Tag Archives: General Electric J47-GE-25

1 July 1960

Boeing RB-47H-1-BW Stratojet 53-4288. This is the same type aircraft as 53-4281. (U.S. Air Force 090824-F-1234S-002)

1 July 1960: A United States Air Force Boeing RB-47H-1-BW Stratojet, 53-4281, assigned to the 38th Strategic Reconnaissance Squadron, 55th Strategic Reconnaissance Wing, based at Forbes Air Force Base, Kansas, was conducting an electronic reconnaissance mission in international airspace over the Barents Sea, north of the city of Murmansk, in the northwest part of the Soviet Union. The RB-47 had departed from RAF Brize-Norton, in Oxfordshire, west-northwest of London, England. The mission was code-named BOSTON CASPER.

On board the RB-47 were a crew of six: Major Willard George Palm, aircraft commander; Captain Freeman Bruce Olmstead, co-pilot/gunner; Captain John Richard McKone, navigator/photographer; and three electronic intelligence officers (known as “Ravens”): Major Eugene E. Posa, Captain Dean Bowen Phillips, and Captain Oscar Lee Goforth.

RB-47 crew 3, left to right: Palm, Posa, Olmstead, Goforth, McKone, Phillips
Captain Vasily Ambrosievich Polyakov

At Monchegorsk Air Base on the Kola Pennisula, Captain Vasily Ambrosievich Polyakov, 174th Guards Red Banner Fighter Aviation Regiment (Boris Feofontovich Safonov) was on strip-alert in the cockpit of his Mikoyan-Gurevich MiG-19 interceptor. Captain Polyakov was interviewed in 1995 and described being “scrambled” to intercept the American reconnaissance plane. Vectored by radar controllers, he flew north-northwest until he located the B-47.

Polyakov said that he waggled his wings at the bomber—an international signal for the intercepted aircraft to follow the fighter. He saw no response. Controllers then ordered him to shoot down the American airplane.

Captain Polyakov made a firing pass and fired two bursts with the MiG’s three 30 mm autocannon, for a total of 111 rounds expended. He saw the B-47 roll inverted and disappear into the clouds below. He did not see any parachutes, nor did he observe the aircraft crash. Polyakov then returned to his base.

Chart showing track of RB-47H 53-4281 and Soviet Air Force fighter response, 6 July 1960. (National Security Agency)

The RB-47’s navigator, Captain McKone, recalled that he had just taken a radar fix of their position when the MiG-19 attacked. 53-4281 was flying at 28,000 feet (8,534 meters) at 425 knots (489 miles per hour/787 kilometers per hour), 50 miles (80 kilometers) to the north of Cape Holy Nose, the northern end of the Kola Peninsula. Their course was 120° (southeast). McKone had given Captain Palm two minor course corrections, both to the left, away from Soviet air space. The American reconnaissance was definitely in international air space. [The Soviet Union claimed a 12 nautical mile (13.8 statute miles/22.2 kilometers) territorial limit.]

The RB-47H was being tracked by NATO ground based radar (probably from Norway). The chart shown above is an “accurate radar plot of the RB-47’s ground track obtained from a ground-based radar tracking facility.” ¹

Captain Olmstead later reported that he had returned fire with the two 20 mm autocannon in the B-47’s tail, expending “two-thirds of my ammunition,” or about 462 rounds. The MiG’s cannon fire knocked out two of the three engines on the left wing.

The bomber entered a spin but Palm and Olmstead were able to recover. After Polyakov’s second firing pass, though, the crew ejected. Now derelict, 53-4821 righted itself and continued to fly to the northeast for approximately 200 miles (322 kilometers).

According to Henry Cabot Lodge, Jr., the United States’ Ambassador to the United Nations, the RB-47 “was still in the air twenty minutes later, over the high seas, 200 miles [322 kilometers] from the point alleged by the Soviet Union and flying in a northeasterly direction.”

A Russian source indicated that this was the first air combat victory for the MiG-19.

A National Security Agency SECRET SPOKE document states “After the shoot down, probably all six crewmen bailed out, but only two men, the co-pilot and navigator, survived the splashdown into the icy waters of the Barents.” ²

After six hours in the freezing water, Captains Olmstead and McKone were rescued. McKone had a crushed vertebra as a result of the ejection. The body of Major Posa was also recovered. Major Palm’s body was recovered on 4 July. Captain Goforth and Captain Phillips were never found and were presumed to have died.

The Lubyanka building, former headquarters of the Soviet KGB. (James Offer)

Olmstead and McKone were imprisoned in the notorious Lubyanka Prison by the Soviet security service, and interrogated extensively. It wasn’t until 15 July that McKone received medical treatment for his broken back. He would spend the next 97 weeks in traction.

On 25 July, Major Palm’s body was returned to the United States for burial. Major Posa’s was sent to Severomorsk, then on to Moscow. Eventually his remains were buried in an unknown cemetery. The Defense POW/MIA Accounting Agency (DPAA) lists his status as unknown, non-recoverable.

Following the inauguration of U.S. President John Fitzgerald Kennedy, Premier Nikita Sergeyevich Khrushchev of the Soviet Union released Captains Olmstead and McKone as a good will gesture. They arrived back in the United States on 27 January 1961.

27 January 1961. Left to right, Gail Olmstead, Captain Freeman Bruce Olmstead, Captain John McKone, Connie McKone. (Abbie Rowe. White House Photographs. John F. Kennedy Presidential Library and Museum AR6299-A)

Boeing RB-47H Stratojet

Boeing RB-47H-1-BW Stratojet 53-4296, 55th Strategic Reconnaissance Wing. (U.S. Air Force)

Designed by Boeing, the Stratojet was a high-subsonic speed strategic bomber and reconnaissance aircraft, in service from 1951 until 1977. When it was introduced, the B-47 could fly higher and faster than jet fighters of the time, and it was also highly maneuverable.

The RB-47H Stratojet (Boeing Model 450-172-52) was an electronics reconnaissance variant of the B-47E strategic bomber, designed to detect, identify and locate electronic signals. It was flown by a two pilots in a tandem cockpit. A navigator was located at a station in the nose. Three electronics intelligence officers were in a reconnaissance compartment. The RB-47H Stratojet is 108.7 feet (33.132 meters) long with a wingspan of 116.3 feet (35.448 meters), and an overall height of 28.0 feet (8.534 meters). The wings are shoulder-mounted with an angle of incidence of 2° 45′, and their leading edges are swept aft to 36° 37′. There is no dihedral, but the wings are very flexible and move considerably during flight. They have a total area of 1,428 square feet (132.67 square meters). The RB-47H had an empty weight of 89,230 pounds (40,474 kilograms)—nearly 10,000 pounds (4,536 kilograms) heavier than the B-47E bomber. Its maximum takeoff weight was 218,728 pounds (99,213 kilograms). Once airborne, the maximum weight could be increased to 221,000 pounds (100,244 kilograms) with inflight refueling.

The RB-47H was powered by six General Electric J47-GE-25 turbojet engines in four nacelles mounted on pylons below the wings. This engine has a 12-stage axial-flow compressor, eight combustion chambers, and single-stage turbine. The -25 has a normal power rating of 5,320 pounds of thrust (23.665 kilonewtons) at 7,630 r.p.m., at Sea Level; Military Power, 5,670 pounds (25.221 kilonewtons) at 7,800 r.p.m.; and Maximum Power, 7,200 pounds (32.027 kilonewtons) at 7,950 r.p.m. with water/alcohol injection. (As of July 1964, there were no time limits on Military or Maximum Power.) The J47-GE-25 has a maximum diameter of 3 feet, 1 inch (0.940 meters) and length of 12 feet, 0 inches (3.658 meters) and weighs 2,653 pounds (1,203 kilograms)

The RB-47H had a basic speed of 419 knots (482 miles per hour/776 kilometers per hour) at 35,000 feet (10,668 meters); combat speed of 460 knots (529 miles per hour/852 kilometers per hour) at 37,200 feet (11,339 meters), and maximum speed of 516 knots (594 miles per hour/956 kilometers per hour) at 15,000 feet (4,572 meters). The service ceiling was 45,000 feet (13,716 meters).

RB-47H inflight refueling. (U.S. Air Force) 090824-F-1234S-003

The combat radius of the RB-47H was 1,520 nautical miles (1,749 statute miles/2,815 kilometers. Ferry range with 18,402 gallons (69,659 liters) of fuel was 3,403 nautical miles (3,916 miles/6,302 kilometers).

For defense, the RB-47H was armed with two M24A1 20 mm autocannons with 350 rounds of ammunition per gun. The remotely-operated tail turret was controlled by a radar-computing A-5 fire control system, operated by the co-pilot, whose seat could swivel to allow him to face rearward.

The forward bomb bay was modified to incorporate a pressurized compartment for the electronic intelligence operators’ stations.

A total of 2,032 B-47s were built by a consortium of aircraft manufacturers: Boeing Airplane Company, Wichita, Kansas; Douglas Aircraft Company, Tulsa, Oklahoma; Lockheed Aircraft Company, Marietta, Georgia. 35 of these were the RB-47H variant, produced by Boeing Wichita. Three of these were further modified to ERB-47Hs.

The Stratojet is 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 below and ahead on pylons. The B-47 served the United States Air Force from 1951 to 1977. From the first flight of the Boeing XB-47 Stratojet prototype, 17 December 1947, to the final flight of B-47E 52-166, was 38 years, 6 months, 1 day.

Boeing RB-47H-1-BW 53-4299 at the National Museum of the United States Air Force. (U.S. Air Force 050321-F-1234P-002)

Mikoyan-Gurevich MiG-19

MiG-19 with AA-2 missiles

The Mikoyan-Gurevich MiG-19 is a single-place, twin-engine swept-wing supersonic interceptor. It made its first flight 24 May 1952 with test pilot Grigory Alexandrovich Sedov in the cockpit,  and was the first Soviet production aircraft that was cable of supersonic speed in level flight.

The MiG-19 is 12.54 meters (41 feet, 1.7 inches) long, with a wingspan of 9.00 meters (29 feet, 6.3 inches) and height of height 3.88 meters (12 feet, 8.8 inches). The wings are swept aft 55° at 25% chord. The total wing area 25.00 square meters (269.10 square feet). The interceptor has an empty weight of 5,298 kilograms (11,680 pounds), and maximum takeoff weight of 7,300 kilograms (16,094 pounds). It carries 1,735 kilograms (3,825 pounds) of fuel, internally.

MiG-19. (Science Photo Library)

The first production MiG-19 was powered by two Tumansky RD-9B afterburning turbojet engines. The RD-9B is a single-spool, axial-flow engine with a 9-stage compressor and two stage turbine. It is rated at 31.87 kilonewtons, (7,165 pounds of thrust), each. The engine is 5.560 meters (18 feet, 2.9 inches) long; 668 mm (2 feet, 2.3 inches) in diameter, and weighs 725 kg (1,598 pounds).

The MiG-19 has a maximum speed of 1,452 kilometers per hour (902 miles per hour). With internal fuel, its range is 1,390 kilometers (864 statute miles) or 2,200 kilometers (1,367 statute miles) with external tanks. The ceiling is 17,900 meters (58,727 feet). The interceptor’s maximum load factor is 8 gs.

Mikoyan-Gurevich MiG-19. (airwar.ru)

The MiG-19 is armed with three Nudelman-Rikhter NR-23 23 mm cannon. It could carry two 250 kilogram (551 pound) bombs, or two ORO-57K 32-round rocket pods.

Three-view illustration of the Mikoyan-Gurevich MiG-19. (airwar.ru)

Mikoyan-Gurevich produced 2,172 MiG-19s between 1954 and 1968. Additional aircraft were built by China (Shenyang J-6) and Chechoslovakia.

¹ “RED TERROR IN THE SKY: SOVIET AERIAL AGGRESSION, 1946–1986,” by Major Martin C. Alvstad, U.S. Air Force. Air Command and Staff College Student Report Number 87-0095, at Page 1

² NSA DOCID: 3972010 C Q, Page 30

Recommended: The Little Toy Dog, by William L. White, E.F. Dutton & Co., Inc., New York, 1962. (Mr. White was also the author of They Were Expendable, which TDiA also recommends.)

© 2023, Bryan R. Swopes

17 June 1986

Boeing B-47E-25-DT Stratojet 52-166 is prepared to Depart NAWC China Lake. (U.S. Navy)
B-47E-25-DT Stratojet 52-166 is prepared to depart Armitage Field, NAWS China Lake, 17 June 1986. (U.S.  Air Force)

17 June 1986: After being returned to flyable condition, B-47E-25-DT Stratojet serial number 52-166, made the very last flight of a B-47 when it was flown by Major General John D. (“J.D.”) Moore and Lieutenant Colonel Dale E. Wolfe, U.S. Air Force, from the Naval Air Weapons Station China Lake in the high desert of Southern California, to Castle Air Force Base in California’s San Joaquin Valley, to be placed on static display.

52-166 had been built by the Douglas Aircraft Company at Air Force Plant No. 3, Tulsa, Oklahoma, in 1952. 52-166 had not been flown in twenty years, having sat in the Mojave Desert serving as a radar target. General Moore and Colonel Wolf were experienced B-47 pilots, though they hadn’t flown one in the same twenty years. Because the B-47 it had not been through a complete overhaul prior to the ferry flight, it was decided to leave the landing gear extended to avoid any potential problems.

During the 43 minute trip, the aircraft had several systems fail, including airspeed sensors, intercom, and partial aileron control. On approach to Castle Air Force Base, a 16 foot (4.9 meters) approach parachute was deployed. This created enough aerodynamic drag to slow the airplane while the early turbojet engines were kept operating at high power settings. These engines took a long time to accelerate from idle, making a go-around a very tricky maneuver. Releasing the chute allowed the airplane to climb out as the engines were already operating at high r.p.m.

B-47E-25-DT Stratojet 52-166 enroute Castle Air Force Base with a Lockheed T-33A Shooting Star chase. California’s Sierra Nevada Mountains are in the distance. (TSGT Michael Hagerty/U.S. Air Force)
Douglas-built B-47E-25-DT Stratojet 52-166 enroute Castle Air Force Base with a Lockheed T-33A Shooting Star chase, 17 June 1986. California’s Sierra Nevada Mountains are in the distance. (U.S. Air Force)

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 time, and it was also highly maneuverable. B-47E (Boeing Model 450-157-35) was flown by a two pilots in a tandem cockpit. A navigator/bombardier was at a station in the nose.

The B-47E Stratojet differed from the earlier B-47B primarily with upgraded engines and strengthened landing gear to handle an increase in maximum weight. The B-47E Stratojet is 107.1 feet (32.644 meters) long with a wingspan of 116.0 feet (35.357 meters), and an overall height of  28.0 feet (8.534 meters). The wings are shoulder-mounted and have a total area of 1,428 square feet (132.67 square meters). The wings’ leading edges are swept aft to 36° 37′. The angle of incidence is 2° 45′ and there is 0° dihedral (the wings were very flexible). The B-47E in standard configuration had an empty weight of 78,620 pounds (35,661 kilograms) and maximum takeoff weight of 200,000 pounds (90,718 kilograms).

The B-47E was powered by six General Electric J47-GE-25 turbojet engines in four nacelles mounted on pylons below the wings. This engine has a 12-stage axial-flow compressor, eight combustion chambers, and single-stage turbine. The -25 has a continuous power rating of 5,320 pounds of thrust (23.665 kilonewtons) at 7,630 r.p.m., at Sea Level; Military Power, 5,670 pounds (25.221 kilonewtons) at 7,800 r.p.m. (30 minute limit); and Maximum Power, 7,200 pounds (32.027 kilonewtons) at 7,950 r.p.m. with water/alcohol injection (5 minute limit). The J47-GE-25 has a maximum diameter of 3 feet, 1 inch (0.940 meters) and length of 12 feet, 0 inches (3.658 meters) and weighs 2,653 pounds (1,203 kilograms)

The B-47E had a maximum speed of 497 knots (572 miles per hour/920 kilometers per hour) at 20,000 feet (6,096 meters), and 485 knots (558 miles per hour/898 kilometers per hour) at 38,600 feet (11,765 meters).

The service ceiling was 31,500 feet (9,601 meters) and combat ceiling 40,800 feet (12,436 meters).

The combat radius of the B-47E was 1,780 nautical miles 2,048 miles (3,297 kilometers with a 10,000 pound (4,536 kilograms) bomb load. Ferry range with 14,720 gallons (55,721 liters) of fuel was 4,095 nautical miles (4,712 miles/7,584 kilometers).

For defense the B-47E was armed with two M24A1 20 mm autocannons with 350 rounds of ammunition per gun. The remotely-operated tail turret was controlled by the co-pilot.

The maximum bomb load of the B-47E was 12,000 pounds (5,443 kilograms). The B-47 could carry up to six 2,000 pound (907 kilogram) bombs, or one 10,670 pound (4,840 kilograms) “Special Store”: a B-41 three-stage radiation-implosion thermonuclear bomb with a yield of 25 megatons).

B-47E-25-DT Stratojet 52-166 flies over California's Central Valley farmland as it heads to Castle Air Force Base on the very last B-47 flight, 17 June 1986. (U.S. Air Force)
B-47E-25-DT Stratojet 52-166 flies over California’s Central Valley farmland as it heads to Castle Air Force Base on the very last B-47 flight, 17 June 1986. (U.S. Air Force)

A total of 2,032 B-47s were built by a consortium of aircraft manufacturers: Boeing Airplane Company, Wichita, Kansas; Douglas Aircraft Company, Tulsa, Oklahoma; Lockheed Aircraft Company, Marietta, Georgia.

The Stratojet is 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 below and ahead on pylons. The B-47 served the United States Air Force from 1951 to 1977. From the first flight of the Boeing XB-47 Stratojet prototype, 17 December 1947, to the final flight of B-47E 52-166, was 38 years, 6 months, 1 day.

B-47E-25-DT Stratojet 52-166 on final approach to land at Castle Air Force Base, 17 June 1986. The braking chute is deployed. This is teh very last time that a B-47 flew.
Douglas-built B-47E-25-DT Stratojet 52-166 on final approach to land at Castle Air Force Base, 17 June 1986. The approach chute is deployed. This was the very last time that a B-47 flew.

© 2018, Bryan R. Swopes

24 April 1959

Boeing RB-47E Stratojet. (U.S. Air Force 050421-F-1234P-009)

24 April 1959: Captain John Stanley Lappo, United State Air Force, flies a Strategic Air Command Boeing RB-47E Stratojet UNDER the Mackinac Bridge. The suspension bridge spans the Straits of Mackinac, connecting the upper and lower peninsulas of the U.S. state of Michigan. The Straits of Mackinac connect the Great Lakes of Lake Michigan and Lake Huron.

The vertical clearance under the Mackinac Bridge at the center of the main span is 155 feet (47 meters). (Wikipedia)

The vertical gap between the highest point on the underside of the bridge’s main span is 155 feet (47.2 meters) above the surface of the water. The RB-47E has an overall height of 28 feet (8.5 meters). And Captain Lappo was flying at just 75 feet (23 meters).

Captain Lappo and his crew were returning to Lockbourne Air Force Base, southeast of Columbus, Ohio, following an overnight simulated bombing mission.

When asked why he did it, he answered: “Why do men climb mountains? Or what motivates them to go into space? It’s just a sense of adventure that some men have and some don’t. . . I’ve always wanted to fly under a big bridge. I thought it would be the Golden Gate. When I was flying missions to the Far East, I was a co-pilot, and I wanted to fly under the Golden Gate at night. But I couldn’t induce the pilot to do it.” ¹

The total length of the Mackinac Bridge is 26,372 feet (8,038 meters). The length of the main span is 3,800 feet (1,158 meters). The height of the main towers is 552 feet (168 meters). The bridge opened to traffic 1 November 1957. (Mackinac Bridge Authority)

Reported by his navigator, Captain Lappo was charged with violating a regulation prohibiting flying an aircraft below 500 feet (152 meters) (AF Reg 60–16). At his court-martial, he pleaded guilty. The court fined him $50.00 per month for six months and he received a reprimand. Based on this, Lieutenant General Walter Campbell Sweeney, Jr., Commanding General, Eighth Air Force, ordered him permanently removed from flight status.

John Lappo had been a highly respected pilot. Several senior officers testified at the court martial as to his skill, dedication and reliability.

John Stanley Lappo had enlisted in the U.S. Army Air Forces 19 February 1943 and was trained as a pilot. On completion of training he was given the warrant officer rank of flight officer. Lappo was commissioned as a second lieutenant in January 1945.

Lieutenant Lappo flew C-46, C-47 and C-54 transports with the 22nd Troop Carrier Squadron, 374th Troop Carrier Group, Fifth Air Force. He was released from active duty in 1948, but remained in the U.S. Air Force Reserve and maintained his flight status.

Flight Officer John Stanley Lappo, United States Army Air Forces, circa 1944. (Suzette Mizelle)

In 1951, Lieutenant Lappo was recalled to active duty for service in the Korean War. He flew 28 bombing missions in the Boeing B-29 Superfortess, including B-29-85-BN 44-87657, Command Decision, one of the best known bombers of the war.

John Stanley Lappo married Miss Olive Kay Robinson, 7 July 1951, at Muskegon, Michigan. He then attended Squadron Officers School at Maxwell AFB, Alabama.

As a B-47 Stratojet pilot, he was assigned to the 10th Strategic Reconnaissance Squadron, 26th Strategic Reconnaissance Wing, at Lockbourne AFB, and later, the 352nd Bombardment Squadron (Medium), 301st Bombardment Wing (Medium), which was also based at Lockbourne.

Captain Lappo was often given the most difficult assignments. As a reconnaissance pilot, he flew clandestine missions over the Union of Soviet Socialist Republics (USSR). For one of these missions he was awarded the Distinguished Flying Cross.

Lieutenant Colonel John S. Lappo, USAF

Even though he was permanently removed from flying duties, Lappo remained in the Air Force. He served in Southeast Asia during the Vietnam War, and was later vice commander of Elmendorf Air Force Base in Alaska. He rose to the rank of lieutenant colonel.

Lieutenant Colonel Lappo retired from the Air Force 31 July 1972.

John Stanley Lappo was born 8 January 1920 at Muskegon, Michigan. He was the fifth of seven children of Jan Stanislaw Lappo, a carpenter, and Zofia A. Stankiewicz Lappo.

In 1940 he was employed as a pattern maker at an iron foundry.

Lappo registered for the draft (conscription) 1 July 1941. The registrar’s report shows that he had brown hair, blue eyes, was 5 feet, 4½ inches (1.638 meters) tall and weighed 165 pounds (74.8 kilograms).

From 1972 to 1982, John Lappo worked for the state of Alaska as a regional administrator for the health department, then from 1982 to 1990, he operated a trucking company, Arctic Fox Trucking.

John Stanley Lappo died 15 November 2003 at Eagle River, Alaska. His remains are interred at the Fort Richardson National Cemetery, Anchorage, Alaska.

A Boeing RB-47E-1-BW Stratojet, 51-5259—the reconnaissance variant. (U.S. Air Force)

The Boeing RB-47E Stratojet was a reconnaissance variant of the B-47E strategic bomber. All RB-47Es were built by Boeing-Wichita. The type made its first flight 3 July 1953. 240 RB-47Es and 15 RB-47Ks were built, with the last one delivered in August 1955.

Designed by Boeing, the B-47 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 time, and it was also highly maneuverable. B-47 was flown by a two pilots in a tandem cockpit. A navigator was at a station in the nose. The RB-47E variant (Boeing Model 450-158-36) differed in that bombing equipment was deleted and photographic and electronic reconnaissance equipment installed. Additional fuel tanks were placed in the former bomb bay.

Illustration of RB-47E fuselage spaces. (U.S. Air Force)

The RB-47E Stratojet is slightly longer than the B-47E. The RB-47E is 109.8 feet (333.467 meters) long with a wingspan of 116.0 feet (35.357 meters), and an overall height of 28.0 feet (8.534 meters). The wings are shoulder-mounted and have a total area of 1,428 square feet (132.67 square meters). The wings’ leading edges are swept aft to 36° 37′. The angle of incidence is 2° 45′ and there is 0° dihedral (the wings were very flexible). The RB-47E had an empty weight of 81,100 pounds (36,786 kilograms) and maximum takeoff weight of 200,000 pounds (90,718 kilograms).

The RB-47E was powered by six General Electric J47-GE-25 turbojet engines in four nacelles mounted on pylons below the wings. This engine has a 12-stage axial-flow compressor, eight combustion chambers, and single-stage turbine. The -25 has a continuous power rating of 5,320 pounds of thrust (23.665 kilonewtons) at 7,630 r.p.m., at Sea Level; Military Power, 5,670 pounds (25.221 kilonewtons) at 7,800 r.p.m. (30 minute limit); and Maximum Power, 7,200 pounds (32.027 kilonewtons) at 7,950 r.p.m. with water/alcohol injection (5 minute limit). The J47-GE-25 has a maximum diameter of 3 feet, 1 inch (0.940 meters) and length of 12 feet, 0 inches (3.658 meters) and weighs 2,653 pounds (1,203 kilograms).

Boeing RB-47E-25-BW Stratojet 52-722, 26th Strategic Reconnaissance Wing, Lockbourne Air Force Base, Ohio, 1954. (Bob Garrard Collection/AirHistory.net/Flickr)

The RB-47E had a cruise speed of 433 knots (498 miles per hour/802 kilometers per hour), and maximum speed of 497 knots (572 miles per hour/920 kilometers per hour) at 20,000 feet (6,096 meters). The service ceiling was 47,800 feet feet (14,569 meters). Its unrefueled range was 3,935 nautical miles (4,528 statute miles/7,288 kilometers). The RB-47E was capable of inflight refueling and had a maximum fuel capacity of 18,280 gallons in six fuselage and two jettisonable wing tanks.

For defense the RB-47E was armed with two M24A1 20 mm autocannons with 350 rounds of ammunition per gun. The remotely-operated tail turret was controlled by the co-pilot through an A-5 fire control system.

A total of 2,032 B-47s were built by a consortium of aircraft manufacturers: Boeing Airplane Company, Wichita, Kansas; Douglas Aircraft Company, Tulsa, Oklahoma; Lockheed Aircraft Company, Marietta, Georgia.

The Stratojet is 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 below and ahead on pylons. The B-47 served the United States Air Force from 1951 to 1977. From the first flight of the Boeing XB-47 Stratojet prototype, 17 December 1947, to the final flight of B-47E 52-166, was 38 years, 6 months, 1 day.

¹ “John Lappo Story,” by Wayland Mayo, at the web site  “B-29s Over Korea,” https://www.b-29s-over-korea.com/john-lappo-story/

© 2023, Bryan R. Swopes