Tag Archives: Boeing Field

18 February 1943, 12:26 p.m., Pacific War Time

The second prototype Boeing XB-29 Superfortress, 41-0003, takes off from Boeing Field, 12:09 p.m., 18 February 1943. (Boeing)
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 T. ("Eddie") Allen. (San Diego Air and Space Museum Archive)
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 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)
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 B-29 Superfortress "Eddie Allen." (U.S. Air Force)
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 acknoledgemnt of the sacrifice of its flight test crew, 18 February 1943,
Boeing’s acknowledgement of the sacrifice of its flight test crew, 18 February 1943, from the annual report to the shareholders.

© 2019, Bryan R. Swopes

20 December 1957

Boeing 707-121 N708PA, photographed during its second flight. (Boeing via Space.com)
Boeing 707-121 N708PA, photographed during its second flight on the afternoon of 20 December 1957. (Boeing)
Boeing 707-121 N708PA makes its first takeoff at 12:30 p.m., on a rainy afternoon, 20 December 1957. (Unattributed)
Boeing 707-121 N708PA makes its first takeoff at 12:30 p.m. on a rainy afternoon, 20 December 1957. (Boeing)

20 December 1957: The first production Boeing 707 jet-powered commercial airliner, N708PA, made its first flight at Renton, Washington. Alvin M. “Tex” Johnston, Boeing’s Chief of Flight Test, was in command, with co-pilot James R. Gannet and flight engineer Tom Layne. Takeoff was at 12:30 p.m., PST. Poor weather limited the first flight to just 7 minutes. The new airliner landed at Boeing Field. Later that day, a second flight was made, this time with a duration of 1 hour, 11 minutes.

N708PA (Serial Number 17586, Line Number 1) was a Model 707-121. The new airliner had been sold to Pan American World Airways, the launch customer, as part of an order for twenty 707s in October 1955.

Boeing test pilot Alvin M. "Tex" Johnston in the cockpit of of the 367–80. (LIFE)
Boeing’s Chief of Flight Test, Alvin M. “Tex” Johnston, in the cockpit of of the 367–80, “Dash Eighty,” 1954. (LIFE Magazine via Jet Pilot Overseas)

The Boeing Model 707 was developed from the earlier Model 367–80, the “Dash Eighty,” prototype for an air-refueling tanker which would become the KC-135A Stratotanker. The 707 was a four-engine jet transport with swept wings and tail surfaces. The leading edge of the wings were swept at a 35° angle.

N708PA was initially used for flight testing by Boeing. Once this was completed, it was prepared for commercial service and delivered to Pan American at San Francisco International Airport (SFO), 30 November 1958. Pan Am named the new airliner Clipper Constitution.

Boeing 707-121 708PA under maintenance at Renton, Washington. (Boeing)
Boeing 707-121 N708PA under maintenance at Renton, Washington. (Boeing)

In February 1965, the airliner was upgraded to 707-121B standards, which replaced the original turbojet engines with quieter, more efficient Pratt & Whitney JT3D-1 turbofan engines which produced 17,000 pounds of thrust. The wing inboard leading edges were modified to the design of the Model 720 and there was a longer horizontal tail plane.

Clipper Constitution flew for Pan Am for nearly seven years, until 17 September 1965 when it crashed into Chances Peak, a 3,002 foot (915 meters) volcano on the Caribbean island of Montserrat. The point impact  was 242 feet (74 meters) below the summit. All aboard, a crew of 9 and 21 passengers, were killed.

Boeing 707-121 N708PA, with both Boeing and Pan American corporate markings. (Unattributed)
Boeing 707-121 N708PA, with both Boeing and Pan American corporate markings. (Unattributed)

The Boeing Model 707-121 was a four-engine jet transport with swept wings and tail surfaces. The leading edge of the wings were swept at a 35° angle. The airliner had a flight crew of four: pilot, co-pilot, navigator and flight engineer.

The 707-121 was 145 feet, 1 inch (44.221 meters) long with a wing span of 130 feet, 10 inches (39.878 meters). The top of the vertical fin stood 42 feet, 5 inches (12.929 meters) high. The 707 pre-dated the ”wide-body” airliners, having a fuselage width of 12 feet, 4 inches (3.759 meters). The airliner’s empty weight is 122,533 pounds (55,580 kilograms). Maximum take off weight is 257,000 pounds (116,573 kilograms).

The first versions were powered by four Pratt & Whitney Turbo Wasp JT3C-6 turbojet engines, producing 11,200 pounds of thrust (49,820 kilonewtons), and 13,500 pounds (60.051 kilonewtons) with water injection. This engine was a civil variant of the military J57 series. It was a two-spool axial-flow turbojet engine with a 16-stage compressor and 2 stage turbine. The JT3C-6 was 11 feet, 6.6 inches (3.520 meters) long, 3 feet, 2.9 inches (0.988 meters) in diameter, and weighed 4,235 pounds (1,921 kilograms).

At MTOW, the 707 required 11,000 feet (3,352.8 meters) of runway to take off.

The 707-121 had a maximum speed of 540 knots (1,000 kilometers per hour). It’s range was 2,800 nautical miles (5,186 kilometers).

The Boeing 707 was in production from 1958 to 1979. 1,010 were built. Production of 707 airframes continued at Renton until the final one was completed in April 1991. As of 2011, 43 707s were still in service.

Boeing 707-121 N708PA retracts its landing gear after taking off at Seattle Tacoma Airport. (Unattributed)
Boeing 707-121 N708PA landing at Seattle Tacoma Airport. (Unattributed)

© 2016, Bryan R. Swopes

17 December 1947

Boeing XB-47 Stratojet 46-065 in flight over a snow-covered landscape. (U.S. Air Force)
Boeing XB-47 Stratojet 46-065 in flight over a snow-covered landscape. (U.S. Air Force)
Robert M. Robbins
Robert M. Robbins

17 December 1947: Boeing test pilots Robert M. Robbins and Edward Scott Osler made the first flight of the Model 450, the XB-47 Stratojet prototype. It was a 52-minute flight from Boeing Field, Seattle, to Moses Lake Air Force Base, five miles north of the town of Moses Lake, Washington.

Robbins later said, “The best way to tell about the performance of the Stratojet is to say that any good crew could have flown it. It took no unusual ability or education. Neither Scott Osler nor I deserve any credit for the flight. Rather, the credit should go to the men who carried out these visions on the drafting boards and the factory workers who made the visions a reality.”

On 11 May 1949, during flight testing at Moses Lake, the canopy of 46-065 came off, killing test pilot Scott Osler. The co-pilot safely landed the airplane.

Designed as a strategic bomber, the B-47 could fly higher and faster than jet fighters of the time, and it was also highly maneuverable. The XB-47 (Boeing Model 450) was flown by a two-man crew in a tandem cockpit. It was 107 feet, 6 inches (32.766 meters) long with a wingspan of 116 feet (35.357 meters). The top of the vertical fin was 27 feet, 8 inches (8.433 meters) high. The wings were shoulder-mounted with the leading edges swept at 35°.

Boeing XB-47 Stratojet 46-065. (U.S. Air Force 061024-F-1234S-004)

The first prototype, 46-065, was powered by six General Electric J35-GE-7 axial flow turbojet engines in four pods mounted on pylons below the wings. The J35 was a single-spool, axial-flow turbojet engine with an 11-stage compressor and single-stage turbine. The J35-GE-7 was rated at 3,750 pounds of thrust (16.68 kilonewtons) at 7,700 r.p.m. (static thrust, Sea Level). The engine was 14 feet, 0.0 inches (4.267 meters) long, 3 feet, 4.0 inches (1.016 meters) in diameter and weighed 2,400 pounds (1,089 kilograms). (The second prototype, 46-066, was completed with J47 engines. 46-065 was later retrofitted with these engines.)

The XB-47 prototype had a maximum speed of 502 knots (578 miles per hour/930 kilometers per hour/0.80 Mach) at 15,000 feet (4,572 meters). The combat speed was 462 knots (532 miles per hour/856 kilometers per hour/0.70 Mach) at 35,000 feet (10,668 meters). The prototype’s empty weight was 74,623 pounds (33,848 kilograms), while its maximum takeoff weight was 162,500 pounds (73,709 kilograms). It required a ground run of 11,900 feet (3,627 meters), or 4,800 feet (1,463 meters) with JATO assist. The bomber could climb at a rate of 3,650 feet per minute (18.5 meters per second) at Sea Level, at combat weight and maximum power. The service ceiling was 37,500 feet (11,430 meters). The XB-47 carried 9,957 gallons (37,691 liters) of fuel. The combat radius was 1,175 nautical miles (1,352 statute miles/2,176 kilometers) with a 10,000 pound (4,536 kilogram) bomb load.

Planned armament (though the XB-47s were delivered without it) consisted of two .50-caliber machine guns in a tail turret, with 1,200 rounds of ammunition, and 10,000 pounds (4,536 kilograms) of bombs.

Boeing XB-47 Stratojet 46-065, the first of two prototypes, on the ramp at Boeing Field, Seattle, 1 December 1947. (U.S. Air Force)
Boeing XB-47 Stratojet 46-065, the first of two prototypes, on the ramp at Boeing Field, Seattle, 1 December 1947. (U.S. Air Force)

The Stratojet was one of the most influential aircraft designs of all time and its legacy can be seen in almost every jet airliner built since the 1950s: the swept wing with engines suspended on pylons, mounted forward of the leading edge.

2,032 B-47s were built by Boeing Wichita, Douglas Tulsa and Lockheed Marietta. They served the United States Air Force from 1951 to 1977.

Right rear quarter view of Boeing XB-47 Stratojet 46-065. (U.S. Air Force)
Right rear quarter view of Boeing XB-47 Stratojet 46-065. (U.S. Air Force)

The very last B-47 flight took place 18 June 1986 when B-47E-25-DT, serial number 52-166, was flown from the Naval Air Weapons Center China Lake to Castle Air Force Base to be placed on static display.

Boeing XB-47 Stratojet 46-065. (U.S. Air Force)
Boeing XB-47 Stratojet 46-065. (U.S. Air Force 061024-F-1234S-003)

XB-47 45-065 stalled while landing at Larson Air Force Base, near Moses Lake, Washington, 18 August 1951. The crew of three escaped uninjured. The airplane suffered major structural damage. It was returned to Boeing at Seattle, Washington in 1953. The second prototype, XB-47 46-066, is in the collection of the Air Force Flight Test Museum, Edwards Air Force Base, California.

Boeing XB-47 Stratojet 46-066, Sandia. (SDASM)

© 2017, Bryan R. Swopes

2 December 1936

Boeing YB-17 Flying Fortress 36-149. (U.S. Air Force)
Boeing YB-17 Flying Fortress 36-149. (U.S. Air Force)

2 December 1936: The first Boeing YB-17, U.S. Army Air Corps serial number 36-149, made its first flight.

Although the prototype Boeing Model 299, X13372, had crashed at Wright Field, Ohio, 30 October 1935, the Army had ordered thirteen Y1B-17 service test aircraft, serials 36-149–36-161. Prior to the model’s first flight, this designation was changed to YB-17. (The “-1-” in the original Y1B-17 designation indicated that the service test bombers were ordered using funding other than the normal appropriations for new aircraft.)

Boeing YB-17. (U.S. Air Force)
Boeing YB-17 36-149. (U.S. Air Force)

The YB-17 had several improvements over the Model 299, which was retroactively designated XB-17. There was a long carburetor intake on top of the engine nacelles which visually distinguishes the YB-17 from the follow-on YB-17A. The main landing gear has one strut rather than the two of the Model 299. A vertical radio mast is just behind the cockpit.

Boeing YB-17 36-149. (U.S. Air Force)

The Boeing Model 299B, designated YB-17 by the Army Air Corps, was 68 feet, 4 inches (20.828 meters) long with a wingspan of 103 feet, 9 inches (31.633 meters) and the overall height was 18 feet, 4 inches (5.588 meters). It had an empty weight of 24,465 pounds (11,097 kilograms), gross weight of 34,880 pounds (15,821 kilograms) and maximum takeoff weight of 42,600 pounds (19,323 kilograms).

Boeing YB-17 36-149. (U.S. Air Force)

Instead of the Pratt & Whitney engines installed on the 299, the YB-17 had four air-cooled, supercharged 1,823.129-cubic-inch-displacement (29.876 liter) Wright Aeronautical Division Cyclone 9 R-1820G5 (R-1820-39) nine-cylinder radial engines with a compression ratio of 6.45:1. They turned three-bladed Hamilton Standard constant-speed propellers through a 16:11 gear reduction drive, in order to match the engines’ effective power range with the propellers. The R-1820-39 was rated at 805 horsepower at 2,100 r.p.m., at Sea Level, and 930 horsepower at 2,200 r.p.m. for takeoff. The R-1820-39 was 45-7/16 inches (1.154 meters) long and 54¼ inches (1.378 meters) in diameter, and weighed 1,198 pounds (543.4 kilograms).

The cruise speed of the YB-17 was 217 miles per hour (349 kilometers per hour) and the maximum speed was 256 miles per hour (412 kilometers per hour) at 14,000 feet (4,267 meters). Its service ceiling was 30,600 feet (9,327 meters). The bomber’s maximum range was 3,320 miles (5,343 kilometers).

Cutaway illustration of the Boeing YB-17. (John T. Jacobsen)

The YB-17 could carry 8,000 pounds (3,629 kilograms) of bombs. Defensive armament consisted of five .30-caliber air-cooled Browning machine guns.

Boeing YB-17 36-149 nosed over on landing at Seattle, 7 December 1936. (Unattributed)

36-149 was damaged in a landing accident 7 December 1936. It was repaired and then flown to Wright Field, Dayton, Ohio, 11 January 1937. After testing at Wright Field, 36-149 was delivered to the 2nd Bombardment Group, Langley Field, Virginia. By 1938 the bomber was back at Wright Field for additional tests.

“In the summer of 1938, Bill [Captain William C. Bentley, Jr., U.S. Army Air Corps, a B-17 test pilot at Langley Field] and his aircrew flew back to Seattle to pick up an additional aircraft, YB-17 tail number 36-149 from Boeing. This aircraft was different from the original thirteen. During its assembly phase at Boeing, it was packed with additional instruments for recording purposes. Once delivered to Langley, the plane was going to be subjected to a variety of stress tests in order to determine how much damage the plane could take and still operate. During its flight to Langley, Bill arrived over the field in a thunderstorm. The strength of the storm flipped the plane upside down, a stress never envisioned by the designers for such a large aircraft, much less one loaded to capacity with measuring instrumentation and a full crew. Using his fighter pilot training, Bill flew the aircraft at its maximum altitude then performed a slow roll to bring the airplane into its proper attitude. After recovering from a harrowing spin, Bill got control of the plane and landed successfully.

“Much to the crew’s amazement, the wings were slightly bent and some rivets were missing. But the measuring instrumentation had recorded all of the stress placed on the plane. . . .”

—The Touch of Greatness: Colonel William C. Bentley, Jr., USAAC/USAF, by Stewart W. Bentley, Jr., Ph.D., AuthorHouse, Bloomington, Indiana, 2010, Chapter 2 at Page 45.

(This meant that a fourteenth YB-17, which had been built specifically as a static test article, could be completed as a Y1B-17A, 37-369.)

Boeing YB-17 at Hamilton Field, California. (U.S. Air Force)

In October 1940 36-149 was transferred to the 19th Bombardment Group at March Field, California. Finally, on 11 February 1942, it was transferred to the Air Park at Amarillo Army Air Field, a B-17 training base in Texas. It was written off 11 December 1942.

After several years of testing, the YB-17 went into production as the B-17 Flying Fortress. By the end of World War II, 12,731 B-17s had been built by Boeing, Douglas and Lockheed Vega.

Boeing YB-17 36-139 arrives at Langley Field, Virginia, 1 March 1937. (U.S. Air Force)
Boeing YB-17 36-139 arrives at Langley Field, Virginia, 1 March 1937. (U.S. Air Force)
Boeing YB-17 36-149 at Langley Field, Virginia, 1 March 1937. (U.S. Air Force)
Boeing YB-17 36-149 at the Golden Gate International Exposition, Treasure Island, California, ca. 1939. (Stephen Fisher)
Two of the 13 Boeing YB-17 Flying Fortress (Model 299B) service test prototypes. This model can be distinguished from other early B-17s by the vertical radio mast behind the cockpit and the long carburetor intakes on the top of the engine nacelles. (Horace Bristol/LIFE Magazine)

© 2023, Bryan R. Swopes

2 October 1952

Boeing XB-52 Stratofortress 49-230 takes off for the first time, at Boeing Field, Seattle, Washington, 2 October 1952. (LIFE Magazine via Jet Pilot Overseas)

2 October 1952: The Boeing XB-52 Stratofortress prototype, 49-230, made its first flight at Boeing Field, Seattle, Washington, with test pilot Alvin M. “Tex” Johnston in command.  Lieutenant Colonel Guy M. Townsend, U.S. Air Force, acted as co-pilot.

The first of two prototype long-range, high-altitude, heavy bombers, the XB-52 had been damaged during ground testing and extensive repairs were required, which delayed its initial flight. The second prototype, YB-52 49-231, made the type’s first flight nearly six months earlier, on 15 April 1952.

Alvin M. “Tex” Johnston, test pilot, after the first flight of the Boeing XB-52 Stratofortress prototype, 2 October 1952. (LIFE Magazine via Jet Pilot Overseas)

The prototype Stratofortress the largest jet aircraft built up to that time. It was 152.7 feet (46.543 meters) long with a wingspan of 185.0 feet, (56.388 meters) and 48.25 feet (14.707 meters) to the top of the vertical fin. The leading edges of the wings were swept back 36° 54′.  The XB-52 had an empty weight of 155,200 pounds (70,398 kilograms) and its maximum takeoff weight was 390,000 pounds (176,901 kilograms). Fuel capacity was 27,417 gallons (103,785 liters).

Lieutenant Colonel Guy M. Townsend, U.S. Air Force. (Jet Pilot Overseas)
Lieutenant Colonel Guy M. Townsend, U.S. Air Force. (Jet Pilot Overseas)

The XB-52 was powered by eight Pratt & Whitney YJ57-P-3 turbojet engines, with a normal power rating of 8,700 pounds static thrust at Sea Level (38.700 kilonewtons). The prototype bomber had  a cruising speed of 519 miles per hour (835 kilometers per hour), and a maximum speed of 611 miles per hour (983 kilometers per hour) at 20,000 feet (6,048 meters). The planned bombing altitude was 46,500 feet (14,173 meters) and it had a service ceiling of 52,300 feet (15,941 meters). The XB-52 had an initial rate of climb of 4,550 feet per minute (23.11 meters per second) at Sea Level. Its maximum unrefueled range was 7,015 miles (11,290 kilometers).

Pilot’s cockpit, Boeing XB-52. (Boeing)
Boeing XB-52 Stratofortress 49-230. (U.S. Air Force)
Boeing XB-52 Stratofortress 49-230. (U.S. Air Force)
Boeing XB-51 Stratofortress 49-230 with a North American F-86 Sabre chase plane. (U.S. Air Force)
Boeing XB-52 Stratofortress 49-230 with a North American F-86 Sabre chase plane. (U.S. Air Force)
Boeing XB-52 Stratofortress 49-230. (U.S. Air Force)
Boeing XB-52 Stratofortress 49-230. (U.S. Air Force)

In its original configuration, the XB-52 was armed with two .50-caliber machine guns in a turret in the tail, with 600 rounds of ammunition per gun, though these guns were not installed on 49-230. The XB-52 was designed to carry a single 25,200 pound (11,431 kilogram) T-28E2 Samson bomb, or other conventional or nuclear weapons.

XB-52 49-230 was used in flight testing for its entire service life. The airplane was scrapped in the mid-1960s.

744 B-52 bombers were built by Boeing at Seattle, Washington and Wichita, Kansas, with the final one, B-52H-175-BW 61-0040, rolled out 22 June 1962.

75 B-52H Stratofortresses are still in service with the United States Air Force.

Boeing XB-52, with Tex Johnston and Guy Townsend in the tandem cockpit. (Boeing)
Boeing XB-52 Stratofortress 49-230 (U.S. Air Force)
Boeing XB-52 Stratofortress 49-230 with two Pratt & Whitney J75 turbojets in single-engine nacelles on the outer pylons, circa 1959. (U.S. Air Force)

© 2017 Bryan R. Swopes