E.I flown by Kurt Wintgens. With this aircraft he made his first victims in July 1915. This early E.I had a synchronized Parabellum MG14 machinegun.
Fokker E.I
role : fighter
first flight : operational : July 1915
country : Germany
design : Anthony Fokker & Martin Kreutzer
production : 68 aircraft at Schwerin
general information :First aircraft with a synchronized machine gun.
At the start of 1915 aircrew started to take guns and pistols with them on their patrols.
The weapons could only be fired sideways and soon the need to fire forward emerged.
The airscrew prevented the possibility to fire forward. Different solutions were figured out, aircraft with pusher propellers, machine guns placed on the top wing but in practice it was not very satisfying
The first usable solution was to fit steel wedges to the airscrew. The wedges deflected the pullets and prevented that the airscrew was shot to pieces. Saulnier, from the Morane-Saulnier company, had fabricated a synchronizing system and tested it but discarded the project because “bad rounds” made it unreliable. Saulnier considered the steel wedges on the airscrew as an improvement (www032). The Frenchman Roland Garros was the inventor of this and he fitted the wedges as first on his Morane Saulnier L parasol. With this airplane he managed to shoot down a couple of enemy planes till he was forced to make an emergency landing at 18 April 1915 behind the German lines. Before he could set fire to his plane he was captured by the Germans and so the Germans discovered the secret method of shooting through de airscrew. The German army then called on to Anthony Fokker to develop a better system. Fokker experimented with a machine gun and within 48 hrs he thought out a system with cams on the airscrew shaft blocking the machine gun at the moment airscrew blade was in front of the gun barrel. Fokker displayed the interrupter gear to the sceptic army staff. First he fired the machine gun from the ground, but the German staff was not convinced. Then he took the airplane in the air and shot at some old wings laid out on the field as target. It worked flawless and the old wings were riddled with bullets but the army staff insisted that Fokker took the airplane to the front and teach a pilot to use it and down an enemy airplane. And so Fokker travelled to the front in may 1915. He reported at the HQ of General Von Heeringen, near Laon, not far from Verdun. Here he was introduced to the Crown Prince. A few days later the order came that Fokker should take up the plane and shoot down an enemy aircraft himself ! Fokker protested in vain that he was a neutral. They gave him an uniform and identification card stating Lieutenant Anthony Fokker of the German air force. He took off and at 6000ft he saw Farman two-seater pop out of a cloud. He directed his E.I towards the French plane. He got within close range and had the plane clearly in his gunsights but could not get it over his heart to shoot it down and he broke off. This task he left for the German flyers and soon they scored the first victories.
Fokker immediately started to fit the synchronized machine guns to the M-5 monoplanes and they were indicated as E.I. Mid July 1915 11 pilots received the E.I. Max Immelmann operating from Douai scored his first victory on 01 august flying E.I s/n 3/15. He shot down a BE2c flown by William Reid. The BE-2c performed a bomb-raid on Vitry and to take more bombs the observer was left behind. Reid had no protection from the observers machine gun and was an easy pray. Was it not that Immelmann’s gun jammed 3 times. Finally the engine of the BE2c stopped and Reid, with a wounded arm made an emergency landing. Immelmann landed next to the BE2c and took Reid POW and gave first aid. Immelmann and Boelcke formed a feared duo that brought down many allied planes. The British soon spoke of a Fokker-scourge. The E.I was no superb airplane, it was fast and agile but the success it had was mostly owed to the synchronized machine gun. It was an armed M.5 and this was designed after Fokker acquired and analysed a Morane Saulnier monoplane before the war. For the first time the German’s could shoot back to the allied airplanes who had dominated the skies with the armed Morane Saulnier L, Voisin III and Bristol Scout. Also French Voisin and Farman bombers had raided Germany unmolested.
The 68.5 litre fuel tank was between the engine and the pilot and was sufficient for 2 hrs flying. The E.I was followed by the E.II with smaller wingspan but the performance were only slightly better.
Immelmann scored his first 5 victories with E.I s/n E.13/15. This airplane was later brought to Berlin and displayed in the Zeughaus but was destroyed in WWII by a British bombardment.
The E.I did not allow to perform a long steep dive, the wings would fall of. (ffs043).
It construction was not very strong and it could not be “thrown about”, then it would probably brake up in flight (www021). It was faster then the Morane Saulnier L and had better rate of climb, but the Morane had a higher ceiling.
users : Luftwaffe
crew : 1
armament : 1 synchronized 7.92 [mm] (0.312 in) Parabellum MG 14 machine-gun
engine : 1 Oberursel U.O air-cooled 7 -cylinder atmospheric inlet-valve rotary engine 80 [hp](58.8 KW)
dimensions :
wingspan : 8.85 [m], length : 7.22 [m], height : 2.9[m]
wing area : 15.9 [m^2]
weights :
max.take-off weight : 563 [kg]
empty weight operational : 360 [kg] bombload : 40 [kg]
performance :
maximum speed : 130 [km/hr] at sea-level
climbing speed : 144 [m/min]
service ceiling : 3000 [m]
endurance : 2.06 [hours]
estimated action radius : 121 [km]
description :
shoulder-winged monoplane with fixed landing gear and tail strut
two spar wing
engines, landing gear, fuel and bombs in or attached to the fuselage
airscrew :
fixed pitch 2 -bladed tractor airscrew with max. efficiency :0.63 [ ]
estimated diameter airscrew 2.32 [m]
angle of attack prop : 18.28 [ ]
reduction : 1.00 [ ]
airscrew revs : 1200 [r.p.m.]
pitch at Max speed 1.81 [m]
blade-tip speed at Vmax and max revs. : 150 [m/s]
calculation : *1* (dimensions)
mean wing chord : 1.80 [m]
calculated wing chord (rounded tips): 2.36 [m]
wing aspect ratio : 4.93 []
seize (span*length*height) : 185 [m^3]
calculation : *2* (fuel consumption)
oil consumption : 6.5 [kg/hr]
fuel consumption(cruise speed) : 21.6 [kg/hr] (29.5 [litre/hr]) at 72 [%] power
distance flown for 1 kg fuel : 5.41 [km/kg]
estimated total fuel capacity : 69 [litre] (51 [kg])
calculation : *3* (weight)
weight engine(s) dry : 116.5 [kg] = 1.98 [kg/KW]
weight 19 litre oil tank : 1.6 [kg]
oil tank filled with 0.4 litre oil : 0.4 [kg]
oil in engine 0 litre oil : 0.3 [kg]
fuel in engine 0 litre fuel : 0.3 [kg]
weight 13 litre gravity patrol tank(s) : 1.9 [kg]
weight cowling 2.4 [kg]
weight airscrew(s) (wood) incl. boss & bolts : 13.5 [kg]
total weight propulsion system : 135 [kg](24.0 [%])
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fuselage skeleton (wood gauge : 5.08 [cm]): 48 [kg]
bracing : 2.4 [kg]
fuselage covering ( 9.8 [m2] doped linen fabric) : 3.2 [kg]
weight controls + indicators: 5.6 [kg]
weight seats : 3.0 [kg]
weight other details, lighting set, etc. : 5.1 [kg]
weight bomb storage : 2.8 [kg]
weight 56 [litre] main fuel tank empty : 4.5 [kg]
weight engine mounts & firewalls : 3 [kg]
total weight fuselage : 77 [kg](13.7 [%])
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weight wing covering (doped linen fabric) : 10 [kg]
total weight ribs (26 ribs) : 33 [kg]
load on front upper spar (clmax) per running metre : 546.4 [N]
load on rear upper spar (vmax) per running metre : 173.6 [N]
total weight 4 spars : 25 [kg]
weight wings : 68 [kg]
weight wing/square meter : 4.29 [kg]
weight cables (35 [m]) : 7.2 [kg] (= 204 [gram] per metre)
diameter cable : 5.8 [mm]
weight fin & rudder (0.9 [m2]) : 4.0 [kg]
weight stabilizer & elevator (1.8 [m2]): 7.8 [kg]
total weight wing surfaces & bracing : 87 [kg] (15.5 [%])
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weight machine-gun(s) : 9.5 [kg]
weight ammunition magazine(s) :2.3 [kg]
weight synchronizing system : 1.0 [kg]
weight armament : 13 [kg]
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wheel cycles : 52
wheel pressure : 281.5 [kg]
weight 2 wheels (660 [mm] by 79 [mm]) : 13.3 [kg]
weight tailskid : 1.5 [kg]
weight undercarriage with axle 16.3 [kg]
total weight landing gear : 31.1 [kg] (5.5 [%]
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calculated empty weight : 344 [kg](61.0 [%])
weight oil for 2.5 hours flying : 16.0 [kg]
weight ammunition (500 rounds) : 17.5 [kg]
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calculated operational weight empty : 377 [kg] (67.0 [%])
published operational weight empty : 360 [kg] (63.9 [%])
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"
weight crew : 81 [kg]
weight fuel for 1.5 hours flying : 32 [kg]
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operational weight : 491 [kg](87.1 [%])
bomb load : 40 [kg]
operational weight bombing mission : 531 [kg]
fuel reserve : 18 [kg] enough for 0.84 [hours] flying
possible additional useful load : 14 [kg]
operational weight fully loaded : 563 [kg] with fuel tank filled for 100 [%]
published maximum take-off weight : 563 [kg] (100.0 [%])
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calculation : * 4 * (engine power)
power loading (operational without bombload) : 8.34 [kg/kW]
total power : 58.8 [kW] at 1200 [r.p.m]
calculation : *5* (loads)
manoeuvre load : 1.6 [g] at 1000 [m]
limit load : 4.5 [g] ultimate load : 6.8 [g] load factor : 2.4 [g]
design flight time : 1.65 [hours]
design cycles : 364 sorties, design hours : 600 [hours]
operational wing loading : 303 [N/m^2]
wing stress (3 g) during operation : 212 [N/kg] at 3g emergency manoeuvre
calculation : *6* (angles of attack)
angle of attack zero lift : -1.35 ["]
max.angle of attack (stalling angle) : 13.43 ["]
angle of attack at max.speed : 3.83 ["]
calculation : *7* (lift & drag ratios
lift coefficient at angle of attack 0° :0.10 [ ]
lift coefficient at max. angle of attack : 1.09 [ ]
lift coefficient at max.speed : 0.38 [ ]
induced drag coefficient at max.speed : 0.0126 [ ]
drag coefficient at max.speed : 0.0802 [ ]
drag coefficient (zero lift) : 0.0676 [ ]
calculation : *8* (speeds
stalling speed at sea-level (OW): 77 [km/u]
landing speed at sea-level (OW without bombload): 92 [km/hr]
min.drag speed (max endurance) : 91 [km/hr] at 1500 [m](power :55 [%])
min. power speed (max range) : 106 [km/hr] at 1500 [m] (power:62 [%])
max.rate of climb speed : 84.1 [km/hr] at sea-level
cruising speed : 117 [km/hr] op 1500 [m] (power:73 [%])
design speed prop : 126 [km/hr]
maximum speed : 130 [km/hr] op 100 [m] (power:99 [%])
climbing speed at sea-level (without bombload) : 196 [m/min]
calculation : *9* (regarding various performances)
take-off distance at sea-level : 271 [m]
lift/drag ratio : 6.55 [ ]
max. practical ceiling : 3550 [m] with flying weight :451 [kg]
practical ceiling (operational weight): 3050 [m] with flying weight :491 [kg]
practical ceiling fully loaded (mtow- 1 hour fuel) : 2450 [m] with flying weight :541 [kg]
published ceiling (3000 [m]
climb to 1500m (without bombload) : 9.11 [min]
max.dive speed : 278.1 [km/hr] at 1450 [m] height
load factor at max.angle turn 1.59 ["g"]
turn radius at 500m: 62 [m]
time needed for 360* turn 14.2 [seconds] at 500m
calculation *10* (action radius & endurance)
operational endurance : 2.34 [hours] with 1 crew and 54 [kg] useful (bomb)load
published endurance : 2.06 [hours] with 1 crew and possible useful(bomb) load : 60 [kg]
action radius : 230 [km] with 1 crew and 20[kg] photo camera/radio transmitter or bombload
max range theoretically with additional fuel tanks for total 167 [litre] fuel : 662 [km]
useful load with action-radius 250km : 30 [kg]
production : 3.51 [tonkm/hour]
oil and fuel consumption per tonkm : 8.01 [kg]
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Literature :
Praktisch handboek vliegtuigen deel 1 page 256, 257
Jagdflugzeuge WOI page 22,24,25
Jachtvliegtuigen page 7 t/m 13
The canvas falcons page 48,49
They fought for the sky page 14,15,45
Warplanes WOI page 21,32,34,42,48,84
Fighters 1914-19 page 162
Fokker – bouwer aan de wereldluchtvaart page 26,27
De groten van het luchtruim page 29
DISCLAIMER Above calculations are based on published data, they must be
regarded as indication not as facts.
Calculated performance and weight may not correspond with actual weights
and performances and are assumptions for which no responsibility can be taken.
Calculations are as accurate as possible, they can be fine-tuned when more data
is available, you are welcome to give suggestions and additional information
so we can improve our program.
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(c) B van der Zalm 04 January 2019 contact : info.aircraftinvestigation@gmail.com python 3.4.1