The Vultee P-66, P-48, V-48/-61 Vanguard (Models 48, 61) incorporated design elements from the Hughes H-1 racer and detachable outer wing panels for storage.

Designed by Dick Palmer as a company demonstrator, the V-48 NX21755 c/n 142 first flew on 9 September 1939, piloted by Vance Breese. The V-48 was powered by a P&W R-1830-S Twin Wasp with an extended propshaft in an elongated low-drag cowling. The original proposal included two rear-firing guns aimed with mirrors. The prototype, NX21755 c/n 142, was later re-designated V-61, then P-48X.

The 1940 P-48X was a redesign of the V-61 with a conventional R-1830-S1 engine because of cooling problems. First flown on 11 February 1940, piloted by Vance Breese, and it crash-landed on May 9 after colliding with a camera plane.

The 1940 V-48C was the V48-X rebuilt and repowered with a R-1830-S2 engine for export to Sweden’s Flygvapen as the J.10. First flown on 6 September 1940, it was re-registered NX19999 c/n 501, and followed by one production prototype, NX28300 c/n 502.

One-hundred and forty-four were built for Sweden (42-6832 to 42-6975), but diverted to the RCAF, who in turn released 129 of them after the outbreak of WW2 as Lend-Lease to China as P-66, and so marked with US insignia. Of the total about 50 were impressed for Army stateside assignment, and 12 transferred to 23 Fighter Group in China.

V-48
Engine: P&W R-1830-S Twin Wasp
Wingspan: 35’10”
Length: 28’5″
Useful load: 2165 lb
Speed: 340 mph
Range: 850 mi
Seats: 1

The prototype Vultee V-11 Army attack bomber NX14999 c/n 28 first flew on 17 September 1935, piloted by T C Van Stone. It crashed on take-off for its second flight the next day, killing Van Stone and project engineer Duald L Blue.

The second V11 prototype, but with 1800hp P&W R-2800 Double Wasp and three-blade prop, NX/NR/NC14980 c/n 29, first flew on 9 October 1935 as a demonstrator for the South America market.

The second V11 prototype, built first as a V-11A, it was later modified as the fixed-gear V-11T for Pratt & Whitney’s use in engine testing, first flying on 21 January 1940.

Ultimately refitted with 2000hp R-2800, it was destroyed in a crash on 20 March 1945.

The V-11G and -11GB were versions with a 1000hp Wright SGR-1820-G2 Cyclone. The V-11G was a two-seater, and -11GB sat three (pilot, bombardier, gunner) with a retractable ventral gun position. One was built as a company test hack on wheels (NX/NR17327) and seven with a 1200hp P&W R-1830-17 went to the USAAC in 1939 for field testing as YA-19 (38-549 to 38-555).

China ordered 30 two-seat Vultee V-11Gs in 1937-38 and then more Vultee V-12s (a more powerful variant) which they were planning to assemble from kits (25 were finished)

At the end of June 1935, information reached Moscow about the new American Vultee V-11 attack and bomber aircraft. In a report to Defense Commissar Kliment Efremovich Voroshilov on the acquisition of aircraft production licenses in the United States, the chief of staff of the VVS RKKA VK Lavrov placed special emphasis on the excellent characteristics of the V-11 in terms of speed and range. In fairness compared to the obsolete R-5Sh and R-5SSS the approach was valid.

As a consequence, the Vultee V-11 was part of the purchase of production licenses approved by the Labor and Defense Committee (STO) on April 11, 1935.

On September 7, 1936, the Soviet foreign trade company “ Amtorg ” signed a contract with the American firm “ Airplane Development Corporation”, to which Vultee belonged at that time . The content of the negotiation stipulated the granting of a license to the Main Directorate of the Aeronautical Industry (GUAP) of the People’s Committee for Heavy Industry (NKTP) for the construction of the V-11 in two variants: V-11G as attack aircraft and V-11GB as a light bomber. This latest version incorporated a third member of the crew serving as navigator-bomber.

In 1937 two examples were received in flight condition and another two unarmed, which were thoroughly studied by the TsAGI and the NII VVS. The four -11GB were NR17328-17329 and 2 unregistered, along with some EDO sets to transform them into -11GBS seaplane and -11GBF floatplane attack bombers.

The North American counterpart delivered the plans with detailed engineering, the specifications, instructions and description of the processes, documentation on the jobs and the technological processes, as well as the technical data of the ground and flight tests of the model, as well as the obtained in tests in wind tunnels; resistance calculations and more than 300 photographs of details and aggregates. The purchase of several copies, parts and pieces was also considered to facilitate the start of series production. An interesting detail was the request from the USSR to modify all the schematics and plans of the model under the international metric system.

The Vultee firm delivered two fully assembled examples to be used as a basis for comparison, both with a Wright SR-1820-G2 engine and full armament and without a radio. The first, with number “ 32 ”, left the production workshops on December 22 , 1936 . It was planned to be sent to the USSR in January 1937, but the appearance of small defects delayed the decision. This first example took flight on January 31, 1937 and was tested by pilot SA Levanievsky on February 2 with the mechanic Chiechin. Levanievsky rated the aircraft positively in terms of maneuverability, stability and ease of flight.

The tests were carried out until mid-February 1937 and the chief of technical supply of the VVS Bazienkov and the director of the TsAGI Jarlamov participated as observers. It was flown from the Vultee factory airfield and from the military base in Long Beach. Tests were carried out over the ocean of weapons firing and bomb drops. The “ 32 ” was tested as an attack aircraft version and as a light bomber. A second specimen with number ” 33 ” flew for the first time on February 26. The Soviet delegation received the first issue in March and the second in April. Two other copies ” 34 ” and ” 35″ were delivered” in parts and without engine.

Upon arrival in the USSR the planes were studied in depth. The “ 33 ” plane was sent directly to the NII VVS to carry out the state tests, keeping the American equipment and weapons. In the first half of 1937 the V-11GB was studied in detail at the TsAGI and the NII VVS. The test pilot designated to lead the tests was Captain AK Dolgov, but the plane was flown by a large number of pilots, including the head of the institute NN Bazhenkov and the experienced test pilots Stefanovski, Fedrov, Niuxtikov.

The tests of the ” 33 ” contemplated the complete range, including its air combat simulation, completing a total of 70 flight hours. Test results were conflicting. On the one hand, the NII VVS concluded that due to its weapons and equipment capacity, the V-11 could be used as an attack and bomber aircraft. However, due to its speed and turnaround time, it was already obsolete. With a similarly underpowered engine, the Nieman R-10 bested the V-11 by 30 km/h and reached 5000 meters 5.6 minutes earlier. In the parameters of takeoff and landing characteristics, the R-10 was also superior.

The V-11’s armament was also considered obsolete. The rear firing point had a poor operating angle and did not guarantee the protection of the plane against the attack of the fighters. The absence of a lower turret (which was removed from the aircraft delivered to the USSR ) left all that area exposed to enemy attack. During simulated combats with I-16 Type 4 it was demonstrated that the V-11 was unable to escape before the attack of the fighters and to defend against their attack. Another conclusion established the absence of capacity to carry containers of chemical weapons (at that time in the USSR great importance was given to this type of armament). The bomb racks were not designed to allow the attachment of Soviet containers. Finally the Vultee V-11 was not prepared to work in the harsh Russian winter.

On the other hand, the Vultee V-11 showed the Soviet builders many new aspects. The construction technology, the materials used, many construction details and technological solutions were carefully studied and documented in order to introduce them into the productive process of the Soviet aeronautical industry.

High value was given to the comfort of the cockpit and the excellent visibility, the effective amortization system of the landing gear and brakes. The retraction system of the landing gear units was studied in detail. The measures taken to reduce the vibrations transmitted by the engine to the fuselage structure were highly valued.

The aircraft was easy to assemble and disassemble, and the designers provided easy access to all vital mechanisms and accessories for maintenance and repairs.

From the point of view of the flight, the stability in flight, the excellent work of all the mechanisms and the reliability of the engine were highly valued.

After evaluating the positive and negative aspects of the V-11G, it was decided to proceed to mass production of the model under the name BSh-1, its production being assigned to the OKB-1 led by S. A Kochierigin. In the issued documents it is clear that the fundamental reason was not to assess the possibilities of the model, but the possibility of becoming familiar with the new technological processes used in the construction of this aircraft. The production of the V-11G was considered to be the first step towards the development of a modern and effective bomber and attack aircraft for Soviet aviation.

Forty -11GB went to Turkey redesignated -11GBT, and 26 -11GB to Brazil in 1938-39 as -11GB2, the last of which was modified with EDO floats as 11GB2F for the Brazilian Navy, as also was prototype NX21719 in hopes of civil sales, which didn’t occur.

The three-place A-19 attack bomber from the V-11GB was all-metal except for the tail control surfaces. The YA-19 (Model V-11GB) first flew on 27 January 1939 and of the seven, three were converted from V-11G and repowered as XA-19 series.

Out of the five Vultee YA-19 (Pratt & Whitney Twin Wasp R-1830-17 radials) three-seat attack bombers delivered to the USAAF in 1939, three underwent engine changes to become the XA-19A (Lycoming); XA-19B (P&W Double Wasp R-2800-1) and XA-19C (P&W Twin Wasp R-1839-51).

The XA-19A served as a flying testbed for the 12-cylinder, liquid cooled XO-1230-1, with 1200 hp for take-off. To compensate for the increased side area and fuselage length (increased by 5in to 38ft 3in) the Gerald Vultee fin was altered to give more area. Despite the improved frontal area streamlining, the XA-19A improved the maximum speed by only 2 mph, to 232 mph. The span was 50 ft.

The 1940 XA-19A (Model V-11) featured an enlarged, triangular fin and 1200hp Lycoming O-1230-1 engine. The one was converted from a YA-19 and first flew on 22 May 1940. It later became a XA-19C.

YA-19 38-550 was converted to the XA-19B in 1939, powered by an 1800hp P&W R-2800-1 engine.

Converted from XA-19A 38-555, the 1939 XA-19C 1939 was powered by a 1200hp P&W R-1830-1/-51.

The aircraft had limited combat success with the Chinese, and a Brazilian Vultee V-11 made an attack on a submarine, damaging itself in the process. Later developments would have a rear facing gunner at the back of the cockpit plus a rear-facing ventral gun position protruding from the bottom. Most were later used as high speed liaison and transport aircraft.

Gallery

Second V11 prototype
Engine: 1800hp P&W R-2800 Double Wasp
Prop: three-blade
Wingspan: 50’0″
Length: 37’6″
Useful load: 3450 lb
Max speed: 232 mph
Cruise speed: 213 mph
Stall: 68
Range: 1220 mi

V-11
Engine: 750hp Wright SGR-1820
Prop: 2 blade
Wingspan: 50’0″
Length: 37’6″
Useful load: 3265 lb
Max speed: 229 mph
Cruise speed: 207 mph
Stall: 68 mph
Range: 1225 mi
Ceiling: 28,000′
Seats: 2

Engine: Wright SR-1820-F53
Time to 20,000ft: 14 min
Service ceiling: 27,000 ft
Absolute ceiling: 29,000 ft
Cruise: 220 mph
Top speed: 265 mph
Seats: 2

YA-19 / V-11GB
Engine: P&W R-1830-17 Wasp, 1200hp
Wingspan: 50’0″
Length: 37’10”
Useful load: 3969 lb
Max speed: 230 mph
Cruise speed: 207 mph
Stall: 80 mph
Range: 1110-1385 mi
Ceiling: 24,400′

XA-19A / V-11
Engine: 1200hp Lycoming O-1230-1
Useful load: 3680 lb
Speed: 232 mph

XA-19B
Engine: P&W R-2800-1, 1800hp

XA-19C
Engine: P&W R-1830-1/-51, 1200hp