Aircraft investigation info>>>>>>> HOME PAGE
weight and performance calculations for the Fokker F.VII
Fokker F.VII
Role : medium weight passenger aircraft
importance : ***
first flight : 11 April 1924 piloted by Herman Hess operational : October 1924
country : The Netherlands
design : Walter Rethel
production : 5 aircraft at Papaverweg, Amsterdam-Noord
general information :
After the failure of the F.V designed by Reinhold Platz working in Veere, Fokker asked Walter Rethel who was the technical man in Amsterdam-Noord, to design a new passenger aircraft that also could be used to fly all the way to Indonesia, a dream shared by Albert Plesman , director of KLM and Anthony Fokker. For stability on the ground Rethel designed a complicated wider-track landing gear what gave considerable drag during flight. At first the F.VII was used on the route from Amsterdam to London. With the 360hp Rolls Royce engine it was underpowered and in some F.VII aircraft it was later replaced by a Napier Lion or Bristol Jupiter engine. For the trial flight to Indonesia, the interior was stripped and the passenger seats removed. Additional fuel tanks were installed increasing fuel capacity from 300 (?) to 1020 litre what would give a non-stop range of about 1725 km.
An additional radiator was installed for the hot climate it would engage on the way to the Dutch east indies.
The crew for the flight consisted of A.N.J. Thomassen a Thuessink van der Hoop, military flyer (LVA) Lt. H.van Weerden Poelman and P.A.van den Broeke as mechanic. H-NACC made an epic trial flight to Indonesia. Leaving from Amsterdam airport (Schiphol) on 01 October 1924 then flew over 15.373 km (55 flying days, 127 flying hours > average 121 km/hr) arriving 24 November 1924 in Jakarta (Batavia).
The route was as follows : Amsterdam 1 oct 1924 -Praag – Belgrado – (Philipoppel emergency landing 3 October 1924 engine needed to be replaced) – Constantinopel (Istanbul) 2-3 nov – Andorra - Aleppo – Bagdad 6-7 nov – Basra – Bushire (Bushehr) – Bandar Abbas – Chabahar – Karachi 9-10 nov – Multan (Pakistan) – Ambala – Alahabad – Calcutta 13-14 nov – Akyab (Sittwe) – Rangoon – Bangkok 17-18 nov – Sengora (Malaysia) – Medan (Sumatra) – Muntok (Mentok) – Tjilitan/ Batavia (Jakarta, Java) 24 nov 1924. The F.VIIa H-NACC returned to Europe by ship. It would take years before aircraft could make the round trip to Indonesia. The last part it flew from Marseille to Amsterdam and was received by an enthusiastic crowd at Schiphol on 14 April 1925.
The F.VII was in service with the KLM till 1936 when the last one was retired.
Registrations : H-NACC s/n 4759 prototype, H-NACJ s/n 4839, H-NACK s/n 4840 > sold to USA, Reynolds Airways inc., H-NACL s/n 4841, H-NACR s/n 4845
Users : KLM
crew : 2 passengers : 8
engine : 1 Rolls Royce Eagle XI liquid-cooled 12 -cylinder V-engine 360 [hp](268.5 KW)
dimensions :
wingspan : 21.3 [m], length : 13.5 [m], height : 3.7[m]
wing area : 71.7 [m^2]
weights :
max.take-off weight : 3255 [kg]
empty weight operational : 1955 [kg] useful load : 800 [kg]
performance :
maximum speed :169 [km/u] op 100 [m]
cruise speed :152 [km/u] op 100 [m]
service ceiling : 3250 [m]
range : 509 [km]
description :
parasol wing with fixed landing gear and tail strut
two spar wing
engines, landing gear attached to the fuselage, luggage compartment in the rear of the fuselage
airscrew :
fixed pitch 4 -bladed tractor airscrew with max. efficiency :0.59 [ ]
estimated diameter airscrew 3.00 [m]
angle of attack prop : 22.08 [ ]
reduction : 0.62 [ ]
airscrew revs : 1178 [r.p.m.]
pitch at Max speed 2.39 [m]
blade-tip speed at Vmax and max revs. : 161 [m/s]
calculation : *1* (dimensions)
measured wing chord : 3.30 [m]
mean wing chord : 3.37 [m]
wing aspect ratio : 6.33 []
gap : 0.00 [m]
gap/chord : 0.00 [ ]
seize (span*length*height) : 1064 [m^3]
calculation : *2* (fuel consumption)
oil consumption : 4.6 [kg/hr]
fuel consumption(cruise speed) : 57.9 [kg/hr] (78.9 [litre/hr]) at 68 [%] power
distance flown for 1 kg fuel : 2.63 [km/kg] at 1625 [m] cruise height, sfc : 318.0 [kg/kwh]
estimated total fuel capacity : 300.05 [litre] (219.93 [kg])
calculation : *3* (weight)
weight engine(s) dry : 379.0 [kg] = 1.41 [kg/KW]
weight reduction gear : 29.5 [kg]
weight 27.1 litre oil tank : 2.31 [kg]
oil tank filled with 2.0 litre oil : 1.8 [kg]
oil in engine 15.0 litre oil : 13.4 [kg]
fuel in engine 1.8 litre fuel : 1.34 [kg]
weight 33.6 litre gravity patrol tank(s) : 5.0 [kg]
weight radiator : 38.5 [kg]
weight exhaust pipes & fuel lines 31.7 [kg]
weight self-starter : 6.6 [kg]
weight cowling 10.7 [kg]
weight airscrew(s) (wood) incl. boss & bolts : 111.1 [kg]
total weight propulsion system : 658 [kg](20.2 [%])
***************************************************************
fuselage skeleton (steel tubes) : 5.51 [cm]): 323 [kg]
cabin layout : pitch : 87 [cm] (1+1) seating in 4.0 rows
weight toilet : 5 [kg]
weight 8.0 windows : 7.20 [kg]
passenger cabin width : 1.70 [m] cabin length : 3.48 [m] cabin height : 1.90 [m]
weight cabin furbishing : 26.13 [kg]
weight cabin floor : 37.97 [kg]
bracing : 30.8 [kg]
fuselage covering ( 34.4 [m2] doped linen fabric) : 10.6 [kg]
weight radio navigation equipment : 7.0 [kg]
weight instruments. : 4.0 [kg]
weight lighting : 2.0 [kg]
weight dual controls + indicators: 27.0 [kg]
weight seats : 50.0 [kg]
weight 266 [litre] main fuel tank empty : 21.3 [kg]
weight air conditioning : 12 [kg]
weight engine mounts & firewalls : 13 [kg]
total weight fuselage : 578 [kg](17.8 [%])
***************************************************************
weight plywood wing covering : 59 [kg]
total weight ribs (53 ribs) : 193 [kg]
load on front upper spar (clmax) per running metre : 733.2 [N]
load on rear upper spar (vmax) per running metre : 372.0 [N]
total weight 4 spars : 191 [kg]
weight wings : 443 [kg]
weight wing/square meter : 6.17 [kg]
cantilever wing without bracing cables
weight fin & rudder (5.3 [m2]) : 33.3 [kg]
weight stabilizer & elevator (8.1 [m2]): 50.3 [kg]
total weight wing surfaces & bracing : 526 [kg] (16.2 [%])
*******************************************************************
wheel pressure : 1627.5 [kg]
weight 2 wheels (980 [mm] by 151 [mm]) : 81.1 [kg]
weight tailskid : 5.5 [kg]
weight undercarriage with axle 59.9 [kg]
total weight landing gear : 146.5 [kg] (4.5 [%]
*******************************************************************
********************************************************************
calculated empty weight : 1909 [kg](58.6 [%])
weight oil for 4.0 hours flying : 18.3 [kg]
weight cooling fluids : 58.0 [kg]
calculated operational weight empty : 1985 [kg] (61.0 [%])
published operational weight empty : 1955 [kg] (60.1 [%])
***o***
"
weight crew : 162 [kg]
weight fuel for 2.0 hours flying : 116 [kg]
********************************************************************
H-NACR with the early landing gear construction. At first it had a 450 hp Napier Lion engine. Later replaced by a 400 hp Jupiter radial engine with metal Reed propellor
In 1929 H-NACR received new registration PH-ACR. In 1931 it was sold to Australia were it flew under registration VH-UQF.
operational weight empty: 2263 [kg](69.5 [%])
weight 8 passengers : 616 [kg]
weight luggage & freight : 184 [kg]
operational weight loaded: 3063 [kg](69.5 [%])
fuel reserve : 104.2 [kg] enough for 1.80 [hours] flying
possible additional useful load : 88 [kg]
operational weight fully loaded : 3255 [kg] with fuel tank filled for 100 [%]
published maximum take-off weight : 3255 [kg] (100.0 [%])
||
I||==|
||
calculation : * 4 * (engine power)
power loading (Take-off) : 12.13 [kg/kW]
power loading (operational without useful load) : 8.43 [kg/kW]
total power : 268.5 [kW] at 1900 [r.p.m]
The Rolls Royce engine of H-NACJ F.VII was later replaced by a Jupiter radial. Later H-NACJ was registered as PH-ACJ, it was destroyed 10 May 1940 at Schiphol by a German bombardment.
19000 ft = 5791m ! This was reached with a F.VIIa flown by Ir.Bertus Grasé on 30 April 1925, not with the depicted F.VII H-NACJC which had a ceiling of only about 4000m without load.
calculation : *5* (loads)
manoeuvre load : 2.8 [g] at 1000 [m]
limit load : 3.0 [g] ultimate load : 4.5 [g] load factor : 1.5 [g]
design flight time : 2.68 [hours]
design cycles : 1008 sorties, design hours : 2700 [hours]
operational wing loading : 310 [N/m^2]
wing stress (3 g) during operation : 150 [N/kg] at 3g emergency manoeuvre
calculation : *6* (angles of attack)
angle of attack zero lift : -1.24 ["]
max. angle of attack (stalling angle) : 12.91 ["]
angle of attack at max. speed : 1.64 ["]
calculation : *7* (lift & drag ratios
lift coefficient at angle of attack 0° :0.10 [ ]
lift coefficient at max. angle of attack : 1.14 [ ]
lift coefficient at max. speed : 0.23 [ ]
induced drag coefficient at max. speed : 0.0036 [ ]
drag coefficient at max. speed : 0.0349 [ ]
drag coefficient (zero lift) : 0.0313 [ ]
calculation : *8* (speeds
stalling speed at sea-level (OW loaded): 90 [km/u]
landing speed at sea-level: 106 [km/hr]
min. drag speed (max endurance) : 126 [km/hr] at 1625 [m](power :63 [%])
min. power speed (max range) : 126 [km/hr] at 1625 [m] (power:63 [%])
cruising speed : 152 [km/hr] op 1625 [m] (power:81 [%])
design speed prop : 160 [km/hr]
maximum speed : 169 [km/hr] op 100 [m] (power:109 [%])
climbing speed at sea-level : 218 [m/min]
calculation : *9* (regarding various performances)
take-off speed : 109.2 [km/u]
emergency/TO power : 375 [hp] at 2236 [rpm]
static prop wash : 113 [km/u]
take-off distance at sea-level : 380 [m]
lift/drag ratio : 10.92 [ ]
climb to 1000m with max payload : 14.63 [min]
climb to 1500m with max payload : 28.76 [min]
climb to 2000m with max payload : 62.55 [min]
practical ceiling (operational weight) : 3973 [m] with flying weight :2263 [kg] line 3385
practical ceiling fully loaded (mtow- 30 min.fuel) : 2253 [m] with flying weight :3226 [kg]
max. dive speed : 380.9 [km/hr] at 1253 [m] height
turning speed at CLmax : 108.8 [km/u] at 50 [m] height
turn radius at 50m: 52 [m]
time needed for 360* turn 10.9 [seconds] at 50m
load factor at max. angle turn 2.04 ["g"]
calculation *10* (action radius & endurance)
published range : 509 [km] with 2 crew and 913.9 [kg] useful load and 88.1 [%] fuel
range : 808 [km] with 2 crew and 800.0 [kg] useful load and 139.9 [%] fuel
range : 1081 [km] with 8.0 passengers with each 10 [kg] luggage and 187.2 [%] fuel
Available Seat Kilometers (ASK) : 8651 [paskm]
max range theoretically with additional fuel tanks for total 1621.6 [litre] fuel : 3122.3 [km] > high theoretical range, so it was nicely designed for long range flights.
useful load with range 500km : 998 [kg]
useful load with range 500km : 8 passengers
production (useful load): 151.74 [tonkm/hour]
production (passengers): 1216.00 [paskm/hour]
oil and fuel consumption per tonkm : 0.41 [kg]
oil and fuel consumption per paskm : 0.05 [kg]
fuel cost per paskm : 0.05 [eur]
writing off per paskm : 0.43 [eur]
insurance per paskm : 0.01 [eur]
crew cost per paskm : 0.12 [eur]
__
I=°°°°°/
°
maintenance cost per paskm : 0.32 [eur]
direct operating cost per paskm : 0.94 [eur]
serious accidents and incidents :
F.VII H-NACC s/n 4759 made an emergency landing near Philippopel (now Plovdiv) in Bulgeria on 03 October 1924. It was on a long distance flight to Indonesia. Cooling water was leaking away from the defect additional radiator which resulted in an overheated engine. The undercarriage could be repaired but the engine needed to be replaced. The money for this was raced by an collection under the readers of the magazine “Het Leven”. Resulting in a delay of 1 month before the journey could continue on 02 November 1924.
Clearly visible the additional cooler under the nose of H-NACC
On 27 May 1926 H-NACJ c/n 4839 made a hard landing at Waalhaven. Came in to low, Jupiter engine with new Triplex-carburettor did not respond quick enough. Langing gear collapsed. No casualties.
21 June 1926 F.VII H-NACL with Jupiter engine c/n 4841, made an emergency landing on Sandgate beach , Hythe, near Folkstone, UK. Crew and passengers OK. A fisherman on the ground was lightly wounded when hit by the wing. The fuel flow was interrupted, the pilot forgot to switch from fuel tank. Pilot : Evert van Dijk . SPF RTM > LHR (Croydon)
On 9 July 1926 H-NACC crashed at Wolverthem , Belgium in fog and rain, lost direction on a flight from Schiphol (Amsterdam) to Paris. Pilot A.C.de Vree
and his passenger W.Hepner killed.
H-NACK s/n 4840 was sold to Reynolds Airways in the USA. 17 September 1927 it crashed near Dunellen (Hadley ?), New Jersey. US Registration : C776. It had an engine failure and crashed out of control. 7 of the 12 people on board died.
Literature :
Fokker verkeersvliegtuigen 1920-1940 page 20,21,78
Piston-engined airliners page 12
Alles over de Fokker Friendship page 23,24,25,114
Geschiedenis van de Nederlandse en Belgische luchtvaart page 26
Praktisch handboek vliegtuigen deel 2 page 200
Fokker verkeersvliegtuigen
World directory of airliner crashes page 13
Vermetele vliegende Hollanders page 28,29
Ongevallen/incidenten 1926 (hdekker.info)
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 16 March 2021 contact : info.aircraftinvestigation@gmail.com python 3.7.4
