Fokker D.XXIII
Страна: Нидерланды
Год: 1939

Единственный экземпляр
Одноместный истребитель
Flight, December 1938
The Paris Aero Show


Fokker D.XXIII

   Прототип истребителя Fokker D.XXIII, появившийся в 1939 году, вызвал интерес у авиационных специалистов во всем мире во многом благодаря своей необычной компоновке. Его разработчиком был инженер Мариус Билинг. Он разместил в оконечностях цельнометаллической гондолы фюзеляжа два двигателя с тянущим и толкающим винтами. Между ними в закрытой кабине размещался пилот. К низкорасположенному свободнонесущему крылу деревянной конструкции крепились две балки с килями и рулями направления; кили были соединены горизонтальным оперением. Использовалось полностью убирающееся шасси с носовым колесом.
   Силовая установка самолета состояла из двух маломощных двигателей жидкостного охлаждения Walter Sagitta I-SR. "Fokker" надеялась получить заказ от правительства Голландии и, возможно, от зарубежных покупателей. Учитывая не очень впечатляющие характеристики, продемонстрированные прототипом, рассматривалась возможность установки на него двигателей Rolls-Royce или Daimler-Benz. Учитывая высказанные опасения о безопасности пилота, который в случае покидания самолета мог бы попасть под хвостовой винт, Билинг начал проектировать катапультное кресло, но здесь его постигла неудача.
   Первый полет D.XXIII состоялся 30 мая 1939 года, и он выявил недостаточное охлаждение заднего двигателя. Поэтому до момента германского вторжения в Нидерланды прототип успел налетать всего несколько часов. После оккупации Голландии никаких данных о дальнейшей судьбе D.XXIII нет.


   Fokker D.XXIII

   Тип: одноместный истребитель
   Силовая установка: два 12-цилиндровых V-образных двигателя Walter Sagitta I-SR мощностью по 530 л. с. (395 кВт)
   Летные характеристики (проектные): макс. скорость 525 км/ч; потолок 9000 м; дальность полета 840 км
   Масса: пустого снаряженного 2180 кг; максимальная взлетная 2950 кг
   Размеры: размах крыла 11,50 м; длина 10,20 м; высота 3,80 м; площадь крыла 18,50 м!

Flight, December 1938

The Paris Aero Show

A Tandem Tricycle

   Fokker has the only "novelty"’ in the show, a tandem-engined single-seater fighter with a tricycle undercarriage. It may be remembered that a few weeks ago Flight published a scale drawing of a design which a French constructor, Albert, put up to the French Air Ministry two or three years ago. Except for the tricycle undercarriage the general conception was the same. And, incidentally, the Fokker F.23 provides a good demonstration of the price one has to pay for the nose-wheel in the matter of extra weight and bracing, and the loss of internal stowage space by reason of the retracted nose-wheel. In the Albert design the idea was to have a shell-gun in the pusher engine so that the pilot could fire at his adversary when turning away after having delivered the attack with the front guns.



   MOST unorthodox and interesting of the new Continental single-seater fighters is the Fokker D.23 twin-engined monoplane which at first sight suggests derivation from the G.I or Faucheur two-seater shown last year. Actually the machine resembles the G.I only in the method of carrying the tail on two booms.
   An essential factor governing the layout was the provision of a good field of view for the pilot, who is located forward of the leading edge with one inverted Walter Sagitta in front and a second behind him driving a pusher airscrew. Thanks to the tricycle undercarriage the view while taxying is rather better than from most modern single-seaters.
   Although the internal wing structure is not visible it is of interest because it departs from the standard Fokker methods, being all-metal with duralumin spars, ribs and covering. The fuselage or nacelle is of welded steel tubes and has integral engine mountings; it is covered with detachable duralumin and aluminium panels. The tail booms are of stressed duralumin construction.
   Being sandwiched between two engines, the pilot is afforded a good measure of protection from enemy fire and his safety is further ensured by armour plating to the front and rear of his seat, just above the engines. Additional plates alongside the cockpit guard against lateral fire.
   Each of the three wheels of the undercarriage is of the Argus type with an Olaer strut. The main wheels retract inwardly and the nose wheel in a rearward sense.
   The particular Sagittas fitted are of the I.S.R. type giving 528 h.p. each at 13,400ft. The forward engine is cooled in a normal fashion, but the cooling air for the rear one enters through a scoop under the fuselage. Three-bladed fully feathering V.D.M. airscrews are fitted and the engines are supplied with a Garrelli compressed-air starting system. The fuel tank is installed in the fuselage and has a capacity of 88 gallons.
   Four fixed guns are fitted, two in the fuselage and two in the wing. The fuselage guns are Browning-F.N.s of 7.9 mm. calibre each, firing at the rate of 1,300 rounds a minute. The wing guns are of the same manufacture but of 13.2 mm. bore and with a rate of fire of 1,000 rounds a minute. For these guns a special explosive bullet has been introduced. This explodes 8 seconds after being fired. An interesting development noted in the fuselage is the circular cartridge conveyer.
   The D.23 has not yet been flown and no performance figures are being issued, though a figure of about 330 m.p.h. was being commonly quoted.
   In spite of its advanced design the new Fokker can hardly be such a formidable weapon as the Hurricane and Spitfire shown nearby on the Hawker-Siddeley and Royal Air Force stand respectively.
Fokker D.XXIII являлся интересной попыткой решить проблему с асимметрией тяги при отказе одного из двух двигателей, но мощность силовой установки прототипа оказалась недостаточной. Кроме того, при покидании машины с парашютом пилот рисковал попасть под удар заднего винта.
FOKKER DEVELOPMENTS: The tandem-engined Fokker D.23 single-seater fighter is now doing its initial test flights. The prototype has Walter Sagittas, but the much more powerful Rolls-Royce Merlins or Daimler-Benz 601s may later be fitted.
A view showing the layout of Fokker’s new D.23 single-seater twin-engined fighter, powered with two Walter Sagitta inverted vees.
DUTCH PROTOTYPE: The Fokker D.23 single-seater twin-engined fighter (inverted vee-twelve air-cooled Walter Sagittas) photographed shortly after its first flight. This machine was exhibited at the last Paris Salon and may be regarded as the prototype of aircraft with two Rolls-Royce Merlins or Daimler Benz D.B. 601s. It is designed for one shell-gun and two large-bore machine guns firing explosive bullets.
Fokker D.23
The unusual D XXIII of centreline-thrust concept
The unorthodox Fokker D.23 single-seater fighter has unusual ammunition feed arrangements for its Browning guns, designed to economise space.
The cooling air for the rear Walter Sagitta on the Fokker D.23 is admitted through this scoop.
The nose wheel of the Fokker D.23 tricycle undercarriage showing that when retracted it occupies a good deal of fuselage space.
A neat stabiliser on the tricycle under­carriage leg of the Fokker D.23, to check wheel shimmy
Armament of Single-seaters: Curtiss Hawk 75A with one 0.3in gun and one 0.5 in.; Curtiss Hawk 75A with six rifle-calibre machine gun; Curtiss Hawk 75A with two shell-guns and two machine guns; Fiat G.50 with two 0.5in. guns and two rifle-calibre machine guns; Hawker Hurricane with eight rifle-calibre machine guns; Morane M.S.406 with one 20 mm. shell-gun and two machine guns; Bloch 151 with two shell-guns and two rifle-calibre machine guns; Fokker D.23 with two shell-guns and two machine guns; Bell experimental pursuit with one 37 mm. shell-gun (unconfirmed).
Fokker Ont.156, dated December 23, 1937.