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Afbeeldingsresultaat voor Albatros D.III

Albatros D.III

role : fighter

first flight : operational : January 1917

country : Germany

design : Robert Thelen

production : 800 aircraft

general information :

Superb fighter mainly responsible for “Bloody April”

It was the best fighter plane Albatros built in WWI. Adopted V-struts and monospar lower wing like on the excellent Nieuport 11 and 17. Giving even better performance and better visibility down below for the pilot.

Soon a serious problem occurred. The lower wing spar and ribs failed during flight, a defect shared with the Nieuport 17. On 27 Januar 1917 all D.III were grounded for this reason. Albatros reinforced the lower wing and after 19 februar 1917 the D.III’s took to the sky again.

The lower wing twisted under aerodynamic loads, due to its single-spar layout and this could not be solved and pilots were advised not to perform long steep dives.

There also was a problem with the Teves und Braun airfoil-shaped radiator in the center of the upper wing, where it tended to scald the pilot if punctured. From the 290th D.III onward, the radiator was offset to the right on production machines to prevent this.

Apart from its structural deficiencies, the D.III was considered pleasant and easy to fly, if somewhat heavy on the controls. The sesquiplane arrangement offered improved climb, maneuverability, and downward visibility compared to the preceding D.II. Like most contemporary aircraft, the D.III was prone to spinning, but recovery was straightforward.

With the D.III famous aces like Manfred von Richthofen, Werner Voss, Ernst Udet, Eduard von Schleich and Bruno Lorzer scored many victories.

November 1917 a maximum of 446 D.III’s were flying at the front.

span upper wing : 9.03m

lower wing : 8.75m

tail : 2.40m

Chord upperwing : 1.5m in the center to 1.75m at the tips

stagger : 0.22m gap : 1.5m

"Axial" airscrew diam. 2.73m pitch : 2.20m

users : Luftwaffe, Austria-Hungaria

crew : 1

armament : 2 synchronized 7.92 [mm] (0.312 in) Spandau LMG 08/15 machine-guns

engine : 1 Mercedes D.IIIa liquid-cooled 6 -cylinder inline engine 175 [hp](128.7 KW)

dimensions :

wingspan : 9.03 [m], length : 7.33 [m], height : 2.9[m]

wing area : 20.5 [m^2]

Afbeeldingsresultaat voor Albatros D.III

weights :

max.take-off weight : 886 [kg]

empty weight operational : 670 [kg] bombload : 0 [kg]

performance :

maximum speed : 175 [km/u] op 1000 [m]

climbing speed : 303 [m/min]

service ceiling : 5500 [m]

endurance : 2.0 [hours]

estimated action radius : 158 [km]

description :

1-bay biplane with fixed landing gear and tail strut

upper wing 2 spars, lower wing single spar

engines, landing gear, fuel and bombs in or attached to the fuselage

airscrew :

fixed pitch 2 -bladed tractor airscrew with max. efficiency :0.64 [ ]

diameter airscrew 2.73 [m]

angle of attack prop : 17.95 [ ]

reduction : 1.00 [ ]

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

pitch at Max speed 2.08 [m]

blade-tip speed at Vmax and max revs. : 206 [m/s]

calculation : *1* (dimensions)

mean wing chord : 1.14 [m]

calculated wing chord (rounded tips): 1.27 [m]

wing aspect ratio : 7.96 []

gap : 1.50 [m]

gap/chord : 1.32 [ ]

seize (span*length*height) : 192 [m^3]

Afbeeldingsresultaat voor Albatros D.III

calculation : *2* (fuel consumption)

oil consumption : 3.6 [kg/hr]

fuel consumption(cruise speed) : 29.2 [kg/hr] (39.9 [litre/hr]) at 65 [%] power

distance flown for 1 kg fuel : 5.39 [km/kg]

estimated total fuel capacity : 91 [litre] (66 [kg])

calculation : *3* (weight)

weight engine(s) dry : 297.0 [kg] = 2.31 [kg/KW]

weight 13 litre oil tank : 1.1 [kg]

oil tank filled with 1.0 litre oil : 0.9 [kg]

oil in engine 7 litre oil : 6.4 [kg]

fuel in engine 1 litre fuel : 0.6 [kg]

weight 17 litre gravity patrol tank(s) : 2.5 [kg]

weight radiator : 18.4 [kg]

weight exhaust pipes & fuel lines 11.6 [kg]

Afbeeldingsresultaat voor Albatros D.III

weight cowling 5.1 [kg]

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

total weight propulsion system : 362 [kg](40.8 [%])

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fuselage skeleton (wood gauge : 5.38 [cm]): 54 [kg]

bracing : 2.8 [kg]

fuselage covering ( 10.1 [m2] doped linen fabric) : 3.2 [kg]

weight controls + indicators: 5.7 [kg]

weight seats : 3.0 [kg]

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

weight 74 [litre] main fuel tank empty : 5.9 [kg]

weight engine mounts & firewalls : 6 [kg]

total weight fuselage : 87 [kg](9.8 [%])

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weight wing covering (doped linen fabric) : 13 [kg]

total weight ribs (64 ribs) : 53 [kg]

load on front upper spar (clmax) per running metre : 660.5 [N]

load on rear upper spar (vmax) per running metre : 294.6 [N]

total weight 6.0 spars : 31 [kg]

weight wings : 97 [kg]

weight wing/square meter : 4.71 [kg]

weight 4 interplane struts & cabane : 11.7 [kg]

weight cables (45 [m]) : 2.9 [kg] (= 65 [gram] per metre)

diameter cable : 3.3 [mm]

weight fin & rudder (0.9 [m2]) : 4.6 [kg]

weight stabilizer & elevator (2.3 [m2]): 11.0 [kg]

total weight wing surfaces & bracing : 127 [kg] (14.3 [%])

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Afbeeldingsresultaat voor Albatros D.III

weight machine-gun(s) : 34.0 [kg]

weight ammunition magazine(s) :3.5 [kg]

weight synchronizing system : 2.0 [kg]

weight armament : 40 [kg]

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wheel pressure : 443.0 [kg]

weight 2 wheels (680 [mm] by 81 [mm]) : 17.9 [kg]

weight tailskid : 1.7 [kg]

weight undercarriage with axle 17.4 [kg]

total weight landing gear : 37.0 [kg] (4.2 [%]

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calculated empty weight : 652 [kg](73.6 [%])

weight oil for 2.4 hours flying : 8.6 [kg]

weight cooling fluids : 27.8 [kg]

weight ammunition (1000 rounds) : 35.0 [kg]

weight signal pistol with cartridges : 3.6 [kg]

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calculated operational weight empty : 727 [kg] (82.0 [%])

published operational weight empty : 670 [kg] (75.6 [%])

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weight crew : 81 [kg]

weight fuel for 1.5 hours flying : 44 [kg]

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operational weight : 852 [kg](96.1 [%])

estimated bomb load : 25 [kg]

operational weight bombing mission : 877 [kg]

fuel reserve : 9 [kg] enough for 0.32 [hours] flying

operational weight fully loaded : 886 [kg] with fuel tank filled for 80 [%]

published maximum take-off weight : 886 [kg] (100.0 [%])

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calculation : * 4 * (engine power)

power loading (operational without bombload) : 6.62 [kg/kW]

total power : 128.7 [kW] at 1400 [r.p.m]

calculation : *5* (loads)

manoeuvre load : 2.4 [g] at 1000 [m]

limit load : 4.5 [g] ultimate load : 6.8 [g] load factor : 1.7 [g]

design flight time : 1.60 [hours]

design cycles : 188 sorties, design hours : 300 [hours]

operational wing loading : 407 [N/m^2]

wing stress (3 g) during operation : 259 [N/kg] at 3g emergency manoeuvre

calculation : *6* (angles of attack)

angle of attack zero lift : -1.17 ["]

max.angle of attack (stalling angle) : 12.25 ["]

angle of attack at max.speed : 2.46 ["]

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 : 0.31 [ ]

induced drag coefficient at max.speed : 0.0068 [ ]

drag coefficient at max.speed : 0.0557 [ ]

drag coefficient (zero lift) : 0.0488 [ ]

calculation : *8* (speeds

stalling speed at sea-level (OW): 87 [km/u]

landing speed at sea-level (OW without bombload): 104 [km/hr]

min.drag speed (max endurance) : 117 [km/hr] at 2750 [m](power :43 [%])

min. power speed (max range) : 132 [km/hr] at 2750 [m] (power:48 [%])

max.rate of climb speed : 108.8 [km/hr] at sea-level

cruising speed : 158 [km/hr] op 2750 [m] (power:63 [%])

design speed prop : 170 [km/hr]

maximum speed : 175 [km/hr] op 1000 [m] (power:89 [%])

climbing speed at sea-level (without bombload) : 297 [m/min]

calculation : *9* (regarding various performances)

take-off distance at sea-level : 175 [m]

lift/drag ratio : 8.49 [ ]

max. practical ceiling : 5900 [m] with flying weight :784 [kg]

practical ceiling (operational weight): 5325 [m] with flying weight :852 [kg]

practical ceiling fully loaded (mow- 1 hour fuel) : 5300 [m] with flying weight :857 [kg]

published ceiling (5500 [m]

climb to 1500m (without bombload) : 5.60 [min]

climb to 3000m (without bombload) : 13.56 [min]

max.dive speed : 409.9 [km/hr] at 4300 [m] height

load factor at max.angle turn 2.00 ["g"]

turn radius at 500m: 72 [m]

time needed for 360* turn 12.9 [seconds] at 500m

calculation *10* (action radius & endurance)

operational endurance : 1.99 [hours] with 1 crew and 20 [kg] useful load and 87.8 [%] fuel

published endurance : 2.00 [hours] with 1 crew and possible useful (bomb) load : 20 [kg] and 88.1 [%] fuel

action radius : 157 [km] with 1 crew and 20[kg] photo camera/radio transmitter or bombload

max range theoretically with additional fuel tanks for total 159 [litre] fuel : 629 [km]

useful load with action-radius 250km : 24 [kg]

production : 3.78 [tonkm/hour]

oil and fuel consumption per tonkm : 8.68 [kg]

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Literature :

Praktisch handboek vliegtuigen deel 1 page 275

Fighters 1914-19 page 39

German aircraft of the first world war page 48

Wikepedia

Warplanes WOI page 54,56,59,60f,088f,90,94,96

Jane’s fighting aircraft WWI page 127,137,141

Jagdflugzeuge WWI page 45

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 04 January 2019 contact : info.aircraftinvestigation@gmail.com python 3.7.2(32-bit)

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