Breguet Br.14B2
role : light bomber
first flight : 21 November 1916 operational : September 1917
country : France
design : Louis Breguet & Marcel Vuillerme
production : 8000 aircraft
general information :
The Breguet 14 was a French biplane bomber and reconnaissance aircraft of the First World War. It was built in very large numbers and production continued for many years after the end of the war. Apart from its widespread usage, the Breguet 14 is known for being the first mass-produced aircraft to use large amounts of metal, rather than wood, in its structure. This allowed the airframe to be lighter than a wooden airframe of the same strength, in turn making the aircraft relatively fast and agile for its size; in combat situations, it was able to outrun many of the contemporary fighters of the day. The Breguet 14's strong construction allowed it to sustain considerable damage, in addition to being easy to handle and possessing favourable performance. The type has often been considered to have been one of the best aircraft of the war.
14 A2 was the reconnaissance version.
Load carrying cables : 4.5mm thick
Tank capacity : 2 x 130 litre tanks & 2 5.6 litre auxiliary tanks > total patrol : 271.2 litre. Oil : 18 litre. Climb to 5000m : 47 min 30 sec ceiling : 5750m
users : France
crew : 2
armament : 1 synchronized 7.70 [mm] (0.303 in) Vickers machine-gun
and 1 or 2 movable 7.70 [mm] (0.303 in) Lewis machine-gun for the observer
engine : 1 Renault 12 Fcx liquid-cooled 12 -cylinder V-engine 300 [hp](220.7 KW)
dimensions :
wingspan : 14.36 [m], length : 8.87 [m], height : 3.45[m]
wing area : 50.2 [m^2]
weights :
max.take-off weight : 1765 [kg]
empty weight operational : 1030 [kg] bombload : 300 [kg]
performance :
maximum speed : 177 [km/u] op 2000 [m]
climbing speed : 292 [m/min]
service ceiling : 4267 [m]
endurance : 3.3 [hours]
estimated action radius : 263 [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 :0.64 [ ]
estimated diameter airscrew 2.96 [m]
angle of attack prop : 14.38 [ ]
fine pitch
reduction : 1.00 [ ]
airscrew revs : 1650 [r.p.m.]
pitch at Max speed 1.79 [m]
blade-tip speed at Vmax and max revs. : 260 [m/s]
calculation : *1* (dimensions)
mean wing chord : 1.75 [m]
calculated wing chord (rounded tips): 1.92 [m]
wing aspect ratio : 8.22 []
estimated gap : 1.69 [m]
gap/chord : 0.97 [ ]
seize (span*length*height) : 439 [m^3]
calculation : *2* (fuel consumption)
oil consumption : 4.6 [kg/hr]
fuel consumption(cruise speed) : 53.0 [kg/hr] (72.3 [litre/hr]) at 63 [%] power
distance flown for 1 kg fuel : 3.01 [km/kg]
estimated total fuel capacity : 271 [litre] (198 [kg])
calculation : *3* (weight)
weight engine(s) dry : 350.0 [kg] = 1.59 [kg/KW]
weight 26 litre oil tank : 2.2 [kg]
oil tank filled with 1.7 litre oil : 1.5 [kg]
oil in engine 9 litre oil : 7.7 [kg]
fuel in engine 2 litre fuel : 1.1 [kg]
weight 31 litre gravity patrol tank(s) : 4.6 [kg]
weight radiator : 31.6 [kg]
weight exhaust pipes & fuel lines 26.4 [kg]
weight self-starter : 5.4 [kg]
weight cowling 8.8 [kg]
weight airscrew(s) (wood) incl. boss & bolts : 33.1 [kg]
total weight propulsion system : 470 [kg](26.6 [%])
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fuselage skeleton (wood gauge : 6.26 [cm]): 89 [kg]
bracing : 5.6 [kg]
fuselage covering ( 14.9 [m2] doped linen fabric) : 4.8 [kg]
weight controls + indicators: 6.8 [kg]
weight seats : 6.0 [kg]
weight other details, lighting set, etc. : 5.1 [kg]
weight bomb storage : 21.0 [kg]
weight Doran/Lafay bomb sight : 1.5 [kg]
weight 240 [litre] main fuel tank empty : 19.2 [kg]
weight engine mounts & firewalls : 11 [kg]
total weight fuselage : 170 [kg](9.6 [%])
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weight wing covering (doped linen fabric) : 32 [kg]
total weight ribs (83 ribs) : 105 [kg]
load on front upper spar (clmax) per running metre : 513.7 [N]
load on rear upper spar (vmax) per running metre : 337.3 [N]
total weight 8 spars : 61 [kg]
weight wings : 198 [kg]
weight wing/square meter : 3.94 [kg]
weight 8 interplane struts & cabane : 20.6 [kg]
weight cables (81 [m]) : 7.7 [kg] (= 96 [gram] per metre)
diameter cable : 4.0 [mm]
weight fin & rudder (2.4 [m2]) : 9.8 [kg]
weight stabilizer & elevator (5.6 [m2]): 22.6 [kg]
total weight wing surfaces & bracing : 258 [kg] (14.6 [%])
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weight machine-gun(s) : 28.6 [kg]
weight pivot mounting mg :5.0 [kg]
weight ammunition magazine(s) :1.8 [kg]
weight synchronizing system : 1.0 [kg]
weight armament : 36 [kg]
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wheel pressure : 882.5 [kg]
weight 2 wheels (780 [mm] by 98 [mm]) : 34.2 [kg]
weight tailskid : 2.3 [kg]
weight undercarriage with axle 33.4 [kg]
total weight landing gear : 69.9 [kg] (4.0 [%]
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calculated empty weight : 1005 [kg](56.9 [%])
weight oil for 4.0 hours flying : 18.3 [kg]
weight cooling fluids : 47.7 [kg]
weight 5 drums empty : 1.0 [kg]
weight ammunition (635 rounds) : 22.6 [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 : 1098 [kg] (62.2 [%])
published operational weight empty : 1030 [kg] (58.4 [%])
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weight crew : 162 [kg]
weight fuel for 2.0 hours flying : 106 [kg]
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operational weight : 1366 [kg](77.4 [%])
bomb load : 300 [kg]
operational weight bombing mission : 1666 [kg]
fuel reserve : 92 [kg] enough for 1.75 [hours] flying
possible additional useful load : 6 [kg]
operational weight fully loaded : 1765 [kg] with fuel tank filled for 100 [%]
published maximum take-off weight : 1765 [kg] (100.0 [%])
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calculation : * 4 * (engine power)
power loading (Take-off) : 8.00 [kg/kW]
total power : 220.7 [kW] at 1650 [r.p.m]
calculation : *5* (loads)
manoeuvre load : 3.0 [g] at 1000 [m]
limit load : 3.0 [g] ultimate load : 4.5 [g] load factor : 1.1 [g]
design flight time : 2.64 [hours]
design cycles : 152 sorties, design hours : 400 [hours]
wing loading (MTOW) : 345 [N/m^2]
A battered and bruised Breguet 14B2 of Escadrille 131 limps home just over the German trenches
wing stress (3 g) during operation : 248 [N/kg] at 3g emergency manoeuvre
calculation : *6* (angles of attack)
angle of attack zero lift : -1.16 ["]
max. angle of attack (stalling angle) : 12.14 ["]
angle of attack at max. speed : 1.39 ["]
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 : 0.22 [ ]
induced drag coefficient at max. speed : 0.0033 [ ]
drag coefficient at max. speed : 0.0335 [ ]
drag coefficient (zero lift) : 0.0302 [ ]
calculation : *8* (speeds
stalling speed at sea-level (OW): 70 [km/u]
landing speed at sea-level (OW without bombload): 84 [km/hr]
min. drag speed (max endurance) : 103 [km/hr] at 2134 [m](power :29 [%])
min. power speed (max range) : 110 [km/hr] at 2134 [m] (power:31 [%])
max. rate of climb speed : 109.1 [km/hr] at sea-level
cruising speed : 159 [km/hr] op 2134 [m] (power:55 [%])
design speed prop : 168 [km/hr]
maximum speed : 177 [km/hr] op 2000 [m] (power:72 [%])
climbing speed at sea-level (without bombload) : 376 [m/min]
calculation : *9* (regarding various performances)
take-off distance at sea-level : 116 [m]
lift/drag ratio : 10.97 [ ]
max. practical ceiling : 5650 [m] with flying weight :1178 [kg]
practical ceiling (operational weight): 5100 [m] with flying weight :1366 [kg]
practical ceiling fully loaded (mtow- 1 hour fuel) : 4150 [m] with flying weight :1712 [kg]
published ceiling (4267 [m]
climb to 1500m (without bombload) : 4.48 [min]
climb to 3000m (without bombload) : 11.14 [min]
max. dive speed : 441.5 [km/hr] at 3150 [m] height
load factor at max. angle turn 2.12 ["g"]
turn radius at 500m: 56 [m]
time needed for 360* turn 11.0 [seconds] at 500m
calculation *10* (action radius & endurance)
operational endurance : 3.75 [hours] with 2 crew and 306 [kg] bombload and 100.0 [%] fuel
published endurance : 3.30 [hours] with 2 crew and possible useful (bomb) load : 330 [kg] and 88.1 [%] fuel
action radius : 729 [km] with 2 crew and 20[kg] photo camera/radio transmitter or bombload
max range theoretically with additional fuel tanks for total 836 [litre] fuel : 1844 [km]
useful load with action-radius 250km : 338 [kg]
production : 53.91 [tonkm/hour]
oil and fuel consumption per tonkm : 1.07 [kg]
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Crashed Breguet 14 from Escadrille Br.127 / Winged elephant emblem
Literature :
Praktisch handboek vliegtuigen deel 1 page 155
Bombers 1914-19 page 67
Jane’s FAWOI page 105
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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