aircraft investigation Albatros B.II WWI two-seat reconnaissance biplane weight and performance calculations

Albatros B.II

role : two-seat unarmed reconnaissance

first flight : summer 1914 operational : July 1914

country : Germany

design : Ernst Heinkel

production : unknown

general information :

Summer 1914 a Albatros B.II flown by Ernst van Lossl set a new height record reaching 4500m. At the start of WWI the Albatros B.II was the best German reconnaissance plane and most used. The observer sat in front of the pilot and his sight was hampered by the wings and engine. After the arrival of the armed fighterplanes summer 1915 it was withdrawn from the front. Because of its good flying qualities and strengt hit was used for the remaining of the war as training aircraft. The fuselage was strong, the wooden rectanqular frame covered with plywood

users : Luftwaffe, Austria

crew : 2

armament : no fixed armament

engine : 1 Mercedes D.I liquid-cooled 6 -cylinder inline engine 100 [hp](73.6 KW)

dimensions :

wingspan : 12.8 [m], length : 7.62 [m], height : 3.15[m]

wing area : 40.12 [m^2]

https://static.rcgroups.net/forums/attachments/6/3/5/4/8/a6205265-219-Albatros%20BII-1%20cropped.jpg

weights :

max.take-off weight : 1069 [kg]

empty weight operational : 696 [kg] bombload : 0 [kg]

performance :

maximum speed : 105 [km/hr] at sea-level

climbing speed : 78 [m/min]

service ceiling : 3000 [m]

endurance : 4.0 [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

airscrew :

fixed pitch 2 -bladed tractor airscrew with max. efficiency :0.62 [ ]

estimated diameter airscrew 2.77 [m]

angle of attack prop : 13.13 [ ]

fine pitch

reduction : 1.00 [ ]

airscrew revs : 1150 [r.p.m.]

pitch at Max speed 1.52 [m]

blade-tip speed at Vmax and max revs. : 169 [m/s]

calculation : *1* (dimensions)

mean wing chord : 1.57 [m]

calculated wing chord (rounded tips): 1.72 [m]

https://static.rcgroups.net/forums/attachments/6/3/5/4/8/a6205268-228-Albatros%20BII-4%20cropped.jpg

wing aspect ratio : 8.17 []

estimated gap : 1.70 [m]

gap/chord : 1.08 [ ]

seize (span*length*height) : 307 [m^3]

calculation : *2* (fuel consumption)

oil consumption : 1.7 [kg/hr]

fuel consumption(cruise speed) : 23.4 [kg/hr] (32.0 [litre/hr]) at 73 [%] power

distance flown for 1 kg fuel : 4.03 [km/kg]

estimated total fuel capacity : 145 [litre] (106 [kg])

calculation : *3* (weight)

weight engine(s) dry : 191.2 [kg] = 2.60 [kg/KW]

weight 11 litre oil tank : 0.9 [kg]

oil tank filled with 0.6 litre oil : 0.5 [kg]

oil in engine 4 litre oil : 3.7 [kg]

fuel in engine 1 litre fuel : 0.4 [kg]

weight 14 litre gravity patrol tank(s) : 2.0 [kg]

weight radiator : 10.5 [kg]

weight exhaust pipes & fuel lines 9.0 [kg]

weight cowling 2.9 [kg]

weight airscrew(s) (wood) incl. boss & bolts : 16.9 [kg]

total weight propulsion system : 237 [kg](22.2 [%])

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https://static.rcgroups.net/forums/attachments/6/3/5/4/8/a6205266-56-Albatros%20BII-2%20cropped.jpg

fuselage skeleton (wood gauge : 7.69 [cm]): 115 [kg]

bracing : 6.2 [kg]

fuselage covering ( 11.0 [m2] doped linen fabric) : 3.5 [kg]

weight controls + indicators: 6.2 [kg]

weight seats : 6.0 [kg]

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

weight 132 [litre] main fuel tank empty : 10.5 [kg]

weight engine mounts & firewalls : 4 [kg]

total weight fuselage : 157 [kg](14.7 [%])

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weight wing covering (doped linen fabric) : 26 [kg]

total weight ribs (56 ribs) : 64 [kg]

load on front upper spar (clmax) per running metre : 863.9 [N]

load on rear upper spar (vmax) per running metre : 227.7 [N]

total weight 8 spars : 81 [kg]

weight wings : 170 [kg]

weight wing/square meter : 4.25 [kg]

weight 8 interplane struts & cabane : 25.6 [kg]

weight cables (75 [m]) : 9.5 [kg] (= 128 [gram] per metre)

diameter cable : 4.6 [mm]

weight fin & rudder (1.9 [m2]) : 8.4 [kg]

weight stabilizer & elevator (4.5 [m2]): 19.5 [kg]

total weight wing surfaces & bracing : 233 [kg] (21.8 [%])

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weight armament : 0 [kg]

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https://static.rcgroups.net/forums/attachments/6/3/5/4/8/a6205267-24-Albatros%20BII-3%20cropped.jpg

wheel pressure : 534.5 [kg]

weight 2 wheels (730 [mm] by 87 [mm]) : 26.2 [kg]

weight tailskid : 3.5 [kg]

weight undercarriage with axle 28.7 [kg]

total weight landing gear : 58.4 [kg] (5.5 [%]

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calculated empty weight : 686 [kg](64.1 [%])

weight oil for 4.8 hours flying : 8.1 [kg]

weight cooling fluids : 15.9 [kg]

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calculated operational weight empty : 710 [kg] (66.4 [%])

published operational weight empty : 696 [kg] (65.1 [%])

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weight crew : 162 [kg]

weight fuel for 2.0 hours flying : 47 [kg]

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operational weight : 918 [kg](85.9 [%])

estimated bomb load : 50 [kg]

operational weight bombing mission : 968 [kg]

weight camera : 20 [kg]

operational weight photo mission : 938 [kg]

fuel reserve : 60 [kg] enough for 2.54 [hours] flying

possible additional useful load : 71 [kg]

operational weight fully loaded : 1069 [kg] with fuel tank filled for 100 [%]

published maximum take-off weight : 1069 [kg] (100.0 [%])

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calculation : * 4 * (engine power)

power loading (operational without bombload) : 12.49 [kg/kW]

total power : 73.6 [kW] at 1150 [r.p.m]

calculation : *5* (loads)

manoeuvre load : 1.5 [g] at 1000 [m]

limit load : 3.75 [g] ultimate load : 5.6 [g] loadfactor : 2.8 [g]

design flight time : 3.20 [hours]

design cycles : 547 sorties, design hours : 1750 [hours]

operational wing loading : 229 [N/m^2]

wing stress (3 g) during operation : 162 [N/kg] at 3g emergency manoeuvre

calculation : *6* (angles of attack)

angle of attack zero lift : -1.16 ["]

max.angle of attack (stalling angle) : 12.16 ["]

angle of attack at max.speed : 3.89 ["]

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 : 0.44 [ ]

induced drag coefficient at max.speed : 0.0131 [ ]

drag coefficient at max.speed : 0.0749 [ ]

Afbeeldingsresultaat voor Albatros B.IIa

drag coefficient (zero lift) : 0.0618 [ ]

calculation : *8* (speeds

stalling speed at sea-level (OW): 64 [km/u]

landing speed at sea-level (OW without bombload): 77 [km/hr]

min.drag speed (max endurance) : 76 [km/hr] at 1500 [m](power :58 [%])

min. power speed (max range) : 88 [km/hr] at 1500 [m] (power:66 [%])

max.rate of climb speed : 68.7 [km/hr] at sea-level

cruising speed : 94 [km/hr] op 1500 [m] (power:74 [%])

design speed prop : 100 [km/hr]

maximum speed : 105 [km/hr] op 100 [m] (power:99 [%])

climbing speed at sea-level (without bombload) : 126 [m/min]

calculation : *9* (regarding various performances)

take-off distance at sea-level : 181 [m]

lift/drag ratio : 7.64 [ ]

max. practical ceiling : 3575 [m] with flying weight :802 [kg]

practical ceiling (operational weight): 2700 [m] with flying weight :918 [kg]

practical ceiling fully loaded (mtow- 1 hour fuel) : 1800 [m] with flying weight :1046 [kg]

published ceiling (3000 [m]

climb to 1500m (without bombload) : 14.18 [min]

max.dive speed : 250.4 [km/hr] at 800 [m] height

load factor at max.angle turn 1.50 ["g"]

turn radius at 500m: 47 [m]

time needed for 360* turn 13.0 [seconds] at 500m

calculation *10* (action radius & endurance)

operational endurance : 4.54 [hours] with 2 crew and 91 [kg] useful (bomb)load and 100.0 [%] fuel

Afbeeldingsresultaat voor Albatros B.IIa

published endurance : 4.00 [hours] with 2 crew and possible useful (bomb) load : 104 [kg] and 88.1 [%] fuel

action radius : 358 [km] with 2 crew and 20[kg] photo camera/radio transmitter or bombload

max range theoretically with additional fuel tanks for total 380 [litre] fuel : 1123 [km]

useful load with action-radius 250km : 154 [kg]

production : 14.59 [tonkm/hour]

oil and fuel consumption per tonkm : 1.72 [kg]

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Literature :

Praktisch handboek vliegtuigen deel 1 page 247

Jagdflugzuege WOI page 12

Bombers 1914-19 page 31,108

Warplanes of WOI page 9,27,35,147 f

German aircraft of the first world war page 17

www.flyingmachines.ru > Flight articles !!

Jane’s fighting aircraft WWI page 144

last check python :

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 3.7.2(32-bit)