Aviatik C.I |aircraft investigation|WWI aircraft

AIRCRAFT INVESTIGATION

weight and performance calculations for the Aviatik C.I

Aviatik C.I

role : two-seat armed reconnaissance and artillery observation

importance : ***

first flight : operational : September 1915

country : Germany

design :

production : unknown

general information :

Armed development from the B.II. The observer was still in the front seed so he was hampered to use his free-mounted machine gun. (www036) Configuration comparable with the British BE2c. Positions where switched, and this version was indicated as C.Ia which entered service in may 1916.

users : Luftwaffe

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 : 12.5 [m], length : 7.93 [m], height : 2.95[m]

wing area : 43.0 [m^2]

weights :

max.take-off weight : 1284 [kg]

empty weight operational (estimation): 870.0 [kg] bombload : 50 [kg]

performance :

maximum speed : 120 [km/hr] at sea-level

service ceiling : 4000 [m]

endurance : 3.5 [hours]

estimated action radius : 189 [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

C.I with observer in front seat

airscrew :

fixed pitch 2 -bladed tractor airscrew with max. efficiency :0.63 [ ]

estimated diameter airscrew 2.76 [m]

angle of attack prop : 12.39 [ ]

fine pitch

reduction : 1.00 [ ]

airscrew revs : 1400 [r.p.m.]

pitch at Max speed 1.43 [m]

blade-tip speed at Vmax and max revs. : 205 [m/s]

calculation : *1* (dimensions)

mean wing chord : 1.72 [m]

calculated wing chord (rounded tips): 1.91 [m]

wing aspect ratio : 7.27 []

estimated gap : 1.84 [m]

gap/chord : 1.07 [ ]

seize (span*length*height) : 292 [m^3]

calculation : *2* (fuel consumption)

oil consumption : 2.5 [kg/hr]

fuel consumption(cruise speed) : 31.8 [kg/hr] (43.3 [litre/hr]) at 70 [%] power

distance flown for 1 kg fuel : 3.40 [km/kg]

estimated total fuel capacity : 172 [litre] (126 [kg])

calculation : *3* (weight)

weight engine(s) dry : 299.0 [kg] = 2.49 [kg/KW]

weight 15 litre oil tank : 1.3 [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 18 litre gravity patrol tank(s) : 2.8 [kg]

weight radiator : 17.2 [kg]

weight exhaust pipes & fuel lines 11.1 [kg]

weight cowling 4.8 [kg]

weight airscrew(s) (wood) incl. boss & bolts : 19.0 [kg]

total weight propulsion system : 361 [kg](28.1 [%])

***************************************************************

fuselage skeleton (wood gauge : 7.26 [cm]): 107 [kg]

bracing : 6.0 [kg]

fuselage covering ( 11.9 [m2] doped linen fabric) : 3.8 [kg]

weight controls + indicators: 6.3 [kg]

weight seats : 6.0 [kg]

weight other details, lighting set, etc. : 5.1 [kg]

weight bomb storage : 3.5 [kg]

weight 154 [litre] main fuel tank empty : 12.3 [kg]

weight engine mounts & firewalls : 6 [kg]

total weight fuselage : 156 [kg](12.1 [%])

***************************************************************

weight wing covering (doped linen fabric) : 28 [kg]

total weight ribs (61 ribs) : 76 [kg]

load on front upper spar (clmax) per running metre : 782.1 [N]

load on rear upper spar (vmax) per running metre : 278.0 [N]

total weight 8 spars : 70 [kg]

weight wings : 174 [kg]

weight wing/square meter : 4.04 [kg]

weight 8 interplane struts & cabane : 30.6 [kg]

weight cables (76 [m]) : 8.4 [kg] (= 110 [gram] per metre)

diameter cable : 4.2 [mm]

weight fin & rudder (1.8 [m2]) : 7.6 [kg]

weight stabilizer & elevator (4.8 [m2]): 19.9 [kg]

total weight wing surfaces & bracing : 240 [kg] (18.7 [%])

*******************************************************************

weight machine-gun(s) : 9.5 [kg]

weight Schneider ring mounting mg :5.5 [kg]

weight armament : 15 [kg]

********************************************************************

wheel pressure : 642.0 [kg]

weight 2 wheels (790 [mm] by 100 [mm]) : 33.6 [kg]

weight tailskid : 3.1 [kg]

weight undercarriage with axle 24.7 [kg]

total weight landing gear : 61.4 [kg] (4.8 [%]

*******************************************************************

********************************************************************

calculated empty weight : 834 [kg](64.9 [%])

weight oil for 4.2 hours flying : 10.6 [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]

*******************************************************************

calculated operational weight empty : 888 [kg] (69.2 [%])

estimated operational weight empty : 870 [kg] (67.8 [%])

_____________

| | o | |

-------------

weight crew : 162 [kg]

weight fuel for 2.0 hours flying : 64 [kg]

********************************************************************

operational weight : 1113 [kg](86.7 [%])

bomb load : 50 [kg]

operational weight bombing mission : 1163 [kg]

weight camera : 20 [kg]

operational weight photo mission : 1133 [kg]

fuel reserve : 63 [kg] enough for 1.97 [hours] flying

possible additional useful load : 88 [kg]

operational weight fully loaded : 1284 [kg] with fuel tank filled for 100 [%]

published maximum take-off weight : 1284 [kg] (100.0 [%])

I||==|

calculation : * 4 * (engine power)

power loading (operational without bombload) : 9.29 [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 : 3.75 [g] ultimate load : 5.6 [g] load factor : 2.1 [g]

design flight time : 2.80 [hours]

design cycles : 321 sorties, design hours : 900 [hours]

operational wing loading : 258 [N/m^2]

wing stress (3 g) during operation : 192 [N/kg] at 3g emergency manoeuvre

calculation : *6* (angles of attack)

angle of attack zero lift : -1.20 ["]

max. angle of attack (stalling angle) : 12.53 ["]

angle of attack at max. speed : 3.31 ["]

calculation : *7* (lift & drag ratios

lift coefficient at angle of attack 0° :0.10 [ ]

lift coefficient at max. angle of attack : 1.15 [ ]

lift coefficient at max. speed : 0.38 [ ]

induced drag coefficient at max. speed : 0.0111 [ ]

drag coefficient at max. speed : 0.0769 [ ]

drag coefficient (zero lift) : 0.0658 [ ]

calculation : *8* (speeds

stalling speed at sea-level (OW): 68 [km/u]

landing speed at sea-level (OW without bombload): 82 [km/hr]

min. drag speed (max endurance) : 84 [km/hr] at 2000 [m](power :52 [%])

min. power speed (max range) : 97 [km/hr] at 2000 [m] (power:59 [%])

max. rate of climb speed : 76.5 [km/hr] at sea-level

cruising speed : 108 [km/hr] op 2000 [m] (power:70 [%])

design speed prop : 114 [km/hr]

maximum speed : 120 [km/hr] op 100 [m] (power:99 [%])

climbing speed at sea-level (without bombload) : 187 [m/min]

calculation : *9* (regarding various performances)

take-off distance at sea-level : 128 [m]

lift/drag ratio : 6.98 [ ]

max. practical ceiling : 4800 [m] with flying weight :967 [kg]

practical ceiling (operational weight): 3800 [m] with flying weight :1113 [kg]

practical ceiling fully loaded (mtow- 1 hour fuel) : 2950 [m] with flying weight :1252 [kg]

published ceiling (4000 [m]

climb to 1500m (without bombload) : 9.19 [min]

max. dive speed : 275.5 [km/hr] at 1950 [m] height

load factor at max. angle turn 1.65 ["g"]

turn radius at 500m: 49 [m]

time needed for 360* turn 12.3 [seconds] at 500m

calculation *10* (action radius & endurance)

operational endurance : 3.97 [hours] with 2 crew and 108 [kg] useful (bomb)load and 100.0 [%] fuel

published endurance : 3.50 [hours] with 2 crew and possible useful (bomb) load : 123 [kg] and 88.1 [%] fuel

action radius : 364 [km] with 2 crew and 20[kg] photo camera/radio transmitter or bombload

max range theoretically with additional fuel tanks for total 467 [litre] fuel : 1163 [km]

useful load with action-radius 250km : 195 [kg]

production : 21.07 [tonkm/hour]

oil and fuel consumption per tonkm : 1.63 [kg]

I_°°=/

Literature :

Jane’s Fighting aircraft WWI page 143

Praktisch handbook vliegtuigen deel.1 page 250

German aircraft of the first world war page

Warplanes WWI page 36,42

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