Aircraft investigation >>>>>>> HOME PAGE
weight and performance calculations for the Voisin 8 LA.P
Voisin 8 LA.P
role : light bomber
importance : ****
first flight : operational : November 1916
country : France
design : Gabriel Voisin
production : 1123 aircraft
general information :
At the end of 1916, the Voisin 8 entered service. It suffered from many problems with the Peugeot engine. The engine ran irregularly and thedifficulties could never be completely remedied. However, 1,100 pieces were employed.
It was built as a night bomber and as such referred to as LA. P.
The LB. P was a "cannon" version equipped with a 37mm or 47mm cannon that was mainly used for ground attacks.
Later, a 221 KW Renault engine was installed, which allowed almost double the bomb load. This was called the type 10.
users : France, RFC
crew : 2
armament : 1 movable 7.70 [mm] (0.303 in) Lewis machine-gun for the observer
engine : 1 Peugeot 8 Aa liquid-cooled 8 -cylinder inline engine 220 [hp](161.8 KW)
dimensions :
wingspan : 18.0 [m], length : 11.02 [m], height : 3.5[m]
wing area : 63.2 [m^2]
weights :
max.take-off weight : 1860 [kg]
empty weight operational : 1310 [kg] bombload : 180 [kg]
performance :
maximum speed : 118 [km/hr] at sea-level
service ceiling : 4300 [m]
endurance : 4.0 [hours]
estimated action radius : 212 [km]
description :
3-bay biplane with fixed landing gear with nosewheel
two spar upper and lower wing
tail supported by two open tail booms
engine, landing gear and bombload in or attached to fuselage, fuel in/on the wing
airscrew :
fixed pitch 2 -bladed pusher airscrew with max. efficiency :0.63 [ ]
estimated diameter airscrew 3.51 [m]
angle of attack prop : 9.64 [ ]
fine pitch
reduction : 1.00 [ ]
airscrew revs : 1400 [r.p.m.]
pitch at Max speed 1.40 [m]
blade-tip speed at Vmax and max revs. : 259 [m/s]
calculation : *1* (dimensions)
mean wing chord : 1.76 [m]
calculated wing chord (rounded tips): 1.89 [m]
wing aspect ratio : 10.25 []
estimated gap : 1.59 [m]
gap/chord : 0.91 [ ]
seize (span*length*height) : 694 [m^3]
calculation : *2* (fuel consumption)
oil consumption : 3.6 [kg/hr]
fuel consumption(cruise speed) : 42.8 [kg/hr] (58.4 [litre/hr]) at 68 [%] power
distance flown for 1 kg fuel : 2.48 [km/kg]
estimated total fuel capacity : 265 [litre] (194 [kg])
calculation : *3* (weight)
weight engine(s) dry : 412.6 [kg] = 2.55 [kg/KW]
weight 23 litre oil tank : 2.0 [kg]
oil tank filled with 1.2 litre oil : 1.1 [kg]
oil in engine 9 litre oil : 8.1 [kg]
fuel in engine 1 litre fuel : 0.8 [kg]
weight 25 litre gravity patrol tank(s) : 3.7 [kg]
weight radiator : 23.2 [kg]
weight exhaust pipes & fuel lines 19.7 [kg]
weight self-starter : 4.0 [kg]
weight cowling 6.5 [kg]
weight airscrew(s) (wood) incl. boss & bolts : 24.3 [kg]
total weight propulsion system : 504 [kg](27.1 [%])
***************************************************************
weight tail boom : 49 [kg]
fuselage skeleton (wood gauge : 7.22 [cm]): 147 [kg]
Voisin 8 LB.P , “cannon”-version with a 37 or 47mm Hotchkiss cannon. This version is slightly smaller and heavier and was used for ground-attack.
bracing : 12.9 [kg]
fuselage covering ( 14.9 [m2] doped linen fabric) : 4.8 [kg]
weight controls + indicators: 7.8 [kg]
weight seats : 6.0 [kg]
weight other details, lighting set, etc. : 5.1 [kg]
weight bomb storage : 12.6 [kg]
weight Doran/Lafay bomb sight : 1.5 [kg]
weight engine mounts & firewalls : 8 [kg]
total weight fuselage : 206 [kg](11.1 [%])
***************************************************************
weight wing covering (doped linen fabric) : 40 [kg]
total weight ribs (87 ribs) : 111 [kg]
weight fuel tanks empty for total 120 [litre] fuel : 10 [kg]
load on front upper spar (clmax) per running metre : 818.8 [N]
load on rear upper spar (vmax) per running metre : 277.8 [N]
total weight 8 spars : 171 [kg]
weight wings : 322 [kg]
weight wing/square meter : 5.10 [kg]
weight 12 interplane struts & cabane : 28.6 [kg]
weight cables (106 [m]) : 22.9 [kg] (= 216 [gram] per metre)
diameter cable : 5.9 [mm]
weight fin & rudder (3.8 [m2]) : 19.7 [kg]
weight stabilizer & elevator (6.0 [m2]): 31.3 [kg]
total weight wing surfaces & bracing : 434 [kg] (23.3 [%])
*******************************************************************
weight machine-gun(s) : 12.7 [kg]
weight pivot mounting mg :6.0 [kg]
weight armament : 19 [kg]
********************************************************************
wheel pressure : 465.0 [kg]
weight 4 wheels (790 [mm] by 99 [mm]) : 42.4 [kg]
weight tailskid : 0.0 [kg]
weight undercarriage with axle 77.8 [kg]
total weight landing gear : 120.1 [kg] (6.5 [%]
*******************************************************************
********************************************************************
calculated empty weight : 1283 [kg](69.0 [%])
weight oil for 4.8 hours flying : 17.1 [kg]
weight cooling fluids : 35.0 [kg]
weight 5 drums empty : 1.0 [kg]
weight ammunition (235 rounds) : 7.5 [kg]
weight signal pistol with cartridges : 3.6 [kg]
weight automatic pistol with spare magazines : 1.2 [kg]
*******************************************************************
calculated operational weight empty : 1347 [kg] (72.4 [%])
published operational weight empty : 1310 [kg] (70.4 [%])
_____________
| | |o| | |
-------------
"
""
weight crew : 162 [kg]
weight fuel for 2.0 hours flying : 86 [kg]
********************************************************************
operational weight : 1595 [kg](85.7 [%])
bomb load : 180 [kg]
operational weight bombing mission : 1775 [kg]
fuel reserve : 85 [kg] enough for 1.99 [hours] flying
operational weight fully loaded : 1860 [kg] with fuel tank filled for 88 [%]
published maximum take-off weight : 1860 [kg] (100.0 [%])
||
||
=||I>|
||
||
calculation : * 4 * (engine power)
power loading (Take-off) : 11.49 [kg/kW]
total power : 161.8 [kW] at 1400 [r.p.m]
calculation : *5* (loads)
manoeuvre load : 1.5 [g] at 1000 [m]
limit load : 3.0 [g] ultimate load : 4.5 [g] load factor : 2.2 [g]
design flight time : 3.20 [hours]
design cycles : 516 sorties, design hours : 1650 [hours]
wing loading (MTOW) : 289 [N/m^2]
wing stress (3 g) during operation : 162 [N/kg] at 3g emergency manoeuvre
calculation : *6* (angles of attack)
angle of attack zero lift : -1.11 ["]
max. angle of attack (stalling angle) : 11.28 ["]
angle of attack at max. speed : 3.10 ["]
calculation : *7* (lift & drag ratios
lift coefficient at angle of attack 0° :0.10 [ ]
lift coefficient at max. angle of attack : 1.12 [ ]
lift coefficient at max. speed : 0.38 [ ]
induced drag coefficient at max. speed : 0.0080 [ ]
drag coefficient at max. speed : 0.0746 [ ]
drag coefficient (zero lift) : 0.0667 [ ]
calculation : *8* (speeds
stalling speed at sea-level (OW): 68 [km/u]
landing speed at sea-level (OW without bombload): 82 [km/hr]
min. drag speed (max endurance) = minimum speed*1.1 at cruise height : 84 [km/hr] at 2150 [m] (power:47 [%])
min. power speed (max range) : 84 [km/hr] at 2150 [m] (power:47 [%])
max. rate of climb speed : 72.7 [km/hr] at sea-level
cruising speed : 106 [km/hr] op 2150 [m] (power:67 [%])
design speed prop : 112 [km/hr]
maximum speed : 118 [km/hr] op 100 [m] (power:99 [%])
climbing speed at sea-level (without bombload) : 196 [m/min]
calculation : *9* (regarding various performances)
take-off distance at sea-level : 82 [m]
lift/drag ratio : 8.24 [ ]
max. practical ceiling : 5000 [m] with flying weight :1437 [kg]
practical ceiling (operational weight): 4350 [m] with flying weight :1595 [kg]
practical ceiling fully loaded (mtow- 1 hour fuel) : 3450 [m] with flying weight :1817 [kg]
published ceiling (4300 [m]
climb to 1500m (without bombload) : 8.59 [min]
climb to 3000m (without bombload) : 21.53 [min]
max. dive speed : 276.6 [km/hr] at 2450 [m] height
load factor at max. angle turn 1.68 ["g"]
turn radius at 500m: 54 [m]
time needed for 360* turn 12.7 [seconds] at 500m
calculation *10* (action radius & endurance)
operational endurance : 3.99 [hours] with 2 crew and 180 [kg] bombload and 88.0 [%] fuel
published endurance : 4.00 [hours] with 2 crew and possible useful (bomb) load : 180 [kg] and 88.1 [%] fuel
action radius : 411 [km] with 2 crew and 20[kg] photo camera/radio transmitter or bombload
max range theoretically with additional fuel tanks for total 606 [litre] fuel : 1102 [km]
useful load with action-radius 250km : 149 [kg]
production : 15.87 [tonkm/hour]
oil and fuel consumption per tonkm : 2.92 [kg]
_
°°_I>-/
° °
Literature :
praktisch handboek vliegtuigen deel I page 145
Jane's Fighting aircraft WWI page 125
Bombers 1914-19 page 21
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 November 2019 contact : info.aircraftinvestigation@gmail.com python 3.7.4