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weight and performance calculations for the Avro 685 York

Avro 685 York role : commuter prop airliner importance : *** first flight : 5 July 1842 at Ringway apt. Manchester operational : April 1944

This aircraft was derived from the Lancaster and designed as a transport aircraft for RAF Transport Command, which used it intensively. It had the same wing, tail section, engines and landing gear as the Lancaster bomber. Priority was given for the production of the Lancaster bomber, so first production of the York was slow. Production speeded up in 1945. The BOAC managed to get 5 pieces in 1944 and 25 more at the end of 1945. These had more powerful engines and were referred to as M-class. In 1957 BOAC sold here last Yorks to Skyways.

Fuel capacity : 11270 liters. The passengers were subjected to very noisy conditions due to the engines.

primary users : BOAC (30), British South American Airways (12), Skyways (3), FAMA (5),

RAF

flight crew : 4 cabin crew : 1 passengers : 42

flight crew consist of captain, first officer, navigation officer and wireless operator

engine : 4 Rolls Royce Merlin 24 liquid-cooled 12 -cylinder V-engine 1175 [hp](876.2 KW)

normal rating, supercharged engine, high blower, constant power to height : 5340 [m]

and with 1620 [hp](1208.0 KW) available for take-off

dimensions :

wingspan : 31.09 [m], length : 23.93 [m], height : 5.03 [m]

wing area : 120.5 [m^2]

weights :

max.take-off weight : 31751 [kg]

empty weight operational : 18144 [kg] useful load : 5600 [kg]

performance :

maximum continuous speed : 480 [km/u] op 5340 [m]

normal cruise speed : 430 [km/u] op 5334 [m] (80 [%] power)

service ceiling : 7000 [m]

range with max fuel : 3709 [km] and allowance for 285.7 [km] diversion and 30 [min] hold

description :

high-winged monoplane with retractable landing gear with tail wheel

tapered wing with slotted flaps airfoil : RAF

engines and landing gear attached to the wings, fuel tanks in the wings

construction : all-metal stressed-skin (Alclad-aluminium) airplane

fuselage shape : [ ]

airscrew :

four Hamilton-Standard constant speed full-feathering 3 -bladed tractor airscrews with max.

efficiency :0.76 [ ]

diameter airscrew 4.00 [m]

relative pitch (J) : 1.67 [ ]

power loading prop : 146.03 [KW/m]

theoretical pitch without slip : 7.45 [m]

blade angle prop at max.speed : 39.34 [ ]

tip-speed close to speed of sound (above Mach 0.85) > loose of efficiency

reduction : 0.42 [ ]

airscrew revs : 1197 [r.p.m.]

aerodynamic pitch at max. continuous speed 6.68 [m]

blade-tip speed at max.continuous speed : 284 [m/s]

propellor noise in flight : 98 [Db]

2+1 seating layout, giving room for 42 passengers in 14 rows, also 2+2 layout was possible giving room for 56 passengers

calculation : *1* (dimensions)

measured wing chord : 3.87 [m] at 50% wingspan

mean wing chord : 3.88 [m]

calculated average wing chord tapered wing with rounded tips: 3.86 [m]

wing aspect ratio : 8.0 []

seize (span*length*height) : 3742 [m^3]

calculation : *2* (fuel consumption)

oil consumption : 42.1 [kg/hr]

fuel consumption (econ. cruise speed) : 843.8 [kg/hr] (1151.2 [litre/hr]) at 80 [%] power

distance flown for 1 kg fuel : 0.51 [km/kg] at 5334 [m] height, sfc : 300.0 [kg/kwh]

estimated total fuel capacity : 11270 [litre] (8261 [kg])

calculation : *3* (weight)

weight engine(s) dry with reduction gear : 2632.0 [kg] = 0.75 [kg/KW]

weight 572.5 litre oil tank : 48.67 [kg]

oil tank filled with 26.3 litre oil : 23.6 [kg]

oil in engine 195.2 litre oil : 175.2 [kg]

fuel in engine 23.9 litre fuel : 17.52 [kg]

weight 489.4 litre gravity patrol tank(s) : 73.4 [kg]

weight radiator : 560.8 [kg]

The York was used as military (VIP) transport by the RAF, the third prototype LV633 Ascalon was custom-built as the personal transport for Winston Churchill

weight exhaust pipes & fuel lines 144.6 [kg]

weight Burgess type silencers : 70.1 [kg]

weight cowling 35.0 [kg]

weight variable pitch control : 27.6 [kg]

weight airscrew(s) incl. boss & bolts : 690.8 [kg]

total weight propulsion system : 4472 [kg](14.1 [%])

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

fuselage aluminium frame : 3022 [kg]

cabin layout : pitch : 81 [cm] (2+1) seating in 14.0 rows

pax density (normal seating) : 0.84 [m2/pax]

high density seating passengers : 59 at 4 -abreast seating in 14.7 rows

weight 1 toilets : 9.3 [kg]

weight 3 hand fire extinguisher : 10 [kg]

weight buffet : 65.9 [kg]

weight racks for hand luggage : 21.0 [kg]

weight 30 windows : 27.0 [kg]

weight 4 emergency exits : 12.0 [kg]

weight 2 entrance/exit doors : 10.0 [kg]

extra main deck space for freight/mail/luggage etc. : 0.97 [m3]

cabin volume (usable), excluding flight deck : 60.35 [m3]

passenger cabin max.width : 2.43 [m] cabin length : 14.57 [m] cabin height : 1.90 [m]

fuselage covering ( 131.2 [m2] duraluminium 5.69 [mm]) : 1938.5 [kg]

weight floor beams : 31.9 [kg]

weight cabin furbishing : 177.8 [kg]

weight cabin floor : 202.6 [kg]

fuselage (sound proof) isolation : 42.0 [kg]

weight radio transceiver equipment : 7.0 [kg]

weight radio direction finding (RDF) equipment : 5.0 [kg]

weight artificial horizon : 1.1 [kg]

weight instruments. : 13.0 [kg]

weight APU / engine starter: 43.8 [kg]

weight lighting : 10.5 [kg]

weight electricity generator : 26.4 [kg]

weight controls : 11.4 [kg]

weight seats : 235.0 [kg]

weight air conditioning : 63 [kg]

total weight fuselage : 5913 [kg](18.6 [%])

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

total weight aluminium ribs (418 ribs) : 1132 [kg]

weight engine mounts : 175 [kg]

weight fuel tanks empty for total 10781 [litre] fuel : 862 [kg]

weight wing covering (painted aluminium 2.05 [mm]) : 1332 [kg]

total weight aluminium spars (multi-cellular wing structure) : 1333 [kg]

weight wings : 3797 [kg]

weight wing/square meter : 31.51 [kg]

cantilever wing without bracing cables

weight rubber de-icing boots : 34.2 [kg]

weight fin & rudder (11.2 [m2]) : 355.2 [kg]

weight stabilizer & elevator (13.6 [m2]): 428.1 [kg]

weight slotted flaps (10.0 [m2]) : 164.2 [kg]

total weight wing surfaces & bracing : 5816 [kg] (18.3 [%])

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

Can only operate from paved runways

wheel pressure : 15875.5 [kg]

weight 2 Dunlop main wheels (1580 [mm] by 316 [mm]) : 641.1 [kg]

weight tailwheel(s) : 5.9 [kg]

weight hydraulic wheel-brakes : 23.7 [kg]

weight pneumatic-hydraulic shock absorbers : 31.7 [kg]

weight wheel hydraulic operated retraction system : 102.2 [kg]

weight undercarriage struts with axle 729.0 [kg]

total weight landing gear : 1533.6 [kg] (4.8 [%]

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

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

calculated empty weight : 17735 [kg](55.9 [%])

weight oil for 10.4 hours flying : 435.3 [kg]

weight ethylene glycol cooling fluids : 567.8 [kg]

calculated operational weight empty : 18738 [kg] (59.0 [%])

published operational weight empty : 18144 [kg] (57.1 [%])

weight crew : 405 [kg]

weight fuel for 2.0 hours flying : 1688 [kg]

weight catering : 126.8 [kg]

weight water : 101.4 [kg]

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

operational weight empty: 21059 [kg](66.3 [%])

weight 42 passengers : 3234 [kg]

weight luggage : 512 [kg]

weight cargo : 1854 [kg]

operational weight loaded: 26659 [kg](84.0 [%])

fuel reserve : 5092.4 [kg] enough for 6.04 [hours] flying

operational weight fully loaded : 31751 [kg] with fuel tank filled for 82 [%]

published maximum take-off weight : 31751 [kg] (100.0 [%])

calculation : * 4 * (engine power)

power loading (Take-off) : 6.57 [kg/kW]

power loading (operational without useful load) : 6.01 [kg/kW]

power loading (Take-off) 1 PUF: 8.76 [kg/kW]

max.total take-off power : 4832.1 [kW]

calculation : *5* (loads)

manoeuvre load : 3.1 [g] at 1000 [m]

limit load : 3.0 [g] ultimate load : 4.5 [g] load factor : 1.4 [g]

design flight time : 6.04 [hours]

design cycles : 3100 sorties, design hours : 18717 [hours]

operational wing loading : 2337 [N/m^2]

wing stress (3 g) during operation : 223 [N/kg] at 3g emergency manoeuvre

calculation : *6* (angles of attack)

angle of attack zero lift : -1.40 ["]

max. angle of attack (stalling angle, clean) : 11.98 ["]

max. angle of attack (full flaps) : 11.09 ["]

angle of attack at max. speed : 1.77 ["]

calculation : *7* (lift & drag ratios

lift coefficient at angle of attack 0° : 0.12 [ ]

lift coefficient at max. speed : 0.27 [ ]

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

max.lift coefficient full flaps : 1.40 [ ]

induced drag coefficient at max.speed : 0.0039 [ ]

drag coefficient at max. speed : 0.0248 [ ]

drag coefficient (zero lift) : 0.0209 [ ]

calculation : *8* (speeds

stalling speed at sea-level (OW loaded : 30907 [kg]): 215 [km/u]

stalling speed at sea-level with full flaps (normal landing weight): 178 [km/u]

landing speed at sea-level (normal landing weight : 25688 [kg]): 205 [km/hr]

max. rate of climb speed : 219 [km/hr] at sea-level

max. endurance speed : 215 [km/u] min.fuel/hr : 489 [kg/hr] at height : 610 [m]

max. range speed : 335 [km/u] min. fuel consumption : 1.970 [kg/km] at cruise height : 3962 [m]

cruising speed : 430 [km/hr] at 5334 [m] (power:80 [%])

max. continuous speed* : 480.00 [km/hr] at 5340 [m] (power:100 [%])

climbing speed at sea-level (loaded) : 348 [m/min]

climbing speed at 1000 [m] with 1 engine out (PUF / MTOW) : 216 [m/min]

climbing speed at 1000 [m] with 2 engines out (2xPUF / MTOW) : 24 [m/min]

calculation : *9* (regarding various performances)

take-off speed : 262.0 [km/u]

emergency/TO power : 1620 [hp] at 3000 [rpm]

static prop wash : 167 [km/u]

high wheel pressure, can only take off from paved runways

take-off distance at sea-level concrete runway : 1027 [m]

take-off distance at sea-level over 15 [m] height : 1184 [m]

landing run : 918 [m]

landing run from 15 [m] : 1730 [m]

lift/drag ratio : 15.06 [ ]

climb to 1000m with max payload : 4.69 [min]

climb to 2000m with max payload : 9.70 [min]

climb to 3000m with max payload : 15.12 [min]

climb to 5000 [m] with max payload : 28.52 [min]

practical ceiling (operational weight empty 21059 [kg] ) : 9100 [m]

practical ceiling fully loaded (mtow- 30 min.fuel:31329 [kg] ) : 6600 [m]

calculation *10* (action radius & endurance)

published range : 3709 [km] with 5 crew and 5330.0 [kg] useful load and 88.1 [%] fuel (no

reserves)

Arctic Wings Avro York C.1CF-HMX hit a snow bank at Hall Lake, NU, Canada 12 April 1955 and was damaged beyond repair.

range : 3571 [km] with 5 crew and 5600.0 [kg] useful load and 84.8 [%] fuel

range : 4516 [km] with 42.0 passengers with each 12.2 [kg] luggage and 107.3 [%] fuel

Available Seat Kilometres (ASK) : 189673 [paskm]

max range theoretically with additional fuel tanks total 17642.9 [litre] fuel : 6563 [km]

useful load with range 500km : 11951 [kg]

useful load with range 500km : 42 passengers

production (theor.max load): 5139 [tonkm/hour]

production (useful load): 2408 [tonkm/hour]

production (passengers): 18060 [paskm/hour]

combi aircraft mail/freight/passengers

oil and fuel consumption per tonkm : 0.172 [kg]

fuel cost per paskm : 0.049 [eur]

crew cost per paskm : 0.042 [eur]

economic hours : 18250 [hours] is less then design hours

time between engine failure : 261 [hr]

can continue fly on 3 engines, low risk for emergency landing for PUF

writing off per paskm : 0.045 [eur]

insurance per paskm : 0.0022 [eur]

maintenance cost per paskm : 0.107 [eur]

direct operating cost per paskm : 0.244 [eur]

direct operating cost per tonkm (max. load): 0.858 [eur]

direct operating cost per tonkm (normal useful load): 1.830 [eur]

literature :

praktisch handboek vliegtuigen deel 5 page 99

Jane's Fighting Aircraft WWII page 105

Verkeersvliegtuigen Moussault page 45, 119, 120

Piston engined airliners page 61

AVRO 685 York - Specifications - Technical Data / Description (flugzeuginfo.net)

* max. continuous speed : max. level speed maintainable for minimal 30 min.

Wireless operator position in the Avro York

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 03 April 2022 contact : info.aircraftinvestigation@gmail.com python 3.7.4