Gotha G.V
role : medium-weight bomber
first flight : operational : August 1917
country : Germany
design :
production : 205 aircraft
general information :
Operational use of the G.IV demonstrated that the incorporation of the fuel tanks into the engine nacelles was a mistake. In a crash landing the tanks could rupture and spill fuel onto the hot engines. This posed a serious problem because landing accidents caused 75% of operational losses. In response Gotha produced the G.V, which housed its fuel tanks inside the fuselage. The smaller engine nacelles were mounted on struts above the lower wing.
The Gotha G.V pilot seat was offset to port with the fuel tanks immediately behind. This blocked the connecting walkway that previously on earlier machines allowed crew members to move between the three gun stations. All bombs were carried externally in this model. The Gotha included an important innovation in the form of a "gun tunnel" whereby the underside of the rear fuselage was arched, early versions allowing placement of a rearward-facing machine gun protecting from attack from below, removing the blind spot.[1] Later versions expanded the tunnel to remove the lower gun, providing a slot in the upper fuselage that allowed the rear gunner to remain stationary.
The base variant of G.V offered no performance improvement over the G.IV. The G.V was up to 450 kg (990 lb) heavier than the G.IV due to additional equipment and the use of insufficiently seasoned timber. The Mercedes D.IVa engines could not produce the rated 190 kW (260 hp) due to inferior quality of fuel.
On the night of ˝ oktober 1917 18 Gotha’s were sent out from there base near Ghent but only 8 reached London. British fighters could not intercept the bombers and AA-guns fired 10532 rounds with no result. 1 person was killed and 13 injured by fragments.
Distance between Ghent and London is 275 km
6/7 December 1917 19 Gotha’s took of for London, loaded with 4672 kg incendiary bombs and 395 kg explosives, total 5067 kg divided by 19 Gotha’s = 267 kg for each Gotha. Action radius with 300 kg bomb load is 376 km. For a raid on London the maximum bomb load of 600 kg could not be carried > action radius with 600 kg bombs is 182 km
Wheels : 810 by 125 mm
The G.Vb had additional nosewheels to prevent tipping over, could carry higher payload
users : Germany
crew : 3
armament : 3 movable 7.92 [mm] (0.312 in) Parabellum MG 14 machine-guns
engine : 2 Mercedes D.IVa liquid-cooled 6 -cylinder inline engine 252 [hp](185.3 KW)
dimensions :
wingspan : 23.7 [m], length : 12.36 [m], height : 4.3[m]
wing area : 89.5 [m^2]
weights :
max.take-off weight : 3975 [kg]
empty weight operational : 2740 [kg] bombload : 600 [kg]
performance :
maximum speed : 140 [km/hr] at sea-level
service ceiling : 5500 [m]
endurance : 6.0 [hours]
estimated action radius : 378 [km]
description :
4-bay biplane with fixed underwing 4 -wheel landing gear and tail strut
two spar upper and lower wing
engines and landing gear attached to the wings, fuel and bombload in or attached to fuselage
airscrew :
two fixed pitch 2 -bladed pusher airscrews with max. efficiency :0.64 [ ]
estimated diameter airscrew 3.05 [m]
angle of attack prop : 13.06 [ ]
fine pitch
reduction : 1.00 [ ]
airscrew revs : 1400 [r.p.m.]
pitch at Max speed 1.67 [m]
blade-tip speed at Vmax and max revs. : 227 [m/s]
G.V > note the changed engine nacelles
calculation : *1* (dimensions)
mean wing chord : 1.89 [m]
calculated wing chord (rounded tips): 2.00 [m]
wing aspect ratio : 12.55 []
estimated gap : 2.05 [m]
gap/chord : 1.09 [ ]
seize (span*length*height) : 1260 [m^3]
calculation : *2* (fuel consumption)
oil consumption : 8.5 [kg/hr]
fuel consumption(cruise speed) : 89.0 [kg/hr] (121.5 [litre/hr]) at 66 [%] power
distance flown for 1 kg fuel : 1.42 [km/kg]
estimated total fuel capacity : 827 [litre] (606 [kg])
calculation : *3* (weight)
weight engine(s) dry : 850.0 [kg] = 2.29 [kg/KW]
weight 78 litre oil tank : 6.6 [kg]
oil tank filled with 2.8 litre oil : 2.5 [kg]
oil in engine 21 litre oil : 18.5 [kg]
fuel in engine 3 litre fuel : 1.9 [kg]
weight 52 litre gravity patrol tank(s) : 7.7 [kg]
weight radiator : 55.6 [kg]
weight exhaust pipes & fuel lines 21.8 [kg]
weight self-starter : 4.5 [kg]
weight cowling 7.4 [kg]
weight airscrew(s) (wood) incl. boss & bolts : 55.6 [kg]
total weight propulsion system : 1026 [kg](25.8 [%])
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fuselage skeleton (wood gauge : 10.87 [cm]): 374 [kg]
bracing : 32.6 [kg]
fuselage covering ( 28.9 [m2] doped linen fabric) : 9.2 [kg]
weight controls + indicators: 8.9 [kg]
weight seats : 9.0 [kg]
weight other details, lighting set, etc. : 9.1 [kg]
weight bomb storage : 42.0 [kg]
weight Görz bomb sight with 90 cm Zeiss-telescope: 2.5 [kg]
weight two 388 [litre] main fuel tanks empty : 62.0 [kg]
weight oxygen/compressed air flasks for high altitude : 19.5 [kg]
weight interior + equipment + fuel lines: 59 [kg]
total weight fuselage : 627 [kg](15.8 [%])
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weight wing covering (doped linen fabric) : 57 [kg]
total weight ribs (172 ribs) : 236 [kg]
weight engine mounts : 19 [kg]
load on front upper spar (clmax) per running metre : 941.1 [N]
load on rear upper spar (vmax) per running metre : 462.0 [N]
total weight 8 spars : 209 [kg]
weight wings : 503 [kg]
weight wing/square meter : 5.62 [kg]
weight 16 interplane struts & cabane : 85.3 [kg]
weight cables (155 [m]) : 58.9 [kg] (= 379 [gram] per metre)
diameter cable : 7.9 [mm]
weight fin & rudder (6.5 [m2]) : 37.6 [kg]
weight stabilizer & elevator (10.1 [m2]): 57.3 [kg]
total weight wing surfaces & bracing : 760 [kg] (19.1 [%])
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weight machine-gun(s) : 28.5 [kg]
weight pivot mounting mg :10.0 [kg]
weight armament : 38 [kg]
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wheel pressure : 993.8 [kg]
weight 4 wheels (810 [mm] by 125 [mm]) : 85.7 [kg]
weight tailskid : 7.0 [kg]
weight undercarriage with axle 95.7 [kg]
total weight landing gear : 188.3 [kg] (4.7 [%]
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calculated empty weight : 2640 [kg](66.4 [%])
weight oil for 7.2 hours flying : 61.4 [kg]
weight cooling fluids : 80.1 [kg]
weight 3 drums empty : 6.8 [kg]
weight ammunition (1500 rounds) : 59.3 [kg]
weight signal pistol with cartridges : 3.6 [kg]
weight automatic pistol with spare magazines : 1.2 [kg]
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calculated operational weight empty : 2846 [kg] (71.6 [%])
published operational weight empty : 2740 [kg] (68.9 [%])
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weight crew : 243 [kg]
weight (electrical heated) clothing for high altitude : 18.0 [kg]
weight fuel for 2.0 hours flying : 178 [kg]
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operational weight : 3285 [kg](82.6 [%])
bomb load : 600 [kg]
operational weight bombing mission : 3885 [kg]
fuel reserve : 90 [kg] enough for 1.01 [hours] flying
operational weight fully loaded : 3975 [kg] with fuel tank filled for 44 [%]
published maximum take-off weight : 3975 [kg] (100.0 [%])
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calculation : * 4 * (engine power)
power loading (Take-off) : 10.72 [kg/kW]
total power : 370.7 [kW] at 1400 [r.p.m]
calculation : *5* (loads)
manoeuvre load : 1.2 [g] at 1000 [m]
limit load : 2.5 [g] ultimate load : 3.8 [g] load factor : 1.5 [g]
design flight time : 4.20 [hours]
design cycles : 310 sorties, design hours : 1300 [hours]
wing loading (MTOW) : 436 [N/m^2]
wing stress (3 g) during operation : 227 [N/kg] at 3g emergency manoeuvre
calculation : *6* (angles of attack)
angle of attack zero lift : -1.07 ["]
max. angle of attack (stalling angle) : 10.28 ["]
angle of attack at max. speed : 3.12 ["]
calculation : *7* (lift & drag ratios
lift coefficient at angle of attack 0° :0.10 [ ]
lift coefficient at max. angle of attack : 1.06 [ ]
lift coefficient at max. speed : 0.39 [ ]
induced drag coefficient at max. speed : 0.0069 [ ]
drag coefficient at max. speed : 0.0736 [ ]
drag coefficient (zero lift) : 0.0667 [ ]
calculation : *8* (speeds
stalling speed at sea-level (OW): 85 [km/u]
landing speed at sea-level (OW without bombload): 102 [km/hr]
min. drag speed (max endurance) = minimum speed*1.1 at cruise height : 107 [km/hr] at 2750 [m] (power:49 [%])
min. power speed (max range) : 107 [km/hr] at 2750 [m] (power:49 [%])
max. rate of climb speed : 85.1 [km/hr] at sea-level
cruising speed : 126 [km/hr] op 2750 [m] (power:64 [%])
design speed prop : 133 [km/hr]
maximum speed : 140 [km/hr] op 100 [m] (power:100 [%])
climbing speed at sea-level (without bombload) : 225 [m/min]
calculation : *9* (regarding various performances)
take-off distance at sea-level : 225 [m]
lift/drag ratio : 9.12 [ ]
max. practical ceiling : 5550 [m] with flying weight :2907 [kg]
practical ceiling (operational weight): 4775 [m] with flying weight :3285 [kg]
practical ceiling fully loaded (mtow- 1 hour fuel) : 3650 [m] with flying weight :3886 [kg]
published ceiling (5500 [m]
climb to 1500m (without bombload) : 6.90 [min]
climb to 3000m (without bombload) : 16.65 [min]
max. dive speed : 385.9 [km/hr] at 2650 [m] height
load factor at max. angle turn 1.65 ["g"]
turn radius at 500m: 88 [m]
time needed for 360* turn 16.4 [seconds] at 500m
calculation *10* (action radius & endurance)
operational endurance : 3.22 [hours] with 3 crew and 600 [kg] bombload and 47.2 [%] fuel
published endurance : 6.00 [hours] with 3 crew and possible useful (bomb) load : 352 [kg] and 88.1 [%] fuel
action radius : 613 [km] with 3 crew and 20[kg] photo camera/radio transmitter or bombload
max range theoretically with additional fuel tanks for total 1518 [litre] fuel : 1574 [km]
useful load with action-radius 250km : 533 [kg]
production : 67.16 [tonkm/hour]
oil and fuel consumption per tonkm : 1.45 [kg]
Literature :
Warplanes WOI page 62,75,131
Bombers 1914-19 page 26
Praktisch handbook vliegtuigen deel 1 page 271
Jane’s fighting aircraft WWI page 157,158,159f
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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lehrgewicht 2740 kg nutzlast 1235 kg gesamtgewicht 3975 kg.
G.Vb with additional wheels to prevent tipping over on landing 
(c) B van der Zalm 21 August 2019 contact : info.aircraftinvestigation@gmail.com python 3.7.4