weight and performance calculations for the Bleriot XI
Louis Bleriot standing in his airplane at Les Baraques shortly before his cross channel flight.
Bleriot XI
role : experimental/research/flying trials
importance : *****
first flight : 23 January 1909 at Issy operational : 10 July 1909
country : France
production : ca.100 aircraft
design : Raymond Saulnier (1881-1964) & Louis Bleriot (1872-1936)
General information :
On 25 July 1909, Louis Bleriot made the first crossing of the Channel with a heavier-than-air aircraft. The 38 km (straigh-line) flight from Les Baraques (Calais) to Dover lasted 36.5 minutes (groundspeed 62.5 km/hr). The tour did not go entirely smoothly; Due to the lack of a compass, he became disoriented and the engine also overheated. Fortunately, a rainstorm cooled and eventually reached the coast of England. He landed on a grassy area (Northfall Meadow) near dover castle. The trough airspeed (TAS) was about 72 km/hr at 76m height, Bleriot flew about 43.8 km. Bleriot gained worldwide fame and also won the £1,000 sterling prize awarded by the Daily Mail for the first successful crossing.
After the first flight in January 1909, the aircraft was further improved. On July 4, it already made a 50-minute flight. The steering was done by wing warping of the wing tips.
After the successful crossing, several pilots wanted to have a copy in possession and so it soon went into production and was taken away by fliers like Alfred Leblanc and Leon Delagrange .
Soon the aviators installed a more powerful 50 hp Gnome rotary engine, with this engine it was also referred to as Bleriot XI bis . With the Gnome engine
It established several records: on 10 July 1910 Leon Morane (1885-1918) reaches a speed of 106.5 km/h at Reims.
James Radley (1884-1959), on Portholme Meadow near to the Godmanchester Parish Church
The aircraft used to cross the Channel from Bleriot is kept at the Conservatoire des Arts et Métiers in Paris .
motor : 1 Anzani luchtgekoelde 3-cil stermotor van 18.4[KW] (25[pk]) die een twee-bladige houten Chauvière propellor aandreef
users : Louis Bleriot ,
crew : 1
passengers : 1
engine : 1 Anzani 25 hp air-cooled 3 -cylinder radial engine 25 [hp](18.6 KW)
dimensions :
wingspan : 7.8 [m], length : 8.0 [m], height : 2.6[m]
wing area : 14.0 [m^2]
weights :
max.take-off weight : 300 [kg]
empty weight operational : 210 [kg] useful load : 0 [kg] 
performance :
maximum speed :75 [km/hr] at sea-level
cruise speed :68 [km/u] op 50 [m]
service ceiling : 650 [m]
range : 45 [km]
estimated endurance : 0.67 [hours]
description :
low-wing monoplane with fixed landing gear with tail wheel(s)
two spar wing
engine, landing gear and useful-load in or attached to fuselage, fuel in gravity tank
airscrew :
fixed pitch 2 -bladed tractor airscrew with max. efficiency :0.61 [ ]
diameter airscrew 2.08 [m]
angle of attack prop : 9.65 [ ]
fine pitch
reduction : 1.00 [ ]
airscrew revs : 1500 [r.p.m.]
pitch at Max speed 0.83 [m]
blade-tip speed at Vmax and max revs. : 165 [m/s]
calculation : *1* (dimensions)
wing chord : 1.83 [m]
mean wing chord : 1.79 [m]
calculated wing chord (rounded tips): 2.44 [m]
wing aspect ratio : 4.35 []
gap : 0.00 [m]
gap/chord : 0.00 [ ]
seize (span*length*height) : 162 [m^3]
calculation : *2* (fuel consumption)
oil consumption : 1.2 [kg/hr]
fuel consumption(cruise speed) : 7.3 [kg/hr] (10.0 [litre/hr]) at 85 [%] power
distance flown for 1 kg fuel : 9.25 [km/kg] at 325 [m] cruise height, sfc : 459.8 [kg/kwh]
estimated total fuel capacity : 7.53 [litre] (5.52 [kg])
calculation : *3* (weight)
weight engine(s) dry : 66.0 [kg] = 3.54 [kg/KW]
weight 1.5 litre oil tank : 0.13 [kg]
oil tank filled with 0.1 litre oil : 0.1 [kg]
oil in engine 0.1 litre oil : 0.1 [kg]
fuel in engine 0.1 litre fuel : 0.09 [kg]
weight 7.5 litre gravity patrol tank(s) : 1.1 [kg]
weight cowling 0.7 [kg]
weight airscrew(s) (wood) incl. boss & bolts : 4.6 [kg]
total weight propulsion system : 73 [kg](24.3 [%])
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fuselage skeleton (wood gauge : 4.40 [cm]): 40 [kg]
bracing : 2.2 [kg]
weight instruments. : 1.1 [kg]
weight controls : 4.2 [kg]
weight seats : 3.0 [kg]
weight engine mount : 0.9 [kg]
total weight fuselage : 51 [kg](17.1 [%])
***************************************************************
weight wing covering (doped linen fabric) : 16 [kg]
total weight ribs (14 ribs) : 18 [kg]
load on front upper spar (clmax) per running metre : 441.4 [N]
total weight 4 spars : 15 [kg]
weight wings : 49 [kg]
weight wing/square meter : 3.49 [kg]
weight cables (31 [m]) : 4.0 [kg] (= 128 [gram] per metre)
diameter cable : 4.6 [mm]
weight fin & rudder (0.7 [m2]) : 2.6 [kg]
weight stabilizer & elevator (1.6 [m2]): 5.6 [kg]
total weight wing surfaces & bracing : 61 [kg] (20.3 [%])
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good soft ground capabilities
wheel pressure : 150.0 [kg]
weight 2 wheels (650 [mm] by 76 [mm]) : 10.3 [kg]
weight tailwheel(s) : 5.9 [kg]
weight undercarriage with axle 8.6 [kg]
total weight landing gear : 24.8 [kg] (8.3 [%]
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After her friend, Léon Delagrange, was killed 4 January 1910 when the wing of his Blériot XI with Gnome 50 hp rotary engine failed near Croix d’Hins, Mme. Therese Peltier never flew again.
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calculated empty weight : 210 [kg](69.9 [%])
weight oil for 0.8 hours flying : 1.0 [kg]
calculated operational weight empty : 211 [kg] (70.2 [%])
published operational weight empty : 210 [kg] (70.0 [%])
___o___
"
weight crew : 81 [kg]
weight fuel for 0.4 hours flying : 3 [kg]
********************************************************************
operational weight : 295 [kg](98.2 [%])
fuel reserve : 2.6 [kg] enough for 0.36 [hours] flying
possible additional useful load : 3 [kg]
operational weight fully loaded : 300 [kg] with fuel tank filled for 100 [%]
published maximum take-off weight : 300 [kg] (100.0 [%])
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calculation : * 4 * (engine power)
power loading (Take-off) : 16.09 [kg/kW]
power loading (operational without useful load) : 15.80 [kg/kW]
total power : 18.6 [kW] at 1500 [r.p.m]
calculation : *5* (loads)
manoeuvre load : 0.7 [g] at 1000 [m]
limit load : 3.0 [g] ultimate load : 4.5 [g] load factor : 3.3 [g]
design flight time : 0.53 [hours]
design cycles : 950 sorties, design hours : 152 [hours]
operational wing loading : 206 [N/m^2]
wing stress (3 g) during operation : 177 [N/kg] at 3g emergency manoeuvre
calculation : *6* (angles of attack)
angle of attack zero lift : -1.42 ["]
max. angle of attack (stalling angle) : 13.62 ["]
angle of attack at max. speed : 9.68 ["]
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 : 0.78 [ ]
induced drag coefficient at max. speed : 0.0594 [ ]
Bleriot XI with 50 hp Antoinette engine.
drag coefficient at max. speed : 0.1447 [ ]
drag coefficient (zero lift) : 0.0853 [ ]
calculation : *8* (speeds
stalling speed at sea-level (OW): 64 [km/u]
landing speed at sea-level: 75 [km/hr]
min. drag speed (max endurance) = minimum speed*1.1 at cruise height : 72 [km/hr] at 325 [m] (power:93
[%])
min. power speed (max range) : 72 [km/hr] at 325 [m] (power:93 [%])
cruising speed : 68 [km/hr] op 325 [m] (power:88 [%])
design speed prop : 71 [km/hr]
maximum speed : 75 [km/hr] op 50 [m] (power:99 [%])
climbing speed at sea-level : 35 [m/min]
calculation : *9* (regarding various performances)
take-off speed : 71.3 [km/u]
static prop wash : 75 [km/u]
take-off distance at sea-level : 91 [m]
lift/drag ratio : 5.48 [ ]
max. theoretical ceiling : 773 [m] with flying weight :294 [kg] line 3370
climbing speed at 500m : 12.10 [m/min]
time to 500m : 28.11 [min]
published ceiling (650 [m]
practical ceiling (operational weight) : 673 [m] with flying weight :295 [kg] line 3385
practical ceiling fully loaded (mtow- 30 min.fuel) : 638 [m] with flying weight :296 [kg]
turning speed at CLmax : 68.0 [km/u] at 50 [m] height
turn radius at 50m: 74 [m]
time needed for 360* turn 24.7 [seconds] at 50m
load factor at max. angle turn 1.11 ["g"]
calculation *10* (action radius & endurance)
operational endurance : 0.76 [hours] with 1 crew and 2.8 [kg] useful load and 100.0 [%] fuel
published endurance : 0.67 [hours] with 1 crew and possible useful load : 3.4 [kg] and 88.1 [%] fuel
published range : 45 [km] with 1 crew and 3.4 [kg] useful load and 88.1 [%] fuel
max range theoretically with additional fuel tanks for total 11.3 [litre] fuel : 76.7 [km]
useful load with action-radius 250km : 0 [kg]
production (500 km) : 0 [tonkm/hour]
Literature :
Jane’s record breaking aircraft page13,14,15
Praktisch handbook vliegtuigen deel 1 page 57
Historische vliegtuigen page 62,106
Prop : 6.5 ft = 1.98m chord : 6 ft = 1.83m wheel : 2 ft = 61 cm
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
(library of congres)
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