U.S. Air Force 061024-F-1234S-007)
B-47A 49-1900 made its first flight 25 June 1950.
Designed by Boeing, the Stratojet was a high-subsonic-speed strategic bomber and reconnaissance aircraft, in service from 1951 until 1977. The B-47 could fly higher and faster than jet fighters of the early 1950s, and it was also highly maneuverable. The B-47 was flown by a two pilots in a tandem cockpit. A navigator/bombardier was at a station in the nose. The crew area was pressurized.
This photograph shows Boeing B-47A Stratojet 49-1905. The single-piece plexiglas nose of 49-1900 has been replaced by four separate windows. (U.S. Air Force)
The Boeing B-47A Stratojet was the first production model of the B-47 series. The B-47A was 106 feet, 10 inches (32.563 meters) long with a wingspan of 116 feet, 0 inches (35.357 meters), and an overall height of 27 feet, 11 inches (8.509 meters). The wings were shoulder-mounted with the leading edges swept aft to 36° 37′. Their angle of incidence was 2° 45′ and there was no dihedral. (The wings were very flexible, showing marked anhedral on the ground and flexing upward when in flight.) The B-47A had an empty weight of 73,240 pounds (33,221 kilograms), and a maximum takeoff weight of 157,000 pounds (71,214 kilograms).
The B-47A was powered by six General Electric J47-GE-11 turbojet engines in four nacelles mounted on pylons below the wings. This engine had a 12-stage axial-flow compressor, eight combustion chambers, and single-stage turbine. The J47-GE-11 had a maximum power rating of 5,610 pounds of thrust (24.95 kilonewtons) at 8,030 r.p.m. (30-minute limit), and continuous power rating of 4,860 pounds (21.62 kilonewtons) at 7,450 r.p.m. It had a maximum diameter of 3 feet, 3.0 inches (0.991 meters), length of 12 feet, 0.0 inches (3.658 meters), and weighed 2,475 pounds (1,123 kilograms).
The B-47A was also equipped with 18 Aerojet 14AS1000 solid-fuel rocket engines (ATO) located in the aft fuselage. These produced a maximum 18,000 pounds of thrust (80.07 kilonewtons) for 14 seconds. (49-1901 did not have provisions for ATO.)
A Boeing B-47A Stratojet demonstrates a rocket-assisted takeoff (ATO) The configuration of windows in the nose differs from that of 49-1905, in the image above. (McMahan Photo Archive)
The B-47A Stratojet had maximum speed of 474 knots (545 statute miles per hour/878 kilometers per hour) at 35,000 feet (10,668 meters). The bomber’s speed was limited to 0.815 Mach due to buffeting. The service ceiling was 46,200 feet (14,082 meters) and the combat ceiling, 44,300 feet (13,503 meters).
The B-47A had a maximum ferry range of 2,856 nautical miles (3,287 statute miles/5,289 kilometers) at 424 knots, and a combat radius with a 10,000 pound (4,536 kilograms) bomb load of 1,350 nautical miles (1,554 statute miles/2,500 kilometers). The maximum fuel load was 9,518 gallons (36,030 liters) carried in four fuselage tanks.
The B-47A had space and provisions to mount two Browning AN-M3 .50-caliber machine guns in a remotely-operated tail turret.
Boeing B-47A Stratojet 49-1900 with its bomb bay doors open. (Mary Evans Picture Library)
The B-47A could carry a single T-14 22,000 pound (9,979 kilogram) or T-10 12,000 pound (5,443 kilogram) general purpose bomb (both were U.S. versions of the British World War II Grand Slam and Tallboy bombs); up to 16 1,000 pound (454 kilogram) general purpose bombs; or one 10,000 pound (4,536 kilogram) nuclear bomb.
The B-47As were considered as training aircraft and most were assigned to the 306th Bomb Wing (Medium) at MacDill Air Force Base, Florida.
NACA 150, the first Boeing B-47A Stratojet,49-1900, decelerates after landing at Edwards Air Force Base, California, circa 1953. (NASA Photo E-1004)
The first B-47A, 49-1900, was tested by the U.S. Air Force at Wright Field, Ohio, and then at the National Advisory Committee for Aeronautics’ Langley Memorial Aeronautical Laboratory at Hampton, Virginia, where it was identified as NACA 150. It was later transferred to the NACA High Speed Flight Research Station at Edwards Air Force Base in the high desert of southern California. It flew there from 1953 to 1957. 49-1900 was placed in storage at Davis-Monthan Air Force Base, Tucson, Arizona, 28 February 1958.
Boeing B-47A Stratojet 49-1900 as NACA 150, at Edwards AFB, California. Note the reconfigured nose. (NASA)
B-47A production ended in June 1951, as production shifted to the B-47B. Just ten B-47As were built.
A total of 2,032 B-47s were built by a consortium of three aircraft manufacturers: Boeing Airplane Company, Wichita, Kansas; Douglas Aircraft Company, Tulsa, Oklahoma; Lockheed Aircraft Company, Marietta, Georgia.
Seven Boeing B-47A Stratojets at the Boeing Airplane Co. Plant II, Wichita, Kansas, 26 June 1951. (U.S. Air Force)
The second prototype Boeing XB-29 Superfortress, 41-0003, takes off from Boeing Field, 12:09 p.m., 18 February 1943. (Boeing)
18 February 1943: At 12:09 p.m., Boeing Aircraft Company Chief Test Pilot Edmund Turney (“Eddie”) Allen took off from Boeing Field, Seattle, Washington, in the Number 2 prototype XB-29 Superfortress long-range heavy bomber, serial number 41-0003. Allen’s co-pilot was engineering test pilot Robert R. Dansfield. The rest of the XB-29 flight crew were Charles Edmund Blaine, flight test engineer; Fritz Mohn, senior inspector; Vincent W. North, aerodynamicist; Harry William Ralston, radio operator; Barclay J. Henshaw, flight test analyst; Thomas R. Lankford, engineer; Robert Willis Maxfield, flight test engineer; Raymond Louis Basel, flight test engineer; Edward I. Wersebe, flight test engineer.
Edmund Turney Allen. (San Diego Air & Space Museum Archive)
41-0003 had first flown on 30 December 1942, piloted by Allen. During that flight, the prototype bomber suffered a major engine fire and Eddie Allen’s performance in returning the airplane to the airport later earned him the U.S. Army’s Air Medal, awarded on the specific orders of President Harry S. Truman.
Problems with the XB-29s’ Wright R-3350-13 engines had caused major delays in the B-29 testing program. The Number 2 aircraft had its engines replaced with those from the first XB-29, 41-0002. By 18 February, 41-0003 had made only eight flights, with a total flight time of 7 hours, 27 minutes.
The ninth test flight of 41-0003 was planned to test the climb performance to 25,000 feet (7,620 meters) and to collect engine cooling data.
At 12:17 p.m., 41-0003 was climbing through 5,000 feet (1,524 meters) when the #1 engine (the outboard engine on the left wing) caught fire. The engine was shut down and CO2 fire extinguishers were activated. Eddie Allen began a descent and turned back toward Boeing Field.
The wind was out of the south at 5 miles per hour (2.24 meters per second) so it was decided to land on Runway 13, the southeast/northwest runway. At 12:24, radio operator Harry Ralston reported that the XB-29 was 4 miles (6.4 kilometers) northeast of the field at 1,200 feet (366 meters).
The airplane was in the landing pattern turning from the downwind leg to the base leg when at 12:25 an explosion occurred. Ralston was heard to say, “Allen, better get this thing down in a hurry. The wing spar is burning badly.”
In order to save weight, various parts of the Wright R-3350 engine were made of magnesium, a flammable metal which burned at a very high temperature. With an engine on fire, the bomber’s wing structure was extremely vulnerable.
The prototype bomber was now shedding parts and left a trail behind it on the ground. The fire was now burning inside the fuselage. Three crew members bailed out but the altitude was too low and they were killed.
At 12:26 p.m., Boeing XB-29 41-0003 crashed into the Frye Meat Packing Plant, south of downtown Seattle, and exploded. Nearly 5,000 gallons (18,927 liters) of gasoline started a massive fire. The 8 men still aboard the prototype bomber were killed, as were 20 employees inside the building. A firefighter who responded was also killed.
The Frye packing plant on fire, 18 February 1943. (Seattle Post-Intelligencer)
Three XB-29 prototypes were built. The XB-29 was 98 feet, 2 inches (29.896 meters) long with a wing span of 141 feet, 3 inches (43.053 meters), and 27 feet, 9 inches (8.458 meters) high to the top of its vertical fin. The prototype bomber had a gross weight of 105,000 pounds (47,627.2 kilograms).
Boeing XB-29-BO, 41-002, the first XB-29 built. (U.S. Air Force)
The XB-29 was powered by four 3,347.662-cubic-inch-displacement (54.858 liter) air-cooled, supercharged, Wright Aeronautical Division Cyclone 18 670C18H1 (R-3350-13) two-row 18-cylinder radial engines (also known as the Duplex-Cyclone) with a compression ratio of 6.85:1. The R-3350-13 had a Normal Power rating of 2,000 horsepower at 2,400 r.p.m., and 2,200 horsepower at 2,800 r.p.m. for takeoff, using 100 octane aviation gasoline. The engines turned 17-foot-diameter (5.182 meters) three-bladed Hamilton Standard Hydromatic constant-speed propellers through a 0.35:1 gear reduction. The R-3350-13 was 76.26 inches (1.937 meters) long, 55.78 inches (1.417 meters) in diameter, and weighed 2,668 pounds (1,210 kilograms).
The XB-29 had a maximum speed of 368 miles per hour (592 kilometers per hour) and cruised at 255 miles per hour (410 kilometers per hour). Its service ceiling was 32,100 feet (9,784 meters). The airplane was designed to carry 20,000 pounds (9,072 kilograms) of bombs.
The B-29 Superfortress was the most technologically advanced—and complex—aircraft of the War. It required the manufacturing capabilities of the entire nation to produce. Over 1,400,000 engineering man-hours had been required to design the prototypes. It would be manufactured by Boeing at Seattle and Renton, Washington and at Wichita, Kansas; by Glenn L. Martin Company at Omaha, Nebraska; and by Bell Aircraft Corporation, Atlanta, Georgia.
There were three XB-29 prototypes; 14 YB-29 pre-production test aircraft; 2,513 B-29; 1,119 B-29A; and 311 B-29B Superfortress aircraft. The bomber served during World War II and the Korean War and continued in active U.S. service until 1960.
The Eddie Allen.
The employees of the Boeing plant at Wichita, Kansas donated the money to build a B-29 to be named in honor of Eddie Allen. B-29-40-BW 42-24579 flew 24 combat missions. On its final mission over Tokyo, Japan, the Eddie Allen was so badly damaged that, though it was able to reach its base on the island of Tinian, it never flew again.
Boeing Wichita-built B-29-40-BW Superfortress 42-24579, “Eddie Allen,” of the 45th Bombardment Squadron (Very Heavy), 40th Bombardment Group (Very Heavy), XX Bomber Command, circa 1944. (U.S. Air Force)Boeing’s acknowledgement of the sacrifice of its flight test crew, 18 February 1943, from the annual report to the shareholders.
The prototype Boeing 747, RA001, City of Everett, takes off at Paine Field, 9 February 1969. (The Museum of Flight)
9 February 1969: At 11:34 a.m., Boeing Chief Test Pilot Jack Wadell, with Engineering Test Pilots Brien Singleton Wygle, co-pilot, and Jesse Arthur Wallick, flight engineer, took off from Paine Field, Everett, Washington, aboard RA001, the prototype Boeing 747-121, and made a 1 hour, 15 minute test flight. The ship was named City of Everett after the home of the factory where it was built. It was originally registered N7470.
The test pilots who flew the first Boeing 747: Left to right, Brien S. Wygle, Jack Waddell and Jesse A. Wallick. (Seattle Times)
The 747 was the first “wide body” airliner and was called a “jumbo jet.” It is one of the most widely used airliners and air freighters in service world-wide. The latest version is the 747-8, the “Dash Eight.” After 53 years, production ended with a total of 1,574 747s built.
Boeing 747-121 RA001, City of Everett, 9 February 1969. A Canadair CL-13B Sabre Mk.6, N8686F, is the chase plane, flown by test pilot Paul Bennett. (Boeing/The Seattle Times)
The Boeing 747 is a very large swept wing, four engine commercial transport. The 747-100 series was the first version to be built. It was operated by a flight crew of three—pilot, co-pilot and flight engineer—and was designed to carry 366 to 452 passengers. The airplane is 231 feet, 10.2 inches (70.668 meters) long with a wingspan of 195 feet, 8 inches (59.639 meters) and overall height of 63 feet, 5 inches (19.329 meters). The wings are swept aft to 37° and have a total area of 5,500 square feet (511 square meters). The angle of incidence is 2°, and there are 7° of dihedral.
The interior cabin width is 20 feet (6.096 meters), giving it the name “wide body.” Its empty weight is 370,816 pounds (168,199 kilograms) and the Maximum Takeoff Weight (MTOW) is 735,000 pounds (333,390 kilograms).
Boeing 747 RA001 flight crew, left to right, Jack Wadell, Brien Wygle and Jess Wallick. (Image courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)
The 747-100 is powered by four Pratt & Whitney JT9D-7A high-bypass ratio turbofan engines. The JT9D is a two-spool, axial-flow turbofan engine with a single-stage fan section, 14-stage compressor (11 high- and 3 low-pressure stages) and 6-stage turbine (2 high- and 4 low-pressure stages). The engine is rated at 46,950 pounds of thrust (208.844 kilonewtons), or 48,570 pounds (216.050 kilonewtons) with water injection (2½-minute limit). This engine has a maximum diameter of 7 feet, 11.6 inches (2.428 meters), is 12 feet, 10.2 inches (3.917 meters) long and weighs 8,850 pounds (4,014 kilograms).
The 747-100 has a cruise speed of 0.84 Mach (555 miles per hour, 893 kilometers per hour) at 35,000 feet (10,668 meters). The maximum certificated operating speed is 0.92 Mach. The airliner’s maximum range is 6,100 miles (9,817 kilometers).
The prototype Boeing 747 during its first flight. (Boeing)
City of Everett last flew in 1995. It is on static display at The Museum of Flight, Boeing Field, Seattle, Washington.
Boeing 747-121, City of Everett, on take off from Boeing Field. The prototype has been re-registered N1352B. RA001 carried this registration number from July 1970 to April 1975. (The Museum of Flight)
