Category Archives: U.S. Army Air Force

U.S.A.

Douglas A-26B „Invader“ (Airfix)

TYPE: Light bomber, ground-attack aircraft

ACCOMMODATION: Crew of three

POWER PLANT: Two Pratt & Whitney R-2800-27 “Double Wasp” radial engines, rated at 2,000 hp each

PERFORMANCE: 355 mph


COMMENT
: The A-26 “Invader” was Douglas Aircraft’s successor to the A-20 (DB-7) “Havoc”, also known as Douglas “Boston”, one of the most successful and widely operated types flown by Allied air forces in World War II. The Douglas XA-26 prototype first flew on 10 July 1942. Flight tests revealed excellent performance and handling, but problems with engine cooling led to cowling changes and elimination of the propeller spinners on production aircraft. Repeated collapses during testing led to strengthening of the nose landing gear.
The Douglas A-26 was originally built in two different configurations. The Douglas A-26B had a gun nose, which originally could be equipped with a combination of armament including 12.7 mm machine guns, 20mm or 37mm auto cannon, or even a 75mm pack howitzer (which was never used operationally). Normally the gun nose version housed six (or later eight) .50 caliber machine guns, officially termed the “all-purpose nose”, later commonly known as the “six-gun nose” or “eight-gun nose”. The Douglas A-26C “Invader” had a glass” nose, officially termed the “Bombardier nose” and contained a Norden bombsight for medium altitude precision bombing.
After about 1,570 production aircraft, three guns were installed in each wing, coinciding with the introduction of the “eight-gun nose” for A-26Bs, giving some configurations as many as 14 12.7 mm machine guns in a fixed forward mount. A-26C nose section could be exchanged for an A-26B nose section, or vice versa, in a few man-hours, thus physically and officially changing the designation and operational role. The “flat-topped” canopy was changed in late 1944 after about 820 production aircraft, to a clamshell style with greatly improved visibility.
Alongside the pilot in an A-26B, a crew member typically served as navigator and gun loader for the pilot-operated nose guns. A tractor-style “jump seat” was located behind the “navigator’s seat”. In most missions, a third crew member in the rear gunner’s compartment operated the remotely controlled dorsal and ventral gun turrets, with access to and from the cockpit possible via the bomb bay but only when that was empty. The gunner operated both dorsal and ventral turrets via a novel and complex (and problematic) dual-ended periscope sight, which was a vertical column running through the center of the rear compartment, with traversing and elevating/depressing periscope sights on each end. The gunner sat on a seat facing rearward, and looked into a binocular periscope sight mounted on the column, controlling the guns with a pair of handles on either side of the column. When aiming above the centerline of the aircraft, the mirror in the center of the column would flip, showing the gunner what the upper periscope was seeing. When he pressed the handles downward, as the bead passed the centerline the mirror would automatically flip, transferring the sight “seamlessly” to the lower periscope. The guns would aim wherever the periscope was aimed, automatically transferring between upper and lower turrets as required, and computing for parallax and other factors. While novel and theoretically effective, a great deal of time and trouble was spent trying to get the system to work effectively, which delayed production, and it was difficult to keep maintained in the field even once production started.
The Douglas Company began delivering the production model A-26B to the USAAF on September 1943, with the new bomber first seeing action with the Fifth Air Force in the Southwest Pacific Theater on June 1944, when Japanese-held islands near Manokwari were attacked. The pilots in the 3rd Bomb Group’s 13th Squadron, “The Grim Reapers”, who received the first four A-26s for evaluation, found the view from the cockpit to be restricted by the engines and thus inadequate for low-level attack. General George Kenney, commander of the Far East Air Forces stated that, “We do not want the A-26 under any circumstances as a replacement for anything”.
Douglas needed better results from the “Invader’s” second combat test, so A-26s began arriving in Europe in late September 1944 for assignment to the Ninth Air Force. The initial deployment involved 18 aircraft and crews assigned to the 553rd Squadron of the 386th Bomb Group. This unit flew its first mission on September 1944. No aircraft were lost on the eight test missions, and the Ninth Air Force announced that it was happy to replace all of its Douglas A-20s and Martin B-26 “Marauders” with the Douglas A-26 “Invader” (Ref.: 24).

Lockheed C-69 “Constellation” (Heller)

TYPE: Personnel and cargo transport

ACCOMMODATION: Crew of four plus troops or freight

POWER PLANT: Four Wright R-3350-35 “Duplex-Cyclone” radial engines, rated at 2,200 hp each

PERFORMANCE: 330 mph at 10,000 ft

COMMENT: Following the Attack on Pearl Harbor and the United States entering WWII, the assembly lines at the Lockheed Aircraft Corporation were taken over by the American government for the war effort. Along with the assembly lines, the Lockheed L-049 “Constellation” airliner was also requisitioned and designated C-69 and was to be used as a cargo and personnel transport by the United States Army Air Forces (USAAF).
Due to the direction the war was heading during summer 1942, the need for a large troop transport capable of crossing the Atlantic Ocean o Pacific Ocean (by flying from island to island) became more important. This would help avoid the risks the convoys in the Atlantic were facing due to U-Boat attacks.
The Douglas C-54 “Skymaster” planned for these roles was not completely capable. So on September 1942, the American War Department signed contract with Lockheed for nine L-049 aircraft under construction for TWA. Soon after 150 more C-69A and C-69B aircraft were ordered along with C-69C and C-69D VIP transport versions. In reality, only one C-69C was produced out of all these planned variants.
Around the same time the prototype XC-69 was completed and rolled out in December 1942. The aircraft was painted in olive green and grey camouflage colors and the civilian registration. However, problems developed with the aircraft’s powerplant, the Wright R-3350 “Duples Cyclone”. A consideration to replace the R-3350 engines with Pratt & Whitney R-2800 had been taken up.
On July 1943, the XC-69 was symbolically handed over to the USAAF and later that same day, the XC-69 returned to Lockheed for further testing. It is worth mentioning that the C-69 was able to attain a higher maximum speed than the Mitsubishi A6M “Zero” fighter.
Major problems, however, surfaced with the Wright R-3350 powerplant that powered the C-69 and  finally the USAAF ceased production of the R-3350 until the troubles that plagued the engines were solved. This caused the development of the C-69 to slow down and furthermore, the C-69 was not declared a priority. Lockheed continued to focus on building combat aircraft while the Douglas C-54 “Skymaster”, the C-69’s competitor was already flying and officially ordered.
Unfortunately for Lockheed, the C-69 became less important to the war effort as time progressed, especially since the tide of the war had turned in favor of the Allies. Only a small number of C-69 aircraft would see service in the last year of the war. Even so, Lockheed was able to conduct tests at the expense of the government to solve problems with the aircraft’s design. Although the problems with the R-3350 were being solved, the B-29 had priority for the engines over the C-69. Even with all the effort put forth by Lockheed, the USAAF favored the C-54 “Skymaster” over the C-69. At the end of the war, only 22 Lockheed C-69s “Constellations” were produced, seven of which were never delivered (Ref.: 24).

Bell P-59B “Airacomet” (MPM Models)

TYPE: Fighter

ACCOMMODATION: Pilot only

POWER PLANT: Two General Electric J31-GE-5 turbojet engines, rated at 750 kp each

PERFORMANCE: 413 mph at 30,000 ft

COMMENT: The Bell P-59 “Airacomet” was a twin turbojet-engine fighter aircraft, the first produced in the United States, designed and built by Bell Aircraft Corporation during WW II. The United States Army Air Force was not impressed by its performance and cancelled the contract when fewer than half of the aircraft ordered had been produced. Although no P-59s entered combat, the fighter paved the way for another design generation of U.S. turbojet-powered aircraft, and was the first turbojet fighter to have its turbojet engine and air inlet nacelles integrated within the main fuselage.
Major General H. H. “Hap” Arnold became aware of the United Kingdom’s turbojet program when he attended a demonstration of the Gloster E.28/39 in April 1941. He requested, and was given, the plans for the aircraft’s powerplant, the Power Jets W.1, which he took back to the U.S. He also arranged for an example of the engine, the Whittle W.1X turbojet, to be flown to the U.S in October 1941 in the bomb bay of a USAAF Consolidated B-24 “Liberator” along with drawings for the more powerful W.2B/23 engine and a small team of Power Jets engineers. On 4 September, he offered the U.S. company General Electric a contract to produce an American version of the engine, which subsequently became the General Electric I-A. On the following day, he approached L. D. Bell, head of Bell Aircraft Corporation, to build a fighter to utilize it. Bell agreed and set to work on producing three prototypes. As a disinformation tactic, the USAAF gave the project the designation “P-59A”, to suggest it was a development of the unrelated Bell XP-59 fighter project which had been canceled. The design was finalized in January 1942, and construction began. In March, long before the prototypes were completed, an order for 13 “YP-59A” preproduction machines was added to the contract.
In September 1942, the first XP-59A was sent to Muroc Army Air Field in California by train for testing. While being handled on the ground, the aircraft was fitted with a dummy propeller to disguise its true nature. The aircraft first became airborne during high-speed taxiing tests on October although the first official flight one day later. A handful of the first “Airacomets” had open-air flight observer later cut into the nose; over the following months, tests on the three XP-59As revealed a multitude of problems including poor engine response and reliability – common shortcomings of all early turbojets – , insufficient lateral stability, i.e., in the roll axis, and performance that was far below expectations. Chuck Yaeger flew the aircraft and was dissatisfied with its speed, but was amazed at its smooth flying characteristics. Nevertheless, even before delivery of the YP-59As in June 1943, the USAAF ordered 80 production machines, designated P-59A “Airacomet”.
The 13 service test YP-59As had a more powerful engine than their predecessor, the General Electric J 31, but the improvement in performance was negligible, with top speed increased by only 5 mph and a reduction in the time they could be used before an overhaul was needed. One of these aircraft, the third YP-59A was supplied to the Royal Air Force, in exchange for the first production Gloster “Meteor”. British pilots found that the aircraft compared very unfavorably with the turbojets that they were already flying. Two YP-59A “Airacomets” were also delivered to the U.S. Navy where they were evaluated as the YF2L-1 but were quickly found completely unsuitable for carrier operations.
Faced with their own ongoing difficulties, Bell eventually completed 50 production “Airacomets”, 20 P-59As and 30 P-59Bs; deliveries of P-59As took place in the fall of 1944. Each was armed with one 37 mm M4 cannon and 44 rounds of ammunition and three 12.7 mm machine guns with 200 rounds per gun. The P-59Bs were assigned to the 412th Fighter Group to familiarize USAAF pilots with the handling and performance characteristics of jet aircraft. While the P-59 was not a great success, the type did give the USAAF experience with the operation of jet aircraft, in preparation for the more advanced types such as the Lockheed P-80 “Shooting Star” that would shortly become available. Nevertheless, early in 1944 Bell designers began the development of a turbojet powered fighter of similar configuration as the P-59 “Airacomet” but improved performance, the Bell XP-83. But the performance was somewhat disappointing, too, and the project was cancelled, only two prototypes were built (Ref.: 8, 24).

Vultee XP-54 “Swoose Goose” (Planet Models, Resin)

TYPE:  High-altitude interceptor

ACCOMMODATION: Pilot only

POWER PLANT: One Lycoming XH-2470-1 liquid-cooled engine, rated at 2,300 hp

PERFORMANCE: 381 mph at 28,500 ft

COMMENT: The Vultee Company had submitted a proposal in response to a US Army Air Corps request for an unusual configuration. The Vultee design won the competition, beating the Curtiss XP-55 “Ascender” and Northrop XP-56 “Black Bullet”. Vultee designated it Model 84, a descendant of their earlier Model 78. After completing preliminary engineering and wind tunnel tests, a contract for a prototype was awarded on January 1941. A second prototype was ordered on March 1942..
The XP-54 was designed with a pusher engine in the aft part of the fuselage. The tail was mounted rearward between two mid-wing booms, with the 12-ft propeller between them. The design included a “ducted wing section” developed by the NACA (National Advisory Committee of Aeronautics)  that enabled installation of cooling radiators and intercoolers in the inverted gull wing. The Pratt & Whitney X-1800 engine was initially proposed as the power plant but after its development was discontinued, the liquid-cooled Lycoming XH 2470 was substituted.
In September 1941, the XP-54 mission was changed from low altitude to high altitude interception. Consequently, a turbo-supercharger and heavier armor had to be added, and the estimated empty weight increased from 5,200 to 8,200 kg.
The XP-54 was unique in numerous ways. The pressurized cockpit required a complex entry system: the pilot’s seat acted as an elevator for cockpit access from the ground. The pilot lowered the seat electrically, sat in it, and raised it into the cockpit. Bail-out procedure was complicated by the pressurization system and necessitated a downward ejection of the pilot and seat in order to clear the propeller arc. Also, the nose section could pivot through the vertical, three degrees up and six degrees down. In the nose, two 37 mm T-9 cannon were in rigid mounts while two .50 cal. machine guns were in movable mounts. Movement of the nose and machine guns was controlled by a special compensating gun sight. Thus, the cannon trajectory could be elevated without altering the flight attitude of the airplane. The large nose section gave rise to its whimsical nickname, the “Swoose Goose”, inspired by a song about Alexander who was half swan and half goose: “Alexander was a swoose.”
Flight tests of the first prototype, Serial Nr. 41-1210, began on 15 January 1943. Initial trials showed performance to be substantially below guarantees. At the same time, development of the XH-2470 engine was discontinued and, although it appeared possible to substitute the Allison V-3420 engine without substantial airframe changes, the projected delay and costs resulted in a decision not to consider production buys.
The prototypes continued to be used in an experimental program until problems with the Lycoming engines and lack of spare parts caused termination. The second prototype, 42-108994 (but mistakenly painted as 42-1211) equipped with an experimental General Electric supercharger, only made one flight before it was relegated to a “parts plane” in order to keep the first prototype in the air (Ref.: 24).

Consolidated B-24D”Liberator”, 389th BG (H), 8th USAAF (Matchbox)

TYPE: Heavy long-range bomber, in service as Assembly ship

ACCOMMODATION: Crew of five to six

POWER PLANT: Four Pratt & Whitney R-1830-35 turbocharged “Twin-Wasp” radial engines, rated at 1.200 hp each

PERFORMANCE: 290 mph

COMMENT: In February 1944, the 2nd Division of the Eight Army Air Force in Europe authorized the use of “Assembly Ships” (or “Formation Ships”) specially fitted to aid assembly of individual group formations. They were equipped with signal lighting, provision for quantity discharge of pyrotechnics, and were painted with distinctive group-specific high-contrast patterns of stripes, checkers or polka dots to enable easy recognition by their flock of bombers. The aircraft used in the first allocation were B-24Ds retired by the 44th, 93rd and 389th Groups. Arrangements for signal lighting varied from group to group, but generally consisted of white flashing lamps on both sides of the fuselage arranged to form the identification letter of the group. All armament and armor was removed and in some cases the tail turret. In the B-24Hs used for this purpose, the nose turret was removed and replaced by a “carpetbagger” type nose. Following incidents when flare guns were accidentally discharged inside the rear fuselage, some assembly (formation) ships had pyrotechnic guns fixed through the fuselage sides. As these aircraft normally returned to base once a formation had been established, a skeleton crew of two pilots, navigator, radio operator and one or two flare discharge operators were carried. In some groups an observer officer flew in the tail position to monitor the formation. These aircraft became known as „”Judas goats“.
The assembly ship shown here belonged to the 389th Bombardment Group (Heavy) “The Sky Scorpions” stationed at Hethel, UK from 1943 to 1945 (Ref: 24).

Lockheed YP-49 (Anigrand, Resin)

TYPE: Fighter

ACCOMMODATION: Pilot only

POWER PLANT: Two Continental XI-1430-1 liquid-cooled engines, rated at 1,600 hp each

PERFORMANCE:  406 mph at 15,000 ft

COMMENT: The Lockheed XP-49 was a further development of the P-38 “Lightning” for a fighter in response to U. S. Army Air Corps proposal 39-775. Intended to use the new 24-cylinder Pratt & Whitney X-1800 engine, this proposal, which was for an aircraft substantially similar to the P-38, was assigned the designation XP-49, while the competing Grumman Model G-46 was awarded second place and designated XP-50 “Skyrocket”, US Army Air Corps version of the US Navy Grumman XF5F-1 “Skyrocket”.
Ordered in October 1939 and approved on January 8, 1940, the XP-49 would feature a pressurized cockpit and armament of two 20 mm (0.79 in) cannon and four .50 in (12.7 mm) machine guns. Two months into the contract, a decision was made to substitute the Continental XI-1430-1 (or IV-1430) for the X-1800. The XP-49 first flew on 11 November 1942. The prototype force-landed on 1 January 1943, when the port landing gear failed to lock down due to combined hydraulic and electrical system failures. The XP-49 next flew 16 February 1943, after repairs were made. Preliminary flight data showed performance was not sufficiently better than the production P-38, especially given the questionable future of the XI-1430 engine, to warrant disruption of the production line to introduce the new model aircraft. Consideration of quantity production was therefore abandoned (Ref.: 24).

De Havilland “Mosquito” F-8, 25th BG(R) -802 RG(P) (Matchbox)

TYPE: Photo-reconnaissance aircraft

ACCOMMODATION: Pilot and radio-operator/navigator

POWER PLANT: Two Packard “Merlin” 31 or 33 liquid-cooled engines, rated at 1,460 hp each

PERFORMANCE: 408 mph at 28,000 ft

COMMENT: Until the end of WW II the de Havilland Company Canada rolled out 1,133 “Mosquito” aircraft of different subtypes.  The “Mosquito” B Mk XX was the Canadian version of the “Mosquito” B. Mk. IV bomber aircraft of which 145 were built. From these 40 were converted into F-8 photo-reconnaissance aircraft for the USAAF and used with the 8th USAAF in the European Theatre of Action. It had the same Packard “Merlin” engines and was equipped with three overload fuel tanks, totaling 3,500 L in the bomb bay. Additionally, for range extension it could also carry two 230 L or 450 L drop tanks.
The de Havilland “Mosquito” of 25th BG(R) -802 RG(P) were painted in normal RAF P.R. Blue finish. In August 1944 the vertical tail was colored in red and in September 1944 all tail surfaces were painted red. This marking was necessitated by frequency of misidentification of “Mosquito” as enemy type. Similar marking were used on BoeingB-17G of 652 BS.
The 25th Bombardment Group (Reconnaissance) was constituted in the days after D-Day and activated in England in August 1944 to carry out photographic and mapping missions over mainland Europe as the Allied armies pushed east. The Group were designated a Bombardment Group but they did not drop bombs. Instead they flew bombers to drop ‘chaff’ screenings for other Bomb Groups. ‘Chaff’, strips of metallic paper, would interfere with the enemy’s ability to detect aircraft using radar (Ref.: 24).

Douglas A-26C „Invader“ (Airfix)

TYPE: Light bomber, ground-attack aircraft

ACCOMMODATION: Crew of three

POWER PLANT: Two Pratt & Whitney R-2800-27 “Double Wasp” radial engines, rated at 2,000 hp each

PERFORMANCE: 355 mph

COMMENT: The Douglas A-26 “Invader” was Douglas Aircraft’s successor to the A-20 “Havoc”, in British service known as Douglas “Boston”, and was one of the most successful and widely operated types flown by Allied air forces in World War II. It was a twin-engine light bomber and ground attack aircraft, was fast and capable of carrying twice its specified bomb load.
A re-designation of the type from A-26 to B-26 led to confusion with the Martin B-26 “Marauder”, which first flew in November 1940, about 16 months before the Douglas design’s maiden flight. Although both types were powered by the widely used Pratt & Whitney R-2800 “Double Wasp” eighteen-cylinder, double-row radial engine, they were completely different and separate designs. Roughly 5,300 Martin “Marauders”, originated in 1939, were produced twice as many in comparison to the Douglas design.
The Douglas XA-26 prototype first flew on July 1942. Flight tests revealed excellent performance and handling, but problems with engine cooling led to cowling changes and elimination of the propeller spinners on production aircraft. Repeated collapses during testing led to strengthening of the nose landing gear. The Douglas A-26 was originally built in two different configurations. The Douglas A-26B had a gun nose housed six to eight .50 caliber machine guns, officially termed the “all-purpose nose”, later commonly known as the “six-gun nose” or “eight-gun nose”. The Douglas A-26C’s “glass” nose, officially termed the “Bombardier nose”, contained a Norden bombsight for medium altitude precision bombing. The A-26C nose section included two fixed M-2 guns, later replaced by underwing gun packs or internal guns in the wings.
After about 1,570 production aircraft, three guns were installed in each wing, coinciding with the introduction of the “eight-gun nose” for A-26Bs, giving some configurations as many as 14 .50 in machine guns in a fixed forward mount. The A-26C nose section could be exchanged for an A-26B nose section, or vice versa, in a few man-hours, thus physically changing the designation and operational role. The “flat-topped” canopy was changed in late 1944 after about 820 production aircraft, to a clamshell style with greatly improved visibility. Alongside the pilot in an A-26B, a crew member typically served as navigator and gun loader for the pilot-operated nose guns. In an A-26C, that crew member served as navigator and bombardier, and relocated to the nose section for the bombing phase of an operation In most missions, a third crew member in the rear gunner’s compartment operated the remotely controlled dorsal and ventral gun turrets, with access to and from the cockpit possible via the bomb bay only when that was empty (Ref.: 24).

Republic XF-15 “Reporter” (Airfix, Parts from Airmodel, Vacu-formed)

TYPE: Photo-reconnaissance aircraft

ACCOMMODATION: Crew of two

POWER PLANT: Two Pratt & Whitney R-2800-65 “Double Wasp” radial engines, rated at 2,000 hp each

PERFORMANCE: 376 mph at 17,000 ft

COMMENT: In autumn 1944, two Northrop P-61B “Black Widow” night fighters were extensively modified in an attempt to improve the performance and to extend the long-range in order to use these aircraft as long-range escort fighters.  Designated XP-61E the fuselage decking was cut flush with the wing to allow a large blown canopy to be fitted. The center and aft section of the fuselage nacelle housed additional fuel tanks and the nose radar was supplanted by four machine guns. The XP-61E’s were tested in the early month of 1945 but the second was lost in an accident on April 1945 and in view of the changing course of the war, further development of the “Black Widow” in this role as long-range escort fighter was abandoned. The first and remaining prototype was converted to the XF-15 “Reporter”, a long-range photo-reconnaissance aircraft, tested after the war. Due to the on-coming new turbojet powered aircraft a production order never was placed (Ref.: 9).

Bell Model 3 (Unicraft, Resin)

TYPE: Fighter, fighter-bomber. Project

ACCOMMODATION: Pilot only

POWER PLANT: One Allison V-1710-35 liquid-cooled engine, rated at 1,150 hp

PERFORMANCE: 350 mph at 10,000 ft

COMMENT: In 1936 the Bell Aircraft Corporation’s design team began work on the Bell XP-39, a radical design of a single-seat fighter with the engine mounted behind the pilot, driving the airscrew by means of an extension shaft. This arrangement appeared to offer superior manoeuvrability, the engine weight being concentrated around the fighter’s center of gravity. But the first flight test proved that this unorthodox fighter had a low ceiling, slow rate of climb and relative lack of manoeuvrability. So alternatively the engine was mounted forward and the cockpit was positioned to the back.  This and some more minor changes led to the design of the Model 3. But calculations proved no advantage of this model compared to the P-39 “Aircrobra”, so the project was not further followed (Ref.: 13).