Halberstadt D.II
role : fighter
first flight : operational : June 1916
country : Germany
design :
production : 84 aircraft (Halberstadt, Aviatik, Hannover)
general information : The Halberstadt fighters came to the front after the Fokker E.III
had lost its supremacy. They fought well, being better than the Fokker D-types, but when the superior Albatros fighters appeared they were soon replaced, starting early spring 1917. The German pilots were at first afraid the frail looking tail would brake up during combat but it proved to be a strong design what could withstand long steep dives and tight manoeuvres. The D.I arrived in February 1916. It was powered by a 100 hp Mercedes D.I engine and had no wing stagger. The D.Ia had a 120 hp Argus As.II engine with a wing-mounted radiator. Boelcke flew the D.II on it’s first operational combat mission from Douai.
After the D. II followed the D. III which was equipped with An Argus As. II engine of 120 hp and with vertical center-section struts but further little differed from the D. II. There were not very many pieces built (about 30?)
Chord : 1.56 m2 gap : 1.30m
users : Germany
crew : 1
armament : 1 synchronized 7.92 [mm] (0.312 in) Spandau LMG 08/15 machine-gun
engine : 1 Mercedes D.II liquid-cooled 6 -cylinder inline engine 120 [hp](88.3 KW)
dimensions :
wingspan : 8.81 [m], length : 7.29 [m], height : 2.67[m]
wing area : 22.75 [m^2]
weights :
max.take-off weight : 730 [kg]
empty weight operational : 519 [kg] bombload : 0 [kg]
performance :
maximum speed : 145 [km/hr] at sea-level
climbing speed : 286 [m/min]
service ceiling : 4000 [m]
endurance : 1.5 [hours]
estimated action radius : 98 [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 2.68 [m]
angle of attack prop : 17.02 [ ]
reduction : 1.00 [ ]
airscrew revs : 1250 [r.p.m.]
pitch at Max speed 1.93 [m]
blade-tip speed at Vmax and max revs. : 180 [m/s]
calculation : *1* (dimensions)
mean wing chord : 1.29 [m]
calculated wing chord (rounded tips): 1.46 [m]
wing aspect ratio : 6.82 []
estimated gap : 1.24 [m]
gap/chord : 0.96 [ ]
seize (span*length*height) : 171 [m^3]
calculation : *2* (fuel consumption)
oil consumption : 2.0 [kg/hr]
fuel consumption(cruise speed) : 27.4 [kg/hr] (37.3 [litre/hr]) at 68 [%] power
distance flown for 1 kg fuel : 4.77 [km/kg]
estimated total fuel capacity : 64 [litre] (47 [kg])
calculation : *3* (weight)
weight engine(s) dry : 204.0 [kg] = 2.31 [kg/KW]
weight 6 litre oil tank : 0.5 [kg]
oil tank filled with 0.7 litre oil : 0.6 [kg]
oil in engine 5 litre oil : 4.4 [kg]
fuel in engine 1 litre fuel : 0.4 [kg]
weight 16 litre gravity patrol tank(s) : 2.4 [kg]
weight radiator : 12.6 [kg]
weight exhaust pipes & fuel lines 10.2 [kg]
weight cowling 3.5 [kg]
weight airscrew(s) (wood) incl. boss & bolts : 19.0 [kg]
total weight propulsion system : 257 [kg](35.2 [%])
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fuselage skeleton (wood gauge : 5.44 [cm]): 55 [kg]
bracing : 2.8 [kg]
fuselage covering ( 10.0 [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 48 [litre] main fuel tank empty : 3.8 [kg]
weight engine mounts & firewalls : 4 [kg]
total weight fuselage : 83 [kg](11.4 [%])
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weight wing covering (doped linen fabric) : 15 [kg]
total weight ribs (46 ribs) : 43 [kg]
load on front upper spar (clmax) per running metre : 661.9 [N]
load on rear upper spar (vmax) per running metre : 237.9 [N]
total weight 8 spars : 29 [kg]
weight wings : 87 [kg]
weight wing/square meter : 3.84 [kg]
weight 8 interplane struts & cabane : 7.2 [kg]
weight cables (53 [m]) : 2.5 [kg] (= 46 [gram] per metre)
diameter cable : 2.8 [mm]
weight fin & rudder (0.9 [m2]) : 3.6 [kg]
weight stabilizer & elevator (2.6 [m2]): 10.0 [kg]
total weight wing surfaces & bracing : 111 [kg] (15.2 [%])
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weight machine-gun(s) : 17.0 [kg]
weight ammunition magazine(s) :2.3 [kg]
weight synchronizing system : 1.0 [kg]
weight armament : 20 [kg]
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wheel pressure : 365.0 [kg]
weight 2 wheels (720 [mm] by 86 [mm]) : 16.2 [kg]
weight tailskid : 1.7 [kg]
weight undercarriage with axle 17.3 [kg]
total weight landing gear : 35.2 [kg] (4.8 [%]
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calculated empty weight : 507 [kg](69.4 [%])
weight oil for 1.8 hours flying : 3.7 [kg]
weight cooling fluids : 19.1 [kg]
weight ammunition (500 rounds) : 17.5 [kg]
weight automatic pistol with spare magazines : 1.2 [kg]
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calculated operational weight empty : 548 [kg] (75.1 [%])
published operational weight empty : 519 [kg] (71.1 [%])
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weight crew : 81 [kg]
weight fuel for 1.5 hours flying : 41 [kg]
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operational weight : 670 [kg](91.8 [%])
estimated bomb load : 25 [kg]
operational weight bombing mission : 695 [kg]
fuel reserve : 6 [kg] enough for 0.20 [hours] flying
possible additional useful load : 29 [kg]
operational weight fully loaded : 730 [kg] with fuel tank filled for 100 [%]
published maximum take-off weight : 730 [kg] (100.0 [%])
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calculation : * 4 * (engine power)
power loading (operational without bombload) : 7.59 [kg/kW]
total power : 88.3 [kW] at 1250 [r.p.m]
View of the all-moving tail surfaces.
calculation : *5* (loads)
manoeuvre load : 2.3 [g] at 1000 [m]
limit load : 4.5 [g] ultimate load : 6.8 [g] load factor : 2.1 [g]
design flight time : 1.20 [hours]
design cycles : 333 sorties, design hours : 400 [hours]
operational wing loading : 289 [N/m^2]
wing stress (3 g) during operation : 226 [N/kg] at 3g emergency manoeuvre
calculation : *6* (angles of attack)
angle of attack zero lift : -1.22 ["]
max. angle of attack (stalling angle) : 12.71 ["]
angle of attack at max. speed : 2.36 ["]
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 : 0.29 [ ]
induced drag coefficient at max. speed : 0.0071 [ ]
drag coefficient at max. speed : 0.0610 [ ]
drag coefficient (zero lift) : 0.0539 [ ]
calculation : *8* (speeds
stalling speed at sea-level (OW): 73 [km/u]
landing speed at sea-level (OW without bombload): 88 [km/hr]
min. drag speed (max endurance) : 96 [km/hr] at 2000 [m](power :47 [%])
min. power speed (max range) : 108 [km/hr] at 2000 [m] (power:51 [%])
max. rate of climb speed : 90.5 [km/hr] at sea-level
cruising speed : 130 [km/hr] op 2000 [m] (power:68 [%])
design speed prop : 141 [km/hr]
maximum speed : 145 [km/hr] op 100 [m] (power:99 [%])
climbing speed at sea-level (without bombload) : 242 [m/min]
calculation : *9* (regarding various performances)
take-off distance at sea-level : 146 [m]
lift/drag ratio : 7.48 [ ]
max. practical ceiling : 4500 [m] with flying weight :624 [kg]
practical ceiling (operational weight): 4075 [m] with flying weight :670 [kg]
practical ceiling fully loaded (mtow- 1 hour fuel) : 3775 [m] with flying weight :703 [kg]
published ceiling (4000 [m]
climb to 1500m (without bombload) : 7.07 [min]
climb to 3000m (without bombload) : 18.54 [min]
max. dive speed : 313.9 [km/hr] at 2775 [m] height
load factor at max. angle turn 1.83 ["g"]
turn radius at 500m: 53 [m]
time needed for 360* turn 11.7 [seconds] at 500m
Halberstadt D.III, piloted by Ltn. Hans von Keudell of Jasta 1
calculation *10* (action radius & endurance)
operational endurance : 1.70 [hours] with 1 crew and 54 [kg] useful (bomb)load and 100.0 [%] fuel
published endurance : 1.50 [hours] with 1 crew and possible useful (bomb) load : 60 [kg] and 88.1 [%] fuel
action radius : 193 [km] with 1 crew and 20[kg] photo camera/radio transmitter or bombload
max range theoretically with additional fuel tanks for total 163 [litre] fuel : 570 [km]
useful load with action-radius 250km : 15 [kg]
production : 1.92 [tonkm/hour]
oil and fuel consumption per tonkm : 15.32 [kg]
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Literature :
Praktisch handboek vliegtuigen deel 1 page 260
Fighters 1914-19 page 34,113
Warplanes WOI page 49,56, 86,87, 94
Jane’s fighting aircraft WWI page 163
They fought for the sky page 107
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 21 August 2019 contact : info.aircraftinvestigation@gmail.com python 3.7.4