AIRCRAFT INVESTIGATION
weight and performance calculations for the Fokker Spin
Anthony Fokker at the controls of his Spin
Fokker Spin
role : experimental/research/flying trials
importance : ****
first flight : December 1910 operational : August 1911
country : Germany
design : Anthony Fokker
production : about 28
general information :
The first aircraft Anthony Fokker built were called Spin, due to the many bracing and flying wires. He built them in Germany in a Zeppelin-shed at Baden-Oos together with his business partner Franz von Daum how provided the financing. Lateral control was done by wing-warping. In December 1910 Anthony Fokker succeeded in making short hops of 100m. But then when Fokker was to Holland for Christmas leave Von Daum took the Spin for a flight and crashed it in a tree. Fokker was able to salvage the engine from the wreckage and together with Jacob Goedecker , a ship-builder, he built the second Spin at Nieder-Walluf am Rhein, near Wiesbaden. It was smaller, lighter and with a triangle shaped rudder and ailerons. For flying trials Fokker and Von Daum moved to the Grosser Sand at Gonsenheim near to Mainz. On 12 May 1911 Fokker takes Von Daum with his him on as flight as passenger. On 16 May 1911 Anthony Fokker earned his flying license with this airplane. Shortly after Von Daum,now the owner, again wrecked the airplane and Fokker broke with Von Daum. With Goedecker he built the third Spin, this was a two-seater. With this aircraft he gained fame on Koninginnedag 31 August 1911 by flying around the St.Bavo church in his native city Haarlem. At the start of 1912 Fokker opened the Fokker Aeroplanbau GMBH company, located in Johannisthal , near to Berlin. Here he built several Spin’s. 10 were sold to the German army, indicated as M.1. The M.I was a two seat aircraft with a more closed fuselage.
In Schwerin Fokker opened a flying school, this flying school was using the Spin for the coming years, upon WWI.
The dihedral wings gave good stability to the Spin.
Propellor : Chauviere , 2.3m diameter.
users : Anthony Fokker, Franz von Daum
crew : 1
passengers : 1
engine : 1 Argus 50ps liquid-cooled 4 -cylinder inline engine 50 [hp](37.3 KW)
dimensions :
wingspan : 11.0 [m], length : 7.75 [m], height : 3.0[m]
wing area : 22.0 [m^2]
Anthony Fokker flying around the St.Bavo church Haarlem
weights :
max.take-off weight : 574 [kg]
empty weight operational : 374 [kg] useful load : 81 [kg]
performance :
maximum speed :90 [km/hr] at sea-level
cruise speed :81 [km/u] op 50 [m]
service ceiling : 2000 [m]
endurance : 1.2 [hours]
range : 97 [km]
description :
shoulder-winged monoplane with fixed landing gear and tail strut
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 [ ]
estimated diameter airscrew 2.12 [m]
angle of attack prop : 16.08 [ ]
reduction : 1.00 [ ]
airscrew revs : 1250 [r.p.m.]
pitch at Max speed 1.20 [m]
blade-tip speed at Vmax and max revs. : 118 [m/s]
Spin I, without rudder
calculation : *1* (dimensions)
wing chord : 1.80 [m]
mean wing chord : 2.00 [m]
calculated wing chord (square tips): 2.14 [m]
***berekende koorde wijkt erg af van gemeten/gepubliceerde koorde > nakijen !!
wing aspect ratio : 5.50 []
gap : 0.00 [m]
gap/chord : 0.00 [ ]
seize (span*length*height) : 256 [m^3]
calculation : *2* (fuel consumption)
oil consumption : 0.8 [kg/hr]
fuel consumption(cruise speed) : 11.5 [kg/hr] (15.7 [litre/hr]) at 78 [%] power
distance flown for 1 kg fuel : 7.02 [km/kg] at 1000 [m] cruise height, sfc : 399.0 [kg/kwh]
estimated total fuel capacity : 21.43 [litre] (15.71 [kg])
calculation : *3* (weight)
weight engine(s) dry : 129.0 [kg] = 3.46 [kg/KW]
weight 2.2 litre oil tank : 0.19 [kg]
oil tank filled with 0.3 litre oil : 0.3 [kg]
oil in engine 2.1 litre oil : 1.9 [kg]
fuel in engine 0.3 litre fuel : 0.19 [kg]
weight 21.4 litre gravity patrol tank(s) : 3.2 [kg]
weight radiator : 5.3 [kg]
weight exhaust pipes & fuel lines 4.3 [kg]
weight cowling 1.5 [kg]
weight airscrew(s) (wood) incl. boss & bolts : 15.3 [kg]
total weight propulsion system : 161 [kg](28.0 [%])
***************************************************************
fuselage skeleton (wood gauge : 4.96 [cm]): 49 [kg]
bracing : 2.7 [kg]
is de romp bekleed met stof ? nee
weight instruments. : 1.1 [kg]
weight controls : 4.5 [kg]
weight seats : 3.0 [kg]
weight engine mount : 1.9 [kg]
total weight fuselage : 62 [kg](10.8 [%])
***************************************************************
weight wing covering (doped linen fabric) : 19 [kg]
total weight ribs (23 ribs) : 34 [kg]
load on front upper spar (clmax) per running metre : 401.2 [N]
load on rear upper spar (vmax) per running metre : 136.4 [N]
total weight 4 spars : 28 [kg]
weight wings : 81 [kg]
weight wing/square meter : 3.67 [kg]
weight cables (44 [m]) : 10.2 [kg] (= 232 [gram] per metre)
diameter cable : 6.2 [mm]
weight fin & rudder (1.4 [m2]) : 5.4 [kg]
weight stabilizer & elevator (2.5 [m2]): 9.3 [kg]
total weight wing surfaces & bracing : 106 [kg] (18.4 [%])
*******************************************************************
wheel pressure : 287.0 [kg]
weight 2 wheels (720 [mm] by 86 [mm]) : 15.9 [kg]
weight tailskid : 1.5 [kg]
weight undercarriage with axle 22.9 [kg]
total weight landing gear : 40.2 [kg] (7.0 [%]
*******************************************************************
********************************************************************
calculated empty weight : 369 [kg](64.3 [%])
weight oil for 1.4 hours flying : 1.2 [kg]
weight cooling fluids : 8.1 [kg]
calculated operational weight empty : 378 [kg] (65.9 [%])
published operational weight empty : 374 [kg] (65.2 [%])
---o---
"
weight crew : 81 [kg]
Spin II
weight fuel for 1.0 hours flying : 12 [kg]
********************************************************************
operational weight : 471 [kg](82.0 [%])
fuel reserve : 4.2 [kg] enough for 0.36 [hours] flying
possible additional useful load : 99 [kg]
operational weight fully loaded : 574 [kg] with fuel tank filled for 100 [%]
published maximum take-off weight : 574 [kg] (100.0 [%])
||
I||==|
||
calculation : * 4 * (engine power)
power loading (Take-off) : 15.39 [kg/kW]
power loading (operational without useful load) : 12.62 [kg/kW]
total power : 37.3 [kW] at 1250 [r.p.m]
calculation : *5* (loads)
manoeuvre load : 1.1 [g] at 1000 [m]
limit load : 3.0 [g] ultimate load : 4.5 [g] load factor : 2.2 [g]
design flight time : 0.96 [hours]
design cycles : 312 sorties, design hours : 90 [hours]
operational wing loading : 210 [N/m^2]
wing stress (3 g) during operation : 171 [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 : 5.87 ["]
Two-seat Spin III.
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 : 0.55 [ ]
induced drag coefficient at max. speed : 0.0234 [ ]
drag coefficient at max. speed : 0.1081 [ ]
drag coefficient (zero lift) : 0.0847 [ ]
calculation : *8* (speeds
stalling speed at sea-level (OW): 63 [km/u]
stalling speed at sea-level (MTOW): 70 [km/u]
landing speed at sea-level: 74 [km/hr]
min. drag speed (max endurance) = minimum speed*1.1 at cruise height : 73 [km/hr] at 1000 [m] (power:68 [%])
min. power speed (max range) : 73 [km/hr] at 1000 [m] (power:68 [%])
cruising speed : 81 [km/hr] op 1000 [m] (power:78 [%])
design speed prop : 86 [km/hr]
maximum speed : 90 [km/hr] op 50 [m] (power:99 [%])
climbing speed at sea-level : 107 [m/min]
calculation : *9* (regarding various performances)
take-off speed : 76.6 [km/u]
static prop wash : 64 [km/u]
take-off distance at sea-level : 241 [m]
lift/drag ratio : 6.18 [ ]
minimum speed op : 2643 [m], vminh :99.0 [km/u] is hoger dan vmax op deze hoogte !!!! line 155
vliegtuig kan op deze hoogte niet in de lucht blijven, vliegt hoger dan theoretisch kan
max. theoretical ceiling : 2643 [m] with flying weight :463 [kg] line 3370
climbing speed at 500m : 85.42 [m/min]
time to 500m : 5.38 [min]
climbing speed at 1000m : 64.31 [m/min]
time to 1000m : 13.16 [min]
climbing speed at 1500m : 43.30 [m/min]
Bernhard de Waal in a Spin III
time to 1500m : 24.70 [min]
climbing speed at 2000m : 22.40 [m/min]
time to 2000m : 47.03 [min]
published ceiling (2000 [m]
practical ceiling (operational weight) : 2438 [m] with flying weight :471 [kg] line 3385
practical ceiling fully loaded (mtow- 30 min.fuel) : 1173 [m] with flying weight :568 [kg]
max. dive speed : 205.6 [km/hr] at 173 [m] height
turning speed at CLmax : 75.6 [km/u] at 50 [m] height
turn radius at 50m: 44 [m]
time needed for 360* turn 13.2 [seconds] at 50m
load factor at max. angle turn 1.43 ["g"]
calculation *10* (action radius & endurance)
published endurance : 1.20 [hours] with 1 crew and possible useful load : 101.1 [kg] and 88.1 [%] fuel
published range : 97 [km] with 1 crew and 101.1 [kg] useful load and 88.1 [%] fuel
range : 238 [km] with 1 crew and 81.0 [kg] useful load and 216.0 [%] fuel
max range theoretically with additional fuel tanks for total 156.8 [litre] fuel : 807.3 [km]
useful load with range 500km : 44 [kg]
production : 3.54 [tonkm/hour]
oil and fuel consumption per tonkm : 3.49 [kg]
I-°=/
°
Literature :
Praktisch handboek vliegtuigen deel 1 page 82,83
Historische vliegtuigen page 39
Fokker Spin or Spider (fokker-history.com)
www.dutch-aviation.nl/index5/Civil/index5-2 Spider 2.html (dutch-aviation.nl)
Fokker -Bouwer aan de wereldluchtvaart page13,14,15
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
Spin III with Renault engine
Spin III crashed at Gorries , near to Schwerin
Sergeant Hans Eberhard, Schwerin 1913
(c) B van der Zalm 07 October 2020 contact : info.aircraftinvestigation@gmail.com python 3.7.4