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KC-10 Aircrew Training System

Principles of Cargo Restraint

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KC-10 Aircrew Training System

Principles of Cargo Restraint

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TABLE OF CONTENTS

1.0 INTRODUCTION .............................................................................................. 1-1

2.0 OBJECTIVES ................................................................................................... 2-1

3.0 TERMINOLOGY ............................................................................................... 3-1

4.0 CARGO RESTRAINT REQUIREMENTS ......................................................... 4-1

5.0 RESTRAINT WITH CARGO NETS .................................................................. 5-1

6.0 RESTRAINT WITH STRAPS AND CHAINS ..................................................... 6-1

7.0 LESSON SUMMARY ........................................................................................ 7-1
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1.0 INTRODUCTION

The KC-10A can carry large amounts of cargo of all types. The primary method 

of transport is by pallets, which are secured in the cargo loading system by side 

(lateral) and end (longitudinal) restraint devices. An alternate method is loading 

cargo directly on the aircraft floor when the system has been removed from the 

aircraft.

It is extremely important that cargo is secured so that it will not shift during any 

phase of the mission. Two methods are used: General cargo, boxes, drums, etc. 

is attached to pallets by nets. Straps and chains tie down larger items, such as 

ground support equipment and vehicles.

AFI 11-2KC-10, Volume 3, Chapter 13, directs responsibility for cargo loading, 

including restraint of the load. Under supervision of the boom operator, air freight 

personnel prepare the aircraft for loading, physically load the aircraft, secure 

cargo and equipment, release tie-downs, and physically offload the cargo.

This workbook provides you with an overview of restraint criteria, fundamental 

principles, and methods for computing restraint requirements. Lesson exercises 

provide the opportunity to compute the restraint required for various loads and 

load configurations.

1.1 References

The information and procedures contained in this workbook have been extracted 

from the following publication:

1. T.O. 1C-10(K)A-9, Cargo Loading Manual

1.2 Additional Equipment

1. T.O. 1C-10(K)A-9, Cargo Loading Manual

2. Pencil

3. Calculator
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2.0 OBJECTIVES

Identify the characteristics of cargo restraint requirements using:

1. Side and top nets

2. Straps and chains

3. Low Profile Cargo

4. Computation Procedures

5. Device Measurement

6. Restraint Computation

7. Practical Application

8. Compute Cargo Restraint
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3.0 TERMINOLOGY

3.1 Load Factor

The ratio between cargo weight and the maximum force that will act in each 

direction is called the load factor. Load factors are expressed in units of the force of 

gravity. For example, a load factor of 2.5 means the tiedowns on a piece of cargo 

must be able to support 250% of its weight. Cargo weight of 2000 lbs. X 2.5 load 

factor = 5000 lb. required restraint.

3.2 Cargo Restraint Load Factors

Factors applied to the weight of the cargo so that it will not shift because of dynamic 

forces encountered during takeoff, flight, and landing. The applied restraint must be 

adequate for the greatest load that may result.

3.3 Criteria

A standard or established rule.

3.4 Restraint Criteria

The minimum restraint used to prevent cargo movement in any direction is called 

the restraint criteria. It is expressed in units of the force of gravity or load factor.

3.5 Forward/Aft Effective Length

The length measured from a point directly beneath the chain or strap attachment 

point on a unit of cargo, along a longitudinal axis, to a point lateral to the pallet 

tiedown ring being used.

3.6 Lateral Effective Length

The length measured from a point directly beneath the chain or strap attachment 

point laterally to the row of pallet tiedown rings being used.

3.7 Vertical Effective Length

The length measured from the chain or strap attachment point on a unit of cargo to 

a point directly beneath it on the pallet.

3.8 Parallel

Extending in the same direction and at a constant distance apart, so as to never 

meet.
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3.9 Symmetrical Tiedown

Tiedown devices attached in a uniform pattern by using corresponding 

tiedown points on each side of the cargo unit.

3.10 Center of Gravity

The center of mass or balance point, of an object.

3.11 Floor Loaded Cargo

Any cargo loaded on shoring and secured directly to the cargo floor.

Complete the lesson exercise on the next page.
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3.12 Lesson Exercise

Complete the statements then compare your answers with those on the next page. 

If necessary, correct to 100% by referring to the text.

1. are applied to the weight of the cargo so 

that it will not shift because of loads resulting from dynamic forces 

encountered during takeoff, flight, and landing.

2. defines the minimum restraint used to 

prevent cargo movement in any direction, expressed in units of the force of 

gravity, or load factor.

3. The center of mass or balance point of an object is it’s .

4. is the length measured from a point 

directly beneath the chain or strap attachment point on a unit of cargo along 

a longitudinal axis, to a point lateral to the pallet tiedown ring being used. 

5. Lateral effective length is measured from a point ___

 laterally to the row of pallet rings being used.

6. A defines devices attached in a uniform pattern 

to tiedown points on each side of the cargo item.
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3.13 Lesson Exercise Answer Key 

1. Cargo Restraint Load Factors

2. Restraint Criteria

3. Center of Gravity

4. Forward/Aft Effective Length

5. Directly beneath the chain or strap attachment point

6. Symmetrical Tiedown
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4.0 CARGO RESTRAINT REQUIREMENTS

The KC-10 cargo handling system utilizes USAF standard HCU-6/E cargo pallets. 

A two-inch lip around the pallet perimeter fits into restraint rails and assemblies. 

When properly configured pallets are locked in place, the cargo load meets all 

restraint requirements.

4.1 Minimum Restraint Factors

The minimum restraint factor used to prevent cargo movement in any direction are

called the restraint criteria. Expressed in units of the force of gravity or load factor, 

minimum restraint criteria for the KC-10 are as follows:

DIRECTION RESTRAINT CRITERIA

Forward (with cargo barrier net) 1.5 g=s

Forward (without cargo barrier net) 9.0 g=s

Aft 1.5 g=s

Lateral 1.5 g=s

Vertical 2.0 g=s
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5.0 RESTRAINT WITH CARGO NETS

Cargo items are secured to pallets by two HCU-7/E side nets and one HCU-15/C 

top net. The nets are fastened to rings, which are arranged, on the pallet edges. 

When properly secured, the three nets provide all necessary restraint including 

longitudinal and lateral restraint of 1.5 g=s, and vertical restraint of 2.0 g=s, for 

palletized loads up to 10,000 pounds.

5.1 Nets

Before the use of cargo nets is covered, lets review how they are used. Nets 

secure cargo items, such as boxes and barrels, etc., to the HCU-6E pallets. Side 

nets are fastened to 22 pallet tie-down rings, 5 on each 88-in. end, and 6 on each 

108-in. side. (Figure 5-1)

Figure 5-1. HCU-6E Pallet Tie Down Rings.
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5.2 Side Nets

Two HCU-7/E side nets are used. The nets are olive drab with yellow markings. 

There are several adjustment fittings to make the net conform to the load profile. 

Each net has 11 hooks on the bottom edges that are fastened to the pallet rings on 

one side and one end.

Figure 5-2. HCU-7/E Side Net.
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5.3 Top Nets

One HCU-15/C top net is used to prevent upward movement of cargo items. Top 

nets are yellow with blue markings. The net is attached to rings on the side nets by 

snap hooks. (Figure 5-3)

Figure 5-3. HCU-15/C Top Net.
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5.4 Attaching Nets To HCU-6/E Pallets

For your general information, these are the procedures used by airfreight personnel 

to properly connect net sets. Start with a side net. Beginning at any corner, fasten 

the net attaching hooks to pallet rings around the pallet periphery to the corner 

diagonally opposite from the beginning corner. Using the other side net, continue 

fastening net attaching hooks to the rings around the pallet to the beginning corner. 

Cross the hook assemblies at all corners. (Figure 5-4a and 5-4b)

Figure 5-4a. Side Net Attachment.
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Figure 5-4b. Side Net Attachment.
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Fasten the two side nets together, using the fastening devices at each end of the 

nets. Use the corner straps to help hold the net in place until the top net is 

attached. (Figure 5-5)

Place an HCU-15/C top net over the cargo. Use the snap hooks to fasten it to the 

rings on the side nets.

Do not connect the hooks to the side net webbing, the pallet tiedown rings, or the

bottom row of side net rings. Lock all fastening devices securely.

Use the adjusting buckles to tighten the nets around the cargo. (Figure 5-6)

When a top net is used with side nets, the top 

net hooks shall only be connected to the side net 

attachment rings. The hook strap shall not be 

routed under side net webbing and then to the 

side net ring. Improperly installed nets do not 

provide required restraint and are a matter of

safety of flight.

NOTE

Netted cargo shall not be loaded into the aircraft 

until the fastening devices are properly 

connected.
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Figure 5-5. Assembled Side Nets.

Figure 5-6. Palletized Cargo.
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5.5 Low Profile Cargo Palletizing Procedures

When low-profile cargo that does not permit the use of side nets is loaded on a 

pallet a top net may be used alone, provided the pallet’s net weight does not 

exceed 2500 lb. and the pallet height is 45 inches or less measured from the pallet 

surface.

The top net will provide all required restraint, when the following procedures are

adhered to:

1. The top net shall be placed over the cargo and cinched to the pallet, using 

the hooks on the net and the pallet tiedown rings.

However, if the pallet’s net weight exceeds 2500 lbs or the pallet height is greater 

than 45 inches, the top net will provide only vertical restraint. Supplemental CGU1/B straps must be added to provide longitudinal and lateral restraint. (Figure 5-8)

Net weight of palletized cargo is 2500 pounds or less 

45 inches in height or less

Figure 5-7. Low Profile Cargo W/ Top Net.
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Net weight of palletized cargo exceeds 2500 pounds

Figure 5-8a. Low Profile Cargo W/ Top Net and 5000 lb. Straps.

Net weight of palletized cargo is less than 2500 pounds, but height is greater than

45 inches.

Figure 5-8b. Low Profile Cargo W/ Top Net and 5000 lb. Straps.
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An alternate method of restraining high-density, low profile cargo on pallets is to use HCU7/E side nets in conjunction with 5,000-pound CGU-1/B straps. (Figure 5-9)

Use the following procedures to connect the nets:

1. HCU-7/E side nets shall be attached to each other.

2. Pull the nets tightly over the top of the cargo and secure them to the pallet 

with CGU-1/B tiedown straps.

3. Connect the straps to the highest level of side-net rings near the top of the 

cargo. Use a minimum of seven straps. Attach four on the 108" sides and 

three on the 88" sides.

Figure 5-9. Low Profile Cargo W/ Side Nets and 5000 lb. Straps
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5.6 LESSON EXERCISE

Complete the following statements then check your answers with those on the next page. 

If necessary, correct to 100% by referring to the text.

1. When properly secured, the HCU-7/E side nets and the HCU-15/C top net provide 

all necessary restraint for palletized loads up to pounds.

2. Improperly installed nets do not provide required restraint and are a matter of ____

 .

3. Netted cargo shall not be loaded into the aircraft until the fastening devices are

 .

4. Top net hooks shall not be connected to side net webbing, the bottom row of side 

net rings, or the .

5. If more than lbs. of low-profile cargo is placed on a pallet, the top net 

will provide only vertical restraint.

6. When securing high-density, low-profile cargo with two side nets and 5,000 pound 

straps, a minimum of straps are required.
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LESSON EXERCISE ANSWER KEY

1. 10,000

2. Safety of flight

3. Properly connected

4. Pallet tiedown rings

5. 2500

6. Seven
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6.0 RESTRAINT WITH STRAPS AND CHAINS

When a tiedown strap or chain is placed around a cargo unit, and the tiedown 

attachment points are to two opposite pallet rings, the value of the strap or chain 

is doubled, provided the pallet ring allowable restraint value is not exceeded.

Ties made solely for one load direction cannot be expected to restrain cargo 

against a load applied simultaneously from another direction.

When a tiedown device is attached directly to a cargo unit and not merely 

passed over or around it, restraint can be applied for more than one load 

direction, depending on the strength of the device and the angle of the pull off 

from the tiedown fitting. By varying the angle of attachment, a tiedown device 

can be attached to the cargo so that restraint is available simultaneously in three 

directions.

The point of attachment of a tiedown device to a cargo unit must be substantial 

enough to withstand the loads for which the cargo unit is being restrained. A 

tiedown device must not be attached to any convenient protrusion on a cargo 

unit without due consideration of the protrusion’s strength.

Tiedowns should be attached in a symmetrical pattern by using corresponding 

fittings on each side of the cargo pallet. Unsymmetrical tiedowns permit load 

distribution, which may ultimately result in tiedown device failure.

If two tiedown devices of the same type and capacity are used to restrain a load 

in a given direction, and one is longer than the other, the longer tiedown with its 

greater stretch potential will permit the shorter tiedown to assume the majority of 

any load.

When two or more tiedown devices are required to restrain a unit of cargo for a 

given load distribution, the devices must be of the same type, and the tiedowns 

must be approximately the same length.

Tiedown devices must be appropriate for the cargo to be restrained so neither 

cargo nor tiedown device will be damaged.

Like types and lengths of tiedown devices should be used for a given direction 

of restraint.

Strength Ratings:

Strap - 5,000 lbs.

Chain -10,000 lbs.

Pallet Ring - 7,500 lbs. per ring in all directions except vertical. The vertical 

limitation is 2,500 pounds per ring. This limitation is due to the strength of the 

cargo handling system components and the floor structure.
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6.1 Application of Devices

Example - A chain (10,000 lbs) attached to a pallet ring (7,500 lbs) can be 

computed for a maximum of 7,500 lbs restraint in the forward, aft or lateral (left 

and right) directions. The same chain can only be applied to a maximum of 

2,500 pounds vertical restraint.

General Rules

1. Compute the number of tiedown devices required.

2. Apply aft restraint in the opposite direction but at the same angle as 

forward restraint. Use the same attachment point where possible.

3. Always use an even number of devices; i.e., 2, 4, 6, 8.

4. Attach devices in a symmetrical pattern.

5. If the cargo item center of gravity is not in the center of the load, add 

an additional pair of restraints so that the center of gravity will be 

between two pairs of tiedowns.

6. When securing vehicles, do not attach more than one half of the 

devices to the axles. (Figure 6 -1)
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This vehicle is restrained (tied down) in accordance with basic rules and principles. The 

four chains are of similar length, and attached directly to the vehicle. They are the 

minimum number required to provide restraint in three directions, forward/aft, lateral 

(side to side), and vertical.

LATERAL

FWD / AFT W0194-14

Figure 6-1. Vehicle Restraint.
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6.2 Attachment of Straps and Chains

During cargo operations not all items of cargo, particularly wheeled vehicles, will 

be “pre-palletized,” or loaded and secured to pallets for you. In many instances 

you will have to direct the assigned load team personnel in the application of 

correct tiedown procedures. Previously in this workbook we have discussed the 

basic rules involved; i.e., even number of devices, symmetrical attachment, etc. 

In this section we’ll look at how to go about determining optimum tiedown 

placement. In many cases the size and/or the available attachment points may 

dictate, or limit, your ability to optimize restraint device capability. In those 

circumstances your procedures will be as dictated by the item of cargo. 

However, in most situations you will have many options as to the attachment 

location of restraint devices. The following example presents a selection of 

choices available. Remember the basic rules: Limit the number of restraint 

devices required, attach each device so that it provides restraint in three 

directions, forward or aft, lateral and vertical. Our first example, Figure 6-2 

Option One, has straps attached to rings at the top of each corner. The circles 

represent lateral and vertical restraint. The dashed lines illustrate forward/aft 

and vertical restraint. If either of these applications were employed separately, 

no restraint would be applied in the opposite direction.

 

LATERAL Top View

FWD / AFT

Figure 6-2. Restraint Option One.
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FWD / AFT

Figure 6-3. Restraint Option Two.

This is one acceptable solution. Each strap provides forward or aft, lateral and vertical 

restraint.

LATERAL

FWD / AFT

Figure 6-4. Restraint Option Three.

This is also an acceptable solution. Each strap provides forward or aft, lateral and 

vertical restraint.
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6.3 Computation Procedures

Computing tiedown restraint is done by the application of standard formulas and 

procedures, which are in the -9 cargo-loading manual. This information has been 

compiled into the KC-10 Restraint Computation Worksheet. All the formulas are 

listed for your convenience, and there are spaces for the entry of all required 

data.

Figure 6-5 is an example of how the form is used. Take some time to review it 

and the information entered.
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RESTRAINT REQUIREMENTVERTICAL - 2.0 X NET WIEGHTALL OTHERS - 1.5 X NET WEIGHT

MAXIMUM

VERTICAL

RESTRAINT

2,500 LBS

PER RING

VERT.

TYPE DEVICE

C - 7,500

S - 5,000

ITEM WEIGHT

RESTRAINT VALUES (LBS)

WHEN VERTICAL IS LESS THAN 2,500 LBS

LONG = X C OR S

D

-

A

WHEN VERTICAL IS EQUALTO OR GREATER

THAN 2,500 LBS

VERTICAL

TOTAL APPLIED RESTRAINT

ECI VED

HT GNEL

REBMUN ECI VED

LACI TREV

EVI TCEFFE

HT GNEL

TFA/ D WF

EVI TCEFFE

HT GNEL

LARETAL

EVI TCEFFE

HT GNEL

ECI VED EPYT

A

123456789

10

11

12131415161718

B D E

TOTAL REQUIRED RESTRAINT

FWD AFT LEFT RIGHT

B

A

X C OR S

D

B

LONG = X 2,500

E

A

LAT = X C OR S

E

B

LAT = X 2,500

D

A

B

E

AF FORM 4130, 19990701 (EF-V1) REPLACES MC FORM 31, DEC 93, WHICH IS OBSOLETE.

KC-10 RESTRAINT COMPUTATION WORKSHEET

3000

60 36 24 33 C 2500 1666 2291

4582 10000

6000

3332

4500

CCC

60 36 24 3360 36 24 3360 36 24 33

250025002500

1666

16661666

2291

22912291

3332 4582

Figure 6-5. Restraint Computation Worksheet Example. Equipment Drawing
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6.3.1 Device Measurement

The first step in computing the values of applied restraint devices is to obtain the 

measurements. In this example we have a vehicle secured to a pallet by the use 

of four symmetric straps, of the same length. (Figure 6-6) Compare your entries 

to the worksheet in Figure 6-7.

Step 1 - Measure the length of each device. Apply your tape measure to the 

device and measure from the center of the pallet ring to the center of the 

attachment point. Refer to the diagram and enter the length of each device on 

the portion of the restraint computation worksheet.

Step 2 - Measure the vertical effective length. Place your tape on the pallet, 

directly beneath the cargo attachment point, and measure up to the center of the 

attachment. Refer to the diagram and enter the vertical effective lengths on the 

worksheet.

Step 3 - Measure the forward or aft effective length. From the center of the 

tiedown ring, measure forward or aft longitudinally along the edge of the pallet 

until directly opposite of the cargo attachment point. Refer to the diagram and 

enter the forward or aft effective lengths on the worksheet.

Step 4 - Measure the lateral effective length. From the point on the pallet directly 

under the cargo attachment point measure laterally to the edge of the pallet 

surface by the tiedown rings. Refer to the diagram and enter the lateral effective 

lengths on the worksheet.
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W019-06 6-9 01 OCT 14 DEVICE NUMBER DEVICE LENGTH VERTICAL EFFECTIVE LENGTH FWD/AFT EFFECTIVE LENGTH LATERAL EFFECTIVE LENGTH TYPE 

DEVICE

A B D E

1

2

3

4

5

6

Figure 6-6. Device Measurement.
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Your entries should match these. DEVICE NUMBER DEVICE LENGTH

VERTICAL

EFFECTIVE

LENGTH

FWD/AFT

EFFECTIVE

LENGTH

LATERAL

EFFECTIVE

LENGTH

TYPE DEVICE

A B D E

1 35 12 30 10 S

2 35 12 30 10 S

3 35 12 30 10 S

4 35 12 30 10 S

5

6

Figure 6-7. Device Measurement Entries.
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6.3.2 Restraint Computation

There are two procedures for computing applied restraint - Ratio Method One 

and Ratio Method Two. These procedures are necessary due to the KC-10's 

specific vertical restraint limitation of 2,500 pounds. At first glance these 

requirements may seem overly complicated, but with a little practice they will 

become easier to apply.

Ratio Method One is used when the computed vertical restraint is less than 2,500 

pounds.

Ratio Method Two is used when the computed vertical restraint is 2,500 pounds 

or greater.

The first rule of restraint is to always compute the applied vertical - FIRST. To 

compute required vertical, simply divide the vertical effective length (height of the 

attachment point from the pallet surface) by the length of the strap or chain. 

Next, multiply by 5,000 (strap) or 7,500 (chain), whichever applies. If the answer 

is not an even number, always round down. For example: 2238.5 rounds to 

2238.

VERTICAL RESTRAINT CALCULATION EXAMPLE

Vertical Effective Length: 40 X Strap or Chain = Applied Restraint Strap or Chain Length: 100

Using Straps

40 ÷ 100 = .40 x 5000 = 2000 lbs. Vertical restraint

Using Chains

40 ÷ 100 = .40 x 7500 = 3000 lbs. Vertical restraint

So, we have determined the applied vertical restraint for this strap or chain. We’ll 

discuss straps first. Since the applied vertical restraint (2000) is less than the

vertical limitation of 2500, we will compute all other applied restraint (lateral, 

forward, or aft) using the applicable effective length divided by the strap or chain 

length. It’s the same formula used to compute the vertical rating - the strap 

length is the common denominator, and it’s known as Ratio Method One.
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RATIO METHOD ONE (Vertical restraint less than 2500 lbs.)

Forward Restraint

Forward Effective Length: 50 X 5000 = Applied Restraint Strap Length: 100

50 ÷ 100 = .50 x 5000 = 2500 lbs forward restraint

Lateral Restraint 

Lateral Effective Length: 25 X 5000 = Applied Restraint Strap Length: 100

25 ÷ 100 = .25 x 5000 = 1250 lbs Lateral restraint

From our calculations we see that this strap provides 2000 lbs. vertical, 2500 lbs. 

forward and 1250-lbs. lateral restraint. Remember the steps: First, compute vertical 

applied restraint. If it is less than 2500 compute the lateral and forward (or aft) restraint 

using the strap or chain length as the divisor. Now, it’s your turn.

Practice Exercise One Compare your entries with the answers on Page 6-15.

Vertical Effective Length: 28

Strap Length: 60

Lateral Effective Length: 42

Aft Effective Length: 50

How much restraint is applied in the vertical?

Vertical Effective Length ( ) ÷ Strap Length ( ) x ( ) = lbs 

Vertical Restraint.

Which ratio method will you use to compute the lateral and longitudinal restraint? 

One or two

Next, use the applicable formulas to compute the aft and lateral restraint.

The applied aft restraint is ___________lbs.

The applied lateral restraint is ____________lbs.
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RATIO METHOD TWO (Vertical restraint greater than 2500 lbs.)

Using the numbers in Exercise One, compute the vertical restraint using a chain in 

place of a strap. 28 ÷ 60 = .46 x 7500 = 3499 lbs. applied vertical restraint.

Here is where it gets interesting. As you can see, the computed vertical restraint, 3499, 

exceeds the KC-10 specific vertical limitation of 2500. Briefly, what this means is the 

chain secures the cargo to the pallet at a higher rate than the pallet is secured to the 

floor. In this case, we mathematically limit the applied vertical restraint to the aircraft 

rate of 2,500 lbs.

The formula used to calculate the applied lateral and forward (or aft) restraint is 

changed to use the vertical effective length as the common denominator. The length of 

the strap or chain is not a factor in Ratio Method Two, as all calculations are based on 

the vertical length. For example, using the measurements in Exercise One, the 

remaining restraint is computed this way:

Forward / Aft

Aft Effective Length: 50 X 2500 = Applied Restraint Vertical Effective Length: 28

50 ÷ 28 = 1.78 x 2500 = 4,464 lbs. aft restraint.

Lateral

Lateral Effective Length: 42 X 2500 = Applied Restraint Vertical Effective Length: 28

42 ÷ 28 = 1.5 x 2500 = 3,750 lbs. lateral restraint.

Practice Exercise Two: Compare your entries with the answers on Page 6-15.

A chain attached to an item of cargo has the following measurements:

Vertical Effective Length: 30

 Chain Length: 50

Lateral Effective Length: 40

 Aft Effective Length: 55

Vertical Effective Length ( ) ÷ Chain Length ( ) x ( ) = lbs. 

Vertical Restraint.
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Principles of Cargo Restraint

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W019-06 6-14 01 OCT 14

Which ratio method will you use to compute the lateral and longitudinal restraint?

Circle your answer- one or two.

Next, use the applicable formulas to compute the aft and lateral restraint.

The applied aft restraint is _____________lbs.

The applied lateral restraint is __________lbs
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Principles of Cargo Restraint

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W019-06 6-15 01 OCT 14

EXERCISE ANSWERS

Exercise One

28 ÷ 60 = .46 x 5000 = 2333

Ratio Method One is used to compute lateral and longitudinal restraint.

Applied aft restraint: 4,166 lbs.

Applied Lateral restraint: 3,500 lbs.

Exercise Two

30 ÷ 50 = .6 x 7500 = 4500. Restricted to 2500.

Ratio Method Two is used to compute lateral and longitudinal restraint.

Applied aft restraint: 4,583 lbs.

Applied Lateral restraint: 3,333 lbs.
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Principles of Cargo Restraint

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W019-06 6-16 01 OCT 14

6.3.3 Restraint Computations Worksheet Exercise One

On the next page, complete the calculations required to determine applied versus 

required restraint. Steps 1, 2, 3, and 4 have the same measurements.

Figure 6-8. Restraint Computation Exercise.
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Figure 6-9. Restraint Computation Exercise Worksheet (1).
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Figure 6-10. Restraint Computation Exercise Worksheet (2).
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Figure 6-11. Restraint Computation Exercise Worksheet (3).
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6.3.4 Restraint Computations Worksheet Exercise Two

On page 6-23, determine the applied versus required restraint.

73" 73"73" 73"

59" 51"59" 51"

FWD

52"

42"

52"

42"

45"

18" 12"

46"

TITLENEW WT: 6425

NOTE:MEASUREMENTS IDENTICALFOR CHAIN PAIRS: 1.2

3.45.67.8

1

2

3

4

5

6

78

 
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RESTRAINT REQUIREMENTVERTICAL - 2.0 X NET WIEGHTALL OTHERS - 1.5 X NET WEIGHT

MAXIMUM

VERTICAL

RESTRAINT

2,500 LBS

PER RING

VERT.

TYPE DEVICE

C - 7,500

S - 5,000

ITEM WEIGHT

RESTRAINT VALUES (LBS)

WHEN VERTICAL IS LESS THAN 2,500 LBS

LONG = - X C OR S D

A

WHEN VERTICAL IS EQUAL TO OR GREATER

THAN 2,500 LBS

VERTICAL

TOTAL APPLIED RESTRAINT

ECI VED

HT GNEL

REBMUN ECI VED

LACI TREV

EVI TCEFFE

HT GNEL

TFA/ D WF

EVI TCEFFE

HT GNEL

LARETAL

EVI TCEFFE

HT GNEL

EPYT

ECI VED

A

123456789

10

11

12131415161718

B D E

TOTAL REQUIRED RESTRAINT

FWD AFT LEFT

: ET ON

LACI TNEDI STNE MERUSAE M

: SRI AP SNI AHC ROF

B

A

X C OR S

D

B

LONG = X 2,500

E

A

LAT = X C OR S

E

B

LAT = X 2,500

B

A

E D

KC-10 RESTRAINT COMPUTATION WORKSHEET

" 37 " 37

" 37 " 37

" 15 " 95

" 15 " 95

2, 1

4, 3

6, 5

8, 7

3

1

2

4

5

6

7

8

D WF

”25 ”25

”24 ”24

”54 ”64

”81 ”21

RIGHT

6425 Hummer

CCCCCCCC

3030353524243030

Figure 6-12. Restraint Computation Exercise 2 - Worksheet.
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Figure 6-13. Restraint Computation Exercise 2 - Answers

9637
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6.3.5 Restraint Computation using strap and strap/chain combinations.

The following diagrams are examples of the various ways an item of cargo (a 

steel box) may be secured. There may be some cases that you have no choice 

and have to use a mixture of both chains and straps on the same piece of 

cargo. This may be due to equipment failures or a lack of devices. 

According to T.O. 1C-10(K)A-9 when two or more tiedown devices are required 

to restrain a unit of cargo for a given load direction, the devices must be of the 

same type and the tiedown must be approximately the same length. Simply 

stated, you may use a combination of straps and chains, however, applied 

restraint cannot be counted in the same direction with dissimilar devices. 

Figure 6-14 is an example of a storage container restrained with all straps. 

Figure 6-17 is the same container with the weight increased to 4,850 lbs 

restrained with a combination of straps and chains.

For Exercise 3 Figure 6-14, use the container information in Figure 6-15 to 

compute the applied restraint. Check your answers against the answers 

provided in Figure 6-16.

For Exercise 4 Figure 6-17, use the container information in Figure 6-18 to 

compute the applied restraint and then check your answers provided in Figure 

6-19.
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6.3.6 Restraint Computations Worksheet Exercise 3 

On the next page, complete the calculations required to determine applied versus 

required restraint. 

 

Figure 6-14. Restraint Strap Example

WEIGHT: 1,350
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Figure 6-15. Restraint Computation Exercise 3 – Worksheet

EB X 2,500
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Figure 6-16. Restraint Computation Exercise 3 – Answers 2500 2500 2500 2500

9,686 11,844
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6.3.7 Restraint Computations Worksheet Exercise 4

On the next page, complete the calculations required to determine applied versus 

required restraint.

Figure 6-17. Mixed Chain and Strap Restraint Example

WEIGHT: 4,850
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Figure 6-18. Restraint Computation Exercise 4 – Worksheet

EB X 2,500
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Figure 6-19. Restraint Computation Exercise 4 – Answers

EB X 2,500

1757

1757

19280 17671 17671 19266

25002500

2500

2500
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7.0 LESSON SUMMARY

The primary means of transporting cargo in the military airlift system is by 

securing cargo items to HCU-6E pallets. Airfreight personnel are responsible for 

planning and assembling cargo loads to include securing items to pallets with 

nets, straps, and chains.

Boom operators are responsible for checking loads for proper assembly and 

security.

Use of Cargo Nets

 When properly secured, the HCU-7/E side nets and the HCU-15/C 

top net provide all necessary restraint for palletized loads up to 

10,000 pounds.

 Side nets must be fastened to pallet rings.

 Top nets must be fastened to side net rings. Check that they are 

not fastened to webbing, the bottom row of side net rings, or pallet 

rings.

 Improperly configured nets will not provide required restraint. This 

is a safety of flight concern.

 Do not allow netted cargo to be loaded unless all fastening devices 

are properly connected.

Use of Straps and Chains

 Devices must be of the same type, and the tiedowns must be 

approximately the same length.

 Like types and lengths of tiedown devices should be used for a 

given direction of restraint.

 Tiedown devices must be appropriate for the cargo to be restrained 

so neither cargo nor tiedown device will be damaged.

 Tiedowns should be attached in a symmetrical pattern by using 

corresponding fittings on each side of the cargo pallet.

 Unsymmetrical tiedowns permit load distribution, which may 

ultimately result in tiedown device failure.

 When a tiedown device is attached directly to a cargo unit, the point 

of attachment must be substantial enough to withstand the loads for 

which the cargo unit is being restrained.
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Restraint Criteria

All cargo must be secured to meet these minimum standards:

DIRECTION RESTRAINT CRITERIA

Forward (with cargo barrier net) 1.5 g’s

Forward (without cargo barrier net) 9.0 g’s

Aft 1.5 g’s

Lateral 1.5 g’s

Vertical 2.0 g’s

Computing Restraint

Two procedures are used to compute restraint requirements. They are 

necessary because KC-10 vertical restraint is limited to 2,500 pounds. 

Regardless of the procedure to be used, vertical restraint must be determined 

first.

 Ratio Method One is used when the computed vertical restraint is 

less than 2,500 pounds.

 Ratio Method Two is used when the computed vertical restraint is 

2,500 pounds or greater.

 The KC-10 Restraint Computation Worksheet (Figure 7-1) has the 

restraint formulas and requirements listed for easy reference. 

There is also a diagram in the upper left corner, which illustrates 

the formulas.
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Figure 7-1. KC-10 Restraint Computation Worksheet.

3,000lbs
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