Sopwith Schneider

AIRCRAFT INVESTIGATION

Weight and performance calculations for the Sopwith Schneider WWI light maritime reconnaissance floatplane

Sopwith Schneider

role : light maritime single-seat scout (ship based)

importance : ****

first flight : operational : December 1914

country : United-Kingdom

design :

production : 136 aircraft

general information :

On April 20, 1914, a Sopwith Schneider flown by Howard Pixton won the Schneider Cup in Monaco. He flew at an average speed of 139.6 km/h and in two extra laps it even reached 148 km/h, a new speed record for seaplanes. At the outbreak of WOI, the RNAS soon decided to order Schneiders for use as a fast scout. During 1915 attempts were made to use Schneiders to intercept Zeppelins over the North Sea, launching them from seaplane carriers including HMS Ben-my-Chree and Engadine, but these efforts were largely unsuccessful due to heavy seas either making takeoff impossible or damaging the floats. On 6 August 1915 a Schneider took off from the aircraft carrier HMS Campania using a jettisonable dolly.

To fight the Zeppelins the Schneider could carry four 20-lb H.E. bombs and an incendiary bomb. Also experiments were done with a Lewis machine gun on the centre-section.

users : RNAS

crew : 1

armament : no fixed armament

engine : 1 Gnome 9 Delta air-cooled 9 -cylinder atmospheric inlet-valve rotary engine 100 [hp](73.6 KW)

dimensions :

wingspan : 7.83 [m], length : 6.96 [m], height : 3.05[m]

wing area : 22.3 [m^2]

weights :

max.take-off weight : 695 [kg]

empty weight operational : 450 [kg] bombload : 45 [kg]

performance :

maximum speed : 139 [km/hr] at sea-level

climbing speed : 132 [m/min]

service ceiling : 2100 [m]

endurance : 3.0 [hours]

estimated action radius : 188 [km]

description :

1-bay two float biplane with tail float

no tip floats

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 :0.66 [ ]

estimated diameter airscrew 2.50 [m]

angle of attack prop : 18.15 [ ]

reduction : 1.00 [ ]

airscrew revs : 1200 [r.p.m.]

pitch at Max speed 1.93 [m]

blade-tip speed at Vmax and max revs. : 162 [m/s]

calculation : *1* (dimensions)

mean wing chord : 1.42 [m]

calculated wing chord (rounded tips): 1.64 [m]

wing aspect ratio : 5.50 []

estimated gap : 1.35 [m]

gap/chord : 0.95 [ ]

seize (span*length*height) : 166 [m^3]

calculation : *2* (fuel consumption)

oil consumption : 6.3 [kg/hr]

fuel consumption(cruise speed) : 29.3 [kg/hr] (40.0 [litre/hr]) at 75 [%] power

distance flown for 1 kg fuel : 4.27 [km/kg]

estimated total fuel capacity : 136 [litre] (100 [kg])

calculation : *3* (weight)

weight engine(s) dry : 135.0 [kg] = 1.84 [kg/KW]

weight 27 litre oil tank : 2.3 [kg]

oil tank filled with 0.6 litre oil : 0.5 [kg]

oil in engine 0 litre oil : 0.4 [kg]

fuel in engine 1 litre fuel : 0.4 [kg]

weight 17 litre gravity patrol tank(s) : 2.5 [kg]

weight cowling 2.9 [kg]

weight airscrew(s) (wood) incl. boss & bolts : 16.9 [kg]

total weight propulsion system : 159 [kg](22.8 [%])

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fuselage skeleton (wood gauge : 6.03 [cm]): 57 [kg]

bracing : 2.5 [kg]

fuselage covering ( 7.1 [m2] doped linen fabric) : 2.3 [kg]

weight controls + indicators: 5.2 [kg]

weight seats : 3.0 [kg]

weight other details, lighting set, etc. : 5.1 [kg]

weight bomb storage : 3.2 [kg]

weight 119 [litre] main fuel tank empty : 9.5 [kg]

weight engine mounts & firewalls : 4 [kg]

total weight fuselage : 91 [kg](13.1 [%])

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weight wing covering (doped linen fabric) : 14 [kg]

total weight ribs (40 ribs) : 41 [kg]

load on front upper spar (clmax) per running metre : 897.2 [N]

load on rear upper spar (vmax) per running metre : 250.5 [N]

total weight 8 spars : 32 [kg]

weight wings : 87 [kg]

weight wing/square meter : 3.91 [kg]

weight 4 interplane struts & cabane : 8.0 [kg]

weight cables (40 [m]) : 2.0 [kg] (= 50 [gram] per metre)

diameter cable : 2.8 [mm]

weight fin & rudder (0.9 [m2]) : 3.5 [kg]

weight stabilizer & elevator (2.5 [m2]): 10.0 [kg]

total weight wing surfaces & bracing : 111 [kg] (15.9 [%])

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weight armament : 0 [kg]

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weight floats : 75 [kg] (10.8 [%])

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calculated empty weight : 435 [kg](62.6 [%])

weight oil for 3.6 hours flying : 22.5 [kg]

weight automatic pistol with spare magazines : 1.2 [kg]

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calculated operational weight empty : 459 [kg] (66.1 [%])

published operational weight empty : 450 [kg] (64.7 [%])

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weight crew : 81 [kg]

weight fuel for 2.0 hours flying : 59 [kg]

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operational weight : 599 [kg](86.1 [%])

bomb load : 45 [kg]

operational weight bombing mission : 644 [kg]

fuel reserve : 41 [kg] enough for 1.40 [hours] flying

possible additional useful load : 10 [kg]

operational weight fully loaded : 695 [kg] with fuel tank filled for 100 [%]

published maximum take-off weight : 695 [kg] (100.0 [%])

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calculation : * 4 * (engine power)

power loading (operational without bombload) : 8.14 [kg/kW]

total power : 73.6 [kW] at 1200 [r.p.m]

calculation : *5* (loads)

manoeuvre load : 2.2 [g] at 1000 [m]

limit load : 3.5 [g] ultimate load : 5.2 [g] load factor : 2.7 [g]

design flight time : 2.40 [hours]

design cycles : 646 sorties, design hours : 1550 [hours]

operational wing loading : 263 [N/m^2]

wing stress (3 g) during operation : 202 [N/kg] at 3g emergency manoeuvre

calculation : *6* (angles of attack)

angle of attack zero lift : -1.30 ["]

max. angle of attack (stalling angle) : 13.22 ["]

angle of attack at max. speed : 2.49 ["]

calculation : *7* (lift & drag ratios

lift coefficient at angle of attack 0° :0.10 [ ]

lift coefficient at max. angle of attack : 1.12 [ ]

Sopwith Schneider during the Schneider Cup, April 914, note the different tail float

lift coefficient at max. speed : 0.29 [ ]

induced drag coefficient at max. speed : 0.0087 [ ]

drag coefficient at max. speed : 0.0608 [ ]

drag coefficient (zero lift) : 0.0521 [ ]

calculation : *8* (speeds

stalling speed at sea-level (OW): 71 [km/u]

landing speed at sea-level (OW without bombload): 85 [km/hr]

min. drag speed (max endurance) : 93 [km/hr] at 1050 [m](power :50 [%])

min. power speed (max range) : 102 [km/hr] at 1050 [m] (power:54 [%])

max. rate of climb speed : 88.7 [km/hr] at sea-level

cruising speed : 125 [km/hr] op 1050 [m] (power:73 [%])

design speed prop : 132 [km/hr]

maximum speed : 139 [km/hr] op 100 [m] (power:98 [%])

climbing speed at sea-level (without bombload) : 224 [m/min]

calculation : *9* (regarding various performances)

take-off distance at sea-level : 179 [m]

lift/drag ratio : 6.83 [ ]

max. practical ceiling : 3275 [m] with flying weight :554 [kg]

practical ceiling (operational weight): 2900 [m] with flying weight :599 [kg]

practical ceiling fully loaded (mtow- 1 hour fuel) : 2350 [m] with flying weight :666 [kg]

published ceiling (2100 [m]

climb to 1500m (without bombload) : 8.14 [min]

max. dive speed : 290.6 [km/hr] at 1350 [m] height

load factor at max. angle turn 1.66 ["g"]

turn radius at 500m: 52 [m]

time needed for 360* turn 12.6 [seconds] at 500m

calculation *10* (action radius & endurance)

operational endurance : 3.40 [hours] with 1 crew and 55 [kg] useful (bomb)load and 100.0 [%] fuel

published endurance : 3.00 [hours] with 1 crew and possible useful (bomb) load : 67 [kg] and 88.1 [%] fuel

action radius : 288 [km] with 1 crew and 20[kg] photo camera/radio transmitter or bombload

max range theoretically with additional fuel tanks for total 213 [litre] fuel : 667 [km]

useful load with action-radius 250km : 39 [kg]

production : 4.89 [tonkm/hour]

oil and fuel consumption per tonkm : 7.27 [kg]

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Literature :

Wikipedia

Praktisch handboek vliegtuigen deel 1 page 95

Jane’s fighting aircraft WWI page 84f, 211f

Armament of British Aircraft 1909-1939 page 323

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

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