Vultee V - 11 The Vultee V - 11 and V - 12 were American attack aircraft of the 1930s . Developed from the Vultee V - 1 single - engined airliner , the V - 11 and V - 12 were purchased by several nation ' s armed forces , including China , who used them in combat against Japan ese forces in the Second Sino - Japanese War . The United States Army Air Corps purchased seven V - 11s as the Vultee YA - 19 in the years before World War II , testing them to gather data to compare against twin engine light attack planes . Design and development . In 1935 , Vultee produced a light bomber derivative of their single - engined passenger transport , the Vultee V - 1 , which , while demonstrating good performance , was only sold in small numbers owing to restrictions placed on the use of single - engined aircraft for scheduled passenger transport operations . The resulting aircraft , the Vultee V - 11 , retained the single - engined , low wing format and all - metal stressed skin structure of the V - 1 . It combined a new fuselage with accommodation for the two or three crew members under a long greenhouse canopy with the wings and tail surfaces of the Vultee V - 1 . Operational history . China . An initial order for 30 two - seat V - 11Gs was placed by China before the end of 1935 . This was followed by orders in 1939 for two versions ( the V - 12 - C and V - 12D ) of the more powerful V - 12 variant . The majority of these were planned to be assembled from kits at the Central Aircraft Manufacturing Company factory at Loiwing near the China - Burma border , and while the first batch of 25 V - 12 - Cs were completed successfully , the factory was heavily bombed just after assembly of the first V - 12 - Ds commenced . This resulted in the part built airframes being evacuated to India , where it was planned that the aircraft be completed at the Hindustan Aircraft Limited factory in Bangalore . However , after a few were assembled , production was stopped as the factory was diverted to more urgent overhaul work . The V - 11s and V - 12s were used as light bombers and achieved some success , including a mission to bomb the Japanese held airfield by 4 aircraft at Yuncheng on February 5 , 1939 by the 10th Squadron of the Republic of China Air Force , before the aircraft were withdrawn from bombing missions to training and liaison duties in 1940 . Brazil . In February 1939 the Brazilian Army Air Corps acquired 10 Vultee V - 11 – GB2s for long range bombing . 26 aircraft were eventually used by the Brazilian Air Force . On 8 November 1939 , aircraft 119 performed a 3250 km non stop flight across the Brazilian hinterland in 11 hours and 45 min . In 26 August 1942 , a U - boat was attacked 50 miles off the town of Ararangua in southern Brazil . Despite the unsuitability for anti submarine operations , the aircraft flew low and dropped its load of three 250 lb bombs , some of which exploded around the submarine . A column of water and debris damaged the low flying aircraft . Soviet Union . In 1936 , the Soviet Union purchased four three - seat V - 11 - GB aircraft , together with a production license . The aircraft entered Soviet production in 1937 as the BSh - 1 ( " Bronirovanny Shturmovik " ) , but the armour fitted for the ground attack role unacceptably reduced performance and production was stopped after 31 aircraft . They were transferred to Aeroflot and redesignated PS - 43 for use as high speed transports until the German invasion in 1941 , when they were returned to the Air Force for liaison purposes . United States . In the late 1930s , the United States Army Air Corps was favoring twin engine light attack aircraft but seven YA - 19 aircraft were ordered in the summer of 1938 for comparison purposes . The YA - 19s were armed with six . 30 in ( 7 . 62 mm ) machine guns and 1 , 080 lb ( 490 kg ) bombs in an internal bomb bay , powered by a 1 , 200 hp ( 895 kW ) Twin Wasp radial engine and was manned by a crew of three - pilot , observer / gunner , and bombardier / photographer . An interesting feature of the YA - 19 design was its horizontal stabiliser located forward of the vertical tail . The small size of the vertical stabilizer caused some directional instability ( about the yaw axis ) so the last YA - 19 ( S / N 38 - 555 ) was equipped with enlarged vertical stabilizer . Service tests showed that twin engine attack aircraft were faster , could be better armed and carried a larger bomb load so no further YA - 19s were ordered . After comparison tests five YA - 19s were redesignated A - 19 and assigned to the 17th Attack Group at March Field in California for a brief period before being transferred to the Panama Canal Zone for utility transport and liaison duties . The A - 19 never saw combat and was quickly replaced in the early 1940s . Operators . Info from Baugher