Unit load device

File:Unloading JAL 747.jpg

Unloading LD3 containers from a Boeing 747

A unit load device (ULD) is a container used to load luggage, freight, and mail on wide-body aircraft and specific narrow-body aircraft. It allows preloading of cargo, provided the containerised load fits in the aircraft, enabling efficient planning of aircraft weight and balance and reduced labour and time in loading aircraft holds compared with 'bulk-loading' single items of cargo or luggage by hand. Each ULD has its own packing list or manifest so that its contents can be tracked. A loaded aircraft cargo pallet secured with a cargo net also forms a ULD, but its load must be gauged for size in addition to being weighed to ensure aircraft door and hold clearances.

The IATA publishes ULD regulations and notes there are 900,000 in service worth more than US$1 billion, averaging ${{#expr:1000/0.9round-2}} each.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Types

ULDs come in two forms: pallets and containers. ULD pallets are rugged sheets of aluminium with rims designed to lock onto cargo net lugs. ULD containers, also known as cans and pods, are closed containers often made of aluminium or a combination of aluminium (frame) and Lexan (walls) but there are examples of containers made of GRP with an insulating foam core. Depending on the nature of the goods to be transported, ULDs may have built-in refrigeration units. Examples of common ULDs and their specifics are listed below.

citation

CitationClass=web }}</ref> volume in cu.ft (m3), dimensions in inches (cm)
Type	Internal volume	Height	Depth	Width			Contour	IATA	Suitability
				Base	Overall	Nominal
citation	CitationClass=web }}</ref>	Template:Cvt	Template:Cvt	Template:Cvt	Template:Cvt	Template:Cvt	Full	Double	AKH	Airbus A319/Airbus A320/Airbus A321
LD2	Template:Cvt	Template:Cvt	Template:Cvt		Template:Cvt	Half	Single	APE	Boeing widebodies
LD3	Template:Cvt		Template:Cvt		Template:Cvt			AKE	Airbus and Boeing widebodies, DC-10/MD-11, L-1011
LD1	Template:Cvt				Template:Cvt			AKC	Boeing widebodies, MD-11
LD4	Template:Cvt		Template:Cvt		Template:Cvt	Full	None	AQP	Boeing 767/777/787
LD8 (2×LD2)	Template:Cvt				Template:Cvt		Double	AQF	Boeing 767/787
LD11	Template:Cvt		Template:Cvt				None	ALP	Boeing 747, 777, 787, DC-10/MD-11
PLA palletTemplate:Efn	Template:Cvt							PLA	747, 777, 787
LD6 (2×LD3)	Template:Cvt				Template:Cvt		Double	ALF	747/777/787, DC-10/MD-11
LD26 (P1P base)	Template:Cvt			Template:Cvt				AAF	Airbus A330, A340, A350, and Boeing 747/777/787, DC-10/MD-11
LD7 winged palletTemplate:Efn	Template:Cvt							P1P	747, 777, 787, DC-10/MD-11
LD7/P1P palletTemplate:Efn	Template:Cvt				Template:Cvt		None	P1P	All widebodies
LD9 (P1P base)	Template:Cvt							AAP	Boeing widebodies, DC-10/MD-11
LD29 (P1P base)	Template:Cvt				Template:Cvt		Double	AAU	747
LD39 (P6P base)	Template:Cvt			Template:Cvt				AMU	747
P6P palletTemplate:Efn	Template:CvtTemplate:Efn				Template:Cvt		None	P6P	747, 767, 777, 787, DC-10, MD-11

Notes

File:Unit load device sizes.png

Unit load device sizes

Aircraft compatibility

File:Airbus A300 cross section.jpg

Cross-section of an Airbus A300 showing LD3 containers

LD3s, LD6s, and LD11s will fit 787s, 777s, 747s, MD-11s, Il-86s, Il-96s, L-1011s and all Airbus wide-bodies. The 767 uses the smaller LD2s and LD8s because of its narrower fuselage. The less common LD1 is designed specifically for the 747, but LD3s are more commonly used in its place because of ubiquity (they have the same floor dimensions such that one LD3 takes the place of one LD1). LD3s with reduced height (Template:Convert instead of Template:Convert) can also be loaded on the Airbus A320 family. LD7 pallets will fit 787s, 777s, 747s, late model 767s (with larger doors), and Airbus wide-bodies.

Interchangeability of certain ULDs between LD3/6/11 aircraft and LD2/8 aircraft is possible when cargo needs to be quickly transferred to a connecting flight. Both LD2s and LD8s can be loaded in LD3/6/11 aircraft, but at the cost of using internal volume inefficiently (33 ft³ wasted per LD2). Only the LD3 of the LD3/6/11 family of ULDs can be loaded in a 767; it will occupy an entire row where two LD2s or one LD8 would otherwise have fit (90 ft³ wasted per LD3). Policies vary from airline to airline as to whether such transfers are allowed.

The 787, intended to replace the 767, was designed to use the LD3/6/11 family of ULDs to solve the wasted volume issue.<ref>Template:Cite book</ref>

ULD capacity

Widebodies

Model	Lower deck			Main deck
	Containers	88×125″	96×125″	96×125″	88×125″	88x108″
Airbus A300-600<ref name=A300>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	{{#expr:12+10}} LD3	4 + 10 LD3	4 + 10 LD3	20	21<ref name= A300-A310P2F/>
Airbus A310<ref name=A310>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	{{#expr:8+7}} LD3	3 + 7 LD3	3 + 7 LD3	15	citation	CitationClass=web }}</ref> ||
Airbus A330-2/800<ref name=A330>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	{{#expr:14+12}} LD3	{{#expr:4+4}}	{{#expr:4+4}}	{{#expr:18+4}}	{{#expr:20+3}}	{{#expr:22+4}}
Airbus A330-3/900<ref name=A330/>	{{#expr:18+14}} LD3	{{#expr:6+5}}	{{#expr:6+4}}	26	citation	CitationClass=web }}</ref> ||
Airbus A340-200<ref name=A342-3>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	{{#expr:14+12}} LD3	{{#expr:5+4}}	{{#expr:5+4}}
Airbus A340-300<ref name=A342-3/>	{{#expr:18+14}} LD3	{{#expr:6+5}}	{{#expr:6+4}}
citation	CitationClass=web }}</ref>	{{#expr:18+12}} LD3	{{#expr:6+4}}	{{#expr:6+4}}
Airbus A340-600<ref name=A345-6/>	{{#expr:24+18}} LD3	{{#expr:8+6}}	{{#expr:8+6}}
Airbus A350-900<ref name=A350>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	{{#expr:20+16}} LD3	{{#expr:6+5}}	{{#expr:6+5}}
citation	CitationClass=web }}</ref>	40 LD3		12	30
Airbus A350-1000<ref name=A350/>	{{#expr:24+20}} LD3	{{#expr:8+6}}	{{#expr:8+6}}
Airbus A380-800<ref name=A380>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	{{#expr:22+16}} LD3	{{#expr:7+6}}	{{#expr:7+6}}
Boeing 747 classic<ref name=B741-2-3-SP>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	Template:Abbr			28	28	36
Boeing 747SP<ref name=B741-2-3-SP/>	Template:Abbr
Boeing 747-400<ref name=B744>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	Template:Abbr	9 + 4 LD1	9 + 2 LD1	30	30
Boeing 747-8/8F<ref name=B748>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	Template:Abbr		12 + 2 LD1	{{#expr:27+5+2}}
Boeing 767-200<ref name=B767>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	Template:Abbr	3 + 10 LD2	3 + 10 LD2
Boeing 767-300<ref name=B767/>	Template:Abbr	4 + 14 LD2	4 + 14 LD2	14	{{#expr:14+2}}	{{#expr:24+2}}
Boeing 767-400<ref name=B767/>	Template:Abbr		5 + 16 LD2
Boeing 777-200<ref name=B777>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	{{#expr:18+14}} LD3	{{#expr:6+4}} + 2 LD3	{{#expr:6+4}}	27
Boeing 777-300<ref name=B777/>	{{#expr:24+20}} LD3	{{#expr:8+6}} + 2LD3	{{#expr:8+6}}	citation	CitationClass=web }}</ref> || ||
Boeing 777-8F<ref>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	40 LD3<ref>Template:Cite news</ref>		13	31
Boeing 777-9<ref name=B779>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	{{#expr:26+22}} LD3	{{#expr:9+7}}	{{#expr:8+6}} + 4 LD3
Boeing 787-8<ref name=B787>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	{{#expr:16+12}} LD3	{{#expr:5+4}}	{{#expr:5+3}} + 2 LD3
Boeing 787-9<ref name=B787/>	{{#expr:20+16}} LD3	{{#expr:6+5}}	{{#expr:6+5}}
Boeing 787-10<ref name=B787/>	{{#expr:22+18}} LD3	{{#expr:7+6}}	{{#expr:7+6}}
Douglas DC-10<ref>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	{{#expr:16+10}} LD3	5 + 8 LD3			22	30
McDonnell Douglas MD-11<ref>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	{{#expr:18+14}} LD3		6 + 14 LD3	26	26	34
Lockheed L-1011<ref>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	{{#expr:12+7}} LD3	4 + 7 LD3
Ilyushin Il-86/Il-96-300<ref>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	16 LD3
Ilyushin Il-96M/T<ref>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	32 LD3

Narrowbodies

Model		Containers	96×125″	88×125″	88x108″
Airbus A319<ref name=A319>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>		{{#expr:2+2}} LD3-45
Airbus A320<ref name=A320>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>		{{#expr:3+4}} LD3-45		citation	CitationClass=web }}</ref> ||
Airbus A321<ref name=A321>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>		{{#expr:5+5}} LD3-45		14<ref name=A320-A321P2F/>
Boeing 707-320C<ref name=B707>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>		no lower ULD		13	13
Boeing 727-100C<ref name=B727>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>		no lower ULDTemplate:Efn		8	8
Boeing 737-200C<ref name=B737>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>		no lower ULD		7	7
Boeing 737-300SF<ref name=B733>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>		no lower ULD		9
Boeing 737-400SF<ref name=B734>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>		no lower ULD		10 ½
Boeing 737-700C<ref name=B737/>		no lower ULD		8	8
Boeing 737-800SF<ref name=B738>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>		no lower ULD		11 ½
Boeing 757-200F<ref name=B757>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>		no lower ULD		15
Comac C919<ref>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>		citation	CitationClass=web }}</ref>
Douglas DC-8-55F<ref name="DC-8">{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>		no lower ULD		13
Douglas DC-8-62/72F<ref name="DC-8" />		no lower ULD		14
Douglas DC-8-61/63/71/73F<ref name="DC-8" />		no lower ULD		18
Douglas DC-9-15F<ref name="DC-9">{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>		no lower ULD			6
Douglas DC-9-32F<ref name="DC-9" />		no lower ULD			8
McDonnell Douglas MD-80SF<ref name="MD-80">{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>		no lower ULD	8	8	12

File:Loading LD3 cargo containers onto United Boeing 777-300ER.webm

LD3 containers being loaded onto a Boeing 777-300ER.

Aircraft loads can consist of containers, pallets, or a mix of ULD types, depending on requirements. In some aircraft the two types must be mixed as some compartments take only specific ULDs.

Container capacity of an aircraft is measured in positions. Each half-width container (LD1/LD2/LD3) in the aircraft it was designed for occupies one position. Typically, each row in a cargo compartment consists of two positions. Therefore, a full-width container (LD6/LD8/LD11) will take two positions. An LD6 or an LD11 can occupy the space of two LD3s. An LD8 takes the space of two LD2s.

Aircraft pallet capacity is measured by how many PMC-type LD7s Template:Cvt can be stored. These pallets occupy approximately three LD3 positions (two positions of one row and half of the two positions of the following row) or four LD2 positions. PMCs can only be loaded in cargo compartments with large doors designed to accept them (small door compartments are container-only).

File:FOIQRATR72.JPG

An ATR 72 with its cargo door open

Regional airliners

Model	LD3	46×66”	88×54”	88×62”	88×108”	96×125”
Fokker 100<ref>Template:Cite news</ref>	11
CRJ200<ref>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>				8
BAe 146-200<ref>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	9				6	4
ATR 72<ref name=ATRfamily>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	7			9	5
ATR 42<ref name=ATRfamily/>	5			6	3
Dash 8-300<ref>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>		9
Xian MA600<ref>Template:Cite news</ref>	5		5
Short 360<ref>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	5
Cessna SkyCourier<ref>{{#invoke:citation/CS1|citation	CitationClass=web }}</ref>	3

Identification

File:ULD nomenclature.svg

Dimension names of ULD (LD3/AKE shown)

All ULDs are identified by their ULD number. A three-letter prefix identifies its type and key characteristics,<ref name=VRR-IATA-ULD>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> followed by a 4 or 5 digit serial number (4 if prior to October 1, 1993; either 4 or 5 if after October 1, 1993) to uniquely identify it from others of the same type, and ending with a two character (alpha-numerical) suffix identifying the ULD's owner (if an airline, often the same as IATA designator codes). For example, AKN 12345 DL means that the ULD is a forkliftable LD3 with the unique number 12345 and its owner is Delta Air Lines.<ref name="Air_Cargo"> {{#invoke:citation/CS1|citation |CitationClass=web }} </ref>

IATA ULD prefix<ref name=VRR-IATA-ULD /><ref name="Air_Cargo"/>

TypeTemplate:Efn	Base sizeTemplate:Efn (depth × base width)	Contour/restraintTemplate:Efn (overall width × height)
Template:Ubl	Template:Ubl	Template:Ubl

Notes

Common prefixes

File:LD-air-freight-containers.jpg

A string of LD3 containers with AKE prefix

File:Germanwings Container 03.jpg

An LD3-45 container with AKH prefix. An AKE prefix ULD is visible to the right.

• AAA: LD7 container (Template:Convert), Template:Convert tall, contoured for maindeck narrow-body
• AAD: LD7 container (Template:Convert), Template:Convert tall, contoured for maindeck wide-body (aka A1)
• AAF:<ref name="Boeing_Cargo">"Boeing Cargo" Template:Webarchive, Boeing, March 2012.</ref> LD26 container
• AAP:<ref name="Boeing_Cargo"/> LD9
• AAU:<ref name="Boeing_Cargo"/> LD29 container
• AAY: LD7 container (Template:Convert), Template:Convert tall, contoured for maindeck wide-body and narrow-body (aka A2)
• AAZ: LD7 container (Template:Convert), Template:Convert tall, contoured for maindeck wide-body and narrow-body and any belly (aka L9)
• AGA:<ref name="Boeing_Cargo"/> M2 container
• AKC:<ref name="Boeing_Cargo"/> LD1 without forklift holes
• AKE:<ref name="Boeing_Cargo"/> LD3 without forklift holes/half ALF
• AKH, AKW: LD3-45 mainly for A320/321, Template:Convert tall, same base as AKE, extensions on both sides
• AKN:<ref name="Boeing_Cargo"/> LD3 with forklift holes
• ALB:<ref name="Boeing_Cargo"/> LD4 with forklift holes
• ALD: LD11 container (aka L11)
• ALF:<ref name="Boeing_Cargo"/> LD6 without forklift holes
• ALP:<ref name="Boeing_Cargo"/> LD11 without forklift holes
• ALP:<ref name="Boeing_Cargo"/> LD4 without forklift holes
• AMA:<ref name="Boeing_Cargo"/> M1 container
• AMD:<ref name="Boeing_Cargo"/> M1H container
• AMJ: LD7 container (Template:Convert), Template:Convert tall, contoured for main deck wide-body (aka M1)Template:Cn
• AMU:<ref name="Boeing_Cargo"/> LD39 container contour similar to ALF, but deeper and bigger extensions. biggest lower-deck container
• AVY:<ref name="Boeing_Cargo"/> LD1 with forklift holes
• AWC:<ref name="Boeing_Cargo"/> LD6 with forklift holes
• AYY:<ref name="Boeing_Cargo"/> Demi, a half-width contoured container typically used for the main deck
• AYX:<ref name="Boeing_Cargo"/> AYY with fittings to connect a fire extinguisher so as to carry Dangerous Goods
• DPE:<ref name="Boeing_Cargo"/> LD2 without forklift holes
• DPN:<ref name="Boeing_Cargo"/> LD2 with forklift holes
• DQF:<ref name="Boeing_Cargo"/> LD8 with forklift holes
• FLA:<ref name="Boeing_Cargo"/> LD11 pallet
• FQA: LD8 pallet (same floor dimensions as DQF)
• HMA:<ref name="Boeing_Cargo"/> Horse stall
• KMA:<ref name="Boeing_Cargo"/> Sheep and goat pen
• P1P:<ref name="Boeing_Cargo"/> LD7, large pallet (Template:Convert), folding wings for overhang
• PAD:<ref name="Boeing_Cargo"/> LD7, large pallet (Template:Convert), flat
• PGA:<ref name="Boeing_Cargo"/> M6, large pallet (Template:Convert), freighter main deck only
• PLA:<ref name="Boeing_Cargo"/> LD11 pallet
• PMC: LD7, large pallet (Template:Convert)
• QKE: LD3 same as AKE but made of KEVLAR and designed to be bombproof. No forklift holes.
• RAP:<ref name="Boeing_Cargo"/> LD9 with refrigeration unit
• RAU:<ref name="Boeing_Cargo"/> LD29 container with refrigeration unit
• RKN:<ref name="Boeing_Cargo"/> LD3 with refrigeration unit
• RWB:<ref name="Boeing_Cargo"/> LD11 with refrigeration unit
• SAA: Full-sized version of the AYY
• SAX: Full-sized version of the AYX
• VRA:<ref name="Boeing_Cargo"/> M6, large pallet (Template:Convert), twin car rack
• XAW:<ref name="Boeing_Cargo"/> LD7, large pallet (Template:Convert), fixed wings for overhang
• XKC: LD3 without forklift holes/half ALFTemplate:Cn

Main-deck ULDs

On the main deck of cargo planes are Template:Convert tall ULDs with footprints similar to those of Template:Convert or Template:Convert wide pallets and Template:Convert or Template:Convert long. A Template:Convert wide × Template:Convert tall ULD is half the volume of a Template:Convert × 88 inch pallet. The 20 foot pallet is Template:Convert long and Template:Convert wide. What the actual dimensions of contoured upper deck ULDs are is very hard to know, because most manufacturers only profile width, length and height data.

There are several common types of contoured main deck ULDs, that are contoured (curved to fit in the plane's body) to provide as much cargo volume as possible. Initially ULD contouring was simply a triangle removed from one or two corners of the profile of the ULD, such as the common LD3 and LD6. Main deck ULDs use curves for the contoured shape to truly maximize cargo volume. Upper deck ULDs are just like lower deck ULDs that are either the full width of the plane with two corners of the profile removed (lower deck LD6 lower), or that container is cut in half, down the center line of the plane, (lower deck LD3 and upper deck AAX).

Main deck ULDs and pallets are not only taller than lower deck ULDs, they are frequently two or four times longer. They are usually organized like an LD6, using the width of the plane and missing two profile corners, or two very long LD3s, stored in parallel to use the plane's width and each missing one profile corner, but often twice or four times as long from plane's nose to tail.

Many air cargo companies use main deck ULDs that have both features called dual-profile, so that on smaller planes such as the Boeing 727, they are stored widthwise and have two corners contoured, and on the bigger Boeing 767, they can be rotated 90 degrees and shipped in parallel like LD3s, so that only one corner is contoured when being used like an LD3. This greatly simplifies transportation of cargo containers at slight cost of cargo volume.

See also

• 463L master pallet, used for military aircraft transport and airdrops
• AAR Corp, parent company of Nordisk Aviation, a manufacturer of ULDs
• Containerization
• Intermodal container
• Pallet
• Rio Tinto Alcan, formerly Alusuisse, a manufacturer of ULDs
• Shipping container
• Unit load

External links

• {{#invoke:citation/CS1|citation

|CitationClass=web }}