Bristol Boxkite
role : primary trainer
first flight : 29 July 1910 operational : January 1912
country : United-Kingdom
design : G.H Challenger
production : 78 aircraft
general information :
The British and Colonial Aeroplane Co. was founded in February 1910 by Sir George White, chairman of the Bristol Tramways and Carriage Co. The first aeroplane they built was a two-seater developed from the Henri Farman biplane. It became known as the Boxkite. It was the 1st British airplane that went into series production and when the production stopped in 1914, 66 were built. Some Boxkite had equal wing-span, but most had extended upper wing-tips. The British Army also employed the Boxkite which she used as a training aircraft. Many famous pilots from the beginning of WWI won their flying license with a Boxkite. The Pupil was seated behind the instructor, to be able to take over the control lever he had to bend over the instructor, from dual controls was still no question. Flying schools were at Brooklands, Eastchurch and Stonehenge.
users : RFC, Germany (2), Russia (9), South-Africa (3), Spain (2)
crew : 2
armament : no fixed armament
engine : 1 Gnome 7 Omega air-cooled 7 -cylinder atmospheric inlet-valve rotary engine 50 [hp](36.8 KW)
dimensions :
wingspan : 14.17 [m], length : 11.73 [m], height : 3.61[m]
wing area : 48.03 [m^2]
weights :
max.take-off weight : 522 [kg]
empty weight operational (estimation): 310.0 [kg] bombload : 0 [kg]
performance :
maximum speed : 64 [km/hr] at sea-level
service ceiling : unknown
endurance : 1.5 [hours]
estimated action radius : 43 [km]
description :
3½-bay biplane with fixed underwing 4 -wheel landing gear and tail strut
upper wingtips supported by slanted struts
two spar upper and lower wing
tail supported by two open tail booms
canard wing
engine, fuel and bombload in or attached to fuselage, landing gear attached to the wing
airscrew :
fixed pitch 2 -bladed pusher airscrew with max. efficiency :0.65 [ ]
estimated diameter airscrew 2.61 [m]
angle of attack prop : 8.58 [ ]
fine pitch
reduction : 1.00 [ ]
airscrew revs : 1150 [r.p.m.]
pitch at Max speed 0.93 [m]
blade-tip speed at Vmax and max revs. : 158 [m/s]
calculation : *1* (dimensions)
mean wing chord : 1.88 [m]
calculated wing chord (rounded tips): 2.10 [m]
wing aspect ratio : 7.52 []
estimated gap : 2.18 [m]
gap/chord : 1.16 [ ]
seize (span*length*height) : 600 [m^3]
calculation : *2* (fuel consumption)
oil consumption : 3.3 [kg/hr]
fuel consumption(cruise speed) : 14.7 [kg/hr] (20.1 [litre/hr]) at 76 [%] power
distance flown for 1 kg fuel : 3.92 [km/kg]
estimated total fuel capacity : 34 [litre] (25 [kg])
calculation : *3* (weight)
weight engine(s) dry : 75.0 [kg] = 2.04 [kg/KW]
weight 8 litre oil tank : 0.6 [kg]
oil tank filled with 0.3 litre oil : 0.2 [kg]
oil in engine 0 litre oil : 0.2 [kg]
fuel in engine 0 litre fuel : 0.2 [kg]
weight 9 litre gravity patrol tank(s) : 1.3 [kg]
weight cowling 1.5 [kg]
weight airscrew(s) (wood) incl. boss & bolts : 8.5 [kg]
total weight propulsion system : 87 [kg](16.6 [%])
***************************************************************
weight tail boom : 13 [kg]
fuselage skeleton (wood gauge : 3.58 [cm]): 39 [kg]
Pilot = Grahame-White ?
bracing : 2.8 [kg]
is de romp bekleed met stof ? nee
fuselage covering ( 16.9 [m2] doped linen fabric) : 0.0 [kg]
weight controls + indicators: 7.5 [kg]
weight seats : 6.0 [kg]
weight other details, lighting set, etc. : 5.1 [kg]
weight 26 [litre] main fuel tank empty : 2.0 [kg]
weight engine mounts & firewalls : 2 [kg]
total weight fuselage : 64 [kg](12.2 [%])
***************************************************************
weight wing covering (doped linen fabric) : 31 [kg]
total weight ribs (23 ribs) : 31 [kg]
load on front upper spar (clmax) per running metre : 128.2 [N]
load on rear upper spar (vmax) per running metre : 72.0 [N]
total weight 8 spars : 12 [kg]
weight wings : 73 [kg]
weight wing/square meter : 1.53 [kg]
weight 16 interplane struts & cabane : 33.4 [kg]
weight cables (109 [m]) : 2.3 [kg] (= 21 [gram] per metre)
diameter cable : 1.8 [mm]
weight fin & rudder (2.3 [m2]) : 3.9 [kg]
weight stabilizer & elevator (4.6 [m2]): 7.4 [kg]
total weight wing surfaces & bracing : 120 [kg] (23.0 [%])
*******************************************************************
weight armament : 0 [kg]
********************************************************************
good soft ground capabilities
wheel pressure : 130.5 [kg]
weight 4 wheels (660 [mm] by 74 [mm]) : 24.4 [kg]
weight tailskid : 0.9 [kg]
weight undercarriage with axle 10.7 [kg]
total weight landing gear : 36.0 [kg] (6.9 [%]
*******************************************************************
Replica made by the RAAF Museum; successful first flight 11 September 2013. Note the wing-tip extensions
********************************************************************
calculated empty weight : 307 [kg](58.8 [%])
weight oil for 1.8 hours flying : 6.0 [kg]
*******************************************************************
calculated operational weight empty : 313 [kg] (59.9 [%])
estimated operational weight empty : 310 [kg] (59.4 [%])
_____________
\| | |o| | |/
-----------
" "
weight crew : 162 [kg]
weight fuel for 1.5 hours flying : 22 [kg]
********************************************************************
operational weight : 497 [kg](95.2 [%])
bombload could not be carried with fuel for 2 hours flying time
fuel reserve : 3 [kg] enough for 0.20 [hours] flying
possible additional useful load : 22 [kg]
operational weight fully loaded : 522 [kg] with fuel tank filled for 100 [%]
published maximum take-off weight : 522 [kg] (100.0 [%])
||
||
=||I>|
||
||
calculation : * 4 * (engine power)
power loading (operational without bombload) : 13.51 [kg/kW]
total power : 36.8 [kW] at 1150 [r.p.m]
calculation : *5* (loads)
manoeuvre load : 1.3 [g] at 1000 [m]
limit load : 2.5 [g] ultimate load : 3.8 [g] load factor : 1.3 [g]
design flight time : 0.60 [hours]
design cycles : 625 sorties, design hours : 375 [hours]
operational wing loading : 101 [N/m^2]
wing stress (3 g) during operation : 199 [N/kg] at 3g emergency manoeuvre
calculation : *6* (angles of attack)
angle of attack zero lift : -1.19 ["]
max. angle of attack (stalling angle) : 12.43 ["]
angle of attack at max. speed : 5.09 ["]
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 : 0.53 [ ]
induced drag coefficient at max. speed : 0.0158 [ ]
drag coefficient at max. speed : 0.1429 [ ]
drag coefficient (zero lift) : 0.1271 [ ]
calculation : *8* (speeds
stalling speed at sea-level (OW): 43 [km/u]
landing speed at sea-level (OW without bombload): 52 [km/hr]
min. drag speed (max endurance) = minimum speed*1.1 at cruise height : 50 [km/hr] at 1000 [m] (power:55 [%])
min. power speed (max range) : 50 [km/hr] at 1000 [m] (power:55 [%])
cruising speed : 58 [km/hr] op 1000 [m] (power:72 [%])
design speed prop : 61 [km/hr]
maximum speed : 64 [km/hr] op 100 [m] (power:98 [%])
climbing speed at sea-level (without bombload) : 143 [m/min]
calculation : *9* (regarding various performances)
take-off distance at sea-level : 38 [m]
lift/drag ratio : 5.90 [ ]
max. practical ceiling : 3800 [m] with flying weight :401 [kg]
practical ceiling (operational weight): 2725 [m] with flying weight :497 [kg]
practical ceiling fully loaded (mtow- 1 hour fuel) : 2600 [m] with flying weight :507 [kg]
published ceiling (0 [m]
climb to 1500m (without bombload) : 12.60 [min]
max. dive speed : 128.5 [km/hr] at 1600 [m] height
load factor at max. angle turn 1.63 ["g"]
turn radius at 500m: 20 [m]
time needed for 360* turn 7.8 [seconds] at 500m
calculation *10* (action radius & endurance)
operational endurance : 1.70 [hours] with 2 crew and 22 [kg] useful (bomb)load and 100.0 [%] fuel
published endurance : 1.50 [hours] with 2 crew and possible useful (bomb) load : 25 [kg] and 88.1 [%] fuel
action radius : 53 [km] with 2 crew and 20[kg] photo camera/radio transmitter or bombload
max range theoretically with additional fuel tanks for total 175 [litre] fuel : 502 [km]
useful load with action-radius 250km : 1 [kg]
production : 0.03 [tonkm/hour]
oil and fuel consumption per tonkm : 572.72 [kg]
_
°°_I>-/
°
Literature :
Historische vliegtuigen page 29,109,110
Jagdflugzuege WOI page 8
Praktisch handboek vliegtuigen deel 1 page 96
Warplanes page 6,9,17,19, 20
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 23 September 2019 contact : info.aircraftinvestigation@gmail.com python 3.7.4