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Curtiss JN-4D "Jenny"

role : primary trainer

first flight : operational : june 1917

country : United States of America

design : Benjamin D.Thomas

production : 2765 aircraft

general information : Important traing aircraft, widely used to train beginning pilots.

The JN-4D “Jenny” was an improved version and is was produced in large numbers.

After WWI thousands of surplus Jennys entered the civil market and were used for a

long time in different roles and gave a boost to vivil aviation in the US.

Chord : 1.51m gap : 1.56m vleugel profiel : Eiffel no.6

normal fuel : 59 kg (80 litre) oil : 17.2 kg

Min.speed : 72.4 km/u Climbing speed : 1.5 m/s max.fuel tank capacity : 21

gallons = 95 litre

oil capacity : 4 gallons = 18.2 litre

users : USAAF

crew : 2

armament : no fixed armament

engine : 1 Curtiss OX-5 liquid-cooled 8 -cylinder V-engine 90 [hp] (66.2 KW)

dimensions :

wingspan : 13.29 [m], length : 8.23 [m], height : 3.01[m]

wing area : 32.7 [m^2]

weights :

max.take-off weight : 871 [kg]

empty weight operational : 630 [kg] bombload : 0 [kg]

performance :

maximum speed : 121 [km/hr] at sea-level

climbing speed : 90 [m/min]

service ceiling : 3350 [m]

estimated action radius : 188 [km]

description :

2-bay biplane with fixed landing gear and tail strut

upper wingtips supported by slanted flyingwires

two spar upper and lower wing

airscrew :

fixed pitch 2 -bladed tractor airscrew with max. efficiency :0.64 [ ]

estimated diameter airscrew 2.54 [m]

angle of attack prop : 13.53 [ ]

fine pitch

reduction : none

airscrew revs : 1400 [r.p.m.]

pitch at Max speed 1.44 [m]

blade-tip speed at Vmax and max revs. : 189 [m/s]

calculation : *1* (dimensions)

mean wing chord : 1.41 [m]

calculated wing chord (rounded tips): 1.55 [m]

wing aspect ratio : 9.45 []

gap : 1.56 [m]

gap/chord : 1.11 [ ]

seize (span*length*height) : 329 [m^3]

calculation : *2* (fuel consumption)

oil consumption : 1.7 [kg/hr]

fuel consumption(cruise speed) : 17.7 [kg/hr] (24.1 [litre/hr]) at 69 [%] power

distance flown for 1 kg fuel : 6.17 [km/kg]

estimated total fuel capacity : 95 [litre] (69 [kg])

calculation : *3* (weight)

weight engine(s) dry : 177.0 [kg] = 2.67 [kg/KW]

weight 8 litre oil tank : 0.7 [kg]

oil tank filled with 0.5 litre oil : 0.4 [kg]

oil in engine 4 litre oil : 3.3 [kg]

fuel in engine 0 litre fuel : 0.3 [kg]

weight 10 litre gravity patrol tank(s) : 1.5 [kg]

weight radiator : 9.5 [kg]

weight exhaust pipes & fuel lines 8.0 [kg]

weight cowling 2.6 [kg]

weight airscrew(s) (wood) incl. boss & bolts : 15.2 [kg]

total weight propulsion system : 218 [kg](25.0 [%])

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Afbeeldingsresultaat voor Curtiss JN-4

fuselage skeleton (wood gauge : 7.31 [cm]): 113 [kg]

bracing : 6.5 [kg]

fuselage covering ( 12.8 [m2] doped linen fabric) : 4.1 [kg]

weight dual controls + indicators: 13.7 [kg]

weight seats : 6.0 [kg]

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

weight 69 [litre] main fuel tank empty : 5.5 [kg]

weight engine mounts & firewalls : 3 [kg]

total weight fuselage : 157 [kg](18.0 [%])

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weight wing covering (doped linen fabric) : 21 [kg]

total weight ribs (51 ribs) : 52 [kg]

load on front upper spar (clmax) per running metre : 631.8 [N]

load on rear upper spar (vmax) per running metre : 180.2 [N]

total weight 8 spars : 64 [kg]

weight wings : 137 [kg]

weight wing/square meter : 4.18 [kg]

weight 8 interplane struts & cabane : 17.3 [kg]

weight cables (58 [m]) : 5.9 [kg] (= 101 [gram] per metre)

diameter cable : 4.1 [mm]

weight fin & rudder (2.1 [m2]) : 8.9 [kg]

weight stabilizer & elevator (3.7 [m2]): 15.6 [kg]

total weight wing surfaces & bracing : 184 [kg] (21.2 [%])

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Afbeeldingsresultaat voor Curtiss JN-4

weight armament : 0 [kg]

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robust landing gear

wheel pressure : 435.5 [kg]

weight 2 wheels (680 [mm] by 80 [mm]) : 18.7 [kg]

weight tailskid : 3.2 [kg]

weight undercarriage with axle 29.1 [kg]

total weight landing gear : 51.0 [kg] (5.9 [%]

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Afbeeldingsresultaat voor Curtiss JN-4D

After WWI the JN-4 was widely used by daredevils, wingwalkers and barnstormers

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calculated empty weight : 610 [kg](70.0 [%])

weight oil for 3.5 hours flying : 6.0 [kg]

weight cooling fluids : 14.3 [kg]

weight signal pistol with cartridges : 3.6 [kg]

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calculated operational weight empty : 634 [kg] (72.8 [%])

published operational weight empty : 630 [kg] (72.3 [%])

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weight crew : 162 [kg]

weight fuel for 2.0 hours flying : 35 [kg]

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operational weight : 831 [kg](95.4 [%])

bombload could not be carried with fuel for 2 hours flying time

fuel reserve : 23 [kg] enough for 1.29 [hours] flying

possible additional useful load : 17 [kg]

operational weight fully loaded : 871 [kg] with fuel tank filled for 100 [%]

published maximum take-off weight : 871 [kg] (100.0 [%])

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calculation : * 4 * (engine power)

power loading (operational without bombload) : 12.56 [kg/kW]

total power : 66.2 [kW] at 1400 [r.p.m]

calculation : *5* (loads)

manoeuvre load : 1.8 [g] at 1000 [m]

limit load : 3.75 [g]

design cycles : 775 sorties, design hours : 900 [hours]

operational wing loading : 249 [N/m^2]

wing stress (3 g) during operation : 179 [N/kg] at 3g emergency manoeuvre

calculation : *6* (angles of attack)

angle of attack zero lift : -1.13 ["]

max.angle of attack (stalling angle) : 11.62 ["]

angle of attack at max.speed : 2.97 ["]

calculation : *7* (lift & drag ratios

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

lift coefficient at max. angle of attack : 1.13 [ ]

lift coefficient at max.speed : 0.36 [ ]

induced drag coefficient at max.speed : 0.0059 [ ]

drag coefficient at max.speed : 0.0549 [ ]

drag coefficient (zero lift) : 0.0490 [ ]

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) : 81 [km/hr] at 1675 [m] (power:45 [%])

min. power speed (max range) : 81 [km/hr] at 1675 [m] (power:45 [%])

max.rate of climb speed : 74.7 [km/hr] at sea-level

cruising speed : 109 [km/hr] op 1675 [m] (power:69 [%])

design speed prop : 115 [km/hr]

maximum speed : 121 [km/hr] op 100 [m] (power:99 [%])

climbing speed at sea-level (without bombload) : 154 [m/min]

calculation : *9* (regarding various performances)

take-off distance at sea-level : 164 [m]

lift/drag ratio : 10.66 [ ]

max. practical ceiling : 4150 [m] with flying weight :720 [kg]

practical ceiling (operational weight): 3425 [m] with flying weight :831 [kg]

practical ceiling fully loaded (mtow- 1 hour fuel) : 3275 [m] with flying weight :853 [kg]

published ceiling (3350 [m

climb to 1500m (without bombload) : 11.23 [min]

climb to 3000m (without bombload) : 30.65 [min]

max.dive speed : 305.3 [km/hr] at 2275 [m] height

load factor at max.angle turn 1.86 ["g"]

turn radius at 500m: 46 [m]

time needed for 360* turn 10.8 [seconds] at 500m

calculation *10* (action radius & endurance)

operational endurance : 2.92 [hours] with 2 crew and 20 [kg] useful load and 74.4 [%]

fuel

published endurance : 3.46 [hours] with 2 crew and possible useful (bomb) load : 10

[kg]

action radius : 159 [km] with 2 crew and 20[kg] photo camera/radio transmitter or

bombload

max range theoretically with additional fuel tanks for total 213 [litre] fuel : 963 [km]

useful load with action-radius 250km : 75 [kg]

production : 8.18 [tonkm/hour]

oil and fuel consumption per tonkm : 2.37 [kg]

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Afbeeldingsresultaat voor Curtiss JN-4D

Literatuur : praktisch handboek vliegtuigen deel 1

Jane’s Fighting Aircraft WWI

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/photograps/content please mail to below mail address

(c) B van der Zalm 13 december 2018 contact : bvanderzalm@ziggo.nl python 3.4.1

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