AIRCRAFT INVESTIGATION
LVG C.II light bomber biplane weight and performance calculations
L.V.G. C.II
role : light bomber
first flight : 1915 operational : November 1915
country : Germany
design : Franz Schneider
production : ca.250 aircraft
general information :
The LVG B-type unarmed reconnaissance planes used in the first year of WOI formed the basis for the first armed reconnaissance planes indicated as C-type and introduced in the spring of 1915. The LVG C.I was based on the B.I and for the first time in WOI the pilot and observer switched places. The pilot in the front seat had a clear view in front and the observer had a better view to the ground for reconnaissance and to the rear to spot any attacker. Additionally the observer was provided with a Schneider ring mounting and a Parabellum machine-gun for defence. This layout became standard for the rest of WOI. The C.I was powered by a 150 hp Bz.III. Only a few where built, it was followed by the C.II version at the end of 1915. The C.II was based on the B.II and had a 160 hp Mercedes D.III engine. This version was built in quantity by LVG but also by Ago and Otto works. It was extensively used for visual and photographic reconnaissance and for light bombing raids. One LVG C.II managed to reach London at noon on 28 November 1915, flown by Deck-Offizier Paul Brandt and Leutnant Walther Ilges. They dropped six 10 kg bombs on Victoria Station wounding 10 citizens and so being the first to drop bombs on London from a heavier-than-air machine. Returning home they suffered engine trouble forcing them to make an emergency landing near Boulogne. They were captured and became POW’s. In some sources the date is set at 28 November 1916 but I think this fate happened in 1915. More research is needed on the exact date. Later a LVG C.II landed on Dutch soil and was interned by the Dutch in 1916 and registered LA29.
Later production C.II where fitted with an additional forward firing machine gun.
During the battle of Verdun in 1916 100 France aircraft were lost, majority was shot down by German C-class two-seaters and also the LVG C.II was responsible for this as the best armed two seater of that era.(www086). Considering this the LVG C.II can be rated as a real multipurpose aircraft !
users : Germany
crew : 2
armament : 1 movable 7.92 [mm] (0.312 in) Parabellum MG 14 machine-gun for the
observer
engine : 1 Mercedes D.III liquid-cooled 6 -cylinder inline engine 163 [hp](119.9 KW)
dimensions :
wingspan : 12.85 [m], length : 8.1 [m], height : 2.93[m]
wing area : 37.6 [m^2]
weights :
max.take-off weight : 1403 [kg]
empty weight operational : 845 [kg] bombload : 68 [kg]
performance :
maximum speed : 130 [km/hr] at sea-level
service ceiling : 3048 [m]
estimated action radius : 375 [km]
description :
2-bay biplane with fixed landing gear and tail strut
two spar upper and lower 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 2.83 [m]
angle of attack prop : 13.07 [ ]
fine pitch
reduction : 1.00 [ ]
airscrew revs : 1400 [r.p.m.]
pitch at Max speed 1.55 [m]
blade-tip speed at Vmax and max revs. : 211 [m/s]
calculation : *1* (dimensions)
mean wing chord : 1.46 [m]
calculated wing chord (rounded tips): 1.60 [m]
wing aspect ratio : 8.78 []
estimated gap : 1.84 [m]
gap/chord : 1.26 [ ]
seize (span*length*height) : 305 [m^3]
calculation : *2* (fuel consumption)
oil consumption : 2.5 [kg/hr]
fuel consumption(cruise speed) : 33.6 [kg/hr] (45.9 [litre/hr]) at 75 [%] power
distance flown for 1 kg fuel : 3.48 [km/kg]
estimated total fuel capacity : 334 [litre] (245 [kg])
calculation : *3* (weight)
weight engine(s) dry : 299.0 [kg] = 2.49 [kg/KW]
weight 25 litre oil tank : 2.1 [kg]
oil tank filled with 0.9 litre oil : 0.8 [kg]
oil in engine 7 litre oil : 6.0 [kg]
fuel in engine 1 litre fuel : 0.6 [kg]
weight 19 litre gravity patrol tank(s) : 2.9 [kg]
weight radiator : 17.2 [kg]
weight exhaust pipes & fuel lines 11.9 [kg]
weight cowling 4.8 [kg]
weight airscrew(s) (wood) incl. boss & bolts : 19.0 [kg]
total weight propulsion system : 362 [kg](25.8 [%])
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fuselage skeleton (wood gauge : 6.57 [cm]): 90 [kg]
bracing : 5.1 [kg]
fuselage covering ( 12.4 [m2] doped linen fabric) : 4.0 [kg]
weight controls + indicators: 6.4 [kg]
weight seats : 6.0 [kg]
weight other details, lighting set, etc. : 5.1 [kg]
weight bomb storage : 4.8 [kg]
weight 314 [litre] main fuel tank empty : 25.1 [kg]
weight engine mounts & firewalls : 6 [kg]
total weight fuselage : 152 [kg](10.8 [%])
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weight wing covering (doped linen fabric) : 24 [kg]
total weight ribs (78 ribs) : 83 [kg]
load on front upper spar (clmax) per running metre : 656.9 [N]
load on rear upper spar (vmax) per running metre : 311.5 [N]
total weight 8 spars : 62 [kg]
weight wings : 170 [kg]
weight wing/square meter : 4.51 [kg]
weight 8 interplane struts & cabane : 28.4 [kg]
weight cables (76 [m]) : 7.5 [kg] (= 98 [gram] per metre)
diameter cable : 4.0 [mm]
weight fin & rudder (1.9 [m2]) : 8.9 [kg]
weight stabilizer & elevator (4.2 [m2]): 19.4 [kg]
total weight wing surfaces & bracing : 234 [kg] (16.7 [%])
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weight machine-gun(s) : 9.5 [kg]
weight pivot mounting mg :6.9 [kg]
weight armament : 16 [kg]
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wheel pressure : 701.5 [kg]
weight 2 wheels (830 [mm] by 128 [mm]) : 35.0 [kg]
weight tailskid : 2.5 [kg]
weight undercarriage with axle 23.7 [kg]
total weight landing gear : 61.2 [kg] (4.4 [%]
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calculated empty weight : 826 [kg](58.8 [%])
weight oil for 7.7 hours flying : 19.4 [kg]
weight cooling fluids : 25.9 [kg]
weight 1 drums empty : 2.3 [kg]
weight ammunition (500 rounds) : 16.4 [kg]
weight automatic pistol with spare magazines : 1.2 [kg]
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calculated operational weight empty : 888 [kg] (63.3 [%])
published operational weight empty : 845 [kg] (60.2 [%])
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weight crew : 162 [kg]
weight fuel for 2.0 hours flying : 67 [kg]
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operational weight : 1118 [kg](79.7 [%])
bomb load : 68 [kg]
operational weight bombing mission : 1186 [kg]
fuel reserve : 177 [kg] enough for 5.28 [hours] flying
possible additional useful load : 40 [kg]
operational weight fully loaded : 1403 [kg] with fuel tank filled for 100 [%]
published maximum take-off weight : 1403 [kg] (100.0 [%])
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calculation : * 4 * (engine power)
power loading (Take-off) : 11.70 [kg/kW]
total power : 119.9 [kW] at 1400 [r.p.m]
calculation : *5* (loads)
manoeuvre load : 1.7 [g] at 1000 [m]
limit load : 3.0 [g] ultimate load : 4.5 [g] load factor : 1.6 [g]
design flight time : 4.49 [hours]
design cycles : 223 sorties, design hours : 1000 [hours]
wing loading (MTOW) : 366 [N/m^2]
wing stress (3 g) during operation : 206 [N/kg] at 3g emergency manoeuvre
calculation : *6* (angles of attack)
angle of attack zero lift : -1.14 ["]
max. angle of attack (stalling angle) : 11.90 ["]
angle of attack at max. speed : 3.07 ["]
calculation : *7* (lift & drag ratios
lift coefficient at angle of attack 0° :0.10 [ ]
lift coefficient at max. angle of attack : 1.14 [ ]
lift coefficient at max. speed : 0.37 [ ]
induced drag coefficient at max. speed : 0.0087 [ ]
drag coefficient at max. speed : 0.0691 [ ]
drag coefficient (zero lift) : 0.0604 [ ]
calculation : *8* (speeds
stalling speed at sea-level (OW): 74 [km/u]
landing speed at sea-level (OW without bombload): 88 [km/hr]
min. drag speed (max endurance) = minimum speed*1.1 at cruise height : 87 [km/hr] at 1524 [m] (power:48 [%])
min. power speed (max range) : 100 [km/hr] at 1524 [m] (power:55 [%])
max. rate of climb speed : 81.6 [km/hr] at sea-level
cruising speed : 117 [km/hr] op 1524 [m] (power:71 [%])
design speed prop : 124 [km/hr]
maximum speed : 130 [km/hr] op 100 [m] (power:99 [%])
climbing speed at sea-level (without bombload) : 195 [m/min]
calculation : *9* (regarding various performances)
take-off distance at sea-level : 198 [m]
lift/drag ratio : 8.02 [ ]
max. practical ceiling : 5125 [m] with flying weight :969 [kg]
practical ceiling (operational weight): 4150 [m] with flying weight :1118 [kg]
practical ceiling fully loaded (mtow- 1 hour fuel) : 2650 [m] with flying weight :1369 [kg]
published ceiling (3048 [m]
climb to 1500m (without bombload) : 8.70 [min]
max. dive speed : 301.1 [km/hr] at 1650 [m] height
load factor at max. angle turn 1.67 ["g"]
turn radius at 500m: 59 [m]
time needed for 360* turn 13.3 [seconds] at 500m
calculation *10* (action radius & endurance)
operational endurance : 7.28 [hours] with 2 crew and 108 [kg] bombload and 100.0 [%] fuel
published endurance : 6.41 [hours] with 2 crew and possible useful (bomb) load : 137 [kg] and 88.1 [%] fuel
action radius : 579 [km] with 2 crew and 20[kg] photo camera/radio transmitter or bombload
max range theoretically with additional fuel tanks for total 615 [litre] fuel : 1570 [km]
useful load with action-radius 250km (with no gunner/observer) : 307 [kg]
useful load with action-radius 250km : 209 [kg]
production : 24.44 [tonkm/hour]
oil and fuel consumption per tonkm : 1.48 [kg]
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Literature :
Praktisch handboek vliegtuigen deel 1 page 252
A history of the luftwaffe page 27
Van Brik tot Starfighter page 37
Bomber 1914-39 page 36,37
Bombers 1914-19 page120
Wikipedia
Warplanes WWI page 86
Jane’s fighting aircraft WWI page 173f,174f
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. For copyright on drawings/photographs/
content please mail to below mail address
(c) B van der Zalm 29 Oktober 2019 contact : info.aircraftinvestigation@gmail.com python 3.7.4