Fokker C-2

После успешной демонстрации в США транспортного самолета Fokker F.VIIA/3m принадлежавшая "Fokker" компания "Atlantic Aircraft Corporation" из Нью-Джерси построила аналогичную машину, но под обозначением Fokker F.9. Три самолета были заказаны для Армии США под обозначением C-2. Причем первый самолет, предназначенный для полетов на большие расстояния и имевший дополнительные топливные баки и специальное крыло размахом 21,7 м, строился на голландском заводе "Fokker". Все три машины оснащались двигателями Wright J-5 - вместо ставившегося изначально J-4.
   1 июня 1927 года "дальний" самолет C-2 "Bird of Paradise", пилотируемый лейтенантами авиакорпуса Армии США Лестером Дж. Мэйтландом и Альбертом Гегенбергером, вылетел из Окленда, штат Калифорния, и прибыл в Гонолулу, Гавайи, преодолев без посадки расстояние в 3862 км. За самолетами модели C-2 последовали еще восемь машин модификации C-2A, имевшие крыло еще большего размаха, чем "рекордный" C-2. Один из C-2A, названный "Question Mark", в январе 1929 года установил рекорд длительности полета, оставаясь в воздухе 150 часов - в полете выполнялась дозаправка топливом от переоборудованного в заправщик грузового биплана Douglas C-1, предоставленного Армией США.


Варианты

   XC-7: один самолет C-2A, переоборудованный под три звездообразных ПД Wright R-975 (J-6-9) мощностью по 330 л. с. (246 кВт)
   C-7A: шесть серийных XC-7; отличались от прототипа большим крылом, новыми килями и фюзеляжем, схожим с коммерческим F.10A
   XLB-2: экспериментальный легкий бомбардировщик, переделанный из C-7 и оснащенный двумя звездообразными двигателями Pratt & Whitney R-1340 мощностью по 410 л. с. (306 кВт); построен один самолет
   TA-1: обозначение ВМС США для варианта C-2; три самолета были куплены в 1927-1928 годах и переданы морской пехоте, позднее они получили обозначение RA-1 - во избежание путаницы с самолетами-торпедоносцами
   RA-2: первоначально TA-2 - три таких самолета ВМС США были аналогичны самолетам C-2A Армии США
   RA-3: один самолет, первоначально получивший обозначение TA-3; оснащался звездообразными двигателями Wright J-6; RA-1 и RA-2 позднее также получили двигатели J-6 - все машины получили обозначение RA-3, несмотря на значительные различия, включая разный размах крыла


ТАКТИКО-ТЕХНИЧЕСКИЕ ХАРАКТЕРИСТИКИ

   Fokker C-2A

   Тип: военно-транспортный самолет вместимостью 10 человек
   Силовая установка: три 7-цилиндровых звездообразных ПД Wright J-5 (R-790) мощностью 220 л. с. (164 кВт)
   Летные характеристики: максимальная скорость 182 км/ч; нормальная крейсерская скорость 145 км/ч; дальность 476 км
   Масса: пустого снаряженного 2951 кг; максимальная взлетная 4715 кг
   Размеры: размах крыла 22,61 м; длина 14,73 м; высота 4,11 м; площадь крыла 66,70 м2

Flight, September 1925

FIRST THREE-ENGINED FOKKER
Latest Development of F.VII Type

   SINCE the first machine was produced, the Fokker VII type has been undergoing steady development and has made its appearance with a variety of engines, such as the Rolls-Royce "Eagle," Napier "Lion," and the "Liberty." It was, it will be remembered, on the Napier engine type that Mynheer Fokker gave a demonstration at Croydon of control at large angles, and on the same machine an altitude which only just misses being a world's record has been attained, while the "Liberty" engined machine holds the world's duration record for useful loads of 1,500 kgs. (3,300 lbs.) and a 1,000 kgs. (2,200 lbs.), with 3 hours 3 1/2 mins.
   Quite recently the F.VII has appeared in yet another form, i.e., as a three-engined monoplane. This machine has been specially produced for night flying on regular air routes, and we understand that the first specimen has already been packed and dispatched to the United States Government, for use on the night air mail services. It seems likely that other machines, if this type is accepted by the United States Government, will be constructed in the American Fokker factory.
   Before referring to the machine itself, it may not be without interest to give a brief outline of the manner of its coming into being. In the beginning of July of this year, Mr. Fokker, who was at that time in the United States on business, cabled instructions to the Amsterdam factory to develop the F.VII as a three-engined machine. Mr. Fokker cabled all principal dimensions and such special constructional details as were required to change the type from a single-engined into a three-engined machine.
   Mr. Platz, chief draughtsman of the Fokker works, at once took the design and construction in hand, and three Wright "Whirlwind" engines with their propellers had, in the meantime, been obtained by Mr. Fokker in the States and despatched to Amsterdam, where they arrived in the beginning of August. At the end of August the machine was ready to leave the factory, and, on September 3, it was dismantled and loaded on barges to be taken to the aerodrome at Schiphol, this being the usual method of transporting new machines from the Fokker factory, which is situated on the Northern bank of the river Ij, to the aerodrome, which is situated several kilometres out of Amsterdam, and on the opposite side of the city. By 9 a.m. on September 4 the parts were unloaded, and by 4 o'clock in the afternoon of the same day the monoplane was ready for flight, having had its engines tested and its tanks filled. At 4.30, Mr. Fokker himself took it up for its first test flight, carrying four passengers and some ballast.
   The next day the machine was demonstrated before officials of the K.L.M., and on Monday, September 7, Mr. Fokker gave demonstration nights before representatives of the Dutch and foreign press at the Schiphol aerodrome. During the demonstration the machine was repeatedly flown with one of the three engines stopped. Mr. Fokker first stopping one and then another, and it was found that with either two engines and carrying full load the machine would not only fly level but would actually climb. During the demonstration, Mr. Fokker throttled down one wing-engine completely just after the start - in other words, just at the most critical moment, and which would represent the accidental stopping of a wing engine just as the machine was taking off. Each time the machine climbed steadily.
   Climbing to a somewhat greater altitude, Mr. Fokker shut off all three engines and stalled the machine. As in the single-engined F.VII, there was no perceptible tendency to spin or nose dive, the machine merely sinking slowly.
   The next demonstration to be given consisted in flying the machine with only one engine running. Under these conditions it was not to be expected, of course, that the machine would fly level with full load, but the altitude lost was amazingly slight, so that even with two engines stopped (during the demonstrations the two idle engines were not merely throttled down, but actually stopped altogether), the machine would have a very good gliding angle, and the pilot should be able to pick a suitable field in which to make a forced landing. The manoeuvre of flying on one engine was successively carried out with each of the three engines in turn, and whichever engine was used, the machine appeared to handle equally well. To show that with only one wing-engine running the machine was still perfectly controllable, Mr. Fokker made a quick turn against the pull of that engine.
   With reference to the machine itself, this is, as will be seen from the photographs, practically a standard F.VII. An alteration which has evidently been necessitated by the addition of the two wing engines is that the telescopic struts of the undercarriage are taken to the wing instead of to the top of the fuselage. This is not a point in the design of which one can really approve, as in a bumpy landing severe stresses may be thrown on the wing structure without actual breakage occurring, and the machine might then be in danger of wing failure on a subsequent flight. The two wing engines are mounted upon what appear to be somewhat sketchy tubular structures attached to the lower bases of the wing spars, and in the photographs it will be seen that no cowling whatever is provided. Presumably, however, when the machine is further developed, suitable cowls will be placed over the wing engines so as to reduce head resistance, as this, one would imagine, must be fairly high with uncowled engines. In other respects, the machine has scarcely been altered with the exception that the fuselage has been slightly lengthened so as to give greater leverage for the rudder, in order to overcome the turning moment set up when one wing engine is stopped.
   Normally, the new machine is fitted with a monoplane wing of 635 sq. ft. area, but a larger wing can be fitted, when the load capacity is increased by about 500 lbs. The three-engined monoplane, with the 635 sq. ft. wing, has seating accommodation for two pilots and eight passengers, and in addition there are two luggage compartments. With this small wing the machine carries a useful load of 3,200 lbs., which figure includes the weight of the two pilots and fuel for six hours at cruising speed. The actual paying load in this case is approximately 1,500 lbs. With this load the maximum speed is stated to be about 125 m.p.h., and the climb to 3,000 ft. is accomplished in 3 3/4 mins., while the altitude of 5,000 ft. is reached in 7 1/4 mins.
   The present machine is, as already mentioned, fitted with three Wright "Whirlwind" engines of 200 h.p. each, but it is stated that the machine can equally well be equipped with other engines of about the same power, such as the Armstrong-Siddeley "Lynx."

Flight, November 1925

THE THREE-ENGINED FOKKER MONOPLANE
The Type F VII-3 m.

   In our issue of September 17, 1925. we published some photographs and a brief general description of the new Fokker three-engined monoplane, the type F.VII-3m, which has since done well in America in the Commercial Airplane Reliability Tour for the Ford Trophy. We have now received from the Fokker Company certain further particulars relating to this machine, as well as the general arrangement drawings and as three-engined machines are much to the fore at the present moment, we have thought that some data relating to the Fokker might be of interest.
   Concerning the constructional features of the Fokker F.VII-3m little need be said, as these follow, in the main, the well-known Fokker practice, which has already been fully dealt with in FLIGHT on several occasions. The fuselage is of welded steel tube construction, of which the famous Dutch designer has by now had many years' experience, and which he has so far seen no reason to change, whatever theoretical objections may be raised against it. The monoplane cantilever wing is an all-wood structure, in which the three-ply covering carries part of the stresses. Several years' experience with commercial machines of this construction have proved it to be easy of maintenance, reliable, durable and largely weatherproof.
   From the general arrangement drawings it will be seen that the three-engined monoplane is of typical Fokker lines with a long fuselage and a monoplane wing of fairly high aspect ratio. The wing section employed is the usual Fokker, which has the characteristic that its lift curve does not show a sharp drop after the critical angle has been passed. In section the wing tapers both in chord and depth, giving a wing of tapering plan form. Ailerons of large span but small chord are fitted, and are said to be very effective, although they do not show the horn balance with which the machine on which Fokker gave his non-stalling exhibition at Croydon was provided.
   The chief departure from the single-engined F.VII is in the lengthening of the nose of the fuselage to trim the machine with an engine of lower weight than the larger engine with which the older type is fitted. This has been accomplished by a simple framework of steel tubes, and the space thus left between the pilot's cockpit and the engine plate is so large that after removing the cowling a man may easily, while standing on the ground, reach the back of the engine and make any adjustments necessary to the engine accessories mounted there.
   The wing engines are supported from the wing by a system of steel tubes, there being two points of attachment on the front spar and one point on the rear spar. The front supports are in the form of a letter N, in the plane of the spar, while the rear struts are in the form of a sharply-sloping tripod. This form of mounting is somewhat unusual for a radial engine, as these tubular struts do not carry the engine direct, but support a horizontal steel tube framework to the front of which the engine is secured. The arrangement may be seen in the photographs. The engine bearer structure is enclosed in a streamline casing, in which the oil tank is housed, but there is no cowling around the engine itself. The petrol tanks are carried in the centre of the wing, with pipes running to the three engines and supplying them with fuel by gravity feed. The cabin has seating accommodation for eight passengers, and a cockpit ahead of the leading edge of the wing is arranged for two pilots.
   A novel feature made desirable by the fitting of three engines is the provision of a trimming tail fin, the object, of course, being to relieve the pilot of the necessity of constant ruddering when one wing engine is out of action.
   The undercarriage is similar to that of the F.VII, but the telescopic legs run to the "power eggs" instead of to the wing itself, and are thus somewhat shortened. The track is wide - about 14 ft.
   The overall dimensions of the F.VII-3m are shown on the general arrangement drawings, but it should be stated that the machine is fitted with two types of wing, one the same as the F.VII (improved type) as regards area, but having, of course, local strengthening where the wing engines are attached, and the other a larger wing (by some 86 sq. ft.) which enables the machine to carry approximately 500 lbs. more paying load at some sacrifice in speed.
   The weight of the F.VII-3m is 4,750 lbs., and the total useful load is 3,200 lbs., made up as follows: Two pilots, 350 lbs.; fuel for 3 1/2 hours at full throttle, 1,150 lbs.; oil for 4 hours, 130 lbs.; eight passengers with luggage, 1,570 lbs. The total loaded weight is thus 7,950 lbs., which, with a wing area of 630 sq. ft., gives a wing loading of 12-6 lbs./sq. ft., and with a total power of 600 h.p. the power loading is 13-3 lbs./h.p. The machine is normally fitted with three Wright J.4 "Whirlwind" engines of 200 h.p. each, but other radials of about the same power can be supplied, and it is of interest to note that the British Air Ministry is reported to have ordered one of these machines fitted with Armstrong-Siddeley "Lynx" engines.
   The following performances relate to the machine as fitted with the "Whirlwind" engines: Maximum speed at ground level, 125 m.p.h.; cruising speed, 106 m.p.h.; landing speed 47 m.p.h.; duration at cruising speed, approximately 5 hours; climb to 1,000 ft. in 1-2 minutes; to 5,000 ft. in 7-25 minutes; to 10,000 ft. in 16-5 minutes; and to 15,000 ft. in 38 minutes. The practical ceiling is 15,500 ft.
   It is of interest, in view of the wide difference between the two types of machines, to compare some of the Fokker figures with those of the Handley Page "Hampstead." The Fokker wing loading is 12-6 lbs./sq. ft. and that of the "Hampstead" is 8-35 lbs./sq. ft. The power loading of the Fokker is 13-3 lbs./h.p. and that of the "Hampstead " is 12-55 lbs./h.p. The paying load of the Fokker for a distance of approximately 450 miles is 2-62 lbs./h.p. and for the "Hampstead" 2-78 lbs. h.p. The rate of climb appears to be roughly the same for the two machines, and one thus finds that, in spite of the fact that one machine is a cantilever monoplane of 8,000 lbs. loaded weight and the other a biplane of 14,500 lbs. loaded weight, the performances and the useful loads per horse-power are very nearly identical. In view of the question monoplane or biplane it is rather interesting to find two concrete examples which seem to indicate that there is little to choose as regards efficiency between the two types. Assuming the Fokker speed figures to be correct, and we have no reason to doubt them, the monoplane seems to score somewhat on the point of speed, both maximum and cruising.

Flight, December 1926

The Paris Aero Show 1926

FOKKER

   THE famous Dutch aircraft constructor, whose firm is the N. V, Nederlandsche Vliegtuigenfabriek of Amsterdam, will be represented by two aeroplanes, one a commercial type and one a military. The former is the three-engined monoplane type F.VII-3m., similar to that on which Commander Byrd flew to the North Pole, and the latter is the C.V. two-seater fighter.

   The Fokker F.VII-3m. monoplane is fitted with three Armstrong-Siddeley "Lynx" engines of 185 h.p. each, and is of the familiar form of Fokker construction with welded steel tube fuselage and all-wood wing. The pilot's cockpit has accommodation for two pilots, and dual controls are provided. The cockpit is equipped with night-landing equipment, and there is ample room for wireless apparatus. A door in the rear wall of the cockpit gives access to the passengers' cabin, which has seating accommodation for 8 passengers. In addition to heating and ventilating arrangements there is a lavatory at the rear end of the cabin, and behind that again, with a separate door in the side of the fuselage, is a large luggage and goods compartment, a smaller luggage space being provided under the pilots' cockpit.
   The Fokker F.VII-3m. can also be used as an ambulance machine, when it gives accommodation for 6 stretchers and one attendant. Furthermore, it can be supplied as a night-bomber, when the armament consists of 1 or 2 machine guns, one of which is fitted over an opening in the roof at the rear of the cabin. As bomb load may be carried 10 bombs of 50 kg. each, or 5 of 100 kg. or 2 of 250 kg. or 1 weighing 500 kilos. The crew consists then of one pilot, one assistant pilot or navigator, and one gunner.
   Finally the Fokker F.VII-3m can be supplied as a torpedo carrier, when a torpedo weighing 1,000 kg. can be slung underneath the fuselage. In this case the crew consists of one pilot and one observer.
   Specification of Fokker F.VII-3m.- In its commercial form the machine has the following characteristics: Span, 19-3 m.; length overall, 14-6 m.; wing area, 58-5 sq. m. (a larger wing having an area of 67 sq. m. can be supplied). Weight empty, 2,150 kg.; fuel and oil, 600 kg.; crew 150 kg.; 8 passengers and luggage, 700 kg.; total loaded weight, 3,600 kg. Wing loading, 61-5 kg./m2; power loading, 6-6 kg. /h.p. Maximum speed, 185 km./h.; cruising speed, 165 km./h.; minimum speed, 80 km./h. The climb is as follows: 1,000 m. in 5-8 mins.; 2,000 m. in 12-3 mins.; 3,000 m. in 22-2 mins.; ceiling approximately 4,700 m. Duration approximately 5 hours. These performance figures are guaranteed to within a margin of 3 per cent, on speed and 6 per cent, on climb.
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   The Fokker F.VII-3m commercial monoplane was seen by many at Paris for the first time, although the type has been used fairly extensively on air line work. The particular specimen exhibited was stated to have been sold to the famous financier Loewenstein for addition to his "stable," which already includes quite a number of different types. The machine is of typical Fokker construction, with welded fuselage and wood wing. The manner of mounting and cowl ing the wing engines is rather neat, and a feature which is of special interest is the undercarriage which, in point of fact, is not new, having been fitted on the single-engined Fokker monoplanes for a long time. Probably the first time it was seen in England was on the occasion of the anti-stall demonstration by Fokker at Croydon, the machine used for this demonstration having an undercarriage of this type.
   The telescopic members of this undercarriage are of welded-up steel tubes (a feature to which some might object, although the undercarriage seems to stand up to its work in practice) and the shock-absorbing medium is in the form of rubber rings of standard size. One of our sketches illustrates the arrangement. It will be seen that individual rings may be removed without interfering with the others. Not only so, but if the machine is to be used with a very light load only (as might sometimes happen) a number of rings can be removed so as to obtain just the right amount of springing. Conversely if the machine is to be used with extra heavy loads, additional rings may be slipped into place. Thus not only can the springing be directly proportioned to the load, but from the point of view of maintenance the undercarriage is about as simple as anything could be.
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Flight, January 1931

THE BRAIN CENTRE OF A MODERN AIRCRAFT
Cockpit Equipment of the "Balair" Fokkers

   THE equipment of the cockpit of a modern comparatively large air liner is probably one of the most vital factors in its successful operation. The Swiss Air Traffic Company "Balair," have ensured that their Fokker F.VII B-3m.’s (3 "Whirlwind" 300 h.p. engines) are fitted up in a manner which will give the pilots every assistance they can have. As the photo shows, the arrangement of the various instruments is thoroughly practical, and while the equipment is extensive there is no over-crowding, so that the cockpit appears to be very roomy and comfortable.
   In spite of the fullness of the equipment, it is worth noting that the view in this type of machine is exceptionally good and the wide clear windows should make flying easy in any weather conditions.
   A view of the cockpit is shown on the right, at the top of which, in the centre, are the oil pressure gauges for the three engines. The group below these, reading from left to right, comprises a longitudinal inclinometer, a controller of flight (consisting of 3 parts, viz.: an airspeed indicator, a bank and turn indicator, and a transverse inclinometer) and an altimeter.
   A little lower, to the left of the photo, are the knobs for regulating the carburettor heating and the oil radiator of the left outboard engine; next to these the compass, and to the right the two knobs for regulating the carburettor heating and the oil radiator of the right outboard engine.
   Below are the switches for the Scintilla magnetos of the three engines, and a little lower again, the throttle levers. The three knobs on the left operate the throttles, while the three knobs on the right are for regulating the altitude control for the three engines.
   Finally, at the bottom are the knobs for regulating the carburettor heating and the oil radiator of the centre engine.
   On the left hand side of the instrument board, under the microlamp at the top, will be seen the revolution counter and underneath the oil-thermometer for the centre engine. The revolution counters and oil-thermometers for the outboard engines are mounted on their respective power-eggs, cearly visible for the pilots.
   On the extreme left, visible between the spokes of the steering wheel, is the clock, which also indicates in minutes the duration of each flight. To the left of the spindle of the steering wheel is the manometer which indicates the pressure of the pneumatic brakes on the wheels. The pedals for operating these brakes, which can be applied to each wheel separately, are mounted on the rudder bar. Part of the pedal for the right-hand wheel brake can be seen a little to the left under the throttle lever for the left outboard engine.
   There is also a microlamp at the top of the right half of the instrument board. The first row under the lamp comprises (from left to right) the contact for operating the left-hand Holt landing flare, the voltmeter for the lighting installation, the main switch, and the contact for operating the right-hand Holt landing flare.
   In the next row are (from left to right) the switch for the voltmeter, the switch for the navigation lights, the control lamp of the generator, the switch for the cabin lights, the switch for the microlamps and a plug contact.
   Below these are the fuses for the navigation lights, cabin lights and Holt flares, besides two holders for spare fuses. To the left of this row is the crank for the starter magneto, and under this the high tension switch.
   At the bottom to the left of the photo are the various wireless levers, etc., comprising, from top to bottom, a switch for regulating wavelengths, and the remote control unit of the Marconi transmitter-receiver, type AD6m. Lower down on the case is the switch and the knob for connecting up the telephone set, and the manipulating key. A little to the fore is the aerial winch and in the corner on the extreme left is the aerial ammeter.
   Finally, in the right-hand bottom corner is the Pyrene fire extinguisher.
   The layout is indicative of careful planning.