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weight and performance calculations for the Fokker F-10A Super Trimotor

Fokker F-10A Super Trimotor

role : multi-engined passenger aircraft

importance : ****

first flight : operational : F-10A December 1928

country : United States of America

production : assemblage Hasbrouck Heights, fuselage at Glendale, West Virginia wing at

Passiac, New Jersey. F-10 : 7 F-10A 57

Design : Alfred A. Gassner

General information :

The F-10 had a bigger fuselage giving space for 12 passenger. It had the F.VIIb/3m wing, built in the Netherlands. Only 7 were built, then production switched to the F-10A Super Trimotor with a new bigger wing, built in the USA and now space for 14 passengers. Western Air Express took the first F-10 in service on 26 May 1928 on the route San Francisco – Los Angeles

Users : Western Air Express (5 F-10 & 20 F-10A), Pan American (12 F-10A), Universal

(16 F-10A), American Airways (17 F-10A), Transcontinental&Western Air (11 F-10A),

Mexico (7)

crew : 2 passengers : 12

Registrations : 4458 F-10 prototype, X5170 F-10 Western Air Express, used on the route

Los Angeles – San Francisco, 5558, NC8047, NC8048

F-10A : 9700, NC814H, X-ABCS, NC9166, 615E, 5614, NC394E, NC8010, 9790,

NC8124, NC535E Rio Grande

engine : 3 Pratt & Whitney R-1340C Wasp air-cooled 9 -cylinder radial engine 450 [hp]

(335.6 KW)

dimensions :

wingspan : 24.16 [m], length : 15.41 [m], height : 3.86[m]

wing area : 78.97 [m^2]

weights :

max.take-off weight : 5942 [kg]

empty weight operational : 3500 [kg] useful load : 1200 [kg]

performance :

maximum speed :248 [km/hr] at sea-level

cruise speed :223 [km/u] op 100 [m]

service ceiling : 5486 [m]

range : 1215 [km]

description :

parasol wing with fixed landing gear and tail strut

two spar tapered wing

2 engines attached to the wings 1 in the nose, landing gear attached to the wings,

useful load in the fuselage, fuel tanks in the wing centre section

airscrew :

ground adjustable 3 -bladed metal Hamilton Standard tractor propeller with max.

efficiency :0.71 [ ]

estimated diameter airscrew 2.53 [m]

angle of attack prop : 18.27 [ ]

reduction : 1.00 [ ]

airscrew revs : 2100 [r.p.m.]

pitch at Max speed 1.97 [m]

blade-tip speed at Vmax and max revs. : 287 [m/s]

calculation : *1* (dimensions)

measured wing chord : 3.34 [m]

mean wing chord : 3.27 [m]

calculated average wing chord tapered wing with rounded tips: 3.26 [m]

wing aspect ratio : 7.39 []

seize (span*length*height) : 1437 [m^3]

F-10A Reg : 5614

calculation : *2* (fuel consumption)

oil consumption : 16.1 [kg/hr]

fuel consumption(cruise speed) : 204.6 [kg/hr] (279.1 [litre/hr]) at 66 [%] power

distance flown for 1 kg fuel : 1.09 [km/kg] at 2743 [m] height, sfc : 309.5 [kg/kwh]

estimated total fuel capacity : 1724 [litre] (1264 [kg])

calculation : *3* (weight)

weight engine(s) dry : 1020.0 [kg] = 1.01 [kg/KW]

weight 142.4 litre oil tank : 12.10 [kg]

oil tank filled with 7.6 litre oil : 6.8 [kg]

oil in engine 5.6 litre oil : 5.0 [kg]

fuel in engine 6.9 litre fuel : 5.03 [kg]

weight 118.6 litre gravity patrol tank(s) : 17.8 [kg]

weight inertia starter : 8.2 [kg]

weight airscrew(s) (wood) incl. boss & bolts : 103.2 [kg]

total weight propulsion system : 1166 [kg](19.6 [%])

***************************************************************

fuselage skeleton (steel tubes) : 6.99 [cm]): 594 [kg]

cabin layout : pitch : 87 [cm] (1+1) seating in 6.0 rows

weight toilet : 5 [kg]

weight 1 fire extinguisher : 3 [kg]

weight 12.0 windows : 10.80 [kg]

passenger cabin width : 1.54 [m] cabin length : 5.22 [m] cabin height : 1.90 [m]

weight cabin furbishing : 33.63 [kg]

weight cabin floor : 51.45 [kg]

bracing : 64.5 [kg]

fuselage covering ( 44.9 [m2] doped linen fabric) : 13.7 [kg]

weight radio navigation equipment : 7.0 [kg]

weight instruments. : 4.0 [kg]

weight lighting : 3.0 [kg]

weight dual controls + indicators: 28.9 [kg]

weight seats : 70.0 [kg]

weight three 535 [litre] main fuel tanks empty : 128.5 [kg]

weight air conditioning : 18 [kg]

weight fuel lines : 6 [kg]

weight engine mount and firewall : 17 [kg]

total weight fuselage : 1058 [kg](17.8 [%])

***************************************************************

weight 2.4 mm plywood wing covering : 121 [kg]

total weight ribs (99 ribs) : 353 [kg]

weight engine mounts : 34 [kg]

load on front upper spar (clmax) per running metre : 1094.3 [N]

load on rear upper spar (vmax) per running metre : 630.2 [N]

total weight 4 spars : 308 [kg]

weight wings : 783 [kg]

weight wing/square meter : 9.91 [kg]

cantilever wing without bracing cables

weight fin & rudder (6.8 [m2]) : 68.2 [kg]

weight stabilizer & elevator (8.9 [m2]): 88.6 [kg]

total weight wing surfaces & bracing : 973 [kg] (16.4 [%])

*******************************************************************

wheel pressure : 2971.0 [kg]

weight 2 wheels (1170 [mm] by 234 [mm]) : 141.7 [kg]

weight tailskid : 8.9 [kg]

weight undercarriage with axle 112.6 [kg]

total weight landing gear : 263.1 [kg] (4.4 [%]

*******************************************************************

Reg. 4458 the F-10 prototype of Western Air Express at Glendale airport, Los Angeles, 1931. In the Background Ford 4-AT Tri-motor NC5577 of Curtiss Flying service.

Drawing : Thijs Postma

********************************************************************

calculated empty weight : 3460 [kg](58.2 [%])

weight oil for 6.5 hours flying : 105.2 [kg]

calculated operational weight empty : 3565 [kg] (60.0 [%])

published operational weight empty : 3500 [kg] (58.9 [%])

weight crew : 162 [kg]

weight fuel for 2.0 hours flying : 409 [kg]

********************************************************************

operational weight empty: 4136 [kg](69.6 [%])

weight 12 passengers : 924 [kg]

weight luggage & freight : 276 [kg]

operational weight loaded: 5336 [kg](89.8 [%])

fuel reserve : 605.8 [kg] enough for 2.96 [hours] flying

operational weight fully loaded : 5942 [kg] with fuel tank filled for 80 [%]

published maximum take-off weight : 5942 [kg] (100.0 [%])

calculation : * 4 * (engine power)

power loading (Take-off) : 5.90 [kg/kW]

power loading (operational without useful load) : 4.11 [kg/kW]

power loading (Take-off) 1 PUF: 8.85 [kg/kW]

total power : 1006.7 [kW] at 2100 [r.p.m]

calculation : *5* (loads)

manoeuvre load : 3.8 [g] at 1000 [m]

limit load : 2.5 [g] ultimate load : 3.8 [g] load factor : 1.3 [g]

design flight time : 3.81 [hours]

design cycles : 2295 sorties, design hours : 8745 [hours]

operational wing loading : 514 [N/m^2]

wing stress (3 g) during operation : 155 [N/kg] at 3g emergency manoeuvre

calculation : *6* (angles of attack)

angle of attack zero lift : -1.19 ["]

max. angle of attack (stalling angle) : 12.48 ["]

angle of attack at max. speed : 0.93 ["]

calculation : *7* (lift & drag ratios

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

lift coefficient at max. angle of attack : 1.15 [ ]

lift coefficient at max. speed : 0.18 [ ]

induced drag coefficient at max. speed : 0.0018 [ ]

drag coefficient at max. speed : 0.0454 [ ]

drag coefficient (zero lift) : 0.0436 [ ]

calculation : *8* (speeds

stalling speed at sea-level (OW loaded : 5737 [kg]): 115 [km/u]

landing speed at sea-level: 135 [km/hr]

min. drag speed (max endurance) : 151 [km/hr] at 2743 [m](power :33 [%])

min. power speed (max range) : 151 [km/hr] at 2743 [m] (power:33 [%])

max. rate of climb speed : 142.3 [km/hr] at sea-level

cruising speed : 223 [km/hr] op 2743 [m] (power:66 [%])

design speed prop : 236 [km/hr]

maximum speed : 248 [km/hr] op 100 [m] (power:104 [%])

climbing speed at sea-level : 623 [m/min]

calculation : *9* (regarding various performances)

take-off speed : 140.0 [km/u]

static prop wash : 179 [km/u]

take-off distance at sea-level : 195 [m]

lift/drag ratio : 10.00 [ ]

climb to 1000m with max payload : 2.76 [min]

climb to 2000m with max payload : 6.25 [min]

climb to 3000m with max payload : 10.52 [min]

practical ceiling (operational weight 4136 [kg] ) : 7633 [m]

practical ceiling fully loaded (mtow- 30 min.fuel:5840 [kg] ) : 5968 [m]

max. dive speed : 580.2 [km/hr] at 4968 [m] height

turning speed at CLmax : 175.7 [km/u] at 50 [m] height

turn radius at 50m: 79 [m]

time needed for 360* turn 10.1 [seconds] at 50m

load factor at max. angle turn 3.25 ["g"]

calculation *10* (action radius & endurance)

published range : 1215 [km] with 2 crew and 1101.4 [kg] useful load and 88.1 [%] fuel

range : 1107 [km] with 2 crew and 1200.0 [kg] useful load and 80.3 [%] fuel

range : 1278 [km] with 12.0 passengers with each 10 [kg] luggage and 92.6 [%] fuel

Available Seat Kilometers (ASK) : 15331 [paskm]

max range theoretically with additional fuel tanks total 3132.3 [litre] fuel : 2505 [km]

F-10 12 passenger lay-out

useful load with range 500km : 1838 [kg]

useful load with range 500km : 12 passengers

production (useful load): 410.17 [tonkm/hour]

production (passengers): 2678.40 [paskm/hour]

oil and fuel consumption per tonkm : 0.54 [kg]

oil and fuel consumption per paskm : 0.08 [kg]

fuel cost per paskm : 0.08 [eur]

crew cost per paskm : 0.06 [eur]

time between engine failure : 165 [hr]

low risk for emergency landing, can continue flying with 1 engine out

writing off per paskm : 0.11 [eur]

insurance per paskm : 0.0214 [eur]

maintenance cost per paskm : 0.2994 [eur]

direct operating cost per paskm : 0.57 [eur]

Serious accidents :

31 March 1931 Transcontinental & Western Air F-10A NC999E TWA flight 599 crashed in the Flint Hills , near Bazaar, Kansas, USA. Notre Dame football team coach Knute Rockne dies in the crash. As a result 35 F-10A were grounded pending the investigation to the cause of the crash. After two weeks it was concluded that the wing failure was not a design failure. All 8 people on board died in the crash. The weather en-route was poor : snow falls, drizzle rain, icing conditions, clouds and fog. Pilot : Robert Fry .

Combination of : icing conditions > stall > wing flutter > wing failure.

The cause of the damage was determined to be that the plane's plywood outer skin was bonded to the ribs and spars with water-based aliphatic resin glue and flight in rain had caused the bond to deteriorate to the point that sections of the plywood suddenly separated.

The reputation of Fokker in the US was much damaged and resulted in the diminish of Fokker aircraft in the USA in the 1930

Literature :

Fokker “Roaring twenties” page 39 - 43

Fokker verkeersvliegtuigen 1920-1940 page 71

Fokker – bouwer aan de wereldluchtvaart page 74,75,87

Fokker verkeersvliegtuigen page 120 - 123

Alles over de Fokker friendship page 49 -52, 123,124

Fokker F.10A Trimotor : Fokker Atlantic / General Aviation (valka.cz)

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 10 May 2021 contact : info.aircraftinvestigation@gmail.com python 3.7.4