Самолеты (сортировка по:)
Страна Конструктор Название Год Фото Текст

Fokker A.I / M.5

Страна: Германия

Год: 1914

Fokker - W.1 - 1913 - Германия<– –>Fokker - A.I / M.6 / M.8 - 1914 - Германия

В.Кондратьев Самолеты первой мировой войны

  Первый в мире истребитель, оснащенный синхронным оружием, был создан немецким авиаконструктором голландского происхождения Антони Фоккером путем установки пулемета "Парабеллум" на самолет M5K, разработанный на базе французского многоцелевого моноплана "Моран G". Но в отличие от изделий фирмы "Пфальц", M5K не был точной копией "Морана". Он выделялся, прежде всего, конструкцией силового набора фюзеляжа и оперения, который на французской машине был деревянным, а у "Фоккера" - сварным из стальных труб. Кроме того, самолет имел оригинальную тележку шасси.
  Невооруженный M5K выпускался серийно с 1914 года, а в варианте истребителя он совершил первый полет 23 мая 1915 г.

A.Weyl Fokker: The Creative Years (Putnam)

Fokker’s close study of the Morane-Saulnier monoplanes brought to Johannisthal by Audemars and Letort has already been mentioned. Despite his examination of the aircraft and the sketches that he had made, Fokker did not have enough information to enable him to make a good copy of the French machine. And Hanuschke’s crashes were proof enough that surreptitious inspections and measurements were a poor basis for successful reproduction. No detailed, authentic description of the Morane-Saulnier had been published.
  It became clear to Fokker that, if he was to make a sound copy of the Morane-Saulnier, he would first have to obtain an actual specimen of the type. The full story of how Fokker acquired cheaply - for 500 marks (about £25), as he told Ernst Ditzuleit with great pride - a dilapidated Morane-Saulnier monoplane is not known: several versions are told by people who were with Fokker at that time. What is known is that late in 1913 (or in January 1914) Fokker and Haller went to Paris, and when they came back they brought with them a Morane-Saulnier monoplane that was slightly damaged and in a state of disrepair.
  It was a single-seater of Type H with a 50-h.p. Gnome rotary engine and a 14-square-metre wing. Fokker’s specimen seems to have been one of the earliest of the Type H Morane-Saulniers, but it was of the 1913 design with sprung undercarriage. With an aircraft of this type Legagneux had won the Pommery Cup contest in April 1913; Audemars had flown an identical machine from Villacoublay to Wanne in Westphalia on April 16, 1913, and the Type H that he flew at Johannisthal differed from standard only in having an 80-h.p. engine and increased tankage. Ordinarily the Type H carried 30 gallons of petrol and oil in a divided tank in front of the cockpit; feed was by gravity. For competition purposes a supplementary tank was sometimes installed behind the cockpit, with air-pressure feed to the main tank. The normal loaded weight was about 400 kg. (880 lb.).
  It is certain that Fokker did not buy his machine from the Morane-Saulnier firm; it must have been acquired “on the side”, and seems to have been sold for scrap. No drawings, erecting or handling instructions accompanied it. Fokker had made no attempt to secure a licence for the construction of the Morane-Saulnier monoplane or any of its patented features.
  On arrival at Schwerin, Fokker’s bargain Type H was unobtrusively put into a remote shed where it was unlikely to arouse the curiosity of the flying-school pupils or the workshop staff. Only a select few of his staff knew about it and helped to restore it to serviceability. Even to them Fokker did not explain why he had bought the Morane: he simply said that he wanted to try out a light monoplane fitted with one of the French rotaries that were so popular.
  During January 1914 the little monoplane was dismantled, overhauled and reassembled; it was rigged as well as might be in the absence of a copy of the manufacturer’s instructions. The Gnome engine was cared for and tuned by a foreman who had had previous experience of the type. Close acquaintance with the Morane-Saulnier showed Fokker and his associates how a light and simple structure could be achieved by sound design.
  The restored aircraft was first flown by Fokker himself, with only de Waal, Richard Schmidt, Alexander von Bismarck, and a few trusted mechanics present. Alter a few tentative hops to accustom himself to the unfamiliar engine Fokker took off. Although the Morane-Saulnier - light, sensitive, with powerful controls - was the antithesis of the Spiders that Fokker knew so well, he quickly mastered the agile machine and soon took advantage of its great manoeuvrability. The Type H was then flown by de Waal, Schmidt and young von Bismarck, and all were unanimous in their praise of it. So delighted was von Bismarck that he immediately asked Fokker to make him a similar aircraft. Fokker asked for, and got, payment in advance.
  Fokker was convinced that for military purposes the Morane-Saulnier monoplane was much better than any of the contemporary German stable aeroplanes, but it needed skilled pilots. Rotary engines were somewhat out of favour in the air service at that time, largely because the Gnomes of the early Farman-type biplanes had suffered from the sand of the Doeberitz exercise ground and the attentions of unskilled mechanics. Elsewhere the Gnome had been so successful that Fokker did not doubt that it was more reliable than German officialdom believed it to be; he also knew that a firm near Frankfurt-am-Main had acquired a licence for the Gnome and was making a batch of them.
  Fokker was therefore in no doubt that he should copy the Morane-Saulnier monoplane, or at least use it as the basis for his next aircraft. Kreutzer and he decided which features of the French design should be reproduced and which should be modified. The machine was flown for a few days, after which it was carefully dismantled to provide the basis for the drawings of the new Fokker M.5. Platz, who was at that time in the workshop, saw no other drawings than those made direct from the Morane-Saulnier. Nevertheless, the M.5 embodied several characteristic differences from its French prototype; indeed, German friends of Fokker still maintain that, apart from a superficial similarity of outward shape, the M.5 was very different from the Morane-Saulnier.
  And in truth the M.5 was different, though the differences were not immediately apparent. It was altogether more robust than the Morane-Saulnier: its fuselage was a welded steel-tube structure, superior in every way to the Morane’s built-up wooden construction with its multiplicity of small fittings; its wings had deeper rear spars and embodied tubular compression struts whereas the French machine’s only compression members were the ribs. The thickness of both spars was 5 mm. greater on the Fokker, and the deeper rear spar produced a different aerofoil section.
  The Fokker wing was more efficient than that of the Morane-Saulnier, not merely because of its new aerofoil section but also because that section was more carefully preserved: the ribs of the Fokker were at a pitch of 340 mm.; those of the Morane were at 395 mm.: moreover the M.5 had riblets to preserve the upper-surface contour between the full ribs. Spanwise strips of tape were applied zig-zag fashion over and under the ribs to prevent the ribs from twisting sideways under the pressure of the doped fabric.
  The Fokker M.5 retained the wing-warping lateral control that characterized the Morane-Saulnier. The compression struts had hinged end joints to allow them to flex during warping. Fokker retained stick control although he knew that the Army preferred wheel control, and he was right to do so.
  This stronger wing imposed a weight penalty - all Fokker wings were 25% heavier than Pfalz-built Morane-Saulnier wings of the same area - but this was offset by the lower weight of the steel-tube fuselage. In the later Fokker fighting monoplanes the fuselage weighed about 45 kg. (100 lb.), whereas the Pfalz E.I fuselage weighed 62 kg. (137 lb.).
  In its shape and size the M.5 fuselage resembled that of the Morane-Saulnier. At the point of maximum cross-section the Fokker fuselage was shallower by about 2 in. to improve the pilot’s view. By a suitable re-disposition of the spacers the cockpit could accommodate a passenger behind the pilot on a sort of longitudinal bench seat. In the M.5 built for young von Bismarck this space was to have been occupied by a long-range tank, but this was never installed.
  Kreutzer gave Platz full particulars of the shape and position of the fuselage attachments and left him to work out the design of the detail features of the fuselage structure. This gave Platz his first experience in the design of a major component, and he and Kreutzer together created the classic Fokker-type fuselage which, with little modification, was not only to serve generations of Fokker aircraft but also to provide the fuselage-design basis for aircraft made by other manufacturers.
  The four-longeron structure had diagonals in the forward bays where rigidity was essential; the remainder was cross-braced by wire. Platz formed the retaining lugs for the wire bracing by welding in small pieces of bent steel tubing at all corner joints of longerons and spacers; through diagonally-opposite lugs a loop of wire was passed, its ends connected by a turnbuckle, thus saving two end connexions in each bracing. This form of fuselage bracing remained a characteristic of Fokker fuselages, including those of the large four-engined aircraft, up to the 1930s.
  The M.5 fuselage was light and strong; it could be easily trued up; it allowed modifications and adaptations to be incorporated simply. The material was seamless mild-steel tubing. During the war it occasionally became scarce but Platz always insisted on the seamless quality and managed to get it. No great skill was required of Fokker welders. The fuselages were usually welded by men but most of the details were welded by girls. After welding, the longerons were usually found to be slightly distorted between the spacers; the degree of distortion depended on the welder’s skill. The deformation could easily be remedied by hammering out, and this straightening-out process caused no failures in 100,000 welds in Fokker fuselages; nor did any Fokker fuselage fail structurally under air or ground loads within the design requirements. Platz would not reject a fuselage solely because of post-welding distortions, but he would never accept tubes of high carbon content nor pass defective welds: any suspicion of a crack meant rejection. From the production standpoint the Fokker fuselage presented no great problems. It was so simple and easily produced that it soon brought substantial profits in spite of low aircraft prices. Platz produced the first monoplane fuselages at piecework rates in about forty working hours. This labour time included collecting the material, cutting, shaping, bending and fitting the tubes, tacking them into place, welding all seams, bending and welding-in the tubular lugs, straightening the structure after welding, wire-bracing and truing-up the fuselage.
  The Fokker M.5 engine mounting was copied from that of the Morane. The Gnome rotary was installed in an overhung mounting, the rear bearing being bolted to the apex of a pyramid of steel-tubing. A cylindrical tank with compartments for castor oil and petrol was mounted between the engine and the cockpit, and fed the engine by gravity. An additional tank could be fitted behind the pilot’s seat when required; it fed the gravity tank either by pressure feed or by pumping.
  The engine cowling was an unabashed copy of that of the Morane-Saulnier despite the fact that the French firm had a valid German patent for this clever feature. In it the Morane company had neatly solved the problem of containing most of the liberal ejection of castor oil and petrol that characterized rotary engines without allowing it to collect where it could catch fire, and yet leaving the engine reasonably accessible.
  Platz made the Fokker cowlings (for the Morane type was retained on all Fokker aircraft until late in 1916, so satisfactory did it prove to be) by welding wheeled or beaten aluminium sheet, using his fluxless welding technique. After the completed cowling and metal panels had been burnished the new aircraft was a splendid sight with its gleaming metalwork.
  Like the Morane fuselage, that of the Fokker M.5 terminated in a horizontal knife edge at the tail: the tube that constituted the sternpost served as the bearing for the elevator hinge axis. The elevator itself was a cantilever, balanced surface. The rudder had originally belonged to the M.4 Stahltaube; there was no fin. The tail surfaces were made of welded steel tubing covered with fabric. They were generally similar to those of the Morane-Saulnier but Platz and Kreutzer made them more substantial at the cost of a small increase in weight. Their wisdom in doing so was later proved when the Pfalz monoplanes fell into disgrace after elevator failures at the front. Fokker monoplanes never suffered from this kind of trouble.
  When he flew the Morane-Saulnier Fokker immediately noticed its tendency to swing on take-off and to ground-loop. The Fokker monoplane therefore had greater track (2 m. as opposed to the Morane’s 1-5 m.), and the axle was further back to allow the tail to come up more quickly on the take-off run. Fokker later discovered that the tendency to ground loop could be cured by giving the wheels slight toe-out (i.e., opposite to the customary toe-in in motor cars). For this feature he took out a German patent (D.R.P. No. 300,181 of July 19, 1914).
  To give the ground clearance stipulated by the military requirements, and to give more favourable angles for the lift-bracing cables, the Fokker undercarriage was made nearly six inches higher than that of the Morane.
  It differed in principle, too. The two bracing pylons under the fuselage were connected by a wood-reinforced tube which carried, at its ends, hinges for the axle frames. Each frame was a V-member consisting of a half-axle and a radius rod. From the wheel hubs a strut ran to the fuselage, its upper end sliding up and down in a vertical slot in the fuselage; within the fuselage this strut’s fork-like end engaged the rubber rings that provided shock absorption. All the undercarriage struts were of steel tubing: the pylon struts were of elliptical cross-section; all the others were circular and had wooden fairings taped on.
  The pilot could see the shock absorbers working and they were reasonably accessible for maintenance. The slots in the fuselage made the cockpit draughty, a point that mattered little to Fokker, who cared little about comfort in flight, but was criticized by pilots who flew operationally in the military machines at high altitudes or in cold weather.
  In spite of all the care that had been taken to give the Fokker monoplane a sound undercarriage, it frequently failed to stand up to rough ground and rough pilots; so much so that Fokkerbruch became the recognized Service slang term for excusable damage following undercarriage collapse. On later Service monoplanes the axle had to be brought forward again after a series of crashes caused by overturning after landing on soft or rough ground.
  The forward pylon provided the anchorage point for the lower ends of the lift cables attached to the front spars of the wings. To the rear pylon was attached the rocking lever that actuated the wing-warping cables. The upper bracing cables of the rear spars were continuous from one wing to the other, running over pulleys mounted at the apex of the top cabane struts.
  The small metal fittings in the undercarriage and wing-warping system were similar to those of the Morane-Saulnier. But whereas the French machine had well-machined but expensive parts, the Fokker components were fabricated simply from welded steel sheet and were correspondingly cheaper.
  The choice of an engine for the new type presented little difficulty. Von Bismarck wanted to make long cross-country flights; Fokker’s thoughts were on the scouting single-seater that the Army wanted and on his desire to have an aerobatic aeroplane. The Army would of course insist on a German-built engine, so the 50-h.p. Gnome would not do: it would have to be either the new Oberursel or the Schwade.
  As already mentioned, space was provided behind the pilot’s seat for the installation of an additional long-range petrol tank. Fokker intended to fit such a tank once the M.5 had completed its flight trials, but the opportunity was taken to put in a long seat that would accommodate a passenger. A removable back-rest half-way along this seat was provided for the pilot to lean against. This accommodation was cramped and uncomfortable, and would not have been acceptable for a military observer; the aircraft’s climbing performance also suffered. However, this primitive expedient facilitated pilot familiarization: there was no dual control, but the passenger could get the feel of the stick and note the reaction of the aeroplane.
  Fokker had great confidence in the M.5: aerodynamically it differed little from the Morane-Saulnier and extensive modifications were not likely to be needed. He was anxious not to lose time by delaying the construction of further M.5s until the completion of the prototype's trials. He decided to build two prototypes simultaneously and to make a small batch of fuselages and other major components to enable him to promise early delivery against the orders he confidently expected. He made sure that Oberursel would supply the engines he wanted, for other manufacturers were also interested in this German-built Gnome for competitions from which foreign-made engines were excluded. Parts for about five Fokker M.5s were put in hand at once.
  It was originally intended that the two prototypes should be identical. However, soon after construction began, it was decided to fit one of them with a longer-span wing of much the same area as that of the Morane-Saulnier Type G two-seater. Fokker wanted to emulate the aerobatic performances of Garros, Hamel and others on Morane-Saulnier monoplanes; he therefore thought it advisable to fit a larger wing, which would, in addition, compensate for the greater weight of the Fokker and its bigger Oberursel. The long-span variant had three bracing cables to each spar, and a taller cabane was fitted to give the landing wires a more favourable angle in view of the greater loads imposed by inverted flight.
  The two versions of the M.5 were called M.5K, with K signifying kurz or short span; and M.5L, with the suffix signifying lang, or long span. The M.5K was intended to be a high-speed military scout which would not be required to indulge in aerobatics; the M.5L was to be the aerobatic and long-range version of the design.
  The two M.5 prototypes were completed during the latter half of April 1914. The M.5K was the first to fly. C. G. Henze recalls that no Oberursel had arrived in time, so the 50-h.p. Gnome of the Morane-Saulnier was installed as a temporary measure.
  Fokker had no difficulty in handling the new monoplane, but its climb was not spectacular and not up to the standard of performance required by the military authorities. The M.4 rudder was barely adequate and a larger surface was desirable: one was designed and the first was fitted to the M.5L, which emerged a few days after the M.5K’s first flight.
  The somewhat disappointing performance of the M.5K with the 50-h.p. Gnome convinced Fokker that the M.5L would need a more powerful engine if it were to be flown before an Oberursel became available. Foreman Auer was sent to his old boss Gustav Otto, at Munich, and bought from him - cheaply - a 70-h.p. Gnome of the older type, from a discarded aircraft. This engine was installed in the M.5L. With it, the new aircraft had quite a creditable performance; furthermore, the new comma-shaped rudder proved to be satisfactory.
  When the first two 80-h.p. Oberursel-Gnome engines arrived from Frankfurt they were installed in both prototypes. De Waal, Richard Schmidt, Kuntner, von Bismarck and other Schwerin pilots now tried the M.5s: they found the long-span version easier to handle, although slightly slower: all were delighted with it. The black-painted, well-finished M.5L was unanimously considered to be a success.
  This opinion was shared by officers of the Army Flying Corps, among them von Beaulieu, who had acted as adviser to Fokker in the M.5 venture, and W. von Buttlar. The latter was so impressed that he immediately ordered an M.5L for his private use. It was perhaps the first time that a Prussian regular officer of the Flying Corps acquired an aeroplane of his own.
  The little M.5K, although temporarily set aside, was to become the progenitor of the famous Fokker single-seat fighters of the 1915-16 period.
  Early in May 1914 the news was allowed to leak out to the Press that Fokker was testing a new aircraft of his own design that was powered by a German rotary engine and showed great promise.
  The Army’s Inspectorate of Aviation (IdFlieg), wearied by other aircraft manufacturers’ slowness to understand official operational requirements, showed interest in the new Fokker aircraft. Their interest grew when Fokker demonstrated the aerobatic capability of his new monoplane, and officers were sent to Schwerin to report on it.
  The latest Army requirements stipulated that the strength of aeroplane wings and their bracing should be evaluated by testing them to destruction by sand loading. Fokker may have complied after a fashion with this strict (but to his mind, wasteful) requirement, but no-one can recall such a test being made on the M.5, nor is there any record of one. His stunt of having an impressive number of people to stand on the wings may have satisfied the more technically ignorant of the Army officers, but it cut no ice with structural engineers. For obvious reasons it could not be carried to the limit where the structure begins to fail, nor could deformations be observed and measured: its technical value was therefore nil. Fokker’s lack of technical understanding prevented him from appreciating the sound reasons for sand-loading tests. They were to be brought home to him rather forcibly at a later date.
  In the case of the M.5L Fokker’s demonstration apparently satisfied the IdFlieg officers by showing that the aircraft was strong enough for inverted flight. The illustration above shows eight people on each wing. Allowing for wing weight relief, this load would roughly correspond to a “safe” load factor of between 2-2 and 2-5, which could be deemed reasonable, though not wholly convincing, proof of adequate strength for mild aerobatics. But in fact the M.5L never gave cause for doubts about its structural strength.
  It was on the M.5L that Fokker essayed his first loop, an event which he describes authentically in Flying Dutchman. Once he had mastered the art of looping smoothly, Fokker fitted a venturi-type air-speed indicator to the M.5L, possibly the first installation of such an instrument.
  Fokker showed young von Bismarck how loops were done, and trained Kuntner and Oblt. von Buttlar in the art. It was Kuntner’s first loop, made after three days’ instruction on June 18, 1914, in the presence of numerous Army officers, that assured the military future of the Fokker M.5 design. The officers were impressed, as Fokker wished them to be, and the type was recommended for adoption.
  A small batch of some ten M.5L monoplanes were ordered for evaluation by the Air Service units. Experienced military pilots had flown both versions of the M.5, and the M.5L had seemed the better of the two for the Army’s purposes.
  By this time Fokker and his new monoplane were well known. Aerobatic displays were popular features at air meetings, and tempting fees were on offer to pilots who could emulate the feats of Pegoud. When Fokker was approached he agreed with alacrity to perform: apart from the immediate financial gain, the opportunity of advertising his new aircraft was too good to miss. His partner under the contract was to be Dr. Josef Sablatnig, a dashing pilot of great experience from Bohemia. Sablatnig had not done any aerobatic flying, nor did he have an aeroplane suitable for it; he was awaiting delivery of a Bleriot.
  Fokker’s contract called for a first public exhibition at Frankfurt am Main. It took place during the Prinz Heinrich-Flug, a competition in which selected groups of Air Corps officers took part. Fokker gave a polished display of stunting on May 18, 1914, which was a rest day for the competitors; Hanuschke and Robert Sommer also flew.
  Further demonstrations followed at other places, and Fokker’s self-assurance and showmanship advanced in step with his experience. For four consecutive days, beginning May 30, he stunted at Johannisthal. His flying skill was undoubtedly at its height. He flew an uninterrupted sequence of daring and carefully planned manoeuvres at low altitude, showing off the new monoplane to the best advantage. His loops, now perfect, were executed at a dangerously low altitude; his turns were the steepest ever seen at Johannisthal: his dives seemed almost vertical; and he brought his M.5L down in parachute-like descents, semi-stalled, a manoeuvre made possible by the powerful wing-warping control. Even his take-offs were spectacular, so short did he make them; and his landings were made with consummate skill, ending with the shortest possible forward run.
  On the last day, the Prussian War Minister, General von Falkenhayn. and his staff came to watch Fokker's exhibition. This was an unprecedented honour at Johannisthal. Fokker was decorated with a laurel wreath, and he was promised a bronze statue by the aerodrome’s grateful management. This was quite a change from the days when he had come, cap in hand, to ask von Tschudi’s clerk for the hire of a shed that was about to become vacant.
  By now it was obvious that Fokker’s mastery of aerobatic flying had made him one of the most accomplished demonstration pilots of the day. It was equally evident that his new M.5 monoplane was an unusually good aircraft. The tour had been the advertisement that Fokker had intended, and it had been accomplished without the slightest mishap. In view of the capriciousness of the Oberursel this was no mean feat and a high testimonial for Hans Schmidt, Fokker's personal mechanic.
  An advertisement in Flugsport for June 6, 1914. justifiably described the new M.5 as an aircraft that “combined aerobatic capability with military usefulness”. The advertisement also quoted a top speed of 127 km./hr. (79 m.p.h.), a climb to 1,000 metres (3,300 ft.) in 2 minutes 4 seconds, a take-off run of 12 metres (13 yd.), and a landing run of 21 metres (23 yd.).
  Fokker had now definitely arrived. He had beaten his contemporaries among German manufacturers by building an aircraft that had good military prospects and was without a rival. He was ahead of Schneider, Hanuschke, and the A.G.O. concern; the Bristol monoplanes had been a failure at Halberstadt and the reorganized firm had gone over to making Taube monoplanes, which were no match for the M.5. The Aviatik firm’s rotary-powered “light” biplane had in fact proved to be nearly as heavy as their ordinary two-seater. The Union works at Teltow had brought out a light biplane with swept-back wings and an 80-h.p. Schwade (Gnome copy) rotary, but Fokker did not regard it as a serious competitor.
  Although everything seemed to be running in the Fokker M.5L’s favour, its introduction into the Army was not a particularly happy one. Late in June 1914 one of the first production machines was sent to the third Air Battalion at Cologne for evaluation. It was flown first by the unit’s adjutant, Oblt. Hermann Kastner; he liked the aircraft immensely and thought it admirably suitable for scouting purposes. From his first acquaintance with the M.5L Kastner always had a preference for the light rotary-powered monoplane. His preference did much, a year later, to speed the introduction of the Fokker fighting monoplane.
  Other officers tried the new Fokker after Kastner had flown it. About a week after its arrival at Cologne the aircraft crashed, killing its pilot, who had attempted an emergency landing near Cologne after the Oberursel had failed. The inference drawn from this unhappy occurrence was that military pilots who had trained on Tauben or biplanes with stationary water-cooled engines were insufficiently experienced to handle the light, fast and manoeuvrable Fokker. Conversion training was needed. It was therefore decided that unless a pilot had previous experience on monoplanes with rotary engines (e.g., by training on the original Bristol monoplanes of the military flying school at Halberstadt) he should be sent to Schwerin for instruction on the Fokker.
  Fokker was asked to provide appropriate facilities at his military flying school. This meant the design of a proper two-seater with dual control, and the provision of a number of M.5Ls for instructional purposes. By the end of July, at least five and possibly more M.5Ls had been completed and supplied; but the total cannot have exceeded ten.
  Alexander von Bismarck went to great pains to obtain dope of the light blue colour he wanted for his M.5L. In his effort to give his Fokker a high-gloss finish he applied a varnish which turned his beautiful blue to a rather unpleasant greenish hue. Von Bismarck’s annoyance over this misfortune became the greater when his aircraft was nicknamed Die Gartenlaube (arbour) - the name of a respectable and somewhat Victorian family magazine well-known for sugary love-stories.
  The other private owner, W. von Buttlar, specified a green finish for his machine. The choice of colour was inspired by the uniform of his regiment, the Marburg Jaeger. As will be told later, von Bismarck’s and von Buttlar’s M.5Ls were taken over by the Army when war broke out.
  During the early months of the war the few M.5Ls that were with the German Air Corps rendered sterling service, and were much sought after by pilots. The Oberursel engine soon acquired a reputation for unreliability, however, and Fokker pilots were officially discouraged from venturing very far into enemy-held territory: during the first weeks a few experienced officers had been taken prisoner after emergency landings.
  The Oberursel-built Gnome’s worst trouble was overheating of the cylinders. This could happen even when it was carefully nursed, but many of the regular officers did not take the trouble to handle the engine well, consequently it gave a great deal of trouble and was disliked by most mechanics. The cause of the overheating apparently lay in the obturator rings on the pistons: it was suspected that the Gnome company had failed to tell their German licensees the correct material for these rings. The suspicion may not have been ill-founded, for other Gnome copies (e.g., the 80-h.p. Schwade Stahlherz) suffered from precisely the same defect. Instead of moving freely in their piston grooves to maintain gas-tightness, the obturator rings of the Oberursel stuck fast in the grooves, letting the combustion mixture pass. To make matters worse, the Oberursel firm did not have a good enough engineering staff to ferret out the cause and provide an early remedy. This proved extremely unfortunate for the Fokker aircraft.
  In February 1915, some fifteen M.5Ls and six M.5Ks were in operational service on all German fronts. They were used for reconnaissance and artillery-spotting duties.
  The military versions of the M.5 had apertures in the wing roots between the spars; these were provided to improve the pilot’s downward view for observation duties. Later, observation flaps were installed in the floor of the cockpit. These production machines also had the metal covering of the nose behind the engine cowling extended aft. This served as a protection against the engine's proneness to catch fire when started after over-generous priming, or when a valve spring broke (a not-infrequent occurrence).
The French captured a few of these early birds. The span of the M.5L was said to be about 11 m. (36-1 ft.) and the length 6-9 m. (22-6 ft.).A few more M.5Ls were supplied to the Army up to August 1915, but none were operational after June 1915.
  The M.5L seems to have been known officially as the Fokker A.I, but the men who flew it talked of their Fokker E (Einsitzer-single-seater) to distinguish it from the M.8 two-seater artillery spotter. This has led to confusion with the later genuine Fokker E-types, which were armed fighters.
  A similar confusion exists over the M.5K. Only two M.5Ks were in operational use in December 1914, and three in June 1915. They were used as flying dispatch riders, maintaining liaison with headquarters during campaigns of rapid movement, and were flown exclusively by selected regular officers. In spite of being single-seaters these aircraft were occasionally listed as Fok. A.III in official records. In other records they were (wrongly) described as Fok. E.II. Some M.5Ks were with aircraft parks, depots or schools behind the fighting zone. The type was less popular than other contemporary Fokker aircraft until its conversion to a fighter in May 1915.
  From the fronts came news of the exploits of Fokker aircraft. Late in August, Hauptmann Goebel had to make a forced landing in French-held territory during a flight to Sedan from Air Depot No. 4 at Trier. Evidently the Oberursel had failed again. On August 30, 1914, Leutnant von Beaulieu, flying an M.5, made an impressive reconnaissance in the Charleroi sector. Leutnant von Hiddessen had been over Paris in a Fokker. In September an M.5 had been forced to land near St.Omer and was captured intact. Allied pilots flew it up to 8,000 ft. and were quite impressed.
  One of the pilots who made good use of the M.5L was Oblt. H. Kastner. He was with No. 38 Feldfliegerabteilung, stationed at Brussels and later at Ghent. Using his M.5L as a two-seater with Lt. Niemann as observer, Kastner made successful reconnaissances during the Dixmude fighting on the Yser. He later took the monoplane to the Eastern Front, where it ended its career during a forced landing, the Oberursel having been at fault again.
  A word must be said about the fighter component of the Marine-Flieger-Abteilung, the coastal defence unit of the German Navy that flew landplanes. The unit had maintained an interest in Fokker aircraft after Ernst Ditzuleit had proved to the Navy’s satisfaction that these aeroplanes could be used for longer flights. In the summer of 1915 he flew the Fokker M.5L “S.27 Kiel” to Kiel-Kopperpahl, the flight lasting 3 1/2 hours. Although the cylinders of his 80-h.p. Oberursel had turned blue by the time he landed, the flight was accepted as evidence of the Fokker’s capabilities. The Navy therefore sent a detachment of seven pilots, including Ditzuleit, to the Kampfeinsitzer-Schule at Mannheim, and a number of Fokker E.IIIs and E.IVs were ordered. These aircraft were used operationally, mainly in the east. Of the seven naval fighter pilots, only two survived the war.

O.Thetford, P.Gray German Aircraft of the First World War (Putnam)

Fokker M 5 K
  This aircraft was a pre-war design and a shorter-span version of the M 5 (the K indicating Kleine Spannweite - small span). A few machines of the type passed into military service as single-seat scouting monoplanes and were retrospectively designated A III. It was this type, subsequently armed, which became the E I. Power unit was 80 h.p. Oberursel U O.

Fokker M 5 L
  With longer-span wings, the M 5 L featured three bracing cables per wing panel. A small number were built and used on scouting and reconnaissance duties, these machines receiving the retrospective military designation AII. Usage continued only a few months into 1915. Engine, 80 h.p. Oberursel U O .

E.Hauke, W.Schroeder, B.Totschinger Die Flugzeuge der k.u.k. Luftfahrtruppe und Seeflieger 1914-1918

00. Versuchs- und Beuteflugzeuge (Опытные и трофейные самолеты)
03.03 Fokker A.II (Type M 5L) Ob/Gn 80
00.13 Fokker M5L Ob/Gn 80

E.Hauke, W.Schroeder, B.Totschinger - Die Flugzeuge der k.u.k. Luftfahrtruppe und Seeflieger 1914-1918
Fokker M 5 L 00.13 Testflugzeug
E.Hauke, W.Schroeder, B.Totschinger - Die Flugzeuge der k.u.k. Luftfahrtruppe und Seeflieger 1914-1918
Fokker M 5 L
A.Weyl - Fokker: The Creative Years /Putnam/
The Fokker M.5K.
Журнал - Flight за 1914 г.
Of the new machines built in Germany since the beginning or immediately before the war, one which is likely to be employed against the Allies is the new Fokker monoplane illustrated in the accompanying photographs. This machine, it will be seen, is very reminiscent of the french Morane monoplane, from which it differs chiefly in the design of under-carriage. As shown in the illustration on the left, the chassis is characterised by short stub axles, whilst the shock-absorbers are placed inside the body, the oblique chassis struts passing through a slot in the side of the fuselage. The engine fitted is an 80 h.p. Gnome.
A.Weyl - Fokker: The Creative Years /Putnam/
Fokker with the M.5K.
A.Weyl - Fokker: The Creative Years /Putnam/
Fokker in the cockpit of the M.5K.
O.Thetford, P.Gray - German Aircraft of the First World War /Putnam/
Fokker M 5 K
A.Weyl - Fokker: The Creative Years /Putnam/
Front view of the M.5K.
A.Weyl - Fokker: The Creative Years /Putnam/
The M.5K undercarriage.
A.Weyl - Fokker: The Creative Years /Putnam/
Elevator detail of the M.5K. The control horn was on the starboard side only.
A.Weyl - Fokker: The Creative Years /Putnam/
The tail unit of the M.5K.
A.Weyl - Fokker: The Creative Years /Putnam/
The Fokker M.5L.
Jane's All The World Aircraft 1919 /Jane's/
A Fokker Monoplane, 1914-15 type, with Uberursel motor. One of the earlier examples of the type which was proved so redoubtable as a "destroyer".
В.Кондратьев - Самолеты первой мировой войны
Авиаконструктор Антони Фоккер в кабине пока еще невооруженного M5L.
A.Weyl - Fokker: The Creative Years /Putnam/
Fokker in the cockpit of the M.5L.
A.Weyl - Fokker: The Creative Years /Putnam/
The Fokker M.5L flown by Ernst Ditzuleit to Kiel-Kopperpahl in 33 hours.
A.Weyl - Fokker: The Creative Years /Putnam/
Ditzuleit’s M.5L at Kiel-Kopperpahl, 1915, Ditzuleit is second from the right; at extreme left, Oppermann; third from left, Truckenbrodt.
A.Weyl - Fokker: The Creative Years /Putnam/
Of the men standing on the wings of the M.5L, de Waal is fifth from the left and Auer seventh from the left. Standing second from the right is Kuntner.
O.Thetford, P.Gray - German Aircraft of the First World War /Putnam/
Fokker M 5 L (foreground only)
A.Weyl - Fokker: The Creative Years /Putnam/
An M.5L and two Fok. A.Is awaiting collection at Schwerin.
Журнал - Flight за 1915 г.
A BATCH OF HOSTILE FLYERS. - Although the German Army is chiefly using machines of the biplane type, the monoplane has not been altogether banned, as will be seen from the accompanying photograph showing a batch of 15 Fokker monoplanes ready for their acceptance tests. That they are intended for military purposes is evident from the fact that they are all marked with the black cross on wings and rudder.
A.Weyl - Fokker: The Creative Years /Putnam/
Fokker M.5L in Austrian service, numbered 00.13.
E.Hauke, W.Schroeder, B.Totschinger - Die Flugzeuge der k.u.k. Luftfahrtruppe und Seeflieger 1914-1918
Fokker-Eindecker. Type M 5 L. Flugzeugnummer 00.13
E.Hauke, W.Schroeder, B.Totschinger - Die Flugzeuge der k.u.k. Luftfahrtruppe und Seeflieger 1914-1918
Fokker A.II, Type M 5 L, Flugzeugnummer 03.03, Fliegerkompanie 8