02 Cruise and Fuel Planning 747 400 v10

CRUISE and FUEL PLANNING 2 - 1

PMDG 747-400 AOM DO NOT DUPLICATE Revision – 26JUL05

CRUISE

TABLE OF CONTENTSSUBJECT PAGECRUISE FLIGHT ..................................................................................................3

Overview .................................................................................................................................3

FUEL PLANNING SCHEMATIC 747-400 ............................................................5(STANDARD UNITS) ...............................................................................................................5

FUEL PLANNING SCHEMATIC 747-400 ............................................................6(METRIC UNITS).....................................................................................................................6

FUEL LOAD PLANNING......................................................................................7(Standard Units).......................................................................................................................7(Metric Units) ...........................................................................................................................8

FUEL REQUIRED TO REACH PLANNED ALTERNATE DESTINATION...........9Landing Weight at Alternate.....................................................................................................9

CONTINGENCY FUEL .........................................................................................9MAXIMUM & OPTIMUM CRUISE ALTITUDES ...................................................9

Optimum Wt.............................................................................................................................9

FOUR ENGINE MACH .86 CRUISE...................................................................10(Standard Units).....................................................................................................................10(Metric) ..................................................................................................................................11

FUEL PLANNING METHODOLOGY .................................................................12Overview ...............................................................................................................................12Determine Trip Length ...........................................................................................................12Estimate Fuel Required..........................................................................................................12Refining Fuel Calculations .....................................................................................................13

Step 1: Minimum Landing Fuel ...........................................................................................13Step 2: Alternate Fuel.........................................................................................................13Step 3: Contingency Fuel ...................................................................................................13Step 4: Flight Plan Fuel ......................................................................................................14Step 5: Takeoff Weight .......................................................................................................15Step 6: Determine Initial Cruise Altitude..............................................................................15

FMC Fuel Management .........................................................................................................16

2 - 2 CRUISE and FUEL PLANNING

Revision – 26JUL05 DO NOT DUPLICATE PMDG 747-400 AOM

THIS PAGE INTENTIONALLY BLANK



CRUISE FLIGHT

Overview: Correct planning for cruise flightis extremely important for the safe andtimely operation of any aircraft. Thisbecomes particularly true when operatingthe 747-400. The tremendous range andendurance capabilities of the aircraft allowfor transition through many different flightenvironments during a single operation andit is not uncommon for flight planning tooccur fifteen to twenty hours prior toscheduled arrival at a destination airport.The time involved in long range flying mayallow for significant changes in weather orATC conditions during the course of a flight,so to ensure safe and consistent results, it isimportant that crews thoroughly understandthe inter-relation of the variables involved incruise flight planning.

The three variables most directly affectingthe aircraft’s cruise flight performance are:Planned Landing Weight, Cruise Altitudeand Cruise Speed. Increasing or decreasingany one of these variables may have asignificant impact on fuel consumption andrange capability of the aircraft. Properdetermination of aircraft load weightscombined with well thought out selection offlight level and Mach cruise speeds areintegral to accurate performance planning.

Definitions: Following are a number ofdefinitions used in flight planning.

Destination: The airport of intendedlanding for the flight.

Alternate: The airport which has beenselected by the crew as an alternate landingairport in case the Destination airport isunusable due to weather conditions, ATC orother factors.

Basic Operating Weight: The weight of theaircraft minus any passengers, baggage,cargo or usable fuel. This weight figureincludes items such as the weight of theaircraft structure, hydraulic fluid, airconditioning fluids, residual fuel, residual oil,crew, crew luggage, potable water,passenger accommodation fluids, and

normal passenger service equipmentnormally carried on board.

Payload: Weight of all passengers, bags orcargo to be carried aboard the aircraft duringflight

Zero Fuel Weight: The weight of the un-fueled aircraft after all passengers, bags andcargo have been loaded. (BOW + Payload= ZFW) This number yields the weight ofthe aircraft prior to any useable fuel beingloaded.

Maximum Zero Fuel Weight: This is theheaviest weight allowed for the airplanebefore adding fuel weight. MZFW for thisairplane as modeled is: 535,000lbs.

Minimum Landing Fuel: This is theabsolute minimum amount of fuel that willremain on the aircraft at the time theairplane lands. Specifically, this numberrepresents the weight of usable fuel stillremaining on board the aircraft in the worstcase scenario. (E.g. the crew is forced tohold enroute, flies an approach to thedestination followed by a missed approach,more holding, diverts to the alternate airportand lands.) The Minimum Landing Fuel forthe 747-400 is normally 24,000lbs. If for anyreason you expect to land with less than thisamount of fuel, it should be considered anemergency condition.

Alternate Fuel: The amount of fuel requiredto the aircraft from the Destination after amissed approach to the alternate airport.

Contingency Fuel: Fuel boarded to allowfor airborne holding, off optimum altitudeflying, off optimum speed flying, or changesin the route of flight that might increase thefuel burn enroute.

Flight Plan Fuel: This figure represents thefuel load which is required to fly the aircraftform the airport of origin to the airport ofdestination. This figure should be correctedfor winds along the route (see later in thischapter) but does not account for holding,missed approaches or other inefficiencies.



Planned Landing Weight: This figurerepresents the weight of the aircraft upontouchdown at the destination airport.(Theoretically, this is the weight of theairplane in a perfect scenario, where thecrew lands at the destination immediatelywithout holding, missed approaches, etc.Thus it represents the highest potentialweight of the aircraft upon landing.)

This weight figure is a critical limitation thatshould be carefully examined to ensure thatit does not exceed 630,000lbs.

This weight is determined by adding:

Minimum Landing Fuel+ Alternate Fuel Contingency Fuel Zero Fuel Weight ============= Planned Landing Weight

This figure is one of the most importantfigures in your flight plan, as it will be usedto determine nearly all other aspects of yourcruise altitude, range and fuel load. (Seeexamples later in the chapter!)

Cruise Speed: The Mach speed selectedfor use during cruise. Mach cruise speedsetting can have a significant impact on thefuel flow encountered during flight. Mach.80 is generally used for Long Range Cruiseflight, while Mach .86 is considered a HighSpeed Cruise. Fuel increases dramaticallywith an increase in mach speed.

Maximum Gross Taxi Weight: Themaximum weight at which the aircraft maybe dispatched for taxi. This is a structurallimit weight which is determined by themanufacturer to prevent over-stressingstructural members within the aircraft. Thisairplane is modeled with an 877,000lbMGTW.

Maximum Gross Takeoff Weight: Thisfigure denotes the maximum weight at whichthe aircraft may be allowed to commencethe takeoff roll. This figure is a structurallimit weight designed to prevent over-stressing of structural members within theaircraft. This airplane is modeled with an875,000lb MTOW.

Maximum Gross Landing Weight: Thisfigure denotes the maximum weight at whichthe aircraft may be allowed to land. Thisfigure is a structural limit weight designed toprevent over-stressing of structuralmembers within the aircraft. This airplane ismodeled with a 630,000lb MGLW.

Maximum Planned Takeoff Weight: UnlikeMax Gross Takeoff Weight, this figure is avariable figure and changes with each flight.This weight limit can be caused byinsufficient runway length at the departureairport, for example but most commonly isexperienced on short flights when theairplane is carrying a large payload over ashorter range.

For example, we know that the MGLW forthe airplane can never be more than630,000lbs. We also know that themaximum weight of the airplane before anyfuel is loaded must not exceed 535,000lbs.

If we are planning a flight with the MZFW at535,000lbs, we must take care to ensurethat we will land with 95,000lbs of fuel, orless. (535,000lbs + 95,000lbs = 630,000lbs)

More information on how to determineMaximum Allowable Takeoff Weight isprovided later in this chapter.

Maximum Planned Landing Weight: Thisfigure is a variable figure specific to eachflight. This weight could be a limit factorcaused by insufficient runway length at thedestination airport, or high density altitude atthe destination airport.

Weight Restrictions: During flight planning,it is important that the aircraft weight ismaintained within the parameters ofMaximum Gross Landing Weight,Maximum Gross Takeoff Weight, andMaximum Taxi Weight. As the fuelplanning schematic is being filled in, crewsshould verify weight compliance. If amaximum structural weight or maximumoperational weight is exceeded, the crewshould either consider reducing aircraftweight by removal of passengers or cargo.If passengers or cargo cannot be removed,a reduced fuel load should be boarded, withplans made for an en-route fuel stop.



Fuel Planning Schematic 747-400(STANDARD UNITS)

Basic Operating Empty Weight: __394,000lbs__

Payload: ____________

Zero Fuel Weight: ____________(Must be less than 535,000)

Zero Fuel Weight: ____________ + Minimum Landing Fuel: ____________ + Alternate Fuel: ____________

+ Contingency Fuel: ____________

Planned Landing Weight: ____________(Must be less than 630,000)

Planned Landing Weight: ____________ + Flight Plan Fuel: ____________

Planned Gross Takeoff Weight: ____________(Must be less than 875,000)

Planned Gross Takeoff Weight: ____________ + Taxi Fuel Burn Off: ____________

Planned Taxi-Out Weight: ____________(Must be less than 877,000)

Schematic should be used to ensure compliance with structural weight limits.

Crews should verify that planned takeoff and planned landing weights are not limited by reducedrunway lengths or high density altitudes.



Fuel Planning Schematic 747-400(METRIC UNITS)

Basic Operating Empty Weight: __179,090kgs__

Payload: ____________

Zero Fuel Weight: ____________(Must be less than 242,671kg)

Zero Fuel Weight: ____________ + Minimum Landing Fuel: ____________ + Alternate Fuel: ____________

+ Contingency Fuel: ____________

Planned Landing Weight: ____________(Must be less than 285,763kg)

Planned Landing Weight: ____________+ Flight Plan Fuel: ____________

Planned Gross Takeoff Weight: ____________(Must be less than 397,727kg)

Planned Gross Takeoff Weight: ____________+ Taxi Fuel Burn Off: ____________

Planned Taxi-Out Weight: ____________(Must be less than 398,636kg)

Schematic should be used to ensure compliance with structural weight limits.

Crews should verify that planned takeoff and planned landing weights are not limited by reducedrunway lengths or high density altitudes.



FUEL LOAD PLANNING(Standard Units)

DISTANCE: When Trip Length in Nautical Air Miles falls between levels on mileage scale,interpolate time and fuel required for trip. Example: 5400 NAM @ FL410 equals11:15 and 230,000.

Table is based on following speed schedule:

CLIMB: 250 KIAS to 10,000 feet; 300 KIAS to FL310; Mach .80 above FL310CRUISE: M.86 at Optimum Altitude for aircraft weight (or step climb procedure)DESCENT: Mach .80 to FL340; 300 KIAS between FL340 and 10,000;

250KIAS below 10,000ft

WEIGHT: Table is valid only for a planned landing weight of 475,000lbs.For every 10,000lbs deviation above (below) 475,000 lbs, add (subtract) fuelburnout correction shown in “Adjust:” row on bottom of table.

Example: For 4800 NAM @ FL410 and 505,000lbs planned landing weight, fuelrequired would equal 198,000lbs + [(700lbs/hr x 3) x 10:00hrs] = 198,000lbs +21,000lbs = 219,000lbs total fuel required.

Table Represents M.86 Cruise at Optimum Altitude (or use of Step Climb Procedures)

Pressure Altitude (Feet) / True Airspeed (Knots)FL410 / 479 FL390 / 479 FL370 / 479 FL350 / 481 FL330 / 486 FL310 / 488

TripLengthNAM Flight Time (Hours:Minutes) and Fuel Burn (Pounds x 1000)

88008400 17:31 380.0 17:31 381.0 17:28 380.1 17:22 378.8 17:20 386.08000 16:43 356.0 16:42 357.0 16:39 356.2 16:33 355.2 16:30 362.0 16:23 381.07600 15:54 338.0 15:54 338.9 15:51 338.3 15:46 336.9 15:42 344.0 15:35 353.07200 15:02 316.0 15:00 317.0 14:47 315.6 14:42 315.4 14:38 321.0 14:31 331.06800 14:12 298.0 14:12 298.6 14:09 298.2 14:05 297.4 14:01 303.0 13:54 313.06400 13:22 275.0 13:21 275.8 13:18 275.2 13:13 274.6 13:09 280.0 13:03 390.26000 12:31 258.0 12:31 258.8 12:28 258.3 12:23 257.5 12:19 260.7 12:13 270.95600 11:43 238.0 11:42 237.6 11:39 237.0 11:35 239.2 11:31 244.0 11:25 254.05200 10:48 222.0 10:48 221.2 10:45 222.2 10:41 224.0 10:37 230.0 10:32 240.04800 10:00 198.0 9:58 197.4 9:55 198.2 9:51 200.0 9:47 206.0 9:42 215.04400 9:12 186.0 9:12 185.6 9:09 186.2 9:06 188.0 9:03 200.0 8:57 210.64000 8:21 169.0 8:21 169.4 8:18 169.2 8:15 171.8 8:13 176.4 8:08 184.43600 7:30 152.0 7:30 152.6 7:28 152.2 7:25 155.0 7:23 170.4 7:20 167.43200 6:43 136.0 6:43 136.6 6:42 136.2 6:40 139.0 6:38 169.8 6:35 176.42800 5:48 121.0 5:48 121.2 5:46 121.4 5:44 124.0 5:42 128.4 5:39 134.22400 5:00 103.0 5:00 102.8 4:59 103.2 4:57 105.6 4:56 108.4 4:53 113.42000 4:13 88.0 4:13 87.6 4:12 88.4 4:10 90.4 4:08 93.6 4:05 97.71400 3:21 73.0 3:21 72.6 3:19 73.2 3:18 75.0 3:18 77.6 3:15 80.81000 2:30 62.0 2:30 62.6 2:29 63.2 2:28 64.6 2:26 66.4 2:22 69.0800 1:41 46.5 1:41 47.2 1:39 48.0 1:39 48.8 1:37 50.0 1:34 51.6400 1:06 34.0 1:06 34.4 1:05 35.2 1:05 35.6 1:04 36.0 1:00 36.8Adjust: 700lbs/hr 880lbs/hr 1000lbs/hr 860lbs/hr 680lbs/hr 320lbs/hr



FUEL LOAD PLANNING(Metric Units)

DISTANCE: When Trip Length in Nautical Air Miles falls between levels on mileage scale,interpolate time and fuel required for trip. Example: 5400 NAM @ FL410 equals11:15 and 104,100kgs fuel.

Table is based on following speed schedule:

CLIMB: 250 KIAS to 10,000 feet; 300 KIAS to FL310; Mach .80 above FL310CRUISE: M.86 at Optimum Altitude for aircraft weight (or step climb procedure)DESCENT: Mach .80 to FL340; 300 KIAS between FL340 and 10,000;

250KIAS below 10,000ft

WEIGHT: Table is valid only for a planned landing weight of 216,000Kgs.For every 4,500Kgs deviation above (below) 216,000 Kgs, add (subtract) fuelburnout correction shown in “Adjust:” row on bottom of table.

Example: For 4800 NAM @ FL410 and 230,400kgs planned landing weight, fuelrequired would equal 89,800kgs + [(317Kg/hr x 3) x 10:00hrs] = 89,800kgs +9,510kgs = 99,310kgs total fuel required.

Table Represents M.86 Cruise at Optimum Altitude (or use of Step Climb Procedures)

Pressure Altitude (Feet) / True Airspeed (Knots)FL410 / 479 FL390 / 479 FL370 / 479 FL350 / 481 FL330 / 486 FL310 / 488

TripLengthNAM Flight Time (Hours:Minutes) and Fuel Burn (Kgs x 1000)

88008400 17:31 172.4 17:31 172.8 17:28 172.4 17:22 171.8 17:20 175.18000 16:43 161.5 16:42 161.9 16:39 161.6 16:33 161.1 16:30 164.2 16:23 172.87600 15:54 153.3 15:54 153.7 15:51 153.4 15:46 152.8 15:42 156.0 15:35 160.17200 15:02 143.3 15:00 143.8 14:47 143.2 14:42 143.1 14:38 145.6 14:31 150.16800 14:12 135.2 14:12 135.4 14:09 135.3 14:05 134.9 14:01 137.4 13:54 142.06400 13:22 124.7 13:21 125.1 13:18 124.8 13:13 124.6 13:09 127.0 13:03 177.06000 12:31 117.0 12:31 117.4 12:28 117.2 12:23 116.8 12:19 118.3 12:13 122.95600 11:43 108.0 11:42 107.8 11:39 107.5 11:35 108.5 11:31 110.7 11:25 115.25200 10:48 100.1 10:48 100.3 10:45 100.8 10:41 101.6 10:37 104.3 10:32 108.94800 10:00 89.8 9:58 89.5 9:55 89.9 9:51 90.7 9:47 93.4 9:42 97.54400 9:12 84.4 9:12 84.2 9:09 84.5 9:06 85.3 9:03 90.7 8:57 95.54000 8:21 76.7 8:21 76.8 8:18 76.8 8:15 99.4 8:13 80.0 8:08 83.63600 7:30 69.0 7:30 69.2 7:28 69.0 7:25 70.3 7:23 77.3 7:20 75.93200 6:43 61.7 6:43 62.0 6:42 61.8 6:40 63.1 6:38 77.0 6:35 80.02800 5:48 54.9 5:48 55.0 5:46 55.1 5:44 56.3 5:42 58.2 5:39 60.92400 5:00 46.7 5:00 46.6 4:59 46.8 4:57 47.9 4:56 49.2 4:53 51.42000 4:13 39.9 4:13 39.7 4:12 40.1 4:10 41.0 4:08 42.5 4:05 44.31400 3:21 33.1 3:21 32.9 3:19 33.2 3:18 34.0 3:18 35.2 3:15 36.71000 2:30 28.1 2:30 28.4 2:29 28.7 2:28 29.3 2:26 30.1 2:22 31.3800 1:41 21.1 1:41 21.4 1:39 21.8 1:39 22.2 1:37 22.7 1:34 23.4400 1:06 15.4 1:06 15.6 1:05 16.0 1:05 16.2 1:04 16.3 1:00 16.7Adjust: 317kg/hr 400kg/hr 454kg/hr 390kg/hr 308kg/hr 145kg/hr



Fuel Required to Reach Planned Alternate Destination

Landing Weight at Alternate x 1000lbsNAM to

AlternateTime to

Alternate430 lb to 475 lb[195kg to 215kg]

476 lb to 540 lb[216kg to 245kg]

541 lb to 630 lb[246kg to 285 kg]

100 0:30 6600lb [3000kg] 7200lb [3,300kg] 8000lb [3600kg]200 0:41 11000lb [5000kg] 11600lb [5250kg] 13200lb [6000kg]300 0:57 14000lb [6400kg] 15700lb [7100kg] 17200lb [7800kg]400 1:10 17700lb [8000kg] 19800lb [9000kg] 21400lb [9700kg]500 1:20 21000lb [9500kg] 22500lb [10200kg] 25400lb [11500kg]

• Based on Optimum Cruise Altitude Selection• Table assumes an assured landing at planned alternate with only one approach flown.

Contingency Fuel

Contingency Fuel: In cases where the flight crew or dispatcher feels that they may encounterairborne holding while en-route, or may be required to fly at other than optimal speeds oraltitudes, it may be beneficial to add contingency fuel to the desired fuel load. The amount of fuelboarded should reflect expectations in terms of total time to be spent in airborne holding bothwhile en-route and during the approach phase of flight, and the amount of excess fuel burn thatmay be required by ATC forcing the aircraft off optimum altitudes and speeds..

Maximum & Optimum Cruise Altitudes

Altitude Optimum Wt Maximum Wt.Time to

BurnFuel Wt.

FL420 470,000lbs [213,000kg] 520,000lbs [238,000kg] -FL410 500,000lbs [227,500kg] 550,000lbs [250,000kg] 1:42FL400 520,000lbs [238,000kg] 570,000lbs [247,500kg] 1:07FL390 550,000lbs [250,000kg] 600,000lbs [272,500kg] 1:35FL380 570,000lbs [247,500kg] 630,000lbs [285,000kg] 1:02FL370 600,000lbs [272,500kg] 670,000lbs [305,000kg] 1:22FL360 630,000lbs [285,000kg] 700,000lbs [315,000kg] 1:24FL350 670,000lbs [305,000kg] 740,000lbs [335,000kg] 1:36FL340 700,000lbs [315,000kg] 770,000lbs [350,000kg] 1:14FL330 740,000lbs [335,000kg] 810,000lbs [367,500kg] 1:27FL320 770,000lbs [350,000kg] 840,000lbs [385,000kg] 1:05FL310 810,000lbs [367,500kg] 870,000lbs [395,000kg] 1:26FL300 840,000lbs [385,000kg] - 1:00

For purposes of flight planning, crews should plan to follow ICAO step climb procedures in orderto most closely mimic a constant optimum altitude climb profile. This will provide for the mostefficient fuel burn possible while working within the constraints of the ATC system.

Time to Burn Fuel Wt Explained: The Time to Burn Fuel Weight column provides an estimateof how long it will take to burn into the next highest optimum flight level, given performanceaccording to the Four Engine Mach .86 Cruise table. This information will allow crews to plan thetime to be spent at each altitude, but can also be used to help estimate the highest altitude thatcan be reached during cruise flight of a known time duration. [Example: Takeoff at 770,000lbs fora six hour flight will yield an initial cruise altitude of FL320. After six hours of cruise flight, theoptimum cruise altitude would be FL360.]



FOUR ENGINE MACH .86 CRUISE(Standard Units)

Gross Weight (x1000lbs)FLTAT

IASTAS 880.0 840.0 800.0 760.0 720.0 680.0 640.0 600.0 560.0 520.0 480.0 440.0

420-26

230475

98.022.0

91.716.8

89.815.2

410-26

235475

94.018.4

91.716.8

89.515.2

400-26

240475

N1%Fuel/Hr x 1000lbs

95.022.0

91.318.0

90.017.2

87.014.8

390-26

246475

93.720.0

92.619.2

91.418.4

89.716.8

87.214.8

380-26

252475

98.827.2

93.322.0

90.119.2

89.318.0

87.917.2

86.416.0

370-26

258475

97.526.0

93.422.0

90.118.8

89.318.0

87.917.2

86.516.0

360-26

264475

97.228.4

91.522.0

90.020.0

88.719.2

88.018.8

86.717.6

86.316.4

350-23

276476

98.529.2

95.226.0

91.522.0

90.020.4

88.718.8

88.218.8

86.717.6

85.316.4

340-21

289480

97.830.8

93.024.8

91.623.6

90.322.0

89.120.8

87.919.6

87.319.2

86.618.4

85.518.0

330-19

296482

99.032.0

95.728.0

94.927.2

90.922.4

89.621.2

88.920.8

87.920.0

87.319.2

86.618.8

85.518.0

320-17

302484

99.437.2

94.428.8

93.627.6

91.725.2

90.624.0

89.422.4

88.121.2

87.220.8

86.620.0

86.019.6

86.020.0

310-14

309486

99.5*33.6

96.7*31.6

93.626.8

92.326.0

91.725.2

90.623.6

89.421.6

88.321.6

87.220.8

86.620.4

86.020.0

85.319.2

300-12

316489

95.9*32.4

93.429.6

92.427.6

91.325.6

90.825.6

89.724.4

88.722.8

87.622.4

87.422.4

86.421.6

85.820.8

85.320.8

Shaded Area represents approximate Optimum Altitude Profile.

Adjustments:

TAS in knots is for standard TAT: Add (subtract) 1 knot/degree C above (below)standard.



FOUR ENGINE MACH .86 CRUISE (Metric)

Gross Weight (x1000lbs)FLTAT

IASTAS 880.0 840.0 800.0 760.0 720.0 680.0 640.0 600.0 560.0 520.0 480.0 440.0

420-26

230475

98.010.0

91.77.6

89.86.9

410-26

235475

94.08.4

91.77.6

89.56.9

400-26

240475

N1%Fuel/Hr x 1000Kgs

95.010.0

91.38.2

90.07.8

87.06.7

390-26

246475

93.710.0

92.68.7

91.48.4

89.77.6

87.26.7

380-26

252475

98.812.3

93.310.0

90.18.7

89.38.2

87.97.8

86.46.7

370-26

258475

97.511.8

93.410.0

90.18.5

89.38.2

87.97.8

86.57.3

360-26

264475

97.212.9

91.510.0

90.09.1

88.78.7

88.08.5

86.78.0

86.37.4

350-23

276476

98.513.2

95.211.8

91.510.0

90.09.3

88.78.5

88.28.5

86.78.0

85.37.4

340-21

289480

97.814.0

93.011.3

91.610.7

90.310.0

89.19.4

87.98.7

87.38.7

86.68.4

85.58.2

330-19

296482

99.014.5

95.712.7

94.912.3

90.910.2

89.69.6

88.99.4

87.99.1

87.38.7

86.68.5

85.58.2

320-17

302484

99.416.9

94.413.1

93.612.5

91.711.4

90.610.9

89.410.2

88.19.6

87.29.4

86.69.1

86.08.9

86.09.1

310-14

309486

99.5*15.2

96.7*14.3

93.612.2

92.311.8

91.711.4

90.610.7

89.49.8

88.39.8

87.29.4

86.69.3

86.09.1

85.38.7

300-12

316489

95.9*14.7

93.413.4

92.412.5

91.311.6

90.811.6

89.711.1

88.710.3

87.610.2

87.410.2

86.49.8

85.89.4

85.39.4

Shaded Area represents approximate Optimum Altitude Profile.

Adjustments:

TAS in knots is for standard TAT: Add (subtract) 1 knot/degree C above (below)standard.



FUEL PLANNING METHODOLOGY

Overview: Accurate fuel planning is not adifficult process, but does require someunderstanding of the charts and termsdescribed earlier in this chapter.

This section of the chapter will walk youthrough a typical fuel planning exercise tohelp you understand how the process works,and what factors should be considered.

Follow each of the steps below in order, andrefer to the definitions at the beginning ofthis chapter if you need a refresher!

For the purpose of this exercise, a flight isbeing planned using the following conditionsand parameters:

Origin: KSFODestination: KIADAlternate: KJFK

BOW: 394,000lbsPayload: 106,000lbsZero Fuel Wt. 500,000lbs

Determine Trip Length: To determine thelength of our flight, we must make stepsbeyond simply measuring the distance overthe ground. The air through which we will flyis moving, after all, so we must adjust ourplanning to account for the effects of thiswind on our flight.

The first step in planning an accurate fuelload is to determine the geographic distancewhich will be traveled during flight.

The approximate distance between SanFrancisco and Washington DC is 2,400nm.

This geographic distance must then beadjusted in order to account for the effects ofwind along the route of flight. The prevailingwinds along this route tend to be from thewest, which results in a nearly continualtailwind along the route. For the purpose ofthis exercise, we will assume that the tailwind component is 75knots along the entireroute of flight.

Determining the effect of these winds is atwo step process:

Step One: Use the Fuel Planning table(page 2-7) and find 2,400nm on the TripLength column. Moving horizontally to theright, determine the approximate time it willtake to fly the route. In this case, a 2,400NM trip will take approximately 5:00 hours.(You can approximate the time by looking atyour desired altitude, or by averaging all thetime figures in your row.)

Step Two: Multiply the wind component bythe estimated time-in-flight. We havealready assumed that the wind along thisroute is 75knots from behind the airplane.Thus, to determine it’s effect, we multiply:

Time Enroute x Wind Component 5:00hrs -75knots

(Note: Headwinds are positive numbers,tailwinds are negative numbers..)

Thus: (5:00 hours x -75kts) = -375.

By adding this result to the total flightdistance, we receive the total Nautical AirMiles to be flown. (2,400nm + -375) =2,025 NAM.

Nautical Air Miles are miles flown the airmass. Since the air itself is moving in thesame direction as our flight, we will fly fewermiles through this air mass than if we werein still air, or headed into the wind. Theeffect of wind on Nautical Air Miles to beflow is simple to remember: Headwindsmake the number larger, Tailwinds make thenumber smaller.

Estimate Fuel Required: Once again usingthe Trip Length in NAM column, enter theFuel Planning table being careful to selectthe correct flight length in NAM, as well asthe planned cruising altitude. In thisexample, we will select FL390 with a NAMtrip distance of 2,000 NAM. This yields atime/fuel estimate of 4:13 minutes in flightand 87,600lbs of fuel on board to complete



the flight. It is important for crews tounderstand that this is an estimate of fuelrequired, and that the Fuel PlanningSchematic Charts provided earlier in thischapter should be used to plan the actualfuel load.

Refining Fuel Calculations: Now that agood fuel load estimate has been calculated,it is time to refine the fuel load to account forall possible stages of the flight.

The most effective way to plan any fuel loadis to start at the end of any possible fuelscenario, and work backward to thebeginning of the flight.

For example, we will assume that in thisinstance, the weather at KIAD is marginaland we have selected KJFK as an alternateairport for the trip.

Step 1: Minimum Landing Fuel: Workingthe flight backward, we know that we want toland with at least Minimum Landing Fuel.For the 747-400, this is commonly acceptedto be 24,000lbs on international flights and19,000lbs on domestic or short haul flights.

KSFO-KIAD is a short trip for a 747-400,and the East Coast of the United States hasplenty of suitable airports for a 747, so wewill elect to use 19,000lbs as the MinimumLanding Fuel for our flight.

Note for Advanced Users: If your flightrequires a second alternate due to alternateminimums or dispatches under Exemption3585, you should work backward from thesecond alternate airport!

Step 2: Alternate Fuel: Currently we need19,000lbs of fuel on the aircraft at the time oflanding, so to this figure we are going to addthe amount of fuel it will take us to fly fromKIAD – KJFK, our alternate airport.

Refer to the Fuel Required to ReachPlanned Alternate Destination table (page2-9).

This table requires two pieces ofinformation:

1) How far is it from Destination toAlternate? (200nm between KIAD-KJFK)

2) What will the airplane weigh when ittouches down at JFK?

The distance between KIAD-KJFK is 200nm,approximately.

The weight of the airplane upon landing atJFK can be determined easily by adding our19,000lbs Minimum Landing Fuel to theZero Fuel Weight of the airplane for this trip:

In this instance, we assume that the airplanewill weigh 500,000lbs fully loaded withpassengers, bags and cargo, but withoutfuel on board.

As such, our landing weight at KJFK wouldbe:

ZFW + Min. Ldg Fuel500,000lbs 19,000lbs = 519,000lbs

With this information, enter the FuelRequired to Reach Planned AlternateDestination table using the distance to thealternate and the estimated landing weightof the aircraft at the Alternate Destination.

The table indicates that we need 11,600lbsof fuel to reach our alternate on this flight.

Thus, our total required fuel thus far is:

19,000lbs + 11,600lbs = 30,600lbs.

Step 3: Contingency Fuel: To determine ifwe need contingency fuel depends largelyupon weather conditions, known problems inthe Air Traffic Control System, and a general“feel” for the operation of the airplane thatcomes primarily through experience.

For example, if we were planning a flight toarrive at KIAD late in the evening, we arenot likely to be concerned about holding orlengthy vectors before landing. On the otherhand, KIAD tends to be a very busy airportat 4PM local time, so if we were planning toland at 4:15PM, we would carefully considerthe fact that we could expect lengthy vectorsfor landing, or, in the case of poor weather,holding enroute.



For the purpose of this planning exercise,we are assuming that the weather at KIAD ispoor enough to require the use of analternate airport in our flight planning, so wewill also assume that we are planning toland at 4:15PM during the peak of theafternoon arrivals.

As such, we will elect to add an extra :45 offuel to ensure we have enough fuel toaccount for possible holding, slow-downsand lengthy vectors to final approach.

A good rule of thumb for loadingcontingency fuel is to expect holding fuelburn at a rate of 18,000lbs / hour.

This being the case, we will elect to add :45minutes of fuel, or: 13,500lbs.

At this point, we have boarded all of the fuelrequired for any “unusual events” such asholding, diversion and landing at analternate airport.

Our fuel required thus far is:

19,000 + 11,600 + 13,500 = 44,100lbs.

Incidentally, if we depart KSFO and are ableto land at KIAD without holding or divertingto our alternate, we should have all44,000lbs of fuel still in the tanks uponlanding at KIAD.

If you are filling in the Fuel Planning Sheetfrom page 2-3, you will notice that:Zero Fuel Weight 500,000Minimum Landing Fuel 19,000Alternate Fuel 11,600Contingency Fuel 13,500 ======Planned Landing Weight 544,100

Step 4: Flight Plan Fuel: Now that wehave determined how much fuel we need tohandle all possible events at our destination,we need to add the amount of fuel requiredfor the flight itself.

To do this, we follow the “estimation”process outlined in the beginning of theexercise, but now we need to refine thecalculation to accurately reflect theconditions of the flight.

When we originally estimated the fuelrequired to fly KSFO – KIAD, we determinedthat 87,600lbs was required to complete theflight using FL390 as our final cruisingaltitude.

This estimation was made based on thetable on page 2.7, but it requires furtherrefinement in order to complete the fuel loadcalculation.

The notation at the top of the fuel planningtable indicates that the table is valid for aplanned landing weight of 475,000lbs. Inorder to compute your total required fuelload for the trip, you must note the“ADJUST” figure at the bottom of the tablebased upon your cruising altitude.

In our case, FL390 is the correct column,and this ADJUST figure is 880lbs of fuel /hour of flight time for each 10,000lbs above475,000lbs of landing weight.

In our case:

Planned Landing Weight: 544,100Table Description Weight 475,000

======Difference from Table: 69,100

To calculate our fuel adjustment, it is safe toround the number UP to 70,000lbs.

Thus, 70,000lbs / 10,000lbs = 7.

Our final fuel adjustment for the cruiseportion of flight is now calculated as:

7 x 880lbs = 6,160lbs (round this to 6200 lbsfor simplicity!)

Our Flight Plan fuel is now:

Original Estimation: 87,600Fuel Adjustment: 6,200 =====Flight Plan Fuel: 93,800



Our total cruise fuel requirement indicatesthat you must adjust the fuel load by readingtheAs such, our total fuel requirement fromtakeoff in KSFO is::

Minimum Landing Fuel 19,000Alternate Fuel 11,600+Contingency Fuel 13,500+Flight Plan Fuel 93,800+ ====== 137,900

Step 5: Takeoff Weight: Calculating thetakeoff weight is a simple matter, given theinformation we have already determined:

Zero Fuel Weight 500,000Minimum Landing Fuel 19,000Alternate Fuel 11,600Contingency Fuel 13,500 ======Planned Landing Weight 544,100Flight Plan Fuel 93,800+ ======Planned Takeoff Weight 637,900

Step 6: Determine Initial Cruise Altitude:The 747-400 is a large airplane with a broadrange of capabilities. When lightly loaded,the airplane can fly easily at altitudes up to41,000 feet. When heavily loaded, theairplane will begin the trip by leveling off at31,000 feet until some fuel weight isconsumed.

It is not difficult to determine the properinitial cruising altitude once the PlannedTakeoff Weight is known.

Use the Maximum and Optimum CruiseAltitudes table (page 2-9) to determine theinitial cruising altitude for the flight.

Using our Planned Takeoff Weight of637,900lbs, move down the OptimumAltitude column until finding 630,000lbs.(Rounding numbers when using this table issatisfactory.)

From the Altitude column, we can see thatour initial “Most Optimum” cruise altitude willbe 36,000feet.

We can now calculate how high we shouldclimb during the course of our flight to KIADin order to continue flying at the “MostOptimum” altitudes for the airplane’s weight.

To do this, observe the times written in thefar right column of the table. According tothese figures, it will take 1:24 to burnenough fuel for us to consider moving to ahigher altitude in order to maintain theoptimum altitude during flight.

Repeating this exercise a few times, weknow that our flight is supposed to takeapproximately 4:13, so we can continuemoving up this column as follows:

1:24 + 1:22 + 1:02 = 3:48.

In other words, 1:24 into our flight, weshould climb from FL360 to FL 370. Then,1:22 later, we should expect to climb to FL380, and 1:02 later expect a climb to FL390.

For this flight we would expect then, to climbinitially to FL360, then climb progressively toFL390 before commencing our descent intoKIAD.

We have one more factor to consider,however!

Eastbound flights are required to operate atodd altitudes, while westbound flights areoperated at even altitudes. Thus, FL360 isnot available to us when headed eastbound,so we must limit our climb to FL350 initially,until we have burned enough fuel to reachFL370. (1:24 into our flight!)

The process of finding an optimum altitudeis made far easier by the Step Climbcalculations within the FMC-CDU, and theseare explained in detail in the chapterdetailing use of the FMC.

The fuel burned during cruise flight can becalculated by simply subtracting the figuresin the Optimum Altitude column, or bymanually determining the fuel burn at eachaltitude through use of the Four EngineMach .86 Cruise table.

By simply adding the figures in the OptimumAltitude chart, it would appear thatapproximately 80,000lbs of fuel would be



burned for this example. This coincides veryclosely to the initial estimated figure of88,700lbs.

A second, slightly more complex method tocalculate the required fuel is to use the FourEngine Mach .86 Cruise table. By enteringthe table using the initial cruise altitude(FL350) and initial aircraft cruise weight(631,700lbs in this example) it can bedetermined that the aircraft will burn fuel at arate of approximately 21.6, or 21,600lbs /hour. (This figure is interpolated betweenthe 640,000lb and 600,000lb columns.)

This fuel burn figure can then be used todetermine how long it will take to burnenough fuel that it will be necessary for theaircraft to climb in order to reach the nexthighest optimum cruise altitude. In thisexample, this would be the differencebetween 631,700lbs at the initial cruisealtitude of FL350 and the 600,000lboptimum weight at FL370. (31,700lbs)

31,700lbs / 21,600lbs/hr = 1:28

Following the same process, the fuel to beburned prior to climbing to each successivehigher altitude can be determined.

This process can be followed through eachplanned step climb to ultimately yield thetotal fuel required for the flight.

It is important, however, to consider that it isnot always possible to simply climb to thenext highest cruise altitude while burningfuel. For example, if ATC restrictions willlimit initial cruising altitude to FL320, or ifATC climb restrictions will hold the flight to alower altitude than is considered optimal,fuel burn will be higher than predicted oneither the Fuel Planning Table orMaximum and Optimum Altitudes table.(This is why we boarded contingency fuel!Use it!)

It is important that crews plan their fuel loadsbased on the most reasonable expectationsfor the flight. If it is expected that the aircraftwill be held to a lower altitude, planning thefuel load appropriately will ensure theaircraft arrives with sufficient reserves at theplanned and/or alternate destinations.

In all cases, crews should continuallymonitor actual fuel burn against plannedfuel burn. On long-range segments overwater, or unpopulated areas, early detectionof inaccuracy in fuel planning is essential tosafety of flight.

FMC Fuel Management: Use of the FMC iscovered in detail later in this chapter, butwhile we are considering fuel planning hereis a trick you can use to keep you safe whileflying:

While entering flight data into the FMC,many crews may find it beneficial to enter aRESERVES figure into the INIT PERF pageof the FMC. This figure should generallyconsist of:

Minimum Landing Fuel + Alternate Fuel +between :30 and 1:00 of fuel.

In the case of our flight to KIAD, we wouldenter a value of:Minimum Landing Fuel: 19,000Alternate Fuel: 11,600½ Contingency Fuel: (22mins) 6,250 =====FMC RESERVES entry: 37,850

Once this number is entered into theRESERVES line of the FMC-CDU, theonboard fuel system monitoring willimmediately alert the crew if it appears thatthey will land with less than 37,850lbs onboard at the destination.

The alert will come in the form of anINSUFFICIENT FUEL warning in the FMC-CDU. This alert does not indicate that youhave insufficient fuel to reach yourdestination or alternate, it simply serves toremind you that at the time you land, you willhave less than half of your Contingency fuel,plus whatever fuel is required to reach youralternate.

In this circumstance, the crew should payclose attention to events unfolding on theapproach, as any unplanned delay ormissed approach will mean that they couldbe critically short of fuel upon landing at thealternate airport.

02 Cruise and Fuel Planning 747 400 v10

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Transcript of 02 Cruise and Fuel Planning 747 400 v10