Aircraft investigation >>>>>>> HOME PAGE
weight and performance calculations for the Lockheed L-749 Constellation
Lockheed L-749 Constellation
role : transatlantic airliner
importance : ****
first flight : L-749 : 14 March 1947 operational : June 1947
country : United States of America
design : C.L. “Kelly” Johnson
production : L-749 : 60 aircraft
general information :
After the L-049 followed the L-649, which flew for the first time in October 1946. It had a greater fuel capacity, more powerful Wright R-3350-BD1 radial engines of 2500 [hp], it was more luxuriously furnished and had an improved air refreshment system.
Then came the L-749 with even more fuel capacity, electrically adjustable propellors and a strengthened landing gear due to the increased weight.
Jet stacks were introduced, metal jet pipes attached to the engine exhaust giving a rearward jetstream adding 24 [km/hr] to its cruise speed. The jet stacks increased the noise and more sound-isolation was needed.
Now the Constellation was for the first time able to fly non-stop between Paris and New York on a regular basis.
The airlines that ordered de L-649 changed there orders to the L-749 and the 14 under construction were upgraded to L-749 standard.
KLM ordered a total of 13 L-749s, the first was delivered in August 1947. The last one was taken out of service by KLM in 1958.
However, the L-749 suffered from serious problems and Lockheed had to make several changes to all completed Constellations. This together with the cancelled military orders after WWII brought Lockheed in serious financial problems. In March 1947 it fired 1200 men on the production department and at the end of 1947 the production of the Constellation almost shut down. The Air Force saved however Lockheed by ordering 10 L-749A's as VIP-aircraft. They were given the designation C-121.
Known were the "Columbine" of General Eisenhower and the "Bataan" of General MacArthur. This order gave Lockheed just enough resources to develop the
L-1049 Super Constellation.
Primary users : Eastern air lines, KLM, Air France, TWA, Panam, Cubana de Aviacion,
Linea Aeropostal Venezolana.
flight crew : 4 cabin crew : 3 passengers : 44-64
flight crew consist of pilot, co-pilot, radio operator and engineer
powerplant : 4 Wright R-3350-C18-BD1 Duplex-Cyclone air-cooled 18 -cylinder radial
engine 2100 [hp](1566.0 KW) normal rating, supercharged engine, high blower,
constant power to height : 4260 [m] and with 2500 [hp](1864.2 KW) available for
take-off
dimensions :
wingspan : 37.49 [m], length : 29.67 [m], height : 6.83 [m]
wing area : 153.29 [m^2]
weights :
max.take-off weight : 46310 [kg]
empty weight operational : 25669 [kg] useful load : 8100 [kg]
performance :
maximum continous speed : 555 [km/u] op 4260 [m]
normal cruise speed : 497 [km/u] op 6100 [m] (67 [%] power)
service ceiling : 7300 [m]
range with max fuel : 5890 [km] and allowance for 546.7 [km] diversion and 30 [min]
hold
description :
low-winged monoplane with retractable landing gear with nose wheel
tapered multi-cellular wing with flush-riveted stressed skin
with Fowler flaps airfoil : NACA
engines and landing gear attached to the wings, fuel tanks in the wings
construction : all-metal aluminium-alloy stressed-skin construction with pressurized
Panam L-749 flying over New York
fuselage
fuselage shape : O
airscrew :
four Hamilton-Standard constant speed, reversible pitch 3 -bladed tractor airscrews
max. efficiency :0.82 [ ]
diameter airscrew 4.57 [m]
relative pitch (J) : 2.14 [ ]
power loading prop : 228.44 [KW/m]
high power loading prop > more bladed prop needed
theoretical pitch without slip : 10.85 [m]
blade angle prop at max.speed : 46.22 [ ]
reduction : 0.38 [ ]
airscrew revs : 947 [r.p.m.]
aerodynamic pitch at max. continuous speed 9.77 [m]
blade-tip speed at max.continuous speed : 274 [m/s]
propellor noise in flight : 95 [Db]
calculation : *1* (dimensions)
measured wing chord : 3.96 [m] at 50% wingspan
mean wing chord : 4.09 [m]
calculated average wing chord tapered wing with rounded tips: 3.99 [m]
wing aspect ratio : 9.2 []
seize (span*length*height) : 7597 [m^3]
calculation : *2* (fuel consumption)
oil consumption : 50.1 [kg/hr]
fuel consumption (econ. cruise speed) : 1200.5 [kg/hr] (1637.8 [litre/hr]) at 67 [%]
power
distance flown for 1 kg fuel : 0.41 [km/kg] at 6100 [m] height, sfc : 286.0 [kg/kwh]
estimated total fuel capacity : 22031 [litre] (16148 [kg])
calculation : *3* (weight)
weight engine(s) dry with reduction gear : 4840.0 [kg] = 0.77 [kg/KW]
weight 950.4 litre oil tank : 80.79 [kg]
oil tank filled with 47.0 litre oil : 42.2 [kg]
oil in engine 34.9 litre oil : 31.3 [kg]
fuel in engine 42.7 litre fuel : 31.32 [kg]
weight 696.3 litre gravity patrol tank(s) : 104.4 [kg]
weight jet stacks : 156.6 [kg]
weight NACA cowling 70.2 [kg]
weight variable pitch control : 49.0 [kg]
weight airscrew(s) incl. boss & bolts : 1224.9 [kg]
total weight propulsion system : 6582 [kg](14.2 [%])
***************************************************************
fuselage aluminium frame : 4775 [kg]
cabin layout : pitch : 87 [cm] ( 3+2 ) seating in 12.0 rows
pax density (normal seating) : 0.95 [m2/pax]
high density seating passengers : 87 at 5 -abreast seating in 17.4 rows
weight 4 toilets : 28.3 [kg]
weight 6 fire extinguisher : 18 [kg]
weight pantry : 99.5 [kg]
weight 26 windows : 23.4 [kg]
weight 4 emergency exits : 12.0 [kg]
weight 8 life rafts : 90.0 [kg]
weight oxygen masks & oxygen generators : 39.0 [kg]
weight 2 entrance/exit doors : 24.0 [kg]
weight 2 freight doors (belly) : 8.0 [kg]
weight ladies" powder room : 16 [kg]
weight men"s dressing room : 12 [kg]
weight diplomatic mail locker : 2 [kg]
extra main deck space for freight/mail/luggage etc. : 3.01 [m3]
cabin volume (usable), excluding flight deck : 132.45 [m3]
passenger cabin max.width : 3.31 [m] cabin length : 17.20 [m] cabin height : 2.36 [m]
pressure at cruise height 6100.00 [m] : 0.47 [kg/cm2] cabine pressure : 0.77 [kg/cm2]
weight rear pressure bulkhead : 155.0 [kg]
weight air pressurization system : 33.6 [kg]
fuselage covering ( 210.1 [m2] duraluminium 3.03 [mm]) : 1681.4 [kg]
weight floor beams : 168.8 [kg]
weight cabin furbishing : 386.9 [kg]
weight cabin floor : 306.1 [kg]
fuselage (sound proof) isolation : 74.1 [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: 78.3 [kg]
weight lighting : 15.0 [kg]
weight electricity generator : 15.0 [kg]
weight controls : 13.7 [kg]
weight seats : 335.0 [kg]
weight air conditioning : 90 [kg]
total weight fuselage : 8406 [kg](18.2 [%])
***************************************************************
total weight aluminium ribs (578 ribs) : 1651 [kg]
weight engine mounts : 313 [kg]
weight fuel tanks empty for total 21335 [litre] fuel : 1707 [kg]
Total fuel 5820 US gallon = 22028 litre
weight wing covering (painted aluminium 2.05 [mm]) : 1698 [kg]
total weight aluminium spars (multi-cellular wing structure) : 1850 [kg]
weight wings : 5200 [kg]
weight wing/square meter : 33.92 [kg]
cantilever wing without bracing cables
weight rubber de-icing boots : 41.2 [kg]
weight fin & rudder (16.3 [m2]) : 555.9 [kg]
weight stabilizer & elevator (17.2 [m2]): 586.1 [kg]
weight flight control hydraulic servo actuators: 37.1 [kg]
total weight wing surfaces & bracing : 8440 [kg] (18.2 [%])
*******************************************************************
wielen naar verhouding erg licht
wheelstress is very high , check dimensions & weight
Can only operate from paved runways
wheel pressure : 11577.5 [kg]
weight 4 Dunlop main wheels (1330 [mm] by 266 [mm]) : 537.0 [kg]
weight nose wheel : 67.1 [kg]
weight hydraulic wheel-brakes : 33.8 [kg]
weight pneumatic-hydraulic shock absorbers : 45.0 [kg]
weight wheel hydraulic operated retraction system : 122.0 [kg]
weight undercarriage struts with axle 1026.3 [kg]
total weight landing gear : 1830.5 [kg] (4.0 [%]
*******************************************************************
********************************************************************
calculated empty weight : 25258 [kg](54.5 [%])
weight oil for 14.2 hours flying : 712.6 [kg]
calculated operational weight empty : 25971 [kg] (56.1 [%])
published operational weight empty : 25669 [kg] (55.4 [%])
weight crew : 567 [kg]
weight fuel for 2.0 hours flying : 2401 [kg]
weight catering : 248.9 [kg]
weight water : 199.1 [kg]
********************************************************************
operational weight empty: 29387 [kg](63.5 [%])
weight 60 passengers : 4620 [kg]
weight luggage : 732 [kg]
weight cargo : 2748 [kg]
operational weight loaded: 37487 [kg](80.9 [%])
fuel reserve : 8823.3 [kg] enough for 7.35 [hours] flying
operational weight fully loaded : 46310 [kg] with fuel tank filled for 70 [%]
published maximum take-off weight : 46310 [kg] (100.0 [%])
calculation : * 4 * (engine power)
power loading (Take-off) : 7.39 [kg/kW]
power loading (operational without useful load) : 4.69 [kg/kW]
power loading (Take-off) 1 PUF: 9.86 [kg/kW]
total power : 6263.9 [kW] at 2525 [r.p.m]
calculation : *5* (loads)
manoeuvre load : 6.7 [g] at 1000 [m]
limit load : 3.0 [g] ultimate load : 4.5 [g] load factor : 1.3 [g]
design flight time : 8.30 [hours]
design cycles : 2213 sorties, design hours : 18357 [hours]
operational wing loading : 1880 [N/m^2]
wing stress (3 g) during operation : 166 [N/kg] at 3g emergency manoeuvre
The KLM made also use of the under belly “speed pack” cargo container
calculation : *6* (angles of attack)
angle of attack zero lift : -1.80 ["]
max. angle of attack (stalling angle, clean) : 12.97 ["]
max. angle of attack (full flaps) : 12.08 ["]
angle of attack at max. speed : 0.43 ["]
calculation : *7* (lift & drag ratios
lift coefficient at angle of attack 0° : 0.16 [ ]
lift coefficient at max. speed : 0.20 [ ]
lift coefficient at max. angle of attack : 1.31 [ ]
max.lift coefficient full flaps : 1.67 [ ]
induced drag coefficient at max.speed : 0.0018 [ ]
drag coefficient at max. speed : 0.0221 [ ]
drag coefficient (zero lift) : 0.0203 [ ]
calculation : *8* (speeds
stalling speed at sea-level (OW loaded : 45109 [kg]): 216 [km/u]
stalling speed at sea-level with full flaps (normal landing weight): 147 [km/u]
landing speed at sea-level (normal landing weight : 36037 [kg]): 169 [km/hr]
max. rate of climb speed : 219 [km/hr] at sea-level
max. endurance speed : 236 [km/u] min.fuel/hr : 712 [kg/hr] at height : 610 [m]
max. range speed : 414 [km/u] min. fuel consumption : 2.612 [kg/km] at cruise height :
6096 [m]
cruising speed : 497 [km/hr] at 6100 [m] (power:67 [%])
max. continuous speed* : 555.00 [km/hr] at 4260 [m] (power:100 [%])
climbing speed at sea-level (loaded) : 589 [m/min]
climbing speed at 1000 [m] with 1 engine out (PUF / MTOW) : 304 [m/min]
climbing speed at 1000 [m] with 2 engines out (2xPUF / MTOW) : 89 [m/min]
calculation : *9* (regarding various performances)
take-off speed : 262.4 [km/u]
emergency/TO power : 2500 [hp] at 2755 [rpm]
static prop wash : 157 [km/u]
high wheel pressure, can only take off from paved runways
take-off distance at sea-level concrete runway : 1113 [m]
take-off distance at sea-level over 15 [m] height : 1207 [m]
landing run : 357 [m]
lift/drag ratio : 16.50 [ ]
climb to 1000m with max payload : 2.56 [min]
climb to 2000m with max payload : 5.21 [min]
climb to 3000m with max payload : 7.97 [min]
climb to cruise height 6100 [m] with max payload : 29.96 [min]
practical ceiling (operational weight empty 29387 [kg] ) : 9800 [m]
practical ceiling fully loaded (mtow- 30 min.fuel:45710 [kg] ) : 7300 [m]
calculation *10* (action radius & endurance)
published range : 5890 [km] with 7 crew and 5544.6 [kg] useful load and 88.1 [%] fuel (no reserves)
range : 4832 [km] with 7 crew and 8100.0 [kg] useful load and 72.3 [%] fuel
range : 5970 [km] with 60.0 passengers with each 12.2 [kg] luggage and 89.3 [%] fuel
Available Seat Kilometres (ASK) : 358184 [paskm]
max range theoretically with additional fuel tanks total 27637.5 [litre] fuel : 7757 [km]
useful load with range 500km : 19051 [kg]
useful load with range 500km : 60 passengers
production (theor.max load): 9468 [tonkm/hour]
production (useful load): 4026 [tonkm/hour]
production (passengers): 29820 [paskm/hour]
combi aircraft mail/freight/passengers
oil and fuel consumption per tonkm : 0.13 [kg]
fuel cost per paskm : 0.042 [eur]
Engine start of the Constellation preserved at Lelystad aviodrome museum, the Netherlands
crew cost per paskm : 0.030 [eur]
economic hours : 18250 [hours] is less then design hours
time between engine failure : 3551 [hr]
can continue fly on 3 engines, low risk for emergency landing for PUF
writing off per paskm : 0.039 [eur]
insurance per paskm : 0.000 [eur]
maintenance cost per paskm : 0.168 [eur]
direct operating cost per paskm : 0.279 [eur]
direct operating cost per tonkm (max. load): 0.878 [eur]
direct operating cost per tonkm (normal useful load): 2.064 [eur]
Literature :
praktisch handboek vliegtuigen deel 5 page 46,47,48
Amerikaanse vliegtuigbouwers page 104 - 108
piston engined airliners page 54 - 58
Luchtvaart dec'86 page 347 - 355
Luchtvaart jan'87 page 24 – 31
Lockheed L-749 Constellation - Wikipedia
Lockheed Constellation - L.749 et L.1049 (aviatechno.net)
* max.continous speed : max.level speed maintainable for minimal 30 min.
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 22 January 2022 contact : info.aircraftinvestigation@gmail.com python 3.7.4