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weight and performance calculations for the Boeing 720
***** PRELIMINARY FILE ****
American Airlines Boeing 720-023 N7527A c/n 18013
Boeing 720
role : medium range jet airliner
importance : ***
first flight : 23 November 1959 operational : July 1960
country : United States of America
design :
production : ca. 53 aircraft
general information :
Boeing 707 derivative for shorter flights from shorter runways. It had a 2.36 [m] shorter
fuselage. It was aerodynamically refined and also had a lighter construction.
It had leading edge slats.
primary users : United Airlines (29), Irish Int’l (3), American Airlines (10) , Eastern (15),
Western (4), Braniff (4), Pacific Northern (2)
Accommodation:
flight crew : 3 cabin crew : 4
flight crew consist of pilot, co-pilot and flight engineer
passengers : seating for 131 in two class : 30 business class and 101 coach class seats ( 34 -in pitch)
high density seating for 149 passengers
engine : 4 Pratt & Whitney JT3C-7 turbojet engines of 53.43 [KN](12011.3 [lbf])
dimensions :
wingspan : 39.87 [m], length : 41.5 [m], height : 11.56 [m]
wing area : 226.04 [m^2] fuselage exterior width : 3.76 [m]
weights :
empty weight : 47630 [kg]
operating empty weight : 50260 [kg] max. structural payload : 12790 [kg]
Zero Fuel weight (ZFW) : 63050 [kg] max. landing weight (MLW) : 79380 [kg]
max.take-off weight : 103870 [kg] weight fuel : 48720 [kg] (60900 [liter])
performance :
Max. operating Mach number (Mmo) : 0.90 [Mach] (1003 [km/hr]) at 7620 [m]
normal cruise speed : 897 [km/hr] (Mach 0.85 ) at 11430 [m] (43 [%] power)
service ceiling : 11735 [m]
range with max fuel : 4941 [km] and allowance for 542.5 [km] diversion and 30 [min] hold
description :
low-wing cantilever monoplane with retractable landing gear with nose wheel
tapered multi-cellular wing with flush-riveted stressed skin
with Fowler flaps airfoil : NACA
sweep angle 3/4 chord: 34.0 [°]
engines attached with pylons to the wing, main landing gear attached to the wings, fuel tanks in the wings and fuselage
construction : all-metal aluminium-alloy stressed-skin construction with pressurized fuselage
fuselage shape : 0
calculation : *1* (dimensions)
measured wing chord : 5.67 [m] at 50% wingspan
mean wing chord : 5.67 [m]
calculated average wing chord tapered wing with rounded tips: 5.62 [m]
wing aspect ratio : 7.03 []
seize (span*length*height) : 19127 [m^3]
calculation : *2* (fuel consumption)
oil consumption : 21.4 [kg/hr]
fuel consumption (econ. cruise speed) : 7792.4 [kg/hr] (9740.5 [litre/hr]) at 43 [%] power
distance flown for 1 kg fuel : 0.12 [km/kg] at 11430 [m] height, sfc : 85.0 [kg/KN/h]
total fuel capacity : 60900 [litre] (48720 [kg])
calculation : *3* (weight)
weight engine(s) dry : 7620.0 [kg] = 35.65 [kg/KN]
weight 2265.4 litre water tank for engine injection : 192.56 [kg]
weight 161.9 litre oil tank : 13.76 [kg]
oil tank filled with 1.3 litre oil : 1.2 [kg]
United Airlines 720-022 N7225U c/n 18078 with full flaps
oil in engine 35.7 litre oil : 32.1 [kg]
fuel in engine 26.2 litre fuel : 19.23 [kg]
weight fuel lines 60.9 [kg]
weight engine cowling 641.2 [kg]
total weight propulsion system : 8581 [kg](8.3 [%])
***************************************************************
fuselage aluminium frame : 10870 [kg]
floor loading : 135 [kg/m2]
typical cabin layout for 131 passengers : economy : pitch : 86 [cm] ( 3+3 ) seating in 22.8 rows
pax density (normal seating) : 0.72 [m2/pax]
high density seating passengers : 152 at 6 -abreast seating in 25.4 rows, pitch 83.8 [cm]
weight 3 toilets : 41.8 [kg]
weight 7 hand fire extinguisher : 20 [kg]
weight 1 galleys : 101.0 [kg]
weight overhead stowage for hand luggage : 45.8 [kg]
weight 3 closets : 26.2 [kg]
weight 48 windows : 42.9 [kg]
weight 2 overwing emergency exits : 45.8 [kg]
weight lifejackets : 59.0 [kg]
weight oxygen masks & oxygen generators : 85.2 [kg]
weight emergency flare installation : 10 [kg]
weight 4 emergency evacuation slides : 61.6 [kg]
weight 4 entrance/exit doors : 213.6 [kg]
weight 2 freight doors (belly) : 76.3 [kg]
weight ladies’ powder room : 16 [kg]
weight men’s dressing room : 12 [kg]
Eastern Airlines 720 interior
weight diplomatic mail locker : 2 [kg]
cabin volume (usable), excluding flight deck : 261.51 [m3]
passenger cabin max.width : 3.54 [m] cabin length : 29.72 [m] cabin height : 2.19 [m]
floor area : 94.8 [m2]
pressure difference :0.62 [kg/cm2]
weight rear pressure bulkhead : 150.6 [kg]
weight air pressurization system : 57.6 [kg]
fuselage covering ( 356.2 [m2] duraluminium 2.57 [mm]) : 2419.0 [kg]
weight floor beams : 488.3 [kg]
weight cabin furbishing : 832.8 [kg]
weight cabin floor : 1440.7 [kg]
fuselage (sound proof) isolation : 301.7 [kg]
weight radio transceiver equipment : 7.0 [kg]
weight dual cloud-collision radar : 25.0 [kg]
weight radio direction finding (RDF) equipment : 5.0 [kg]
weight Sperry Integrated Flight System : 11.0 [kg]
weight artificial horizon : 1.1 [kg]
weight instruments. : 38.0 [kg]
weight APU / engine starter: 26.7 [kg]
weight lighting : 32.8 [kg]
weight electricity generator : 32.8 [kg]
weight controls : 17.1 [kg]
weight seats : 690.0 [kg]
weight 30450 [litre] main central fuel tanks empty : 1705.2 [kg]
weight air conditioning : 196 [kg]
total weight fuselage : 19805 [kg](19.1 [%])
***************************************************************
total weight aluminium ribs (936 ribs) : 3704 [kg]
weight engine mounts : 107 [kg]
weight fuel tanks empty for total 30450 [litre] fuel : 1705 [kg]
weight wing covering (painted aluminium 2.08 [mm]) : 2534 [kg]
total weight aluminium spars (multi-cellular wing structure) : 3609 [kg]
weight wings : 9847 [kg]
weight wing/square meter : 43.56 [kg]
weight rubber de-icing boots : 43.9 [kg]
weight fin & rudder (18.5 [m2]) : 806.5 [kg]
weight stabilizer & elevator (25.4 [m2]): 1109.4 [kg]
weight flight control hydraulic servo actuators: 53.8 [kg]
weight fowler flaps (14.1 [m2]) : 312.2 [kg]
total weight wing surfaces & bracing : 13985 [kg] (13.5 [%])
*******************************************************************
wielen naar verhouding erg licht
wheel pressure : 11425.7 [kg]
weight 8 Dunlop main wheels (1130 [mm] by 226 [mm]) : 866.5 [kg]
weight 2 Dunlop nose wheels : 108.3 [kg]
weight hydraulic wheel-brakes : 63.0 [kg]
weight pneumatic-hydraulic shock absorbers : 84.1 [kg]
weight wheel hydraulic operated retraction system : 899.9 [kg]
weight undercarriage struts with axle 2432.8 [kg]
total weight landing gear : 4454.6 [kg] (4.3 [%]
*******************************************************************
Aer Lingus Boeing 720-048 EI-ALC at Manchester airport in 1963.
********************************************************************
calculated empty weight : 46825 [kg](45.1 [%])
weight oil for 6.6 hours flying : 141.3 [kg]
weight engine injection water : 2265.4 [kg]
weight catering : 252.6 [kg]
weight water : 101.0 [kg]
weight crew : 567 [kg]
weight crew lugage,nav.chards,flight doc.,miscell.items : 107 [kg]
operational weight empty : 50260 [kg] (48.4 [%])
********************************************************************
weight 131 passengers : 10087 [kg]
weight luggage : 2096 [kg]
weight cargo : 607 [kg]
zero fuel weight (ZFW): 63050 [kg](60.7 [%])
weight fuel for landing (2.1 hours flying) : 16330 [kg]
max. landing weight (MLW): 79380 [kg](76.4 [%])
max. fuel weight : 98980 [kg] (95.3 [%])
payload with max fuel : 53 passengers+luggage 4890 [kg]
published maximum take-off weight : 103870 [kg] (100.0 [%])
calculation : * 4 * (engine power)
power loading (Take-off) : 486 [kg/KN]
power loading (operational without useful load) : 429 [kg/kN]
power loading (Take-off) 1 PUF: 648 [kg/KN]
max. total take-off power : 213.7 [KN]
calculation : *5* (loads)
manoeuvre load : 10.4 [g] at 1000 [m]
limit load : 3.0 [g] ultimate load : 4.5 [g] load factor : 0.8 [g]
Trans Polar LN-TUW c/n 18158 landing at Arlanda airport, Stockholm, June 1970
design flight time : 3.86 [hours]
design cycles : 2037 sorties, design hours : 7856 [hours]
operational wing loading : 3971 [N/m^2]
wing stress (3 g) during operation : 273 [N/kg] at 3g emergency manoeuvre
calculation : *6* (angles of attack)
angle of attack zero lift : -1.81 ["]
max. angle of attack (stalling angle, clean) : 14.00 ["]
angle of attack at max. speed : 0.44 ["]
calculation : *7* (lift & drag ratios
lift coefficient at angle of attack 0° : 0.15 [ ]
lift coefficient at max. speed : 0.19 [ ]
lift coefficient at max. angle of attack : 1.31 [ ]
max. lift coefficient full flaps : 1.58 [ ]
induced drag coefficient at max.speed : 0.0021 [ ]
drag coefficient at max. speed : 0.0238 [ ]
drag coefficient (zero lift) : 0.0217 [ ]
lift/drag ratio at max. speed : 7.83 [ ]
calculation : *8* (speeds
stalling speed at sea-level (OW loaded : 96078 [kg]): 259 [km/u]
stalling speed at sea-level with full flaps (normal landing weight): 214 [km/u]
landing speed at sea-level (normal landing weight : 79203 [kg]): 247 [km/hr]
max. rate of climb speed : 571 [km/hr] at sea-level
max. endurance speed : 511 [km/u] min. fuel/hr : 4779 [kg/hr] at height : 7315 [m]
max. range speed : 776 [km/u] min. fuel consumption : 7.104 [kg/km] at cruise height :
9754 [m]
Pacific Northern Airlines N720W c/n 18377
cruising speed : 897 [km/hr] at 11430 [m] (power:30 [%])
max. operational speed (Mmo) : 1003.00 [km/hr] (Mach 0.90 ) at 7620 [m]
(power:53.6 [%])
airflow : 264.7 [kg/s]
speed of thrust jet : 2144 [km/hr]
climbing speed at sea-level (loaded) : 1315 [m/min]
climbing speed at 1000 [m] with 1 engine out (PUF / MTOW) : 1133 [m/min]
climbing speed at 1000 [m] with 2 engines out (2xPUF / MTOW) : 1089 [m/min]
calculation : *9* (regarding various performances)
take-off speed : 323.4 [km/u]
high wheel pressure, can only take off from paved runways
take-off distance at sea-level concrete runway : 1964 [m]
take-off distance at sea-level over 15 [m] height : 2072 [m]
landing run : 1183 [m]
landing run from 15 [m] : 2053 [m]
lift/drag ratio : 13.87 [ ]
max. theoretical ceiling : 18800 [m] with flying weight :96078 [kg] line 3359
climb to 1000m with max payload : 0.85 [min]
climb to 2000m with max payload : 1.65 [min]
climb to 3000m with max payload : 2.42 [min]
climb to 5000 [m] with max payload : 3.80 [min]
minimum flying speed at 11735 [m] : 574 [km/hr]
theoretical ceiling fully loaded (mtow- 60 min. fuel:96078 [kg] ) : 18800 [m]
calculation *10* (action radius & endurance)
published range : 4941 [km] with 7 crew and 10687 [kg] useful load and 88.1 [%] fuel
range : 4699 [km] with 12790.0 [kg] max. useful load (83.8 [%] fuel)
range : 4769 [km] with 131.0 passengers with each 16 [kg] luggage and 85.0 [%] fuel
range max. fuel : 5608 [km] with 4890.0 [kg] useful load and 100.0 [%] fuel
Available Seat Kilometres (ASK) : 624705 [paskm]
max range theoretically with additional fuel tanks total 67012.5 [litre] fuel : 7546 [km]
useful load with range 500km : 49266 [kg]
useful load with range 500km : 131 passengers
production (theor.max load): 44192 [tonkm/hour]
production (useful load): 11473 [tonkm/hour]
production (passengers): 117507 [paskm/hour]
combi aircraft mail/freight/passengers
oil and fuel consumption per tonkm : 0.177 [kg]
fuel cost per paskm : 0.066 [eur]
crew cost per paskm : 0.008 [eur]
time between engine failure : 481 [hr]
can continue fly on 3 engines, low risk for emergency landing for PUF
writing off per paskm : 0.042 [eur]
insurance per paskm : 0.0008 [eur]
maintenance cost per paskm : 0.026 [eur]
direct operating cost per paskm : 0.143 [eur]
direct operating cost per tonkm (max. load): 0.380 [eur]
direct operating cost per tonkm (normal useful load): 1.463 [eur]
Literature :
https://www.boeing.com/search/results.html?q=airplane+characteristics
Wat is dat voor een vliegtuig page 38/39
Straalverkeersvliegtuigen page101,102
Praktisch handboek vliegtuigen deel 5 page 70,71
Jane’s all the world aircraft 1964-1965 page 189,190
www.rzjets.net (productionlist)
Air Rhodesia Boeing 720-025 VP-YNN in 1975
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 27 June 2022 contact : info.aircraftinvestigation@gmail.com python 3.7.4