Vultee V-48 (P-66 Vanguard)

Когда компания «Vultee» готовилась к запуску в серию учебного BT-13, началось проектирование истребителя подобной конструкции, но одноместного и с убираемой хвостовой опорой шасси. Изначально мотор Pratt & Whitney 11-1830-S4C4-G мощностью 1200 л. с. (895 кВт) для снижения лобового сопротивления очень тщательно закапотировали; двигатель соединялся с винтом длинным валом.
   Самолет, получивший наименование Vanguard, выполнил первый полет в сентябре 1939 года. Уже в первых полетах выявились проблемы с охлаждением мотора. Возврат к традиционной схеме установки мотора обернулся лишь незначительным увеличением лобового сопротивления. Доработанный второй прототип V-48X выполнил первый полет 11 февраля 1940 года.
   Пятью днями ранее фирма получила заказ от ВВС Швеции на 144 таких истребителя. Прототип серийного V-48C выполнил первый полет 6 сентября 1940 года. Из-за наложенного правительством США эмбарго предназначенные Швеции самолеты хотели отгрузить Великобритании, однако англичане после оценочных испытаний двух машин от истребителей отказались.
   15 самолетов под обозначением P-66 использовались как учебные в авиации Армии США на западном побережье. 129 истребителей по ленд-лизу через Карачи поставили в Китай.
   Несколько самолетов было потеряно в ходе доставки, Китай получил всего 79 истребителей. Хорошо вооруженные, маневренные, с большой продолжительностью полета китайские Vanguard сбили несколько японских аэропланов, но были сняты с вооружения в 1943 году.


ТАКТИКО-ТЕХНИЧЕСКИЕ ХАРАКТЕРИСТИКИ

   Vultee P-66 Vanguard

   Тип: одноместный истребитель
   Силовая установка: один мотор воздушного охлаждения Pratt & Whitney R-1830-33 Twin Wasp мощностью 1200 л. с. (895 кВт)
   Летные характеристики: максимальная скорость на высоте 4600 м - 547 км/ч; практический потолок 8595 м; дальность 1529 км
   Масса: пустого 2375 кг; максимальная взлетная 3349 кг
   Размеры: размах крыла 10,97 м; длина 8,66 м; высота 2,87 м; площадь крыла 18,30 м2
   Вооружение: четыре 7,62-мм и два 12,7-мм пулемета

Flight, May 1940

HIGH LOADINGS
The Vultee Vanguard : Rise in Wing Loading With Power and Armament

  AMONG the new American military aircraft tried out by Wing Cdr. Addams, on behalf of the British Air Ministry, is the Vultee Vanguard single-seater fighter. This low-wing monoplane bears a marked resemblance to the machine in which Howard Hughes set up a world's speed record in 1935 by attaining 352 m.p.h., which is understandable, as both machines were designed by Mr. Richard Palmer. The first pictures of the Vanguard to appear showed it fitted with a Pratt and Whitney Twin Wasp with the new totally enclosed cowling, but the machine is now flying with a more conventional installation. Figures are also quoted for a version powered with the new Wright Two-row Cyclone, and it is intended ultimately to fit the Pratt and Whitney Double Wasp, of even higher horse-power.
  Manufacturers' data issued for the Vanguard 48 powered with a Pratt and Whitney Twin Wasp S3C4-G engine include an empty weight of 4,657 lb. and a gross weight of 6,029 lb. The wing area is 197 sq. ft., which gives a wing loading of 30.6 lb./sq. ft. These weights relate to the machine as armed with two Colt (Browning) 0.5m. machine guns with 250 rounds of ammunition each, the armament weight in this case being 252 lb. It has lately been stated, however, that the Vanguard can carry not only these two heavy machine guns, but eight additional rifle-calibre guns with about 4,000 rounds of ammunition. This additional armament would increase the all-up weight by something like 430 lb. and raise the wing loading to 32.77 lb./sq. ft., which is higher than that of the Messerschmitt Me 109.
  With the Wright Two-row Cyclone, which gives 1,275 h.p. at 12,000ft. and weighs 1,950 lb., the all-up weight with the two heavy machine guns becomes 7,298 lb., and the wing loading is raised to 37.04 lb./sq. ft. The addition of the eight rifle-calibre guns would increase this further to 39.22 lb./sq. ft., which is very high indeed, particularly for a single-seater fighter.
  No figures have been released for the Vanguard as fitted with the Double Wasp (1,450 h.p. at 16,000ft.), but the empty weight would be at least 7,648 lb. With the two 0.5m. guns this would give a wing loading of 38.8 lb./sq. ft., and the addition of the eight smaller guns would result in a loading of at least 40.49 lb./sq. ft. It is believed that the Double Wasp installation will be standardised with an airscrew extension shaft, so in all probability the gross weight and wing loading will be considerably higher even than that.
  According to the best available information, the Heinkel He 112 has a wing loading of only 34 lb. /sq. ft., and this is considered by our designers to be dangerously high. The Hurricane is loaded to between 24 and 25 lb./sq. ft., and the Spitfire is very little siderably higher even than that.
  Apparently the full armament load has not yet been installed on a Vanguard, certainly not on the Double Wasp version. An excellent series of publicity pictures lately issued shows mechanics alleged to be installing the armament. It is obvious on examination that the pictures were specially posed, for one of the guns shown has the handles associated with a free installation. The "blurb" reads as follows: -
  "Believed to be the most heavily armed pursuit airplane of its type in the world to-day, the Vultee Vanguard pursuit can mount eight calibre 30 machine guns, firing approximately 4,000 rounds of ammunition, and two calibre 50 machine guns firing approximately 500 rounds of ammunition.
  "Three of the 30 calibre guns are mounted in each wing, while two 50s and two 30s are installed in the fuselage and are synchronised to fire through the propeller field.

Barrel Removal

  "It was learned to-day that Vultee armament engineers have succeeded in making it possible to remove barrels and internal mechanisms from each of the guns without having to remove the entire gun from its mountings. Heretofore, machine guns on most pursuit airplanes had to be entirely removed, causing delay in getting the airplane back into fighting service and also interfering with delicate sighting adjustments. The company's armament engineers believe that with this special provision for removing barrels and mechanism of all the guns it is possible completely to service the airplane's armament in from 10 to 15 minutes and have it ready for action."
  Perhaps Mr. Palmer would care to submit for publication figures for the Vanguard carrying its ten guns and powered with the big Wright or Pratt and Whitney engine. Until that time we shall not comment further, but will briefly describe the structure.
  The forward section of the Vanguard fuselage is of welded steel tubes, covered with quickly removable metal panels, but the rear section is of semi-monocoque construction. The wing is an all-metal cantilever type consisting of a rapidly detachable centre-section and two outer panels. In the centre-section are integral fuel tanks with a total capacity of 240 U.S. gallons. The undercarriage retracts into the centre-section ahead of the front spar. All exterior metal surfaces have butt joints and flush rivets.
  Fitted with the Pratt and Whitney Twin Wasp S3C4-G engine (a two-speed supercharged model giving 1,050 h.p. at 13,100ft.), the Vanguard is claimed to have a top speed of 358 m.p.h. at 15,600ft. and to climb to 19,680ft. in 6.7 min. A service ceiling of 34,300ft. is claimed and the cruising range is said to be 580 miles on 144 U.S. gallons, though in overload condition, with 240 U.S. gallons, this may be extended to 1,800 miles. The span is 36ft., length 29ft. 2in., and height 9ft. 5in.