Aircraft investigation >>>>>>> HOME PAGE
weight and performance calculations for the Yakolew Yak-42 CLOBBER
***** PRELIMINARY FILE ****
20 rows 6-abreast = 120 pax pax
Yakolew Yak-42 CLOBBER
role : mid-range jet airliner
importance : ****
first flight : 7 March 1975 operational : June 1977
country : Russia
NATO reporting name : CLOBBER
design :
production : 80 aircraft
general information :
First Russian jetliner with high by-pass turbofans
primary users : Aeroflot
Accommodation:
flight crew : 3 cabin crew : 3
flight crew consist of pilot, co-pilot and flight engineer
passengers : seating for 100 in two class : 16 business class and 84 economy class seats ( 32 -in pitch)
high density seating for 120 passengers
engine : 3 Lotarev D-36 turbofan engines of 63.2 [KN](14207.7 [lbf])
dimensions :
wingspan : 34.2 [m], length : 36.38 [m], height : 9.8 [m]
wing area : 150.0 [m^2]
weights :
operating empty weight : 28960 [kg] max. structural payload : 12500 [kg]
Zero Fuel weight (ZFW) : 41460 [kg] max. landing weight (MLW) : 0 [kg]
max.take-off weight : 52000 [kg] weight fuel : 18400 [kg] (23000 [liter])
performance :
Max. operating Mach number (Mmo) : 0.81 [Mach] (900 [km/hr]) at 7600 [m]
normal cruise speed : 820 [km/hr] (Mach 0.76 ) at 10000 [m] (24 [%] power)
service ceiling : 10700 [m]
range with max fuel : 4373 [km] and allowance for 476.5 [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: 23.0 [°]
engines attached to the tail, landing gear attached to the wings, fueltanks in the wings
construction : all-metal aluminium-alloy stressed-skin construction with pressurized
fuselage
fuselage shape : 0
calculation : *1* (dimensions)
measured wing chord : 4.39 [m] at 50% wingspan
mean wing chord : 4.39 [m]
calculated average wing chord tapered wing with rounded tips: 4.38 [m]
wing aspect ratio : 7.80 []
seize (span*length*height) : 12193 [m^3]
calculation : *2* (fuel consumption)
oil consumption : 94.8 [kg/hr]
fuel consumption (econ. cruise speed) : 3040.1 [kg/hr] (3800.1 [litre/hr]) at 24 [%] power
distance flown for 1 kg fuel : 0.27 [km/kg] at 10000 [m] height, sfc : 66.2 [kg/KN/h]
total fuel capacity : 23000 [litre] (18400 [kg])
calculation : *3* (weight)
weight engine(s) dry : 3327.0 [kg] = 17.55 [kg/KN]
weight 679.8 litre oil tank : 57.78 [kg]
oil tank filled with 1.2 litre oil : 1.1 [kg]
oil in engine 31.7 litre oil : 28.4 [kg]
fuel in engine 23.3 litre fuel : 17.06 [kg]
weight fuel lines 23.0 [kg]
weight engine cowling 568.8 [kg]
total weight propulsion system : 4023 [kg](7.7 [%])
***************************************************************
fuselage aluminium frame : 6987 [kg]
typical cabin layout for 100 passengers : economy : pitch : 81 [cm] ( 3+3 ) seating in 17.2 rows
pax density (normal seating) : 0.57 [m2/pax]
high density seating passengers : 114 at 6 -abreast seating in 19.0 rows, pitch 76 [cm]
weight 2 toilets : 33.5 [kg]
weight 5 hand fire extinguisher : 15 [kg]
weight 1 galleys : 74.7 [kg]
weight overhead stowage for hand luggage : 35.0 [kg]
weight 2 closets : 20.0 [kg]
weight 36 windows : 32.8 [kg]
weight 4 overwing emergency exits : 85.0 [kg]
weight lifejackets : 45.0 [kg]
weight oxygen masks & oxygen generators : 65.0 [kg]
weight tail entrance stairs : 95.0 [kg]
weight emergency flare installation : 10 [kg]
weight 2 emergency evacuation slides : 31.7 [kg]
weight 3 entrance/exit doors : 148.8 [kg]
weight 2 freight doors (belly) : 70.8 [kg]
cabin volume (usable), excluding flight deck : 154.48 [m3]
passenger cabin max.width : 3.45 [m] cabin length : 18.48 [m] cabin height : 2.15 [m]
floor area : 57.5 [m2]
pressure difference :0.47 [kg/cm2]
weight rear pressure bulkhead : 139.9 [kg]
weight air pressurization system : 34.3 [kg]
fuselage covering ( 246.6 [m2] duraluminium 2.52 [mm]) : 1634.7 [kg]
weight floor beams : 319.1 [kg]
weight cabin furbishing : 462.2 [kg]
weight cabin floor : 638.8 [kg]
fuselage (sound proof) isolation : 178.6 [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. : 37.0 [kg]
weight APU / engine starter: 31.6 [kg]
weight lighting : 25.0 [kg]
weight electricity generator : 25.0 [kg]
weight controls : 15.0 [kg]
weight seats : 530.0 [kg]
weight air conditioning : 90 [kg]
weight engine mounts : 95 [kg]
total weight fuselage : 11810 [kg](22.7 [%])
***************************************************************
total weight aluminium ribs (606 ribs) : 1854 [kg]
weight fuel tanks empty for total 23000 [litre] fuel : 1288 [kg]
weight wing covering (painted aluminium 2.45 [mm]) : 1982 [kg]
total weight aluminium spars (multi-cellular wing structure) : 2254 [kg]
weight wings : 6091 [kg]
weight wing/square meter : 40.60 [kg]
weight rubber de-icing boots : 37.6 [kg]
weight fin & rudder (13.6 [m2]) : 553.3 [kg]
weight stabilizer & elevator (16.9 [m2]): 686.3 [kg]
weight flight control hydraulic servo actuators: 36.9 [kg]
weight fowler flaps (10.2 [m2]) : 212.3 [kg]
total weight wing surfaces & bracing : 8905 [kg] (17.1 [%])
*******************************************************************
wheel pressure : 11440.0 [kg]
weight 4 Dunlop main wheels (1130 [mm] by 226 [mm]) : 781.3 [kg]
weight 2 Dunlop nose wheels : 195.3 [kg]
weight hydraulic wheel-brakes : 41.5 [kg]
weight pneumatic-hydraulic shock absorbers : 55.3 [kg]
weight wheel hydraulic operated retraction system : 567.6 [kg]
weight undercarriage struts with axle 1168.7 [kg]
total weight landing gear : 2809.7 [kg] (5.4 [%]
*******************************************************************
********************************************************************
calculated empty weight : 27548 [kg](53.0 [%])
weight oil for 6.4 hours flying : 606.7 [kg]
weight catering : 186.7 [kg]
weight water : 74.7 [kg]
weight crew : 486 [kg]
weight crew lugage,nav.chards,flight doc.,miscell.items : 58 [kg]
operational weight empty : 28960 [kg] (55.7 [%])
********************************************************************
weight 100 passengers : 7700 [kg]
weight luggage : 1600 [kg]
weight cargo : 3200 [kg]
zero fuel weight (ZFW): 41460 [kg](79.7 [%])
weight fuel for landing (1.0 hours flying) : 3040 [kg]
max. landing weight (MLW): 44500 [kg](85.6 [%])
max. fuel weight : 47360 [kg] (91.1 [%])
payload with max fuel : 50 passengers+luggage 4640 [kg]
published maximum take-off weight : 52000 [kg] (100.0 [%])
calculation : * 4 * (engine power)
power loading (Take-off) : 274 [kg/KN]
power loading (operational without useful load) : 254 [kg/kN]
power loading (Take-off) 1 PUF: 411 [kg/KN]
max. total take-off power : 189.6 [KN]
calculation : *5* (loads)
manoeuvre load : 8.1 [g] at 1000 [m]
limit load : 3.0 [g] ultimate load : 4.5 [g] load factor : 1.3 [g]
design flight time : 3.73 [hours]
design cycles : 6972 sorties, design hours : 26025 [hours]
operational wing loading : 3150 [N/m^2]
wing stress (3 g) during operation : 233 [N/kg] at 3g emergency manoeuvre
calculation : *6* (angles of attack)
angle of attack zero lift : -1.76 ["]
max. angle of attack (stalling angle, clean) : 11.72 ["]
angle of attack at max. speed : 0.39 ["]
calculation : *7* (lift & drag ratios
lift coefficient at angle of attack 0° : 0.15 [ ]
lift coefficient at max. speed : 0.18 [ ]
lift coefficient at max. angle of attack : 1.15 [ ]
Yak-42 UR-42334 operated by Aerosweet (leased from Lviv airlines) crashed 17 December 1997 in the Pieria mountains, 72km SW of Thessaloniki. Flight AEW241 from Odessa, Ukraine to Thessaloniki, Greece. All 62 passengers and 8 crew died in the crash. It was the first time the flight crew flew to Thessalonik airport. The airplane made several missed approaches to the airport. The crew was disoriented in the darkness, misty weather and low clouds. The aircraft had made its first flight in 1986 and had 12008 flying hours and 6836 cycles. It impacted the snow covered side of Pente Pirgi at 3300 ft height with a speed of 400 km/hr, heading 290°. Crash location : 40°13’33” N 22°15’03”E The wreckage was only found 3 days later on 20 december.
max. lift coefficient full flaps : 1.42 [ ]
induced drag coefficient at max.speed : 0.0018 [ ]
drag coefficient at max. speed : 0.0217 [ ]
drag coefficient (zero lift) : 0.0198 [ ]
lift/drag ratio at max. speed : 8.47 [ ]
calculation : *8* (speeds
stalling speed at sea-level (OW loaded : 48960 [kg]): 243 [km/u]
stalling speed at sea-level with full flaps (normal landing weight): 208 [km/u]
landing speed at sea-level (normal landing weight : 44369 [kg]): 239 [km/hr]
max. rate of climb speed : 677 [km/hr] at sea-level
max. endurance speed : 395 [km/u] min. fuel/hr : 1826 [kg/hr] at height : 4572 [m]
max. range speed : 661 [km/u] min. fuel consumption : 3.189 [kg/km] at cruise height :
8839 [m]
cruising speed : 820 [km/hr] at 10000 [m] (power:18 [%])
max. operational speed (Mmo) : 900.00 [km/hr] (Mach 0.81 ) at 7600 [m] (power:29.1 [%])
airflow : 393.6 [kg/s]
speed of thrust jet : 1240 [km/hr]
climbing speed at sea-level (loaded) : 2895 [m/min]
climbing speed at 1000 [m] with 1 engine out (PUF / MTOW) : 2703 [m/min]
calculation : *9* (regarding various performances)
take-off speed : 300.4 [km/u]
high wheel pressure, can only take off from paved runways
take-off distance at sea-level concrete runway : 894 [m]
take-off distance at sea-level over 15 [m] height : 952 [m]
landing run : 1132 [m]
landing run from 15 [m] : 1977 [m]
Remains in the snow – A passport and a photo of a passenger of the Ukrainian plane that has disappeared over Greece since Wednesday lie in the snow on one of the foothills of Mount Olympus. The plane crashed there, presumably because the pilot did not know exactly where he was during a second landing attempt. All seventy passengers were killed. During the search, an aircraft of the Greek Air Force crashed. All five occupants were killed. Reuters Photo.
lift/drag ratio : 15.22 [ ]
max. theoretical ceiling : 18400 [m] with flying weight :48960 [kg] line 3359
climb to 1000m with max payload : 0.36 [min]
climb to 2000m with max payload : 0.70 [min]
climb to 3000m with max payload : 1.02 [min]
climb to 5000 [m] with max payload : 1.60 [min]
minimum flying speed at 10700 [m] : 503 [km/hr]
theoretical ceiling fully loaded (mtow- 60 min. fuel:48960 [kg] ) : 18400 [m]
calculation *10* (action radius & endurance)
published range : 4373 [km] with 6 crew and 6827 [kg] useful load and 88.1 [%] fuel
range : 2843 [km] with 12500.0 [kg] max. useful load (57.3 [%] fuel)
range : 3706 [km] with 100.0 passengers with each 16 [kg] luggage and 74.7 [%] fuel
range max. fuel : 4963 [km] with 4640.0 [kg] useful load and 100.0 [%] fuel
Available Seat Kilometres (ASK) : 370607 [paskm]
max range theoretically with additional fuel tanks total 28800.0 [litre] fuel : 7226 [km]
useful load with range 500km : 21186 [kg]
useful load with range 500km : 100 passengers
production (theor.max load): 17373 [tonkm/hour]
production (useful load): 10250 [tonkm/hour]
production (passengers): 82000 [paskm/hour]
combi aircraft mail/freight/passengers
oil and fuel consumption per tonkm : 0.180 [kg]
fuel cost per paskm : 0.038 [eur]
crew cost per paskm : 0.009 [eur]
economic hours : 22300 [hours] is less then design hours
time between engine failure : 642 [hr]
writing off per paskm : 0.013 [eur]
insurance per paskm : 0.0007 [eur]
maintenance cost per paskm : 0.007 [eur]
direct operating cost per paskm : 0.067 [eur]
direct operating cost per tonkm (max. load): 0.318 [eur]
direct operating cost per tonkm (normal useful load): 0.539 [eur]
Literature :
Jane’s all the world aircraft 1979-1980 page 221
The observer’s book of aircraft page 220
Flugzeuge der Welt page136
Verkeersvliegtuigen page 78
The flier’s handbook page123
Air International jan’00 page 60
19971217-0_YK42_UR-42334.PDF (aviation-safety.net)
ASN Aircraft accident Yakovlev Yak-42 UR-42334 Thessaloniki (aviation-safety.net)
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