01 Jul 13KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-LEP A 01 JUL 13 INSERT LATEST CHANGED PAGES. DESTROY SUPERSEDED PAGES.

NOTE: A vertical line in the outer margin of the page indicates the portion of the text affected by the changes.

Dates of issue for original and changed pages are:

Original

. . . . 0

. . . . . 01 Mar 06 Change

. . . . 4

. . . . . 01 Jul 11 Change

. . . . 1

. . . . . 01 Nov 07 Change

. . . . 5

. . . . . 01 Jul 13 Change

. . . . 2

. . . . . 01 Jul 08 Change

. . . . 3

. . . . . 01 Apr 10

Page No. *Change No. Page No. *Change No. Page No. *Change No.

Title

. . . . . . . . . . . . . 5 A

. . . . . . . . . . . . . 5 i – ii

. . . . . . . . . . . . 0 1-1 – 1-2

. . . . . . . . . . . 5 2-1 – 2-2

. . . . . . . . . . . 0 3-1 – 3-18

. . . . . . . . . . 5 4-1 – 4-32

. . . . . . . . . . 5 5-1 – 5-12

. . . . . . . . . . 5

Summary of Action (s); 1. Biennial review completed.

* Zero in this column indicates no changes to the current revision. 

### LIST OF EFFECTIVE PAGESKC-10 Aircrew Training System Climb, Cruise, and Holding Data

Original
W836-TOC i 01 MAR 06 TABLE OF CONTENTS

1.0 INTRODUCT ION ............................................................................................... 1-1

2.0 OBJECT IVES .................................................................................................... 2-1

3.0 CLIMB PERFORMANCE COMPUTAT IONS ..................................................... 3-1

4.0 CRUISE PERFORM ANCE ................................................................................ 4-1

5.0 HOLDING PERFO RMANCE ............................................................................. 5-1KC-10 Aircrew Training System Climb, Cruise, and Holding Data

Original
W836-TOC ii 01 MAR 06 THIS PAGE INTENTIONALLY LEFT BLANKKC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-01 1-1 01 JUL 13 1.0 INTRODUCTION

This workbook covers the Climb, Crui se, and Holding computations you will perform as a KC-10 crewmember. It fa miliarizes you with the terminology, conditions, and procedures that are used to compute KC-10 Climb, Cruise, and Holding data.

Airspeed terminology can create confusion in the KC-10. It is possible to prevent most of this confusion by knowing t he required/desired speed. “How slow can I go?” The cruise buffet-onset boundary char ts of the performance manual provide information necessary to determine buffet-ons et limits in terms of load (G) factor, bank angle, Mach number, and pressure altitude. This is the minimum recommended speed for flight and is the 1.2- G speed. The 1.2-G speed, which is lower than the 550,000 FL 290 gross wei ght optimum cruise altitude maximum endurance speed, increases po wer and fuel requirement s and is therefore not recommended for use during normal cruise. It is important to know what airspeed is appropriate for a desired result. Bank Angle limited to 15 degrees anytime the aircraft speed is less than V MM for existing configuration.

Minimum Maneuvering Speeds. Minimum maneuver speeds for various flap/slat configurations and gross weight s are in the pilot’s and FE’s handheld checklists. These speeds are minimum speeds for maneuvering flight providing at least 25 degrees of bank protection and are primarily inte nded for use in the terminal environment. The charts in the handheld checklists and KC-10A Performance Data Computer (Slipsti ck) are valid up to 14,000 feet MSL. However, per the TO 1C-10(K)A-1, Flight Manual (USAF KC-10A Aircraft), these speeds will provide at leas t 25-degrees bank protection, provided the aircraft is not above the standard day cruise ceiling.

Contingency Maneuvering Speeds. During theater operations, compute cruise buffet-onset boundary speed (55-degree bank ) from the performance manual and turn sustainability. The 55-degree bank speed provides added stall margin during 45-degree bank turns, reducing the possibility of structural damage in the event of over banking during the Scram.

Cruise Speeds. Best range, long-range cruise, and maximum endurance speeds are cruise speeds. Use the “specific range charts” in the performance manual to compute cruise speeds. It is not necessa ry to make bank angle corrections to these speeds as long as bank angles are limited to 30 degrees or less.

Best Range. Best Range is the speed providing the highest nautical mile per pound of fuel (NM/LB) used fo r a given gross we ight and altitude. This speed is determined from where the gross weight curve line peaks on the “specific range chart.” This speed is rarely used.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-01 1-2 01 JUL 13 Long-Range Cruise Speed. Long-range cruise speed pr ovides a significant increase in speed over Best Range with only a 1 percent loss in nautical mile per pound (NM/LB) of fuel. The KC-10 perform ance manual labels this speed as the 99 percent maximum nautical mile per pound (99 percent max NM/LB) on the “three-engine specific range charts.” Wh en flying long range, the pilot should request and fly “long-range cruise.” This is the normal cruise speed for the KC10. The long-range cruise speed is a c onstant Mach number when using a step climb profile

Maximum Endurance Speed. Maximum endurance speed is the speed based upon achieving minimum fuel flow, thereby allowing the aircraft to stay airborne for the maximum amount of time. At low altitudes, this speed is slower than minimum maneuver speed. However, at higher altitudes, this speed may be higher than minimum maneuver. This speed may be helpful when needing to slow down to make an en route rendez vous or an airfield opening time. Remember to notify ATC if TAS changes by 5 percent or 10 knots (whichever is greater) from the filed TAS.

Holding Speeds. Holding speeds for 0 to 30 degrees of bank are minimum fuel flow speeds and are always above the 1.2-G buffet ons et speeds. They have been chosen to minimize fuel consumption while maintaining controllability and sufficient speed margin above the buffet or stall during banked flight up to 30 degrees.

1.1 INSTRUCTIONS

The information presented in this workbook is designed to enhance the information presented in the performanc e manual. When you finish this workbook, your instructor wil l check and grade your perf ormance and return it to you. You will use the instructions in th is workbook to accomplish the required performance data prior to the Si mulator Phase of training.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

Original
W836-02 2-1 01 MAR 06 2.0 OBJECTIVES

When you finish this workbook, you will be able to:

1. Compute Climb Performance Data.

2. Compute Cruise Performance Data.

3. Compute Holding Performance Data.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

Original
W836-02 2-2 01 MAR 06 THIS PAGE INTENTIONALLY LEFT BLANKKC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-03 3-1 01 JUL 13 3.0 CLIMB PERFORMANCE COMPUTATIONS

This segment defines the terminology a ssociated with KC-10 Cl imb Performance, Environmental/Aircraft Factors, and Speed and Altitude restrictions.

3.1 CLIMB PERFORMANCE

The climb charts provide information neces sary for planning the aircraft's climb performance. The charts are based on actual flight test results; however, the fuel consumption values have been increased 5%, relative to engine specification levels.

Figure 3-1.

First, look at what is not included in t he climb charts. The climb charts do not include the fuel, time, and distance requi red from brake release to 2000' AGL, including cleanup and acceleration to climb speed. To account for this we use a standard TAKEOFF ALLOWANCE (Fig. 3-1). The takeoff allowances are considered to be typical and constant for th ree or two engine operations. For this reason, they are not included in the c limb charts but will be considered when flight planning. The ta keoff allowances are:

Three Engines Operat ing: 2500 pounds of fuel 8 nautical miles 2.5 minutes

Two Engines Operating: 4000 pounds of fuel 16 nautical miles 5.5 minutesKC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-03 3-2 01 JUL 13 3.2 CLIMB SPEED SCHEDULE

During our climb in the KC-10, we will ma intain a specified c limb speed schedule. The airspeed, at which maximum rates of climb is obtained, varies with gross weight and altitude. Constantly changing airspeed is impractical for the limited benefits realized. The climb speed schedule approximates the speed for maximum rate of climb and results in the best overall climb performance. The climb charts are based on maintaining th e climb speed schedul e. However, due to the schedule being an approximate, a ± 10 knot variance in speed has a negligible effect on climb performance.

Figure 3-2. Three Engine Climb Speed Schedule.

The climb speed schedule is broken in tw o separate segments, below 10,000' and above 10,000'. Whether oper ating on three or two engines, below 10,000' you will maintain 250 KIAS or Minimum Maneuver Speed , whichever is higher (Fig. 3-2).

NOTE: Minimum Maneuver Speed will be requi red at gross weig hts greater than 435,000 lbs.

After passing through 10,000', when operat ing on three engines, the aircraft is accelerated to 330 KIAS and the climbout continued at this s peed until reaching the Mach Changeover Altitude of 27,402'. From this altitude the climb speed is a constant 0.82 Mach (Fig. 3-2). Fo r two engine operation the climb speed schedule above 10,000' is 300 KIAS to the Mach Changeov er Altitude of 27,993', then a constant 0.76 Mach. 250 KIAS OR V MM WHICHEVER IS GREATER 10,000 FT 330 KIAS 27,402 FT 0.82 MACHKC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-03 3-3 01 JUL 13 Figure 3-3. N 1 Setting for Max. Climb Thrust. 103.1%KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-03 3-4 01 JUL 13 3.3 N 1 SETTINGS

As mentioned earlier, the type of climb is dictated by the amount of thrust used. In the climb section of the performance manual, N 1 setting charts are provided for Max Continuous Thrust (MCT), Max Climb (MCL), and Max Cruise Thrust (MCR). While normally the thrust computer displays the selected N 1 setting and the Auto Throttles System will maintain the selected N 1 (in the N 1 mode), the charts are provided in the event of a thrust comput er failure or as a cross check for the thrust computer.

All three charts are constructed in the same general way and the same procedure is used to read all of them. As can be seen in Figure 3-3, the Total Air Temperature (TAT) is listed across the bo ttom of the chart in both Celsius and Fahrenheit. The pressure altitude lin es are individually labeled and any intermediate altitude requires interpolation. One item of interest is how the altitude lines reverse their upward trend at 36,089'; this is to maintain constant turbine temperatures above t he tropopause by lowering the N 1 RPM. Located in the lower right hand corner is the bleed air correction grid. Utilization of the correction grid is explained in the chart notes.

EXAMPLE: (Fig. 3-3)

Use the following values to compute Maximum Climb Thrust N 1 (MCL).

Total Air Temperature (TAT) = +10 ° C

Pressure altitude = 10,000'

The Maximum Climb Thrust N 1 is 103.1%. If a bleed air correction is required, enter the correction grid in the lower left hand corner with the pressure altitude, intersect the appr opriate correction line to obtain the correction value. The correction valu e is then applied to the original N 1 value i.e. 103.1 - 0.8 = 102.3% N 1 (Engine and Wing Anti-Ice on).KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-03 3-5 01 JUL 13 Figure 3-4. Three Engine Distance to Climb. NOTE:
1. CLEAN CONFIGURATION
2. MAXIMUM CLIMB THRUST 3. CLIMB AT SPEED SHOWN IN T.O. 1C-10(K)A-1-1, FIGURE 4-1, TO 10,000 FT THEN AT 330 KIAS TO 27,402 FT., THEN AT MACH = 0.82KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-03 3-6 01 JUL 13 3.4 FUEL, DISTANCE, AND TIME TO CLIMB

Fuel, Distance, and Time to climb char ts are provided for standard and two engine climbs. Figure 3-4 represents a Dis tance to Climb Chart. Fuel and Time charts are similar with the exception of the wind correction grid (fuel and time are not effected by wind). A look at chart construction reveals:

GROSS WEIGHT, across the bottom 2/3 of the chart, this is the normal entry point. The vertical guidelines that curv e to the left depict the normal fuel burn during the climb.

PRESSURE ALTITUDE LINES curving horiz ontally upwards from 250,000 lbs., represent pressure altitude in thousands of feet. Note the two 10,000' lines; they represent the distance, time, and fuel requ ired to accelerate from the climb speed below 10,000' to the climb speed above 10,000'. If a clim b is to stop at 10,000' at 250 KIAS, or start at 10,000' at 250 KIAS, use the bottom line. If a climb is to stop or start at 10,000' and 330 KIAS use the second line. The optimum altitude, cruise, and service ceiling li nes cross both the gross weig ht and altitude lines. The intersection of any point, on any of these lines, will show the altitude capability for that weight.

As defined, OPTIMUM ALTITUDE is where the aircraft achieves the greatest specific range for a given gross weight and speed.

CRUISE CEILING is the highest altitude at which a 300 foot per minute rate of climb can be maintained at a given gros s weight and temperature using rated thrust at the re commended climb speed.

SERVICE CEILING is the highest altitude at which a 100 foot per minute rate of climb can be maintained at a given gros s weight and temperature using rated thrust at the re commended climb speed.

WIND GRID LINES labeled he adwind and tailwind on the Distance charts are to compensate for the wind effects on gr oundspeed. Tailwinds increase the groundspeed, increasing the distance to climb. Headwinds reduce the groundspeed, decreasing the distance to climb.

TEMPERATURE GRID LINES indicate t he effect of tem perature on climb performance. The basic charted in formation is based on standard day temperature; thus the tem perature lines are depicted as positive (above), and negative (below) standard day temperatures. The real implication here is the effect temperature has on engine thrust (i.e. as temperature increases, thrust decreases and as temperature decreases th rust increases.) This will either decrease or increase the rate of climb.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-03 3-7 01 JUL 13 Figure 3-5. Three Engine Distance to Climb. NOTE:
1. CLEAN CONFIGURATION
2. MAXIMUM CLIMB THRUST 3. CLIMB AT SPEED SHOWN IN T.O. 1C-10(K)A-1-1, FIGURE 4-1, TO 10,000 FT THEN AT 330 KIAS TO 27,402 FT., THEN AT MACH = 0.82KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-03 3-8 01 JUL 13 As previously mentioned, the Fuel, Dist ance, and Time charts are similar and the procedures for using them are the same.

EXAMPLE: (Fig. 3-5)

Use the following values to compute t he distance to climb for the standard climb profile.

INITIAL CLIMB WEIGHT = 500,000 lbs.

START OF CLIMB ALTITUDE = sea level

END OF CLIMB ALTITUDE = 25,000'

WINDS = 50 knot headwind

TEMPERATURE = Standard day + 12 °

The required distance to climb is 76 nautical milesKC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-03 3-9 01 JUL 13 Figure 3-6. Three Engine Distance to Climb. NOTE:
1. CLEAN CONFIGURATION
2. MAXIMUM CLIMB THRUST 3. CLIMB AT SPEED SHOWN IN T.O. 1C-10(K)A-1-1, FIGURE 4-1, TO 10,000 FT THEN AT 330 KIAS TO 27,402 FT., THEN AT MACH = 0.82KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-03 3-10 01 JUL 13 For climbs starting at altitudes other then sea level, enter the charts at the start of climb gross weight noting the fuel, distance, or time value for that gross weight. Then follow the gross weight guidelines up to the desired level-off altitude and note that fuel, distance, or time value. The fuel, distance, or time to climb value obtained will be the level-off altitude val ues minus the start of climb values.

EXAMPLE: (Fig. 3-6)

Use the following values to compute t he distance to climb for a standard climb profile to final level-off altitude.

START CLIMB ALTITUDE = 15,000'

START CLIMB GROSS WEIGHT = 500,000 lbs.

FINAL LEVEL-OFF ALTITUDE = 31,000'

WINDS = 50 knot tailwind

TEMPERATURE = Standard Day

The required distance to climb is 130 NM - 41 NM = 89 NMKC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-03 3-11 01 JUL 13 FUEL (LB) DISTANCE (NM)

TIME (MIN)
PRESSURE ALTITUDE (FT) INITIAL CLIMB GROSS WEIGHT (LB)
300,000 325,000 350,000 375,000 400,000 425,000 450,000 475,000 500,000 525,000 550,000 575,000 600,000

41,000 7000 89 13 7900 101

14 8900 116

16 10,200 138

19 12,700 189 25

37,000 6200 70 10 6900 78 11 7700 87 13 8500 98 14 9400 110

16 10,500 123

18 11,800 142 20 13,600 170 24

33,000 5600 58

9 6200 64 10 6800 71 11 7500 79 12 8300 87 13 9100 96 14 10,000 105

16 10,900 117

17 12,000 130

19 13,200 147 21 14,900 168 24 17,300 205

28

29,000 5000 48

7 5600 53

8 6100 59

9 6700 65 10 7400 71 11 8000 78 12 8700 85 13 9500 94 14 10,300 103

15 11,200 113

17 12,200 124

18 13,300 137 20 14,600 152 22

25,000 4330 38

6 4800 42

7 5300 47

8 5800 51

8 6300 56

9 6900 61 10 7400 66 11 8000 72 12 8600 79 12 9300 86 13 10,000 93 14 11,000 102

16 11,800 111

17

20,000 3400 27

5 3800 30

5 4200 33

6 4600 36

6 5000 38

7 5400 43

7 5800 46

8 6300 50

9 6700 54

9 7200 58 10 7700 63 10 8200 68 11 8800 73 12

15,000 2600 18 3 2900 20

4 3200 22

4 3500 24

5 3800 26

5 4100 29

5 4400 30

6 4700 33

6 5000 36

7 5300 39

7 5600 41

7 6000 44

8 6400 48

8

10,000 1800 11 2 2000 12 3 2200 14 3 2400 15 3 2600 16 3 2900 18 4 3100 19 4 3300 20

4 3400 22

4 3600 23

5 3800 25

5 4000 27

5 4200 28

5

10,000 1500 8 2 1600 9 2 1800 10 2 2000 11 3 2100 12 3 2300 13 3 2500 14 3 2700 16 3 2900 18 4 3100 19 4 3300 20

4 3600 23

4 3800 24

5

5,000 700 4 1 800 4 1 900 5 1 1000 5 1 1000 6 1 1100 6 1 1200 7 2 1300 7 2 1400 8 2 1500 8 2 1600 9 2 1700 10 2 1800 10 2

Figure 3-7. Three Engine Climb Table.

Climb data is also provided in tabulated form (Fig. 3-7). This data is based on a climb from sea level to the selected altitude, standard day, and zero wind conditions. The initial gross weight is listed across the top of the table, and the pressure altitudes are listed down the left side. Also note the two rows listing 10,000'; these are used in the same manner as the two 10,000' lines on the fuel, distance, and time charts.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-03 3-12 01 JUL 13 Figure 3-8. Three Engine Service Ceiling.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-03 3-13 01 JUL 13 3.5 SERVICE CEILING

Three and two engine service ceiling ch arts are provided to determine the service ceiling for various temperatures , weights, and drag in dex configurations (Fig. 3-8). Note the s haded area represents Mach C hangeover during climb. Due to decreasing true airspeed (TAS) du ring the climb at constant mach, the effect of drag index decreases resulting in an increase in service ceiling.

These charts are used to compute the se rvice ceiling when climb performance is reduced due to additional drag above the defined level of a clean aircraft. They are based on climbing at MCT power 2 engines operati ng or MCL with 3 engines operating and the initial climb gross weight starting at sea level. As you can see, the bottom of the chart allows you to ent er with a computed drag index number. The gross weight li nes are in 50,000 lb. increment s; intermediate gross weights will require interpolation. The left hand column is the service ceiling in thousands of feet.

EXAMPLE: (Fig. 3-8)

Use the following values to compute the three engine service ceiling with a known drag index.

INITIAL CLIMB WEIGHT = 500,000 lbs.

DRAG INDEX = 71

The three engine service ceiling for a c limb at MCL power and the climb speed schedule of 330 KIAS is 27,402'. However, by transitioning to the Mach climb schedule, where TAS decreases, the servic e ceiling for the same weight is 33,800'.

While normally not climbing with such a lar ge drag index, these charts provide a means to compute a service ceiling if the problem ever presents itself.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-03 3-14 01 JUL 13 11,200 116

17.4

Figure 3-9. Drag Index.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-03 3-15 01 JUL 13 3.6 DRAG

The KC-10 climb profiles are based on a cl ean configuration and a drag index of zero. Any increase in drag will result in a reduced climb per formance. Drag index values other than zero, for non-st andard configurations , are presented in section 1 of the performance manual. Charts are provided for three engine standard climb and a two engine climb profile.

EXAMPLE: (Fig. 3-9)

Use the following values to compute t he fuel, distance, and time to climb with a drag index number.

DRAG INDEX = 50

FUEL TO CLIMB = 8,800 lbs. (drag index 0)

DISTANCE TO CLIMB = 91 naut ical miles (drag index 0)

TIME TO CLIMB = 13.6 minutes (drag index 0)

To apply a drag index correction to the c limb, enter the approp riate grid at the zero drag index on the left with the comput ed fuel, distance, and time from the normal, clean configuration, climb charts. Then follow the guidelines to the point of intersection with the drag index number. Next, exit the chart on the left to find the corrected fuel, distance, and time values.

The actual fuel, distance to climb is:

FUEL TO CLIMB = 11,200 lbs.

DISTANCE TO CLIMB = 116 nautical miles

TIME TO CLIMB = 17.4 minutes

Remember, to apply a drag index correcti on, you must first compute the Fuel, Distance, and Time for a clean configuration.

This completes the instructional part of this segment. A few chart exercises follow. They are to be completed as a review and reinforcement of the lesson. You will need a performance manual and a ca lculator may be helpful. As always, any questions should be directed to an instructor as soon as possible.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-03 3-16 01 JUL 13 3.7 SEGMENT EXERCISE

CLIMB

For the following exercises, use the appropriate charts in Section Four of your Performance Manual.

1. Find the N 1 setting for Maximum Cont inuous Thrust (MCT):

Given: TAT = 20 ° C

Pressure Altitude = 10,000'

2. Find the N 1 setting for Maximum Climb Thrust (MCL):

Given: TAT = 20 ° C

Pressure Altitude = 10,000'

3. Find the N 1 setting for Maximum Cruise Thrust (MCR):

Given: TAT = 20 ° C

Pressure Altitude = 10,000'KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-03 3-17 01 JUL 13 CLIMB

Given for questions 4, 5, 6 & 7:

Standard Climb Profile

Gross weight = 450,000 lbs.

Start of climb = Sea Level

Climb to optimum Altitude

50-knot tailwind

Plus 6 ° Temp Deviation

4. Find Optimum Altitude:

5. Find Fuel to Climb:

6. Find Distance to Climb:

7. Find Time to Climb:

Apply a drag index value of 50 to questions 5, 6 & 7.

Find corrected requirements for 8, 9 & 10.

8. Corrected Fuel to Climb:

9. Corrected Distance to Climb:

10. Corrected Time to Climb:

11. Optimum altitude is that altitude where the greate st is achieved for a given gross weight and airspeed.

12. The cruise ceiling is the altitude at which rate of climb can be maintained at a given gross weight and temperature, using rated thrust and the

. 13. Three engine climb speed sc hedule is , to 10, 000 feet, then for standard climb to , then 0.82 Mach.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-03 3-18 01 JUL 13 3.8 SEGMENT EXERCISE ANSWER KEY

CLIMB

For Aircraft Performance Computation Tolerances, see AFI 11-2KC-10V2.

1. 108.6% 2. 104.9% 3. 98.9% 4. 33,900' 5. 10,500 lbs. 6. 128 NM 7. 16.4 MIN 8. 14,200 lbs. 9. 189 NM 10. 21.8 MIN 11. Specific range 12. 300 fpm, recommended climb speed 13. 250 KIAS, 330 KIAS, 27,402'KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-1 01 JUL 13 4.0 CRUISE PERFORMANCE

This segment will define the terminology and determine the environmental/aircraft factors associated with KC-10 cruise performance. At the end of this segment, there will be a require ment to make several computations, so keep your performance m anual and calculator handy.

The Cruise Charts provide the information necessary for planning a cruise segment for a given mission. The charts ar e based on actual flight test results, however; the fuel consumption values are increased 5% relative to engine specification levels.

4.1 TERMINOLOGY ASSOCIAT ED WITH CRUISE PERFORMANCE

First, let's look at different types of cr uise and the environmental/aircraft factors that effect range performance.

Figure 4-1. Cruise Climb.

Using the Cruise Climb prof ile results in optimum efficiency from the engines and aircraft. The Cruise Climb begins after leve l off from the initial climb usually at the optimum altitude. As fuel is consumed, the gro ss weight decreases, which allows the aircraft to either accelerate or climb. In the Cruise Climb profile, the aircraft is allowed to climb, thus mainta ining its optimum alti tude. The Cruise Climb profile yields the maximum range capabi lity but is impractical for Air Traffic Control because the aircraft will be constantly changing altitudes. NMPP x 1000KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-2 01 JUL 13 Figure 4-2. Optimum Step Cruise.

STEP CRUISE

The Step Cruise involves periodic chan ges in altitude, normally in 4000' increments. It is a compromise betw een a Cruise Climb and a Constant Altitude cruise. When using the Step Cruise profile, begin by leveling off from the initial climb at 2000' above the aircraft's optimum altitude. Maintain this altitude until the fuel burn decreases the gross weight enough to where the aircraft is 2000' below the new optimum altitude; then clim b 4000', to where it will be 2000' above the new optimum altitude. This process is continually repeated as weight decreases. The Step Cruise profile yiel ds a range performance within 0.5% of the Cruise Climb.

CONSTANT RATING CRUISE

As mentioned in Cruise Climb, as the gr oss weight decreases the aircraft will either accelerate or climb. The Cons tant Rating Cruise maintains a constant altitude while increasing the airspeed. This is accomp lished by setting a thrust rating (i.e. MCR) and allowing the airs peed to increase as the gross weight decreases. OPTIMUM STEP CLIMB

A. INITIAL CLIMB

B. INITIAL LEVEL OFF (2,000 0 ABOVE OPTIMUM ALTITUDE)

C. 4,000 FEET STEP AT CLIMB SPEED AND CLIMB THRUST

D. LEVEL OFF

E. 2,000 FEET ABOVE OPTIMUM ALTITUDE

F. OPTIMUM ALTITUDEKC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-3 01 JUL 13 CONSTANT SPEED/MACH CRUISE

This cruise profile is based on maintainin g a constant altitude and airspeed. It requires periodic reductions of thrust as gross weight decreases to maintain the selected airspeed. While being the simplest to fly, it does not take advantage of climbing to higher more efficient altitudes.

START OF CRUISE

START OF CRUISE 6:42

6:08 USING MAX RANGE AIRSPEED

USING LONG RANGE CRUISE (99% MAX) 4,500 NM

4,455 NM 0 - FUEL 0 - FUEL TIME

TIME

Figure 4-3. Maximum Range vs. Long Range.

LONG RANGE CRUISE

The Long Range Cruise proc edure is a compromise between a gain in airspeed and a loss in nautical miles per pound of fuel at a specific weight and altitude. This procedure provides a si gnificant increase in speed with only 1% loss in fuel economy. Long Range Cruise can be flown with Const ant Altitude, Step Cruise, or Cruise Climb profiles. This procedure usually requires a continuous change in airspeed as gross weight decreases. Long Range Cruise speed for the KC-10 is a constant Mach number when used wit h a Step Cruise profile. Figure 4-3 illustrates a Maximum Range versus Long Range Cruise.

MAXIMUM ENDURANCE SPEED

Maximum Endurance Speed provides the gr eatest flying time for amount of fuel burned. It is based on the sp eed at which the fuel cons umption rate is at its minimum.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-4 01 JUL 13 4.2 ENVIRONMENTAL AND AIRCRAFT FACTORS

TEMPERATURE

Temperature deviations fr om Standard Day have neglig ible effects on range performance, but do affect maximum engine thrust limits. Any corrections for Non-Standard Day temper atures are provided in the chart notes.

CENTER OF GRAVITY

The CG location has a minimal effect on range performance for small changes in CG. However, the effect can be large for loadings near the forward limit. All charted cruise performance data is calc ulated using a CG of 24% MAC. The specific range changes by 0.2% for every 1% of MAC movement, with aft movement of the CG location resu lting in improved specific range.

BLEED AIR

All cruise performance is computed on the basis of normal bleed conditions. This includes bleed air for A/C packs operating, lavatory and galley ventilation bleeds, and shaft-power extraction for hydrau lic and electrical requirements.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-5 01 JUL 13 Figure 4-4. Specific Range.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-6 01 JUL 13 4.3 CRUISE PERFORMANCE COMPUTATIONS

SPECIFIC RANGE

Specific Range Charts (Fig. 4-4) are t he basis for cruise computations. One chart, for a specific altitude, will provide most of the basic information required for cruise at that altitude.

In the Cruise section of the performanc e manual are Specific Range Charts for three and two engine operation in the clean configuration and three engine operation with slats ex tended. Since the mechanics and content of these charts are the same, only the three- engine clean confi guration chart will be discussed. Now look at what is on a S pecific Range Chart (Fig. 4-4).

INDICATED AIRSPEED/TRUE MACH NUMBER is presented across the bottom of the chart. Specific R ange Charts are normally read by entering with a known Mach/IAS.

GROSS WEIGHT lines are in 20,000 lbs. increments from 240,000 lbs. to 600,000 lbs. These encompass the KC- 10 weights from average zero fuel weights of approximat ely 250,000 lbs. to a max ta keoff weight of 590,000 lbs.

Note that the 240,000 and 260,000 lbs. lines both have an upward break; 240,000 around 0.657 mach and 260,000 ar ound 0.597 mach. A further examination rev eals the 80% N 1 RPM line doing the same thing. Since compressor discharge bleed is more penalizing than 8 th stage bleed, the losses increase when the bleed switches from 8 th stage to the compressor discharge port (14 th stage). This effect is noticeable on several s pecific range lines as a break where the specific range is reduced.

NAUTICAL MILES PER 1000 POUNDS OF FU EL (NMPP), listed on the left of the chart, it is the distance we can travel on 1000 lbs. of fuel. NMPP will be used to predict a fuel flow when accomplishing fuel planning.

1.2g BUFFET BOUNDARY, MAX ENDU RANCE, 99% MAX NM/LB., and V MO lines allow for computing the selected speed and NMPP for the charted altitude and present or planned gross weight.

%N 1 lines (that cross over the gross weight) 1.2g, Max endurance, and 99% Max lines are used to determine the N 1 setting required to maintain the selected indicated airspeed or mach number.

MAX CRUISE THRUST TEMP ERATURE DEVIATION lines in the lower right hand corner indicate the point where the MCR thrust limit is reached.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-7 01 JUL 13 Figure 4-5. Specific Range. 91.75%

.81 28

27.6KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-8 01 JUL 13 EXAMPLE: (Fig. 4-5)

Use the following values to compute the NMPP and N 1 RPM.

GROSS WEIGHT = 400,000 lbs.

INDICATED AIRSPEED/TRUE MACH = 0.775 Mach

TEMPERATURE = Standard day

Entering the bottom of the chart at 0.775 Mach, and reading vertically to the gross weight of 400,000 lbs., the co mputed NMPP is 28. With a little interpolation, we can compute an N 1 of approximately 91.75%.

For every 1000 lbs. of fuel used, the airc raft will travel 28 nautical miles with the engines operated at 91.75% N 1 . This information can be used in mission planning to predict a fuel flow. A formula to accomplish this is:

True Airspeed (TAS) = Fuel Flow NMPP

0.775 Mach = approximately 454 KTAS for this altitude (Refer to T.O. 1C-10(K)A-1-1).

454 = 16.214 x 1000 yields a fuel flow of 28 16,214 lbs./hr.

NOTE: 5% conservatism built into the char t means an actual fuel flow of 15,403 lbs./hr. (16,214 x 95% = 15,403).

Again using 400,000 lbs., when the weight li ne is followed, it can be seen that the 99% long range cruise point gives a NMPP value of approximately 27.6 and a Mach of 0.810 (300 KIAS).

The three other speed lines that inte rsect the gross weight line are Max Endurance, 1.2g buffet boundary, and V MO . These speeds and NMPP can be computed in the same way.

As mentioned earlier, tem perature deviations from st andard day have negligible affects on range performance, but do affect maximum engine thrust limits. The 5, 10, 15, and 20 degree tem perature deviation lines in the lower right hand corner indicate thrust limits. Reading straight down, at any intersection of a gross weight with one of these lines, re veals the maximum Mach/Airspeed for MCR thrust at that altitude and gross weight.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-9 01 JUL 13 Figure 4-6. Specific Range. 40

35

30

25

20

15

.30 .40 .50 .60 .70 .80 .90 INDICATED AIRSPEED (KNOTS)

TR U E MA C H N U MBER M A X C R U I S E T H R U S T

N A U T I C A L M I L E S P E R 1 0 0 0 P O U N D S O F F U E L 99% MAX
NM/LB

MAX

ENDURANCE

T E M P . D E V I A T I O N ( C )

0

15 20

10 1.2G BUFFET BOUNDARY

120 140 160 180 200 220 240 260 280 300 320 2 4 0

2 8 0

3 2 0

3 6 0

4 0 0

4 4 0

4 8 0

5 2 0

5 6 0

600 G R O S S

W

E I G H T

( 1 0 0 0 L B )

5 THRU -20 %

N

1

8 0

8 5

9 0

9 5

1 0 0 V M O ?

1

. 2 B U

F

F

E

T B

O

U

N

D

A

R

Y M A

X E N

D

U

R A

N C

E 9 9 %

M A X N M / L B V M O GROSS WEIGH T CURVEKC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-10 01 JUL 13 Now take a closer look at the speeds on the specific range chart (Fig. 4-6).

The 1.2g Buffet Boundary Line indicates the slowest acceptable speed for level flight and is a basis for the minimum ai r refueling speed. As can be seen in Figure 4-6, this speed is on the back side of the "power curve." The increased drag, due to the increased angle of attack, requires more power to maintain this speed, thus a lower NMPP value. Anot her explanation of 1.2g speed is it's correlation with angle of bank. The Cruise Buffet - Onset Boundary chart in section 1, shows 1.2g allowing for a 33 degree angle of bank. If the aircraft weighs 500,000 lbs. and is put into a 33 degree angle of bank our effective weight now becomes 600, 000 lbs. (500,000 x 1.2).

Max Endurance speed, as defined earlier, pr ovides the greatest flying time for the amount of fuel burned. It' s based on fuel consumption bei ng at a minimum. It is the combination of minimum airspeed and minimum power requirement, thus allowing for greater time on station or for holding over a destination. As seen in Figure 4-6, it is between 99% Max NM/l bs. and the 1.2g Buffet Boundary speeds.

99% Max NM/LB speed also known as Long Range Cruise (LRC) is a compromise in gain of airspeed and resultant loss in NMPP from the Maximum range airspeed (peak of gross weight curves ). When fuel planning for airlift missions, LRC and optimum altitude should be used. This can also be used to and from the orbit area on refueling missions.

V MO is the "never to exceed speed" and may not be deliberat ely exceeded. As you can see, this is the point where all t he gross weight lines merge (0.88 Mach). While gross weight does not affect this speed like the ot her speeds, it is affected by altitude.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-11 01 JUL 13 Figure 4-7. Effect of Flying Off-Speed on Range. 94.8KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-12 01 JUL 13 Why should Long Range Cruise procedures, 99% maximum range, be used as much as possible? An examination of so me related charts should help show the reason why.

EFFECT OF FLYING OFF-SPEED ON RANGE

This chart (Fig. 4-7) allows for computi ng the reduction in range from flying other than the computed 99% MAX NM /LB speed. As menti oned in the chart notes, this chart is based on cruise at the optimum altitude.

Enter the bottom of the chart with the mach deviation from 99% maximum range mach number and find the perc ent of range. This is the percentage of 99% maximum range required to compute the effect of flying off speed.

EXAMPLE: (Fig. 4-7)

Use the following values to comp ute the reduction in range.

ACTUAL CRUISE SPEED = 0.84 Mach

LONG RANGE CRUISE SPEED = 0.82 Mach

By entering the bottom of the chart at 0.02 Mach faster, (to the right of the 0 line), and reading vertically to the deviation cu rve, the percent of 99% maximum range is 94.8%. This equates to a range reducti on of 5.2% (100% - 94.8%) for flying only 0.02 Mach faster.

Using the same example, by flying at 0.84 Mach an additional 3,900 lbs. of fuel (75,000 x 5.2%) is used, if planned enroute fuel requ irement is 75,000 lbs. at a long range cruise speed of 0.82 Mach,KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-13 01 JUL 13 Figure 4-8. Effect of Wi nd and Altitude on Range. 94.5 108.5KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-14 01 JUL 13 What about altitude? The bes t range is realized at Op timum altitude. Flying within ± 2,000' of optimum will provide a range performance that averages 0.5% less than optimum altitude. Flying outsi de this band causes range performance to decrease rapidly.

EFFECT OF WIND AND ALTITUDE ON RANGE

This is a compound chart (Fig. 4-8) corre cting for both wind and altitude. This chart can also be used to determine the wind advantage required to offset flight at non-optimum altitudes. As mentioned in t he chart notes, this chart is based on cruise at long range speed. Look at the effects of fl ying off altitude first.

EXAMPLE: (Fig. 4-8)

Use the following values to co mpute the reduction in range.

PRESENT ALTITUDE = 31,000'

OPTIMUM ALTITUDE = 37,000'

By entering the bottom of the chart at -6 (6000' below optimum) and reading vertically to the 0 wind line, the percent of 99% ma ximum range is 94.5%. This equates to a 5.5% reduction in range for flying 6000' below optimum.

To see the effect of wind alone, optimum altitude will be used.

Enter the bottom of the chart at the 0 altitu de deviation. Reading vertically to the 40 knot advantage (tailwind), the percent of 99% maximum range is 108.5%. This equates to an additi onal 8.5% range c apability. A 40 knot disadvantage (headwind) results in an 8. 5% reduction in range.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-15 01 JUL 13 Figure 4-9. Effect of Wi nd and Altitude on Range.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-16 01 JUL 13 To determine the wind advantage required to offset flight at non-optimum altitudes, enter the chart at the bottom wit h the altitude deviation. Read vertically to the 100% line and interpolate for the required wind advantage required.

EXAMPLE: (Fig. 4-9)

Compute the wind advantage (tailwind) required to o ffset flying at a nonoptimum altitude.

PRESENT ALTITUDE = 31,000'

OPTIMUM ALTITUDE = 37,000'

Enter the bottom of the chart at -6 (6000' below optimum). Read vertically to the 100% line. The required ta ilwind required to offset flying 6000' below optimum altitude is 27 knots.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-17 01 JUL 13 Figure 4-10. Effect of Drag Index on Range. 1.00

0.95

0.90

0.85

0.80

0.75

0.70

0.65 0 20 40 60 80 100 

## EFFECT OF DRAG INDEX ON RANGE

16.5 0.943KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-18 01 JUL 13 So far a number of factors that effect range have been illustrated. Are there more? Of course; here are two more.

EFFECT OF DRAG INDEX ON RANGE

This chart (Fig. 4-10) is used to apply drag index corrections to cruise data. Note that this is a combined three and two engine chart.

EXAMPLE: (Fig. 4-10)

Use the following values to compute the reduction in range.

NUMBER OF OPERATING ENGINES = 3

DRAG INDEX = 16.5 (Air Refueling Boom deployed)

Enter the chart at the bottom with a drag index of 16.5. Read vertically to three engines operating. The Range Co rrection Factor is 0.943.

If the actual range capability is 1700 NM , with the boom deployed, the additional drag would reduce the range capability to 1603 NM (0.943 x 1700).

The correction factor to the specific range (NMPP) could also be applied.

If the charted NMPP were 24. 0 NM/1000 lbs., then with the correction factor of 0.943 (the actual NMPP) would be 22.6 NM/1000 lbs. of fuel. In this case, plan the flight using the lower NMPP value to compensate for the additional drag.

CENTER OF GRAVITY

As stated earlier, the aircraft center of gravity (CG) affects range capability. The flight manual recommends a CG of at l east 24% whenever possible. All cruise performance charts are based on 24% C G. Any movement of the CG changes the specific range (NMPP) by 0.2% for every 1% change in MAC.

If the change in CG is aft, the range in creases 0.2% for every 1% MAC CG change from 24%. Likewise, there is a 0.2% reduction for every 1% that MAC moves forward of 24%.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-19 01 JUL 13 Figure 4-11. Three Engine Integrat ed Range and Time Step Cruise. 7550

2075 15.7

4.3KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-20 01 JUL 13 THREE ENGINE INTEGRATED RANGE AND TIME STEP CRUISE

The Integrated Range and Time Charts (Fig . 4-11) are just that; range and time data on the same chart. They are based on a long range cruise speed using a step climb profile. These c harts are used to determine cr uise range and time for a given amount of fuel in a clean c onfiguration at standard day conditions.

Notice the two curves; one labeled Crui se Altitude and the other Time. The Cruise Altitude is used to determine t he range based on a step climb profile with the aircraft being at the appropriate alti tude. The breaks or hash marks separate the altitudes (i.e. to the left of the 500,000 lbs. shows 33,000', while the right shows 29,000'). This follows the Op timum step climb profile discussed earlier (Fig. 4-2). After intercepting the Cruise Altitude line read to the left for the range in nautical miles. The top line is the ti me line; it has breaks or hash marks that correspond to the cruise altitude. After in tercepting this line, read to the right for the time in hours.

As mentioned above, these charts are used to determine the cruise range and time for a given amount of fuel. This is accomplished by subtracting the end cruise gross weight range and time data from the start cruise gross weight data.

EXAMPLE: (Fig. 4-11)

Use the following values to co mpute the cruise range and time.

START CRUISE GROSS WEIGHT = 500,000 lbs.

END CRUISE GROSS WEIGHT = 310,000 lbs.

Enter the bottom of the chart with 500,000 lbs. Read vertically to the Cruise Altitude and Time lines. The range is 2 075 NM with a time of 4.3 Hr. Now enter the chart again at 310,000 lbs. Again, read vertically to the cruise altitude and time lines. The range is 7550 NM and 15.7 Hr.

The computed range is 5475 NM (7550 - 20 75 = 5475). The computed time is 11.4 HR (15.7 - 4.3 = 11.4) for 190,000 lbs. of fuel (500,000 - 310,000).

Remember, these charts are based on flyi ng the step cruise profile at the long range cruise speed. Corrections for any wind, drag index, CG other than 24%, or flying off speed must be applied.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-21 01 JUL 13 Figure 4-12. Three Engine Integrated Range and Time Step Cruise Example. 8300

3800

430KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-22 01 JUL 13 Any combination of two know n values can be used on these charts to find the unknown information (i.e. the required end cruise gross weight and the required range are known).

EXAMPLE: (Fig. 4-12)

Use the following values to comp ute the required cruise fuel.

END CRUISE GROSS WEIGHT = 290,000 lbs.

REQUIRED RANGE = 4500 NM

Enter the bottom of the chart with 290,000 lbs. Read vertically to the cruise altitude line. The range is 8300 NM. No w enter the chart on the left at 3800 NM (8300 - 4500 = 3800). Read horizontally to t he range line then vertically down to the required start gross weight of 430,000 lbs.

The computed required cruise fuel is 140,000 lbs. (430,000 - 290,000 = 140,000).

The start gross weight and end gross we ight may be used to compute the time as in the first example.

Again any corrections for wi nd, drag index, CG other t han 24%, or flying off long range cruise speed must be applied.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-23 01 JUL 13 Figure 4-13. Three Engine Integrated Range. 1.73 850 6180 13.09KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-24 01 JUL 13 THREE ENGINE INTEGRATED RANGE

The Integrated Range Chart (Fig. 4-13) allows for the determination of range capabilities when flying at a constant altitu de. They are used in a fashion similar to the step climb charts. These char ts are also based on standard day, clean configuration, and flying at long range cruise speed.

EXAMPLE: (Fig. 4-13)

Use the following values to compute the cruise range.

START CRUISE GROSS WEIGHT = 500,000 lbs. END CRUISE GROSS WEIGHT = 310,000 lbs. CRUISE ALTITUDE = 33,000’

Enter the chart at the botto m with 500,000 lbs. Read ve rtically to the 33,000’ pressure altitude line. The range is 850 NM. Now enter the chart again at 310,000 lbs. Read vertically to the 33,000’ pressure altitude line. The range is 6180 NM.

The computed cruise range is 5330 NM (6180 – 850 = 5330).

THREE ENGINE INTEGRATED TIME

The Three Engine Integrated Time Chart is read in the same manner.

EXAMPLE: (Fig. 4-13)

Use the following values to compute the cruise time.

START CRUISE GROSS WEIGHT = 500,000 lbs. END CRUISE GROSS WEIGHT = 310,000 lbs. CRUISE ALTITUDE = 33,000’

Enter the chart at the botto m with 500,000 lbs. Read ve rtically to the 33,000’ pressure altitude line. The time is 1.73 HR. Now enter the chart again at 310,000 lbs., read vertically to the 33,000’ pressure alti tude line. The time is 13.09 HR.

The computed cruise time is 11.36 HR (13.09 – 1.73 = 11.36).

These charts can also use any two combi nations of known values to find the unknown information as in the Integr ated Range and Time Step Climb Charts.

Also, don’t forget to make corrections for any wind, drag index, CG other than 24% MAC or flying off long range cruise speed.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-25 01 JUL 13 Figure 4-14. Three Engine Optimum Altitude Cruise Performance. 23.8 32 .824KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-26 01 JUL 13 THREE ENGINE OPTIMUM ALTITUDE CRUISE PERFORMANCE

The chart in Figure 4-14 shows the spe ed, altitude, and specific range for optimum cruise performance versus gro ss weight above 25,000'. Curves are provided for both 100% and 99% maximum NMPP for a clean configuration from standard day to standard day + 20°.

EXAMPLE: (Fig. 4-14)

Use the following values to compute the optimum Specific range (NMPP), altitude, and Mach number.

GROSS WEIGHT = 480,000 lbs.

TEMPERATURE = Standard Day

CRUISE PROFILE = 99%

Enter the bottom of the c hart with 480,000 lbs. Read vertically to the 99% Specific Range curve. The computed s pecific range is 23.8 NM/1000 lbs. Continue reading vertically until interc epting the Optimum Altitude curve. The computed optimum altitude is 32,000'. Continue to read vertically until intercepting the 99% Mach number line. The comput ed mach number is 0.824 Mach.

This chart is a quick reference for optim um cruise performance. As with the other cruise charts, remember to apply co rrections to the specific range for wind, drag index, CG other t han 24%, or flying off speed.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-27 01 JUL 13 Figure 4-15. Cruise N 1 and Fuel Flow per Engine - Mach 0.82.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-28 01 JUL 13 CRUISE N 1 and FUEL FLOW per ENGINE - MACH 0.82

Tabulated data (Fig. 4-15) is provided for cruise at 0.82 mach, clean configuration, and standard da y conditions. Corrections are provided in the notes for higher than standard day temper atures. The shaded area represents the optimum range altitude for the se lected gross weight. The heavy line represents the maximum cruise thrust li mit for standard day to standard +15. This line also shows that the KC-10 is not thrust limited for st ep cruise operation.

The N 1 values presented on this table are Target N 1 settings only. Small deviations from charted values may be required to obtain the correct speed.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-29 01 JUL 13 Figure 4-16. Buffet Protection a nd Optimum Cruise Altitude. NOTE: BUFFET PROTECTION AND O PTIM UM CRUISE ALTITUDE

250 300 300 350 350 400 450 500 550 600 4 2

4 0

3 8

3 6

3 4

3 2

3 0

2 8 1. T HR EE EN GINE OPER ATION

2. C LEAN CON FIGUR AT ION

3. G OOD FOR ALL TEMPER AT UR ES

4. APPLICABLE F OR MAC H 0.82 TO M ACH 0.83
5 . C G = 24 % M A C, RE DU CE B UF FE T L IMITE D A L TIT UDE

BY 90 FT AN D OPTIM UM ALTITU DE BY 60 FT

FOR EAC H 1% MAC FORW AR D M OVEM ENT OF THE

CG LOCATION

GROSS W EIGH T (1000 LB) 3 3 3 3KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-30 01 JUL 13 BUFFET PROTECTION AND OPTIMUM CRUISE ALTITUDE

This chart (Fig. 4-16) presents the buffet margin available versus gross weight and altitude. Also shown is the three engine optimum cruise altitude. The data is valid for speeds between 0.82 and 0.83 Mach. The chart shows that the available load factor to buffet onset is 1.5g at the optimum al titude and 1.35g at an altitude 2000' above optimum (the grea test deviation from optimum for step cruise operation). The chart is based on 24% CG. Corrections are provided in the notes for CG movement forward of 24%.

EXAMPLE: (Fig. 4-16)

Use the following values to compute t he load factor/bank angle to buffet onset.

GROSS WEIGHT = 500,000 lbs.

ALTITUDE = 33,000'

CG LOCATION = 24% MAC

Enter the chart at the bottom with 500,000 lbs. and on the left with 33,000. The point of intersection reveals a load factor of 1.4g and a bank angle of 44 °

. The buffet protection provided at this altitude and gross weight is 0.4g (1.4 - 1.0 = 0.4), provided we do not exceed 44 ° of bank.

This completes the instructional part of this segment. A few chart exercises follow. They are to be completed as a re view and reinforcement of this segment. You will need a performance manual and a ca lculator may be helpful. As always, any questions should be directed to an instructor as soon as possible.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-31 01 JUL 13 4.4 SEGMENT EXERCISE CRUISE

For the following exercises, use the appropri ate charts in Section Five of your Performance Manual.

Conditions:

Start Cruise Gross weight = 460,000 lbs.

End Cruise Gross We ight = 275,000 lbs.

Clean Configuration

Three Engines Operating

Standard Day

CG = 24% MAC

Find:

1. Optimum Altitude

2. Long Range Cruise Speed and Mach for Optimum Altitude

3. Long Range Cruise NM PP at Optimum Altitude

4. Max Endurance Speed at Optimum Altitude

5. 1.2g Speed at Optimum Altitude

6. N 1 RPM at Optimum Altitude and Long Range Cruise

7. Cruise Range and Time for Step Cruise Profile

8. Max Endurance Fuel Flow

9. Range Correction Factor (D rag Index) for two main landing gear strut doors missing

10. Effect of flying 4000' below optimum altitude (no wind)

11. Effect of 50 knot headwind at Optimum Altitude

12. Effect of flying .03 ma ch slower than Long Range Cruise speedKC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-04 4-32 01 JUL 13 4.5 SEGMENT EXERCISE ANSWER KEY

CRUISE

1. 33,000' 2. 294 KIAS/ 0.823 Mach 3. 25.0 NMPP 4. 269 KIAS 5. 245 KIAS 6. 96.6% 7. 5850 NM, 12.3 HR 8. 18300 lbs./hr. (0 bank) 9. 0.942 (8.3 x 2 = 16.6 Drag Index) 10. 96.8% 11. 89.5% 12. 100.3%KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-05 5-1 01 JUL 13 5.0 HOLDING PERFORMANCE

This segment defines the terminol ogy associated with KC-10 Holding Performance, and the Environmental/Aircra ft Factors affecting holding. At the end of this segment, you will be required to make several computations, so keep your performance manual and calculator handy.

5.1 HOLDING PERFO RMANCE TERMINOLOGY

Holding tables are provided for three, tw o, and even single engine operation in a clean configuration. Ther e is also a table for thr ee engine holding with slats extended at low altitudes. All holding data is based on actual flight test results; however, the fuel consumption values have been increased 5%, relative to engine specification levels.

The FAA defines holding as "a predetermi ned maneuver which keeps the aircraft within a specified airspace while awaiti ng further clearance from air traffic control." Holding should not be confused with the orbiting used by the KC-10 while awaiting a receiver aircraft.

The Holding speeds have been chosen to minimize fuel consumption while maintaining controllability and a sufficient speed margin above buffet or stall during banked flight up to 30 °

.
A minimum fuel flow speed that is alwa ys above the 1.2g buffet onset speed is the definition of Holding Speed . The minimum fuel flow speed may be less than 1.5 V S (1.4 V S , slats extended). If the use of autot hrottles is desired, holding at a higher airspeed may be necessary since the autothrottles will not allow the aircraft to slow below 1.5 V S in a clean or slats ex tended configuration.

Bank angle imposes a load factor on the airc raft that requires an increase in thrust to maintain altitude. Charted speed, target N 1 , and fuel flow increase with the bank angle due to the increase in load factor.

The tables are based on Standard Day Temperature . Located in the chart notes are corrections for N 1 RPM and fuel flow when tem peratures are above standard day.

A Drag Index greater than zero results in an in crease in fuel flow. A chart is provided to correct charted fuel fl ow values for a Drag Index (DI).

All holding data is computed using normal Engine Bleed . A correction must be made if an engine anti-ice valve is inoperativ e in the open position. Consult your performance manual for the appropriate corrections.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-05 5-2 01 JUL 13 5.2 EFFECT OF HOLDING ON ENDURANCE

The charted holding speeds provide a suffi cient speed margin above the buffet or stall at the published bank angles. In fact, as we saw in the definition of holding speed, it is always above the 1.2g Buffe t Onset speed. But what is a minimum fuel flow speed? Wasn't max endurance speed for minimum fuel consumption? In essence they are one and the same. See if the charts prove this point:

Conditions:

GROSS WEIGHT = 400,000 lbs. TEMPERATURE = Standard Day ALTITUDE = 10,000' CG = 24% MAC CLEAN CONFIGURATION

Vstall Holding Max Endurance 1.5 V S

0 ° bank 155 226 225 233 30 ° bank 167 245 246 251 (Refer to T.O. 1C-10(K)A-1-1, Figures 5-9, 12-26, and 12-27 ).

The major difference in speeds is due to the change in effective weight; 400,000 lbs. straight and leve l, 462,000 lbs. at 30 ° of bank. The 1.2g speed is the same for both (202 KIAS) because the 1.2g speed allows up to 33 ° of bank. When comparing the holding speeds to the 1.5 V S of 233 KIAS (1.5 x 155 = 233), the straight and level speed of 226 KIAS is less, proving t hat the minimum fuel flow speed, and also max enduranc e, can be less than 1.5 V S

. But what about 1.2g buffet Boundary speed? If protected to 33 ° of bank, wouldn't the slower speed be be tter for fuel consumption? Quite frankly, no. As was mentioned in the cruise lesson, 1.2g speed is on the "back side of the power curve." The additional drag from the required angle of attack requires more thrust, resulting in more fuel burned.

If endurance is not a factor and the use of autothrottles is desired, holding may be accomplished at a speed higher than the recommended holding speed.

If endurance is to be maximized, it may be nec essary to turn the autothrottles off.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-05 5-3 01 JUL 13 Figure 5-1. Holding.

Turns during holding effectively decrease endurance. To minimize this effect, airspeed may be varied according to the ba nk angle being used. To accomplish this fly the charted holding speed for 0 ° bank during the straight and level portion, then accelerate up to the charted holding speed for the bank angle to be used in the turn (Fig. 5-1).

Endurance can be further enhanced by ex tending the holding pattern, changing altitudes, or minimizing the bank angle.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-05 5-4 01 JUL 13 Figure 5-2. Three Engine Holding.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-05 5-5 01 JUL 13 5.3 THREE ENGINE HOLDING

Figure 5-2 is for three engine holding in a clean configuration. This table provides holding spe eds, fuel flows, and N 1 RPMs for various weights at bank angles from 0 ° to 30 °

. At the top of the t able are the Gross weights at indi cated bank angles. A look at this reveals that the effective we ight computations have already been accomplished. Note that a 450,000 lb. aircraft in a 30 ° bank is effectively the same as a 520,000 lb. aircraft in straight and level flight. Along the left side of the table is the pressure altit ude, listed in thousands of feet.

EXAMPLE: (Fig. 5-2)

Use the following values to co mpute the holding airspeed, N 1 , and fuel flow.

GROSS WEIGHT = 398,000 lbs.

TEMPERATURE = Standard Day

ANGLE OF BANK = 30 °

ALTITUDE = 10,000'

By entering the top of t he table with 398,000 lbs ., and reading down to the 10,000' line, it can be seen that t he holding airspeed is 244 KIAS, N 1 is 76.8%, and fuel flow is 17,360 lbs./hr.

V MM for the same weight is 240 KIAS, so if desired, autothrottles could be used to hold at the higher airspeed.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-05 5-6 01 JUL 13 Figure 5-3. Three Engine Holding #2.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-05 5-7 01 JUL 13 But what about endurance?

As mentioned earlier, if endurance is a factor, the aircraft can slow down in straight and level flight and accelerate for the turns. To accomplish this simply make another entry into the chart for the gr oss weight in straight and level flight.

From the previous example, we determine the airspeed, N 1 , and fuel flow at 30 ° of bank. This is the speed, N 1 , and fuel flow required to make the turns in holding at 30 ° of bank.

Reentry into the chart reveals that during straight and level f light (400,000 lbs., 0 Bank) we can slow to 226 KIAS with an N 1 of 72.7% and a fuel flow of 15090 lbs./hr. (Fig. 5-3).

Average the two to compute the f uel actually burned in one hour.

17,360 lbs./hr. + 15,090 lbs./hr. 32,450 lbs./hr.

32,450 lbs./hr. = 16, 225 Average lbs./hr. 2

In 1 hour of holding 16,225 lbs. of fuel is used. While in the first example at an airspeed of 244 KIAS 17,360 lbs. is us ed; a difference of 1,135 lbs.

This can be further improved by extending the straight and level legs of the holding pattern or by selecting a higher altitude.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-05 5-8 01 JUL 13 Figure 5-4. Effect of Draft Index on Holding.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-05 5-9 01 JUL 13 EFFECT OF DRAG INDEX ON HOLDING

Any increase in drag also increases t he fuel flow at the recommended holding speed. To compensate for a drag index we use a Fuel Flow Correction Factor (Fig. 5-4).

EXAMPLE: (Fig. 5-4)

Use the following values to co mpute the holding fuel flow.

DRAG INDEX = 80

UNCORRECTED FUEL FLOW = 17,360 lbs./hr.

Enter the bottom of the chart with a drag index of 80. Read vertically to the correction line. The fuel flow correcti on factor is 1.20. To determine the corrected fuel flow, multiply the correction factor by the uncorre cted fuel flow. In this case the corrected fuel flow is 20,832 lbs./hr. (1.2 x 17,360 = 20,832).

Computing holding data is relatively easy, but there are additional holding requirements not addressed. When holding is required in lieu of an alternate at a remote destination carry an additional one h our and 15 minutes of holding fuel. Compute additional holding fuel using t he three-engine holding chart from T.O. 1C-10(K)A-1-1, section 6, 25 degree bank angle, pl anned destination gross weight, and FL 200. A remo te or island destinati on is defined any aerodrome which, due to its unique geographic location , offers no suitable alternate (civil or military) within 2 hours flying time. Th is will be also be covered later in the mission planning lesson.

This completes the instructional part of this segment. A few chart exercises follow. They are to be completed as a review and reinforcement of the segment. You will need a performance manual and a ca lculator may be helpful. As always, any questions should be directed to an instructor as soon as possible.KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-05 5-10 01 JUL 13 5.4 SEGMENT EXERCISE HOLDING

Using the following values, compute hol ding data for the listed conditions:

GROSS WEIGHT = 362,000 lbs. ALTITUDE = 10,000' BANK ANGLE = 25 °

Find three engine holding speed in a clean configuration:

1. Airspeed __________________

2. N 1 RPM __________________

3. Fuel Flow __________________

Find three engine holding speed with slats extended:

4. Airspeed __________________

5. N 1 RPM __________________

6. Fuel Flow __________________

Find Two Engine holding speed:

7. Airspeed ___________________

8. N 1 RPM ___________________

9. Fuel Flow ___________________

Find One Engine holding speed:

10. Airspeed ___________________

11. N 1 RPM ___________________

12. Fuel Flow ___________________

Given a drag index of 50, co mpute a Fuel Flow Factor:

13. Fuel Flow Fa ctor ___________________KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-05 5-11 01 JUL 13 5.5 SEGMENT EXERCISE ANSWER KEY

HOLDING

For Academic Aircraft Performance Comput ation Tolerances, see AFI 11-2KC-10V2.

1. 226 KIAS 2. 72.7% 3. 15,090 lbs./hr. 4. 195 KIAS 5. 76.7% 6. 17,100 lbs./hr. 7. 227 KIAS 8. 83.0% 9. 14,560 lbs./hr. 10. 229 KIAS 11. 105.4% 12. 14,970 lbs./hr. 13. 1.125KC-10 Aircrew Training System Climb, Cruise, and Holding Data

CH 5
W836-05 5-12 01 JUL 13 THIS PAGE INTENTIONALLY LEFT BLANK