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weight and performance calculations for the Bristol 167 Brabazon Mk.I
Bristol 167 Brabazon Mk.I
role : trans-Atlantic airliner
importance : **
first flight : 4 September 1949 at Filton. Chief test pilot Arthur J. “Bill” Pegg was in command with Walter Gibb as co-pilot. operational : not used operational
country : United-Kingdom
design : design team led by L.G.Frise and Archibald Russell
production : 1 prototype reg. G-AGPW
general information :
On 23 December 1942 the Brabazon committee was formed. Her task was to make an inventory of future air traffic and to make proposals for the construction of a post-war generation of airliners. On 9 February 1943 they came up with the ambitious plan to develop an aircraft that could carry 100 passengers non-stop between London and New York. The Bristol factories were chosen to develop this aircraft, the model 167, because they had the required engines, capacity and knowledge. And so began one of the biggest failures of the British aviation industry. The technical problems that had to be solved were considerable, so it was decided to install the eight Centaurus engines, which were needed to get the colossus into the air, in pairs in the wing. Each pair of engines powered two three-blade counter-rotating aircrews. The engines were cooled by inlets in the wing leading edge. With this setup, according to the calculations, the air resistance was reduced by 25%. A giant hall was built at Filton for final assembly. The runway was lengthened from 610m to 2440m and widened. For this the habitants of the village of Charlton had to be relocated to nearby Patchway village. At the beginning of 1947 the aircraft had to be ready, but this lasted until January 1949 and then it took until September 1949 before the first flight could be made. In the meantime, the interest had cooled down considerably due to the long development time. The construction of the 2nd prototype, which would get powerful turboprop engines, also caused a lot of problems. The Brabazon I was used for test flights for the model. In February 1952, the British government halted construction of the Brabazon II. On September 20, 1952, the Brabazon I flew for the last time after being in the air for only 382 hours. In October 1953 they were demolished. It was an economically and practically unusable aircraft.
The British focused on very nice comfort for the wealthy passenger, economic operating came on second plan.
The Brabazon was the first aircraft to be outfitted with 100 per cent powered flying controls; it was also the first to feature electric engine controls, and the first equipped with high-pressure hydraulics.
Fuel capacity : 13650 imp. Gallon (62054 litres)
primary users : none
flight crew : 6 cabin crew : 4 passengers : 100
powerplant : 8 Bristol Centaurus 20 air-cooled 18 -cylinder radial engine 1640 [hp](1222.9 KW)
normal rating, supercharged engine, high blower, constant power to height : 6706 [m]
and with 2500 [hp](1864.2 KW) available for take-off
dimensions :
wingspan : 70.1 [m], length : 53.95 [m], height : 15.24 [m]
wing area : 494.0 [m^2]
weights :
max.take-off weight : 131542 [kg]
empty weight operational : 76884 [kg] useful load : 15000 [kg]
performance :
maximum continuous speed : 483 [km/u] op 7620 [m]
normal cruise speed : 402 [km/u] op 7620 [m] (65 [%] power)
service ceiling : 9500 [m]
range with max fuel : 8800 [km] and allowance for 987.0 [km] diversion and 30 [min]
hold
description :
low-winged monoplane with retractable landing gear with nose wheel
tapered multi-cellular wing with flush-riveted stressed skin
with slotted flaps airfoil : root : T.P.4 tip : T.P.5
engines and landing gear attached to the wings, fuel tanks in the wings
construction : all-metal aluminium-alloy stressed-skin construction with pressurized
fuselage fuselage shape : O
airscrew :
eight Rotol full-feathering contra-rotating 3 -bladed tractor airscrews with max.
efficiency :0.74 [ ]
diameter airscrew 4.90 [m]
relative pitch (J) : 1.71 [ ]
power loading prop : 166.39 [KW/m]
theoretical pitch without slip : 9.35 [m]
blade angle prop at max.speed : 39.99 [ ]
tip-speed close to speed of sound (above Mach 0.85) > loose of efficiency
reduction : 0.40 [ ]
airscrew revs : 960 [r.p.m.]
aerodynamic pitch at max. continuous speed 8.39 [m]
blade-tip speed at max.continuous speed : 280 [m/s]
propellor noise in flight : 97 [Db]
calculation : *1* (dimensions)
wing chord : 7.59 [m]
mean wing chord : 7.05 [m]
calculated average wing chord tapered wing with rounded tips: 6.76 [m]
wing aspect ratio : 9.9 []
seize (span*length*height) : 57636 [m^3]
calculation : *2* (fuel consumption)
oil consumption : 97.8 [kg/hr]
fuel consumption (econ. cruise speed) : 1831.1 [kg/hr] (2498.0 [litre/hr]) at 65 [%]
power
distance flown for 1 kg fuel : 0.22 [km/kg] at 7620 [m] height, sfc : 288.0 [kg/kwh]
estimated total fuel capacity : 62066 [litre] (45494 [kg])
calculation : *3* (weight)
weight engine(s) dry with reduction gear : 9776.0 [kg] = 1.00 [kg/KW]
weight 3107.4 litre oil tank : 264.13 [kg]
oil tank filled with 73.4 litre oil : 65.9 [kg]
oil in engine 54.5 litre oil : 48.9 [kg]
fuel in engine 66.7 litre fuel : 48.92 [kg]
weight 1062.0 litre gravity patrol tank(s) : 159.3 [kg]
weight jet stacks : 244.6 [kg]
weight transmission gear 195.7 [kg]
weight variable pitch control : 107.5 [kg]
weight airscrew(s) incl. boss & bolts : 2687.1 [kg]
total weight propulsion system : 13344 [kg](10.1 [%])
***************************************************************
fuselage aluminium frame : 16997 [kg]
typical cabin layout for 100 passengers : pitch : 81 [cm] ( 3+3 ) seating in 16.7 rows
pax density (normal seating) : 1.96 [m2/pax]
high density seating passengers : 341 at 9 -abreast seating in 37.9 rows
weight 7 toilets : 52.8 [kg]
weight 8 hand fire extinguisher : 23 [kg]
weight buffet : 398.4 [kg]
weight staircase : 110 [kg]
weight 35 windows : 31.8 [kg]
weight 4 emergency exits : 12.0 [kg]
weight 5 life rafts : 125.0 [kg]
weight oxygen masks & oxygen generators : 65.0 [kg]
weight 2 entrance/exit doors : 24.0 [kg]
weight 2 freight doors (belly) : 8.0 [kg]
extra main deck space for freight/mail/luggage etc. : 185.79 [m3]
cabin volume (usable), excluding flight deck : 722.60 [m3]
passenger cabin max.width : 5.24 [m] cabin length : 37.48 [m] cabin height : 2.36 [m]
pressure at cruise height 6100.00 [m] : 0.47 [kg/cm2] cabin pressure : 0.77 [kg/cm2]
weight rear pressure bulkhead : 431.5 [kg]
weight air pressurization system : 115.9 [kg]
fuselage covering ( 672.7 [m2] duraluminium 3.36 [mm]) : 6057.3 [kg]
weight floor beams : 1346.0 [kg]
weight cabin furbishing : 1244.4 [kg]
weight cabin floor : 662.9 [kg]
fuselage (sound proof) isolation : 256.8 [kg]
weight radio transceiver equipment : 7.0 [kg]
weight radio direction finding (RDF) equipment : 5.0 [kg]
weight artificial horizon : 1.1 [kg]
weight instruments. : 17.0 [kg]
weight APU / engine starter: 61.1 [kg]
weight lighting : 25.0 [kg]
weight electricity generator : 25.0 [kg]
weight controls : 24.2 [kg]
weight seats : 530.0 [kg]
weight air conditioning : 150 [kg]
total weight fuselage : 28520 [kg](21.7 [%])
***************************************************************
total weight aluminium ribs (953 ribs) : 4691 [kg]
weight engine mounts : 489 [kg]
weight fuel tanks empty for total 61004 [litre] fuel : 4880 [kg]
weight wing covering (painted aluminium 2.41 [mm]) : 6432 [kg]
total weight aluminium spars (multi-cellular wing structure) : 6531 [kg]
weight wings : 17653 [kg]
weight wing/square meter : 35.74 [kg]
cantilever wing without bracing cables
weight rubber de-icing boots : 77.1 [kg]
weight fin & rudder (57.0 [m2]) : 2046.8 [kg]
weight stabilizer & elevator (55.6 [m2]): 1989.7 [kg]
weight flight control hydraulic servo actuators: 136.5 [kg]
weight slotted flaps (41.2 [m2]) : 741.6 [kg]
total weight wing surfaces & bracing : 28014 [kg] (21.3 [%])
*******************************************************************
Can also operate from unpaved runways
wheel pressure : 16442.8 [kg]
weight 8 Dunlop main wheels (1750 [mm] by 350 [mm]) : 1520.5 [kg]
weight 2 Dunlop nose wheels : 380.1 [kg]
weight hydraulic wheel-brakes : 91.9 [kg]
weight pneumatic-hydraulic shock absorbers : 122.5 [kg]
weight wheel hydraulic operated retraction system : 306.5 [kg]
weight undercarriage struts with axle 2317.2 [kg]
total weight landing gear : 4598.2 [kg] (3.5 [%]
*******************************************************************
********************************************************************
calculated empty weight : 74477 [kg](56.6 [%])
weight oil for 26.3 hours flying : 2570.0 [kg]
calculated operational weight empty : 77047 [kg] (58.6 [%])
published operational weight empty : 76884 [kg] (58.4 [%])
weight crew : 486 [kg]
weight fuel for 2.0 hours flying : 3662 [kg]
weight catering : 766.2 [kg]
weight water : 612.9 [kg]
********************************************************************
operational weight empty: 82574 [kg](62.8 [%])
weight 100 passengers : 7700 [kg]
weight luggage : 1220 [kg]
weight cargo : 6080 [kg]
operational weight loaded: 97574 [kg](74.2 [%])
fuel reserve : 33968.0 [kg] enough for 18.55 [hours] flying
operational weight fully loaded : 131542 [kg] with fuel tank filled for 83 [%]
published maximum take-off weight : 131542 [kg] (100.0 [%])
calculation : * 4 * (engine power)
power loading (Take-off) : 8.82 [kg/kW]
power loading (operational without useful load) : 8.44 [kg/kW]
power loading (Take-off) 1 PUF: 10.08 [kg/kW]
max.total take-off power : 14914.0 [kW]
calculation : *5* (loads)
manoeuvre load : 3.1 [g] at 1000 [m]
limit load : 2.5 [g] ultimate load : 3.8 [g] load factor : 0.9 [g]
design flight time : 15.32 [hours]
design cycles : 1179 sorties, design hours : 18067 [hours]
operational wing loading : 2248 [N/m^2]
wing stress (3 g) during operation : 189 [N/kg] at 3g emergency manoeuvre
calculation : *6* (angles of attack)
angle of attack zero lift : -1.33 ["]
max. angle of attack (stalling angle, clean) : 11.01 ["]
max. angle of attack (full flaps) : 10.12 ["]
angle of attack at max. speed : 2.34 ["]
calculation : *7* (lift & drag ratios
lift coefficient at angle of attack 0° : 0.12 [ ]
lift coefficient at max. speed : 0.33 [ ]
lift coefficient at max. angle of attack : 1.12 [ ]
max.lift coefficient full flaps : 1.37 [ ]
induced drag coefficient at max.speed : 0.0045 [ ]
drag coefficient at max. speed : 0.0182 [ ]
drag coefficient (zero lift) : 0.0137 [ ]
calculation : *8* (speeds
stalling speed at sea-level (OW loaded : 129711 [kg]): 221 [km/u]
stalling speed at sea-level with full flaps (normal landing weight): 171 [km/u]
landing speed at sea-level (normal landing weight : 94977 [kg]): 196 [km/hr]
max. rate of climb speed : 224 [km/hr] at sea-level
max. endurance speed : 221 [km/u] min.fuel/hr : 1389 [kg/hr] at height : 610 [m]
max. range speed : 428 [km/u] min. fuel consumption : 5.466 [kg/km] at cruise height :
7925 [m]
cruising speed : 402 [km/hr] at 7620 [m] (power:66 [%])
max. continuous speed* : 483.00 [km/hr] at 7620 [m] (power:87 [%])
climbing speed at sea-level (loaded) : 266 [m/min]
climbing speed at 1000 [m] with 1 engine out (PUF / MTOW) : 218 [m/min]
climbing speed at 1000 [m] with 2 engines out (2xPUF / MTOW) : 148 [m/min]
calculation : *9* (regarding various performances)
take-off speed : 266.9 [km/u]
emergency/TO power : 2500 [hp] at 2700 [rpm]
static prop wash : 176 [km/u]
take-off distance at sea-level concrete runway : 1407 [m]
take-off distance at sea-level over 15 [m] height : 1618 [m]
landing run : 870 [m]
landing run from 15 [m] : 1650 [m]
lift/drag ratio : 21.15 [ ]
climb to 1000m with max payload : 8.97 [min]
climb to 2000m with max payload : 18.86 [min]
climb to 3000m with max payload : 30.00 [min]
climb to 5000 [m] with max payload : 61.52 [min]
practical ceiling (operational weight empty 82574 [kg] ) : 9900 [m]
practical ceiling fully loaded (mtow- 30 min.fuel:130626 [kg] ) : 6800 [m]
calculation *10* (action radius & endurance)
published range : 8800 [km] with 6 crew and 13926.3 [kg] useful load and 88.1 [%]
fuel (no reserves)
range : 8564 [km] with 6 crew and 15000.0 [kg] useful load and 85.7 [%] fuel
range : 9899 [km] with 100.0 passengers with each 12.2 [kg] luggage and 99.1 [%]
fuel
Available Seat Kilometres (ASK) : 989911 [paskm]
max range theoretically with additional fuel tanks total 74235.0 [litre] fuel : 9955 [km]
useful load with range 500km : 52137 [kg]
useful load with range 500km : 100 passengers
production (theor.max load): 20959 [tonkm/hour]
production (useful load): 6030 [tonkm/hour]
production (passengers): 40200 [paskm/hour]
combi aircraft mail/freight/passengers
oil and fuel consumption per tonkm : 0.092 [kg]
fuel cost per paskm : 0.048 [eur]
crew cost per paskm : 0.019 [eur]
time between engine failure : 580 [hr]
writing off per paskm : 0.085 [eur]
insurance per paskm : 0.0073 [eur]
maintenance cost per paskm : 0.803 [eur]
direct operating cost per paskm : 0.962 [eur]
direct operating cost per tonkm (max. load): 1.845 [eur]
direct operating cost per tonkm (normal useful load): 6.413 [eur]
Literature :
praktisch handboek vliegtuigen deel 5 page 129,130,131
piston-engined airliners page 61
verkeersvliegtuigen Moussault page 37,113,114
Jane’s fighting aircraft WWII page 110
* max. continuous speed : max. level speed maintainable for minimal 30 min.
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 03 April 2022 contact : info.aircraftinvestigation@gmail.com python 3.7.4