Northrop BQM-74 Chukar: the naval partridge from Ventura County

As I pointed out in a post written back in February 2020, Northrop entered the world of unmanned air vehicle development when it acquired the Radioplane Company of Van Nuys in 1952, capitalizing upon Radioplane's drone manufacturing business by developing the KD2R-5/MQM-36 Shelduck and XQ-10 piston-engine target drones, the supersonic jet-powered Q-4/AQM-35, and rocket-powered KD4R and AQM-38 drones, plus a number of advanced target drone projects. By 1962, however, the Radioplane Division of Northrop decided to move its headquarters from Van Nuys to the town of Newbury Park in Ventura County, and it changed its name to Northrop-Ventura after the relocation, opening up a new chapter in the history of drone development in the Los Angeles Basin. Northrop's drone-related business activities in Ventura County are largely overlooked in most published histories of the Southern California aerospace industry, but the Northrop-Ventura Division's most successful unmanned aerial vehicle ever produced was the BQM-74 Chukar. It is no wonder that I first saw this drone while visiting the San Diego Air and Space Museum in the 2010s, I had no idea that it was one of a few target drones built outside the Los Angeles metropolitan area, making it the most successful mass-produced Northrop drone design to be developed in the late Cold War. Given its distinction of being the only mass-produced target drone to built in a locality of southern California outside the Los Angeles and San Diego counties, I've opted to provide a comprehensive synopsis of the development, testing, production, and operational service of the Chukar. 

A Northrop MQM-74A Chukar I on its ground-based launch platform

In the early 1960s, the US Navy issued requirement for a small jet-powered aerial target to be used for anti-aircraft gunnery and missile training and system evaluation. Northrop-Ventura proposed a delta-winged target drone to meet this requirement, designated NV-105 by the company, and power was provided by one Williams J400 turbojet with an air intake slung under the fuselage. Four NV-105 prototypes were constructed, and flight tests began in 1964, but it was clear that the delta wing wasn't aerodynamically satisfactory, so a straight-wing NV-105 variant with a cigar-shaped fuselage was developed as the NV-105A, which made its first flight in 1965. After a few years of flight testing, the NV-105A was cleared for production and operational deployment with the US Navy in 1968 and designated MQM-74A. The Navy christened the MQM-74A the Chukar in reference to a species of partridge because just as a chukar can be hunted for sport, the MQM-74A could be deemed suitable to be shot at during gunnery training. Besides the cigar-shaped fuselage and straight wings, the MQM-74A had the horizontal stabilizers arranged in an inverted V-shape, and it was designed to be launched from land- or ship-based zero-length launch systems aided by two solid-fuel JATO rocket boosters. The MQM-74A featured a command guidance system, and the operator could track it either visually or through radar. When the command link was damaged, a parachute was deployed by remote command or automatically to allow for the drone to be recovered. Mission equipment of the MQM-74 included passive and active radar augmentation devices, wingtip-mounted infrared flares, a smoke system for visual augmentation, and tow targets; if a Chukar landed in the water, a floatation gear kit was provided for recovery. More than 2,000 MQM-74As were built, with the US Navy acquiring 1,800 of them, and hundreds more serving with the Royal Navy, Italian Navy, and a NATO test range on the island of Crete. Northrop proposed an improved version of the MQM-74A in the early 1970s with variable speed, designated MQM-74B, but this was never built. The MQM-74A Chukar I also formed the basis of the XBQM-108 unmanned tail-sitter VTOL research vehicle developed by the US Navy's Naval Surface Weapons Center (NSWC), which began tethered flight tests in late September 1976 but never made a free flight before the Navy canceled the XBQM-108 program. 

Left: An MQM-74C on its launch platform, mid-1970s.
Right: An MQM-74C being retrieved by crewmen aboard the drone recovery craft USS Retriever after a test launching in October 1984.

The Navy was very impressed with the MQM-74A, but in the early 1970s it felt that it needed a slightly faster variant of the Chukar capable of attaining 576 miles per hour (926 km/h). Northrop responded with an slightly larger version of the MQM-74A powered by a higher-rated Williams J400-WR-401 (Model WR24-7) turbojet, which was designated MQM-74C by the Navy. The MQM-74C Chukar II began flight tests in 1973 and production of Chukar II started the following year, with deployment beginning shortly afterwards. A total of at least 1,400 MQM-74Cs built, mostly for the US Navy but also the armed forces of the United Kingdom, West Germany, Greece, Iran, Italy, Japan, Saudi Arabia, the Netherlands, and Spain. In 1975, the MQM-74C was selected by the US Air Force for the Tactical Expendable Drone System (TEDS) competition, and Northrop had four Chukar II drones modified for the TEDS requirement as the NV-130, which eliminated the parachute recovery equipment and carried more fuel space as well as electronic countermeasures systems. Tests of the NV-130 began in 1976 and continued until 1977, and even though performance results were seemingly satisfactory, the NV-130 did not enter production because the TEDS program was canceled due to a lack of funds. The US Army also took an interest in the MQM-74C and ordered a surveillance variant of the Chukar II, designated BQM-74D, which was fitted with a precision navigation system and sensors for target acquisition and battlefield surveillance. Although little is known about the developmental history of the BQM-74D, test flights of this variant took place in the mid-1970s but no production orders were placed.

Top: An air-to-air view of a BQM-74C Chukar III in flight
Bottom: A BQM-74E Chukar III on display at the San Diego Air and Space Museum, photographed by me on August 24, 2019

Even as production of the MQM-74C began, in the mid-1970s Northrop envisaged a significantly improved version of the Chukar II, which became the BQM-74C Chukar III. Differences from the MQM-74C included a new cylindrical forward fuselage measuring 12 feet 11.5 inches (3.95 meters) in length, addition of the provision for air-launch capability, and a new microprocessor-based A/A37G-13 flight control system to enable much more complex pre-programmed flight profiles. The BQM-74C made its first flight in 1978 and following completion of flight testing the following year, production and deliveries of the Chukar III commenced in 1980, with the BQM-74C supplanting the MQM-74C in squadron service. Initial production BQM-74Cs used a Williams J400-WR-402 turbojet, which had slightly greater thrust than the J400-WR-401 that powered the MQM-74C, but beginning in 1986 all production BQM-74Cs were fitted with the J400-WR-403. For ground-based launches, the BQM-74C was fitted with a pair of MK 117 MOD 0 solid-fuel rocket boosters, which were jettisoned shortly after take-off once the target drone reached sufficient altitude. The main launch aircraft for the Chukar III was the DC-130 drone control version of the C-130 Hercules tactical airlifter, although the BQM-74C was also carried aboard the F-15 and F-16. Northrop developed a reconnaissance version of the Chukar III, the BQM-74C/Recce, which housed a TV camera in the nose and a video data link transmitter, and ten BQM-74Cs were converted to BQM-74C/Recce and tested in the mid-1980s, but this version was not procured by the Navy. During the aerial phase of Operation Desert Storm in January 1991, several BQM-74Cs were acquired by the US Air Force and modified as decoys by the fitting of a pair of corner reflectors to enhance the radar signature to imitate a manned aircraft, and these were used as decoys in the midst of US-led coalition airstrikes against Iraq under Project Scathe Mean of the USAF's Big Safari program, ensuring that the air forces of the US and its allies suffered minimal losses in the opening hours of Operation Desert Storm. Even before Operation Desert Storm began, an improved version of the BQM-74C with greater endurance, increased range as well as new-generation software, the BQM-74E, began flight tests in 1989/1990. Despite having the same length and wingspan as the BQM-74C, the BQM-74E uses an Williams J400-WR-404 turbojet delivering 240 lb (1.07 kN) and can fly at a top speed of 621 miles per hour (1,000 km/h), and it incorporates the latest target augmentation devices, namely the AN/DPN-90(V) radar tracking beacon, the AN/DPN-88 IFF transponder, the AN/DRQ-4 and AN/DSQ-50 scoring systems, the AN/DKW-3 and -4(V) target control transponders, and the AN/DPT-2 radar threat simulator. The BQM-74E, which retains the Chukar III moniker to emphasize it derivation from the BQM-74E, is air-launched from the DC-130 and simulates anti-ship cruise missiles as well as maneuvering attack aircraft. The BQM-74E entered service in 1992 and replaced the BQM-74C on existing production lines, and by the time that Chukar III production ended in the early 2000s, more than 2,000 BQM-74C/E target drones had been built and delivered. Before long, Northrop shut down its Ventura Division after the conclusion of the flight test program of the Tacit Blue stealth technology demonstrator in 1985, leading to the relocation of production facilities for the BQM-74E to Hawthorne in the early 1990s and thence to Palmdale in 2002.

The BQM-74F, the last Chukar variant to be built

Although Northrop Grumman's drone manufacturing business in Ventura County was consigned to the dustbin of history, one more BQM-74 variant was developed in the late 1990s, initially marketed by the company as Target 2000 and later designated BQM-74F in March 2002 when a development contract was awarded. The BQM-74F differs from the BQM-74E with having backswept wings spanning 7 feet (2.1 meters), a length of 15 feet (4.5 meters), a top speed of Mach 0.9, a range of more than 1,037 miles (1,670 km), greater maneuverability, an endurance of two hours, and a drastically uprated William J400 turbojet delivering 300 lb (1.32 kN) of thrust. Novel electronic systems fitted to the BQM-74F include a IMU/GPS-based waypoint navigation system as well as new mission planning software (allowing in-flight modification of all parameters). The BQM-74F first flew on August 29, 2005, entering service with the US Navy in 2010, and more than 100 BQM-74Fs have been built. Although the BQM-74E still serves with Navy units despite having been phased out of production in the early 2000s, is it currently being replaced in frontline service by the Kratos BQM-177, which has greater range, maneuverability, and speed than the Chukar and features a new fuselage with area ruling.

References:

Munson, K., 1988. Jane's World Unmanned Aircraft. Coulsdon, UK: Jane's Information Group.

Munson, K., 2000. Jane's Unmanned Aerial Vehicles and Targets, Issue 15. Coulsdon, UK: Jane's Information Group.

Yenne, B., 2012. US Guided Missiles: The Definitive Reference Guide. Manchester, UK: Crecy Publishing. 

Competitors to the B-29 from southern California: Lockheed XB-30, Douglas XB-31, and Consolidated B-32 Dominator

The Boeing B-29 Superfortress long-range strategic bomber is best known in the annals of military history as the US heavy bomber that carried out carpet-bombing raids on Japan in the final months of the Pacific theater of World War II and brought about the ultimate finale to human history's most destructive conflict by dropping atomic bombs on Hiroshima and Nagasaki, which forced Japan to surrender for the first time in its military history on August 14, 1945. However, the B-29 was not a standalone development when it came to fulfilling military aviation requirements for a long-range heavy bomber with greater range and bombload than the B-17 or B-24. In southern California, three aircraft manufacturers --- Consolidated, Douglas, and Lockheed --- came out with heavy bomber designs to compete with the B-29, but only one was selected for full-scale development and became the Consolidated B-32 Dominator. Since the B-32 entered production but only got as far as limited full-scale production before war's end, I am opting to give a comprehensive synopsis of the rival designs to the B-29 envisaged in southern California, including the B-32.

The Boeing B-29 Superfortress, which along with the Consolidated B-32 Dominator won the R-40B competition of 1940.

On November 10, 1939, two months after Germany invaded Poland, US Army Air Corps General Henry "Hap" Arnold requested authorization to contract with major aircraft companies for studies of a Very Long-Range (VLR) bomber to strike enemy targets over greater distances than the B-17 Flying Fortress and B-24 Liberator. In December, the USAAC issued the VLR "superbomber" requirement for a new strategic bomber with a top speed of 400 mph (640 km/h) and able to carry 20,000 lb (9,100 kg) of bombs over a range of 2,667 miles (4,292 km). On January 29, 1940, the War Department issued Request for Data R-40B based on this requirement and circulated it to Boeing, Consolidated, Douglas, and Lockheed, and on April 8, Specification XC-218A was issued which also required additional defensive armament, armor, and self-sealing tanks. 

Left: A wind tunnel model of the Lockheed XB-30 heavy bomber derivative of the Constellation airliner.
Right: Side view of the Douglas XB-31 project, designated Model 332F by Douglas (courtesy of Alan Griffith).

Three companies based in southern California submitted bids for the R-40B competition. Consolidated's design, the Model 33, was a scaled-up B-24 Liberator derived from the company's initial LB-25 design study of late 1939/early 1940, while Lockheed submitted the L-117 (Model 51-58) derivative of the Constellation airliner with a length of 104 feet 8 in (31.91 meters), a wingspan of 123 feet (37.50 meters), a wing area of 1,646 square feet (153 m²), empty and gross weights of 51,616 lb (23,462 kg) and 85,844 lb (39,020 kg) respectively, and armament comprising ten .50 in (12.7 mm) machine guns (eight in four fuselage turrets and two in a single nose turret) and one 20 mm cannon in a remote-controlled tail turret. Douglas envisaged a series of design studies under the internal designation Model 332, all of them resembling a scaled-up A-20 Havoc and distinguished by their tail empennage layouts and engines; the Model 332F submitted for the R-40B was 88 feet 8.5 in (27.04 meters) long with a wingspan of 140 feet 6 in (42.82 meters), a wing area of 1,780 square feet (165.54 square meters), gross and maximum take-off weights of 106,994 lb (48,532 kg) and 120,000 lb (54,432 kg) respectively, and armament comprising seven pairs of 0.50-in (12.70 mm) machine guns (four in pairs facing rearwards in the rear of the outboard engine nacelles, and three in dorsal and ventral turrets below the fuselage) and one 20 mm cannon in the tail. On June 27, 1940, the Lockheed L-117, Douglas Model 332F, and Consolidated Model 33 submissions were designated XB-30, XB-31, and XB-32 respectively, and like the Boeing Model 345 (which became the XB-29), they were powered by four Wright R-3350 Duplex Cyclone radial piston engines. Some older sources (e.g. Francillon 1979; Jones 1984) identify the Douglas Model 423 intercontinental bomber project of October 1941 as the XB-31, but as noted by Buttler and Griffith (2015), the Model 423 was conceived in response to the 1941 intercontinental bomber competition won by the Northrop XB-35 and Convair B-36 Peacemaker and thus never received a military designation.

Top left: The first XB-32 prototype (serial number 41-141) taxiing at Lindbergh Field, San Diego, early September 1942
Top right: The second XB-32 prototype (serial number 41-142) in flight, July 1943
Bottom: The third XB-32 prototype (41-18336) (note the newly installed tall vertical stabilizer that offered better directional stability compared to the initial twin-fin tail empennage and B-29 type vertical stabilizer) during a test flight with the propellers of the port engines feathered in mid-1944.. 

In July 1940, the USAAC announced that the XB-29 and XB-32 had won the R-40B competition, the XB-30 and XB-31 submission having been withdrawn due to Lockheed and Douglas being preoccupied with production of the A-20, P-38, Hudson, and DC-3. On September 6, 1940, a contract was signed for two XB-32 prototypes (serial numbers 41-141/142) at the same time that two XB-29 prototypes were ordered, and a third prototype (serial number 41-18336) was added in November. Mock-ups of the XB-32 was built in late December and later inspected and approved January 6, 1941, after a few structural changes, and thirteen YB-32s (serial numbers 42-108471/108484) were ordered on June 30. The XB-32 was 82 feet 1 in (25.02 meters) long with a wingspan of 135 feet (41.15 meters), a height of 20 feet 10 in (6.35 meters), a wing area of 1,422 square feet (132.1 m²), a gross weight of 101,662 lb (46,113 kg), a top speed of 376 mph (605 km/h), and twelve crewmen, with armament comprising fourteen 0.50 in (12.70 mm) machine guns and two 20 mm cannons (eight in the upper and lower gun turrets, two in the wing's leading edges outboard of the propellers, and four 0.50 in [12.70 mm] machine guns and two 20 mm cannons at the rear of the outboard engine nacelles in rearward firing positions and controlled by aiming stations in the fuselage and tail). It was similar to the B-24 Liberator in its tail empennage, high-mounted Davis-type wing, and twin bomb bays covered over by roll-up doors, but differed in having a cylindrical fuselage, larger wing, and a stepped cockpit nose section. The first XB-32 prototype was rolled out on September 1, 1942, making its first flight from Lindbergh Field, San Diego, on September 7, two weeks before the B-29. However, a number of developmental problems with the fire control system and in February 1943 the YB-32 contract was canceled, but a month later, an order was placed for 300 production B-32s (serial numbers 42-108471/108770) to be built at the Consolidated plant in Forth Worth, Texas.* The first XB-32 crashed shortly after takeoff on May 10 due to a flap malfunction, killing the test pilot and injuring six crewmen, dealing a setback to the B-32 flight test program. The second XB-32 prototype, which first flew on July 2, had modified rudder tabs, a pressurized cabin,  remote-controlled retractable gun turrets in the dorsal and ventral positions, and a manned tail turret, and it was transferred to Muroc Army Air Field (now Edwards Air Force Base) in February 1944 for acceptance tests after thirty test flights. The third XB-32 prototype first flew on September 17, 1943 and differed from the first two prototypes in having ten machine guns in the nose, dorsal, ventral, and tail turrets. Due to longitudinal stability problems after 25 test flights, this aircraft was fitted with the single vertical stabilizer designed for the B-29 in November 1943 and first flown with this new tail empennage on January 6, 1944, but this vertical tail was deemed to offer marginal stability, so an even taller vertical stabilizer measuring 19 feet 4.28 in (5.9 meters) high was installed on the third XB-32, which first flew with this vertical tall in the spring of 1944. The B-32 was initially named Terminator in late 1943 at the behest of Consolidated, but the US Army Air Force's Aircraft Naming Board changed the name to Dominator; the State Department eventually had the B-32 revert to its initial name for the sake of "political correctness", but the name Dominator tends to persist in most aviation literature for the B-32.

* After the cancellation of the YB-32 contract, the serial numbers allocated to the YB-32s were re-used for the first 13 production B-32s.

The first production B-32 Dominator (serial number 42-108471) in flight over Fort Worth, Texas, August 1944 

In June, the US Army Air Force increased the number of B-32s on order to 1,213 aircraft, including a batch of 500 B-32-1-CO aircraft (serial numbers 44-90486/90985) to be built at the Convair factory in San Diego, and it changed the B-32's official name to Dominator. The first two production B-32s, of which the first flew on August 5, 1944, were initially fitted with the vertical stabilizer from the B-29, but the latest single vertical stabilizer built for the third XB-32 was eventually fitted to these aircraft. The production B-32 had a ten-man crew, a maximum bombload of 20,000 lb (9,071 kg), a maximum range of 4,421 miles (7,114 km), and defensive armament comprising ten 0.50 in (12.70 mm) Browning M2 machine guns in five power-operated turrets (four in two Martin turrets on the top of the fuselage, four in Sperry ball turrets on the nose and in the tail, and two in a retractable belly turret). Deliveries of the B-32 to US Army Air Force began in September 1944, but by then the B-29 had begun combat missions over Japan, and although the B-32 had been touted by the USAAF as a back-up in the event that the favored B-29 failed, the success made by Boeing in helping the B-29 overcome engine troubles during flight testing as well as delays and deficiencies in the B-32 program prompted several USAAF officials to recommend that the B-32 program be cancelled outright. By the end of 1944, only fourteen B-32s were delivered to the USAAF, and they even experienced mechanical malfunctions, while complaints were made about faulty workmanship on some of the delivered aircraft. However, in December, Brigadier General Donald Wilson recommended that despite these difficulties it would be unwise to abandon the B-Dominator program until a full set of tests had conclusively demonstrated its unsuitability, and no final decision about the Dominator's future be made until after the completion of service tests, allowing for the crew training program should continue. From January to March 1945, forty B-32s (serial numbers 42-108485/108524) were delivered to the USAAF without gun turrets or bombing equipment for B-32 crew training  and officially designated TB-32. Prospective B-32 pilots underwent 50 hours training in TB-32s and co-pilots received 25 hours of flight time and 25 hours of observer training. The first B-32 to be built in San Diego was flown on March 17, 1945, but following Nazi Germany's surrender on May 8, orders for the B-32 were reduced to 214 aircraft from Fort Worth. Lieutenant General George C. Kenney of the Fifth Air Force had been anxious to acquire B-29s, but when his requests were turned down on the grounds that the B-29 was urgently needed elsewhere, he started requesting B-32s instead. On March 27, 1945, General Henry "Hap" Arnold approved Kenney's request and authorized the USAAF to carry out comprehensive combat tests of the B-32 Dominator. Three B-32s were dispatched to the 386th Bombardment Squadron of the 312th Bombardment Group based on Luzon, Philippines, on May 24-25, 1945, to begin combat testing, and on May 29 the B-32 carried out its first combat mission when two of the three B-32s (42-108529 and 42-108532) attacked a Japanese supply depot in Luzon's Cayagan Valley, followed by a series of strikes in June on targets in Formosa (now Taiwan) and Hainan Island (B-32 serial number 42-108528 did not take part in the May 29 mission because it made an abort during take-off). The B-32s encountered no real enemy opposition except for inaccurate enemy flak, and they returned to their base safely. 

Convair B-32 Dominator Hobo Queen II (serial number 41-108578), which carried out the last combat mission by an Allied aircraft in World War II.

Following the success of the first B-32 combat mission, the 386th Bombardment Squadron made plans to transition from the A-20 Havoc to the B-32, and the 387th Bombardment Squadron began following suit, with eventual plans to relocate the 312th Bombardment Group to Okinawa. Before the conversion could be carried out, however, the dropping of the atomic bombs on Hiroshima and Nagasaki in early August 1945 led to the 312th BG being moved to Okinawa immediately, and six more B-32s joined the squadron on Okinawa a few days later. Combat operations continued in spite of the de-facto cease-fire that had been called following the bombing of Nagasaki, and August 17, four B-32s carrying out a photographic reconnaissance mission over Tokyo to confirm Japan's surrender were fired upon on by radar-directed flak and attacked by Japanese fighters, but suffered only minor damage, claiming three air-to-air kills (two A6M Zeroes and one N1K-J Shiden-Kai). On August 18, the B-32 Hobo Queen II (serial number 42-108532) and a second B-32 (serial number 42-108578) were attacked by Japanese fighters, and tail gunners claimed three air-to-air kills (two A6M Zeroes and one N1K-J Siden-Kai), but Japanese fighters heavily damaged 42-108578, killing Sergeant Anthony Marcione and wounding two more men, including photographer Staff Sergeant Joseph Lacharite. Nonetheless, 42-108578 returned to its base in Okinawa, and the Japanese fighters downed by the B-32s on August 18 constituted the last Axis warplanes to be shot down by American (and more broadly Allied) combat aircraft in World War II.  The last B-32 photographic reconnaissance mission was conducted on August 28, during which two B-32s were destroyed in separate accidents, with 15 of the 26 crewmen killed. Two days later, the 386th Bombardment Squadron stood down from operations, and with the end of the Pacific theater of World War II, unfulfilled B-32 orders were cancelled on September 8 and production of the B-32 halted on October 12. By this time, 115 production B-32s had been delivered (114 from Fort Worth and one from San Diego), while twelve additional aircraft (42-108585/108594, 44-90487/90488) were completed but not delivered, and no fewer than 49 B-32s were nearing completion at Fort Worth. All the B-32s that were operational as well as the undelivered aircraft were flown to storage at a disposal and reclamation center in Walnut Ridge, Arkansas, in 1946, and most of them were scrapped by 1947. One B-32 (serial number 42-108474) was set aside for future display at the National Museum of the US Air Force in Dayton, Ohio, but this plan never materialized and the aircraft was scrapped at Davis-Monthan Air Force Base in Tucson, Arizona, in August 1949. Nevertheless, a few B-32 components survive today, including a B-32 nose turret in storage at the Paul Garber Restoration Facility of the Smithsonian Institution at Suitland, Maryland, another B-32 nose turret on display at the Minnesota Air and Space Museum, and a static test wing panel from a B-32 erected as a monument to aviation pioneer John J. Montgomery on a hill near San Diego.

Two advanced B-32 (Model 33) studies that never were: a cutaway view of a four engine maritime reconnaissance project dated April 28, 1945 (left) and an artist's conception of early B-32 airliner proposal conceived in December 1941 (right)   

In an interesting footnote, several unbuilt variants of the B-32 Dominator were envisaged by Convair for maritime patrol and transport, along with a proposed turboprop-powered version. As early as mid-1941, a passenger airliner variant of the B-32 was conceived with a crew of six and accommodations for 78 passengers in daytime operations or 34 passengers at night, and in 1943, two military transport versions of the B-32 were devised, one which looked like a slightly smaller Convair XC-99 and which would have been used as either a troop transport, a hospital MEDEVAC aircraft, a paratrooper aircraft, or a cargo transport for carrying howitzers, aircraft, military jeeps, anti-tank guns, and/or ammo trucks. The latter design was also envisaged in September 1943 as a 58 passenger airliner, and design studies were also conducted for a B-32 escort aircraft (similar to the Boeing XB-40 and the Consolidated XB-41), a variant powered by four General Electric TG-100 (T31) turboprops, a twin-engine B-32 proposal, and a four-engine maritime reconnaissance B-32 variant armed with ten 0.50 in (12.70 mm) machine guns (four in the forward and aft top fuselage turrets, two in a retractable bottom fuselage turret, and four in the nose and tail turrets) and provisions for photoflash bombs, mines, or depth charges in the bomb bay. However, due to delays in development and production of the B-32, none of these proposals ever materialized.

Although the Consolidated B-32 Dominator is one of the lesser-known American bomber aircraft of World War II due to the fact that it was intended as a back-up in the event of the failure of the B-29, only to nearly arrive too late for the war due to the success of the B-29, it nonetheless holds the honor of undertaking the last combat mission by an Allied aircraft in World War II, considering that the rival B-29 was instrumental in forcing Japan to surrender after repeatedly refusing to do despite defeats at Iwo Jima and Okinawa.       

References:

Andrade, J. M., 1979. US Military and Aircraft Designations and Serials since 1909. Leicester, UK: Midland Counties Publications.

Bradley, R., 2010. Convair Advanced Designs: Secret Projects from San Diego 1923-1962. North Branch, MN: Specialty Press.

Buttler, T., and Griffith, A., 2015. American Secret Projects: Fighters, Bombers, and Attack Aircraft, 1937-1945. Manchester, UK: Crecy Publishing. ISBN 978-1906537487.

Francillon, R. J., 1979. McDonnell Douglas aircraft since 1920, Volume 1. London, UK: Putnam Publishing.

Jones, L.S., 1984. U.S. Bombers: 1928 to 1980s. Fallbrook, CA: Aero Publishers.

Wolf, W., 2006. Consolidated B-32 Dominator: The Ultimate Look: from Drawing Board to Scrapyard. Atglen, PA: Schiffer Publishing.

Competitors to the B-47 Stratojet from southern California: the B-45 Tornado and XB-46

Much has been written about the Boeing B-47 Stratojet, the world's first multi-engine swept-wing jet bomber to go into production and operational service, especially with regards to its development, flight testing, and operational career. However, it should be emphasized that the B-47 was not a product of its own creation despite being the first American swept-wing jet bomber but instead was part of a years-long effort by the United States to shop for a gas turbine-powered strategic bomber to replace its fleets of B-17, B-24, and B-29 bombers through solicitations from different aircraft manufacturers, including Boeing. As a matter of fact, the aviation industry in southern California that manufactured the B-24 Liberator, B-25 Mitchell, and B-32 Dominator during World War II put out two rival designs to the B-47 Stratojet using the old-fashioned straight wing planform, the North American B-45 Tornado and the Convair XB-46. In an unusual twist of fate, the B-45 went into production, but the XB-46 remained at the prototype stage only.

Models of the North American B-45 Tornado (left) and Convair XB-46 (right) at the Lyon Air Museum, Chino (photographed by me in November 2021)

In 1944 the US Army Air Force became aware of Nazi Germany's fielding of the world's first jet bomber, the Arado Ar 234, so in March the US War Department issued a requirement for a multi-engine strategic jet bomber with a top speed of 500 mph (804 km/h), a range of 2,500-3,000 miles (4,023-4,828 km), a service ceiling of 35,000-40,000 feet (10,668-12,192 meters), and a 16,500 lb (7,484 kg) bombload. Four companies -- Boeing, Convair, Martin, and North American -- submitted bids for the intermediate-range strategic bomber requirement, with North American's proposal bearing the company designation NA-130 and the Convair submission being designated the Model 109 (later changed to Model 1). Both the NA-130 and Model 109 were straight-winged designs powered by four Allison J35 turbojets housed in pairs in two underwing nacelles. The designation XB-45 was allocated to the NA-130, and a contract for three XB-45 prototypes (serial numbers 45-59479/59481) was signed on September 8, 1944. Five months later, on February 27, 1945, three Convair Model 109 prototypes (serial numbers 45-59582/59584) were ordered and the Model 109 was officially designated XB-46. (The other submissions, the Boeing Model 432 and Martin Model 223 [designated XB-47 and XB-48 respectively], were designed outside southern California and thus are outside the scope of this blog.) Although the end of World War II caused many wartime aircraft projects and production orders to be cancelled, the War Department did not cancel the XB-45, XB-46, XB-47, and XB-48 programs, given its recognition that jet aircraft were the wave of the future.

Left: First North American XB-45 prototype (serial number 45-59479) in flight
Right: The sole Convair XB-46 prototype (serial number 45-59582) in flight

The XB-45 Tornado was 74 feet (22.55 meters) long with a wingspan of 89 feet 6 in (27.28 meters), a height of 25 feet 2 in (7.67 meters), a wing area of 1,175 square feet (109.2 square meters), an empty weight of 41,876 lb (18,953 kg), a gross weight of 66,820 lb (30,309 kg), and a maximum speed of 516 miles per hour (830 km/h). The engine nacelle arrangement adopted for the B-45 was reminiscent of that of the Arado Ar 234C four-engine variant of the Ar 234 jet bomber, and the nose of the XB-45 had window panels at the upper surface. The XB-45 crew comprised a pilot, co-pilot, bombardier/navigator, and a tail gunner; the pilot and co-pilot sat in a bubble cockpit canopy, while the bombardier/navigator sat in the nose and the tail gunner operated a tail gun turret. The XB-45 prototype made its first flight on March 17, 1947 (which happened to be St. Patrick's Day), and the three XB-45 prototypes (each instrumented for different specialized phases of the flight test program) carried out more than 130 test flights; the first XB-45 prototype crashed on take-off from Wright-Patterson Air Force Base in Dayton, Ohio, on June 28, 1949, due to a failure of the landing gear. The XB-46, on the other hand, had a very slender fuselage oval in cross-section and very high-aspect ratio wings, with its four J35s paired in two integral nacelles, and it featured a bubble cockpit canopy to accommodate the pilot and co-pilot as well as a Plexiglas nose section for the bombardier/navigator. The XB-46 measured 105 feet 9 in (32.23 meters) long with a wingspan of 113 feet (34.44 meters), a height of 27 feet 11 in (8.51 meters), a wing area of 1,285 square feet (119.4 square meters), an empty weight of 48,018 lb (21,781 kg), a gross weight of 91,000 lb (41,277 kg), and a maximum speed of 545 mph (877 km/h); the production version was to be armed with two 0.50-caliber Browning machine guns in the tail and carry 22,000 lb (10,000 kg), with power to be provided by four General Electric J47 turbojets. During the course of developing the XB-46, Convair worked on a forward swept wing attack aircraft project, the XA-44 (redesignated XB-53 in 1946), and the end of the World War II caused severe defense budget cuts, putting Convair in a tight financial bind with regards to the XA-44/XB-53 and XB-46 programs. Facing a tight budget, Convair urged the US Army Air Force to cancel the second and third XB-46 prototypes to save money for the XB-53, and the USAAF agreed to this request in June 1946. (The XB-53 program was cancelled in December 1946 due to concerns about the ability of the forward-swept wing to endure aerodynamic loads at high speed.) The first XB-46 was eventually completed as a stripped-down airframe devoid of armament or military equipment, and it made its first flight on April 2, 1947. A total of 14 test flights at Muroc Army Air Field were conducted until September, after which the XB-46 was used for variety of tests such as noise measurements and tail vibration investigations, with additional stability and control tests being performed at West Palm Beach Air Force Base in Florida from August 1948 to August 1949. After an additional 44 flight hours, the XB-46 was taken out of service due to high maintenance costs and a lack of spare parts, and eventually flown to Eglin Air Force Base where its pneumatic system was tested in cold weather conditions from July to November 1950. The nose section of the sole XB-46 prototype was sent to the Air Force Museum at Wright-Patterson Air Force Base, but the remainder of the aircraft was scrapped in February 1952.

A B-45A Tornado (serial number 47-025) dropping bombs in flight

Even before the XB-45 had made its first flight, on August 2, 1946, the USAAF decided that the XB-45 was superior to the XB-46 because it determined that the XB-46 would be inferior in performance to the XB-45 design and that the slender fuselage of the Convair design would be unable to accommodate the required radar equipment. Therefore, a production order was placed for 96 B-45As and one static test airframe (serial numbers 47-001/097), with the company designation NA-147 used for the B-45A. The B-45A featured improved ejection seats for the pilot and co-pilot, safer emergency exits for the bombardier/navigator and the tail gunner, along with provisions for an E-4 automatic pilot, a bombing navigation radar, and an A-1 fire control system were provided. The first B-45A flew on February 24, 1948, and the first 22 B-45As (deliveries of which began in April) had four Allison J35s, while the remaining B-45As were powered by four General Electric J47 turbojets. Although designed to use a remote-controlled fire control system for the tail gun turret, the B-45As were fitted with a tail gunner's position because of the unavailability of the remote-controlled fire control system. The B-45B was to be a B-45A variant fitted with new radar and fire-control systems, but was not built. The B-45A reached operational USAF units at Barksdale Air Force Base in Louisiana in November 1948, but the B-45A fleet was plagued by maintenance problems with the J47 engines and APQ-24 bombing/navigation radar system, several structural weaknesses in the airframes, difficulties with the gyrocompass at high speed and the E-4 automatic pilot when the bomb doors opened, the lack of suitable bombsights or fire control bombing equipment, and inadequate ferry range and combat radius. Despite these problems, the B-45A found a role as a tactical bomber to deter a Soviet attack on western Europe in the wake of the outbreak the Korean War when the US Air Force in December 1950 initiated the Backbreaker program to fit several B-45As with improved bombing/navigation systems and the Norden bombsight, bomb bays to accommodate lightweight tactical nuclear bombs, and additional electronic equipment, and nuclear-capable B-45As were deployed to the UK beginning in May 1952. As the 1950s progressed, the B-45As were retired from US Air Force service and replaced by the B-47 and also the Douglas B-66 Destroyer tactical bomber, and by July 1958, all B-45As stationed in the UK were relocated to bases in mainland Europe and North Africa, many of them being retired there and broken up for scrap. Some J35-powered B-45As were used for training purposes and designated TB-45A, a few of them serving a target tugs for a Chance Vought target drone glider. On the other hand, one B-45A was modified for use as a launch platform for guided weapons and designated DB-45A, while the last production B-45A (serial number 47-096) was used as an in-flight engine testbed and designated JB-45A.

Left: A classic aerial view of the first B-45C Tornado (serial number 48-001)
Right: An RB-45C Tornado (serial number 48-037)

In September 1947, North American envisaged a variant of the Tornado that could be refueled in midair, the B-45C (company designation NA-153). Although similar to late-production B-45As in having four General Electric J47 turbojets, it differed in having a pair of 1,200-gallon wing tip fuel tanks that could be dropped in flight when necessary, a strengthened cockpit canopy with several reinforcements, a boom receptacle on the top of the fuselage for refueling, and a single-point ground refueling receptacle on the left side of the bomb bays. A total of 43 B-45Cs (serial numbers 48-001/043) were ordered, and the first aircraft flew on May 3, 1949, but by 1950 the US Air Force had decided to place huge orders for the B-47 Stratojet, so the last B-45C to be built in bomber configuration was completed on April 13, 1950. The remaining 33 B-45Cs on order (48-011/043) were completed as reconnaissance aircraft under the designation RB-45C. Unlike the B-45C, the RB-45C had the transparent nose section replaced by a duckbill-shaped nose housing a forward oblique spy camera, and it could carry at least 10 spy cameras (four in the rear fuselage, four at the split vertical section, one tri-metrogen K-17C in a pallet aft of the wing's trailing edge, and one forward oblique camera in the nose) but also 25 M-122 photoflash bombs in the bomb bay. The RB-45C first flew in April 1950, and deliveries of the RB-45C to Strategic Air Command began in June 1950, continuing until October 1951. The RB-45C conducted its first-ever reconnaissance flights over North Korea during the Korean War in the fall of 1950, and for several months the RB-45Cs of the 91st Strategic Reconnaissance Wing were able to evade MiG jet fighters, but after a couple of incidents on 1951 in which the RB-45Cs narrowly escaped interception by MiGs, all RB-45Cs were restricted from overflights of North Korea in daylight operations and converted for night reconnaissance operations in January 1952, receiving black paint to evade interception by enemy searchlights. However, night operations of the RB-45C went awry because the aircraft buffeted badly when the forward bomb bays door opened to release photoflash bombs, and the RB-45Cs were thus withdrawn from use in the Korean War. When the RB-47E reconnaissance version of the B-47 became operational, the RB-45Cs in Air Force service were transferred to the 19th Tactical Reconnaissance Squadron stationed in Europe, with which they served until their retirement in the spring of 1958. The Royal Air Force also used the RB-45C, and four aircraft were leased to RAF crews as part of Operation Ju-jitsu to form the Special Duties Flight, which was headed by Squadron Leader John Crampton and stationed at RAF Sculthorpe in Norfolk, eastern England. The most prolific reconnaissance mission to be carried out by the Special Duties Flight was on April 17, 1952, when three RB-45Cs overflew Kiev from RAF bases in West Germany to obtain intelligence about Soviet military strength; despite being intercepted by Soviet fighters, the RB-45Cs survived and returned to West Germany, and this flight was to serve as a wake-up call for the USSR to reform its air defense systems by making the PVO Strany a branch of the Soviet armed forces independent of the Soviet Army and VVS in 1954. The RB-45C would remain in service until 1959, when it was replaced by the RB-47E and other new-generation reconnaissance aircraft. In the meantime, one B-45C were modified for use as a guided weapons launch platform and designated DB-45C, while the ninth B-45C (serial number 48-009) served as a testbed for the Pratt & Whitney J57 and J75 turbojets under the designated JB-45C. 

Although the B-45 Tornado wasn't as prolific as the better-known B-47 Stratojet given its limitations as a strategic bomber and ended up serving mainly as a reconnaissance platform, its significance was not lost on the fact that it was the first American multi-engine jet bomber to enter service and also the third multi-engine jet bomber to fly, after the Junkers Ju 287 forward-swept wing jet bomber and the Arado Ar 234C four-engine tactical bomber. On the other hand, the XB-46's ability to carry required military equipment was compromised by its fuselage design despite having very high-aspect ratio wings. Like the earlier Douglas XB-43 Jetmaster, the Tornado inadvertently cemented southern California's role as the birthplace of the jet bomber in the United States, but in due time the swept-wing B-47 emerged as the true jet-powered successor to the B-17 and B-29, making clear once again that swept wings were the key for new-generation US bomber aircraft to attain high subsonic speeds.

References:

Bradley, R., 2010. Convair Advanced Designs: Secret Projects from San Diego 1923-1962. North Branch, MN: Specialty Press.

Frederiksen, J.C., 2009. The B-45 Tornado: An Operational History of the First American Jet Bomber. Jefferson, NC: McFarland. ISBN 978-0-7864-4278-2.

Wagner, R., 2004. American Combat Planes of the 20th Century: A Comprehensive Reference. Reno, Nevada: Jack Bacon & Co. ISBN 0-930083-17-2.

Would-be aerial combat masters from Santa Monica: the Douglas XB-42 Mixmaster and XB-43 Jetmaster

During World War II, the Douglas Aircraft Company manufactured thousands of its A-20 Havoc and A-26 Invader medium bomber/close air support aircraft from its factories in Long Beach, Santa Monica and El Segundo, and the A-20 Havoc became widely used by the US Army Air Force and Royal Air Force (which referred to the A-20 as the Boston), while the A-26 Invader (redesignated B-26 after 1948) saw action in the last years of World War II and most notably in the Korean War, Bay of Pigs invasion, Vietnam War, Biafra conflict, and the war against the Simba rebels in the Congo. In the last two years of World War II, however, Douglas also came with two one-of-a-kind bomber aircraft, an unorthodox pusher-engine long-range medium bomber and one of America's first-ever jet bomber designs. Because the XB-42 and XB-43 shared the same design except in the powerplant, I've opted to dedicate this post to discussing the design, development, and testing of these two prototype bomber aircraft created from the manufacturing halls Santa Monica.

Models of the XB-42 Mixmaster and XB-43 Jetmaster at the Lyon Air Museum (photographed by me in November 2021)

In early 1943, Douglas investigated the feasibility of a twin-engine close air support aircraft able to carry 2,000 lb (907 kg) of bombs over a combat radius of 2,000 miles (3,219 km) at speeds exceeding 400 miles per hour (643 km/h), and its designer, Ed Burton, believed that these goals could be attained by having the engines buried in the fuselage and coming up with a completely clean wing. By late April, the Model 459 design emerged which had a bug-eye canopy configuration created by a pair of  bubble canopies, two Allison V-1710 liquid-cooled V-cylinder piston engines buried inside the fuselage behind the pilot's cabin that drove two three-bladed counter-rotating propellers in the extreme tail cone via five lengths of shafting, a ventral vertical stabilizer to prevent the propellers from hitting the ground during nose-high takeoffs and landings, a tricycle undercarriage, and an extremely clean laminar-flow wing at the middle fuselage. Armament comprised six 0.50-caliber machine guns, of which four were housed in two remote-controlled turrets on the trailing edges of the wings between the ailerons and flap, and two were mounted in fixed positions on the sides of the fuselage, but also 8,000 lb (3,628 kg) of bombs. A crew of three was carried, of which the pilot and co-pilot/gunner sat under the twin bubble canopies and the navigator/bombardier sat in a transparent nose. The Model 459 was submitted to the US Army Air Force on June 15, and ten days later two prototypes (serial numbers 43-50224/50225) and a static test airframe were ordered under the designation XA-42. A full-scale mock-up was inspected in September, but by this time the Army Air Force regarded the XA-42 as more of a high-speed long-range bomber than a pure close air support plane, and on November 26 the designation of the Model 459 was changed to XB-42, while the name Mixmaster was applied to the XB-42 because the propellers of the aircraft were reminiscent of the Sunbeam Mixmaster electric kitchen mixer.

Top: First XB-42 Mixmaster prototype (43-50224) in flight
Bottom left: XB-42A during taxi tests
Bottom right: Second XB-42 prototype (43-50225)

The first XB-42 prototype was completed in early 1944, only several months after the XB-42 prototype contract had been signed. It made its first flight at Palm Springs Army Air Field on May 6, with test pilot Bob Brush at the controls, and the second XB-42 flew for the first time on August 1. Performance of the XB-42 during initial flight testing was judged to be outstanding, with speed within a percent of that predicted, and the range and climb rate surpassing expectations. However, the twin bubble canopies were found to inhibit poor communication between the pilot and co-pilot/gunner, so the second XB-42 was later fitted with a more conventional cockpit canopy. In the meantime, test flights of the XB-42 revealed a number of problems, including excessive yaw, propeller vibration, and poor engine cooling, and cruciform nature of the XB-42's horizontal and vertical stabilizers required careful handling during taxiing, take-off, and landing due to limited ground clearance. In any case, the XB-42 was not ordered into production, largely because the onset of the jet age ensured that the XB-42 would be last wartime American piston-engine bomber to reach the design phase, but the XB-42 prototypes continued to fly after the end of the World War II for a number of test purposes. The second XB-42 prototype set a new transcontinental speed record in early December 1945 when it flew from Long Beach, California, to Bolling Army Air Field (renamed Bolling AFB in 1948) in Washington, D.C., at a speed of 433 mph (698 km/h). However, on December 16, it was destroyed in a crash at Oxon Hill, Maryland, while on a routine test flight out of Bolling Army Air Field due to a landing gear extension problem, failure of the left engine, and cooling problems with the right engine, and the crew bailed out of the aircraft safely. In the meantime, the first XB-42 prototype was fitted with two auxiliary Westinghouse J30 turbojets under the wings in accordance with an earlier proposal by Douglas to use this aircraft as a turbojet testbed and redesignated XB-42A, making its first flight in this iteration on May 27, 1947. All guns were removed during the conversion process and the XB-42A attained a speed of 488 mph (785 km/h) during its flight testing at Muroc Air Force Base (later Edwards AFB), making a total of 22 flights until late 1947, when it suffered damage to the lower vertical and horizontal stabilizers and rudder after a hard landing. The XB-42A was repaired but was never flew again, and the US Air Force officially removed the aircraft from its inventory on June 30, 1949. The XB-42A was transferred to the collection of the National Air and Space Museum in Washington, D.C. shortly afterwards, only to be later donated to the National Air Museum Storage Facility in Park Ridge, Illinois years later. In April 1959, the fuselage of the XB-42A was moved to storage at the Paul Garber restoration facility at Suitland, Maryland, where it languished until 2010 when it was transferred to the USAF Museum at Wright-Patterson Air Force Base in Dayton, Ohio, for eventual restoration.

Left: First XB-43 Jetmaster prototype (44-61508) taking off for a test flight at Muroc Army Air Field
Right: Color photo of the second XB-43 prototype (44-61509) taking off. The second XB-43 was also called the YB-43 

Even before the XB-42's first flight, in October 1943 Douglas proposed a jet-powered derivative of the XB-42 Mixmaster with two Allison J35 turbojets in the forward fuselage bays, the XB-43 Jetmaster. Besides jet propulsion, the XB-43 differed from the XB-42 in eliminating the ventral vertical stabilizer, ensuring better ground clearance during taxiing and takeoff, but also a larger upper vertical stabilizer to enable adequate longitudinal stability. Two XB-43 prototypes (serial numbers 44-61508/61509) were ordered on March 31, 1944, and to save time and money Douglas decided to use the sole XB-42 static test airframe on order in the construction of the first XB-43 prototype, while the second XB-43 was manufactured from scratch. However, the slowdown in aircraft manufacturing in southern California following the end of World War II and delays in delivery of the J35s due to teething troubles during bench tests meant that the first XB-43 did not fly until May 17, 1946, when it became the first-ever US jet bomber to fly. Months before the XB-43's first flight Douglas discussed with the US Army Air Force plans for an initial production run of 50 B-43s, and it also submitted a proposal to make preparations for the manufacture of 200 aircraft a month. The production aircraft would have a conventional cockpit canopy and a tail turret with two 0.50-caliber machine guns, and two variants were contemplated, the bomber version with a transparent nose and a 6,000 lb (2,722 kg) bombload, and an attack aircraft variant armed with sixteen forward-firing 0.50-caliber machine guns with an unglazed nose and thirty-five 5-inch rockets. However, production plans were axed on August 18, 1945, because the US Army Air Force was now concentrating on its first generation of multi-engine jet bomber, including the North American B-45 Tornado, Convair XB-46, Boeing B-47 Stratojet, Martin XB-48, and Northrop YB-49. The second XB-43, meanwhile, was completed with a conventional canopy and a plywood nose cover, and first flew on May 15, 1947, by which it bore the designation YB-43. Nearly a year into flight tests, in April 1948 the YB-43 (nicknamed "Versatile II" by US Air Force personnel) became one of several testbeds for the General Electric J47 turbojet when it had one of the J35s replaced by a J47. The first Jetmaster prototype was eventually cannibalized to provide spare parts for the YB-43 after that aircraft was damaged during a flight in February 1951, and it was eventually destroyed during target practice at Edwards Air Force Base. The YB-43 continued to fly until December 1953, when it was retired and put in storage at the Paul Garber facility of the National Air and Space Museum the following year pending restoration work. Like the first XB-42 prototype, the YB-43 was transferred to the USAF Museum at Wright-Patterson Air Force Base in Dayton, Ohio, for eventual restoration in 2010.

Artist's conception of the Douglas DC-8 (aka Model 1004) airliner derivative of the XB-42 Mixmaster fast bomber

As a side note, in late 1945 Douglas proposed an airliner derivative of the XB-42, the DC-8 (not to be confused with the later DC-8 jet airliner), to replace the venerable DC-3 on short- and medium-range routes. Known by the company designation Model 1004, the DC-8 would have been 77 feet 8 in (23.67 meters) long with a wingspan of 110 feet 2 in (33.58 meters), a height of 26 feet 9.75 in (8.17 meters), an empty weight of 24,415 lb (11,074 kg), a gross weight of 40,000 lb (18,144 kg), and seating capacity for 40 to 48 passengers in a pressurized cabin. The V-1710s would be located below and immediately behind the cockpit, driving counter-rotating propellers via driveshafts under the cabin floor (which were also proposed for the Douglas Cloudster II prototype light aircraft). The engine arrangement for this aircraft at first glance would have been an unfamiliar spectacle for airport personnel and passengers alike, but was estimated to reduce drag by 30% and eliminate problems associated with controlling the aircraft with one engine out, while cabin access would have been made through single portside door on the sides of the rear fuselage. Despite its estimated performance being greater than that of conventional twin-engine airliners, the DC-8 project itself was shelved in favor of the less risky Convair Model 240 and Martin 2-0-2 airliners due to high complexity and development costs combined with projected high operating costs.

Although the XB-42 and XB-43 remained at the prototype stage only, the Jetmaster itself provided a wealth of aerodynamic data that would be applied to the development of the first American multi-engine jet bombers, including the B-45 and B-47, effectively making the US the first of the major victorious Allies to get a jet bomber into the sky. Moreover, by a stroke of luck, the first XB-42 and the second XB-43 were spared from the breaker's torch and made their way to museums in preparation for restoration to static display, with the hope that someday visitors to the Air Force Museum in Dayton, Ohio will get a rare glimpse of the first-ever US jet bomber in person.

References:

Boyne, W., 1973. "The First, The Last, And The Only: The Douglas XB-42/42A/43". Airpower 3 (5): 13–14.

Francillon, R., 1988. McDonnell Douglas Aircraft Since 1920: Volume I. Annapolis, MD: Naval Institute Press.

Wagner, R., 2004. American Combat Planes of the 20th Century: A Comprehensive Reference. Reno, Nevada: Jack Bacon & Co.