Designations Of
Copyright © 2001-2003 Andreas
Parsch
1 History
2 Aeronautical
and Support Equipment Type Designation System
2.2
Components,
Groups And Units
2.3
Miscellanea
2.3.1 Training
Equipment (Complete Equipment)
2.3.2 Training
Equipment (Groups and Units)
2.3.3 Dummy
Ordnance
2.3.4 Development
Indicator
2.3.5 Suffix
Numbers
3.2
Components,
Groups And Units
3.2.1 Alphabetical
Listing
3.2.2 Listing
by General Category
4 Sources
From its inception in
1947 until 1952, the US Air Force designated its support equipment with arbitrary
letter/number designations. This was somewhat similar to the Army
Nomenclature System, except that all letters of the alphabet (instead of M
only) were used. Typical designations were "K-5 Bombing System" or
"E-1 Fire Control System".
On 15 March 1952, the Air
Force and Navy released Air Force-Navy Aeronautical (ANA) Bulletin 420,
defining the Type Designation System for Aeronautical Equipment. The system
used arbitrary two-letter codes and a model number. The first letter was always
an M (indicating Military Aeronautical Equipment). Examples for designations
are "MA-3 Fire Control System" and "MB-2 Aircraft Towing
Tractor".
The early designation
systems had the drawback, that the alphanumerical designations were neither
unique nor describing the type and/or purpose of the equipment. For unambiguous
identification of an item, the full nomenclature was needed. Therefore, in
October 1955, the USAF started to develop a new type designation system, which
was intended for all types of aeronautical equipment. The result combined the Joint
Electronics Type Designation System (MIL-STD-196), the Joint
Photographic Type Designation System (MIL-STD-155) and ANA Bulletin 420
into a single system. The new system was proposed for joint service use but was
rejected by the Joint Chiefs of Staff on 31 January 1956 as being too
complicated and impractical.
The USAF then decided to
develop a new type designation system for aeronautical and support equipment,
which should replace ANA Bulletin 420 only. The new system closely followed the
principles of the Joint
Electronics Type Designation System (as will be shown below,
when the system is explained). It was generally known as the Aero/Support
System, but is nowadays formally called the Aeronautical and Support
Equipment Type Designation System (ASETDS). The system was published on 27
August 1956 in Air Force Regulation (AFR) 81-9.
In 1957, the Navy decided
to use ASETDS, too. Accordingly, the Air Force and Navy published ASETDS, in
slightly modified form, in ANA Bulletin 440 on 20 March 1958. An updated system
was published in ANA Bulletin 440a on 25 February 1960. In early 1966, an
improved version of ASETDS was proposed, mainly to provide new type designators
for modern and future non-nuclear munitions. This revision was finally
published as MIL-STD-875 on 1 November 1966. A slightly expanded version was
released in MIL-STD-875A on 30 April 1974.
On 28 February 1991,
ASETDS was incorporated into MIL-STD-1812, together with several other type
designation systems (like Aero
Engines and Photographic
Equipment). There was one significant change in ASETDS for this purpose,
which is detailed in the description of the designations for components,
groups and units. On 14 February 1997, MIL-STD-1812 was renamed as
MIL-HDBK-1812. The change from "Standard" to "Handbook"
means, that the use of ASETDS (and the other systems) is no longer mandatory.
Otherwise, MIL-HDBK-1812 is identical to MIL-STD-1812.
The following table
summarizes the various documents containing the ASETDS:
|
Document ID |
Date |
|
AFR
81-9 |
27
August 1956 |
|
ANA
Bulletin 440 |
20
March 1958 |
|
ANA
Bulletin 440a |
25
February 1960 |
|
MIL-STD-875 |
1
November 1966 |
|
MIL-STD-875A |
30
April 1974 |
|
MIL-STD-1812 |
28
February 1991 |
|
MIL-HDBK-1812 |
14
February 1997 |
It should be noted, that
only the Air Force uses ASETDS consistently for all its aeronautical and
support equipment. The Navy uses its MARK/MOD
numbering system for a lot of equipment used in naval aviation. The Army did
never use ASETDS, relying instead on the Army
Nomenclature system for all its equipment.
ASETDS
distinguishes between complete systems and components. The US military uses
detailed definitions of "Item Levels" from single "Parts"
to complete "Systems", and a brief explanation of all terms relevant
to the discussion of ASETDS can be found here.
ASETDS does not designate parts and assemblies, and uses different designation
schemes for the other item types.
These designations cover
sets, subsystems and systems and also include equipment items like vehicles,
shelters, etc.
|
Examples: |
A / |
A |
24 |
G |
- |
5 |
A |
|
|
|
A / |
E |
37 |
T |
- |
24 |
|
(V)2 |
|
|
|
(1) |
(2) |
(3) |
|
(4) |
(5) |
(6) |
All designations are
prefixed by "A/" (for "Aero"). In the original (AFR 81-9)
form of the system, the prefix "AF/" (for "Air Force") was
used, but this was changed with the introduction of ANA Bulletin 440.
Letter (1) indicates the
installation location of the equipment:
The two-digit code (2)
indicates the type of the equipment. Digits 0 and 1 were originally omitted, to
avoid confusion with letters O and I. MIL-STD-1812, however, introduced the new
type codes 40 and 41.
Letter (3) defines the
purpose of the equipment:
(4) is the model number.
Each Installation-Type-Purpose combination uses its own model number sequence, starting
at 1.
The optional suffix
letter (5) denotes a specific version of the equipment. The first version uses
no suffix, the first modifcation uses "A", etc. The letters
"I" and "O" are not used as version suffix.
(6) The "(V)"
symbol indicates an equipment with variable components (sets, groups or units).
A number following the "(V)" is used to designate a specific
version of the equipment, i.e. with a specific component configuration. If a
component of a set or system is of variable configuration, i.e. carries a
"(V)" symbol, the set or system itself must also use the
"(V)" symbol.
Notes:
1. Installation letter "N" is only used, if the
equipment is neither installed in the aerospace vehicle (letter "A")
nor mission-expendable (letter "B").
2. Electronic equipment is always designated under JETDS.
Up to and including
MIL-STD-875A, ASETDS distinguished between components and units. A component
was part of an equipment, and couldn't be used on its own. A unit could
function on its own and was usually used with some equipment. With the
introduction of MIL-STD-1812, the component/unit differentiation was changed to
group/unit. This is essentially the way JETDS
does it, and is in accordance with the Item Level
definitions of MIL-HDBK-505.
|
Examples: |
GB |
U |
- |
10 |
F |
|
/ |
B |
|
|
TR |
K |
- |
55 |
|
|
/ |
A24J-13 |
|
|
MH |
U |
- |
131 |
|
|
/ |
E32K |
|
|
GB |
U |
- |
31 |
|
(V)4 |
/ |
B |
|
|
CN |
U |
- |
80 |
|
|
/ |
E25 |
|
|
AD |
G |
- |
770 |
|
|
/ |
B |
|
|
AG |
U |
- |
1 |
B |
|
/ |
U |
|
|
(2) |
(1) |
|
(3) |
(4) |
(6) |
|
(5) |
Letter (1) indicates the
category of the equipment:
The two-letter indicator
(2) designates the type of equipment:
(3) is the sequential
model number, starting at 1. Each type uses a single numbering sequence for all
three equipment categories (e.g. if there is a MXK-856, then there is no
MXU-856 or MXG-856).
The optional suffix
letter (4) denotes a specific version of the equipment. The first version uses
no suffix, the first modifcation uses "A", etc. The letters
"I" and "O" are not used as version suffix.
(5) The full type
designation of a group, unit or component includes a slant bar, followed by the
designation of the equipment, of which it is part of or used with. If the
group, unit or component can be used with several equipment items, a more
general designator is appended. E.g. the MHU-131/E32K is a munition handling
unit (an ammunition transporter in this case), which is used with several
A/E32K-n systems, while the CNU-80/E25 is a ground-based container,
which is used for several explosive items with different purpose indicators. A
designation for a general purpose group, unit or component, i.e. one that is
not designed to be used in a specific environment, uses only the general
installation letter "U" after the slant bar.
(6) The "(V)"
symbol indicates an equipment (usually a group) with variable components. A
number following the "(V)" is used to designate a specific
version of the equipment, i.e. with a specific component configuration.
Aircraft Ordnance:
For aircraft-carried
ordnance (bombs, rockets, etc.) designated under ASETDS, two special rules
apply:
Notes:
1. Nuclear bombs are not designated under ASETDS.
2. This designator is only used, if the Joint
Photographic Type Designation System cannot be applied.
3. Powered versions of guided bombs are designated as guided missiles
(e.g. a GBU-15/B with a rocket motor is designated as AGM-130).
There are also a few unpowered guided weapons, which are nevertheless
designated as missiles (AGM-62, ADM-141, AGM-154).
4. Dummy missiles can also be designated in the
designation system for unmanned
aerospace vehicles. E.g. DATM-9L and GDU-6/C are both dummy
versions of the AIM-9 Sidewinder missile.
5. Live and dummy rockets can also be designated in the
designation system for unmanned
aerospace vehicles.
6. The different designators for missile components and
their precedence rules are a bit confusing. The warheads are preferrably
designated with WD, WE and WT. If these don't apply, WF is used. The missile
shell components are designated WA, WG or WP, according to function. Other
control components not covered by WG are designated WC. All remaining body
parts are designated WN, if they form part of the nose, and WB otherwise.
Training items designed
to be used with a certain equipment item are designated by adding "-Tn"
to the equipment designator. E.g., the second training set for the A/A24G-6 set
is designated as A/A24G-6-T2. If an item can be used for training with
different equipment of a certain type, or is a general purpose training
equipment of a certain type, the model number is omitted. E.g., A/E37M-T15 is
the 15th training set in the E37M (Ground Electromechanical Aircraft
Maintenance Equipment) category designed as a multi-purpose training set or to
be used with several different A/E37M-n systems. Modifications are
indicated by suffix letters, e.g. A/F37A-T26A.
Training equipment for
types of equipment not covered by ASETDS (like aircraft engines or
electronics), is assigned installation and type indicators as appropriate,
followed by purpose letter "U". An example is the A/E37U-T34 (a
fire-control trainer for F-16 aircraft).
Training versions of
groups and units are designated by adding "(T-n)" between the
item designator and the slant bar. E.g., the second training version of the
CDU-4/B dispenser is called CDU-4(T-2)/B.
While training versions
of munitions may contain explosives, dummy versions are always completely
inert. Dummy versions of live munitions are designated by adding "(D-n)"
between the item designator and the slant bar. The number n is not
assigned sequentially, but indicates the nature of the dummy:
An example is the
BLU-7A(D-1)/B.
During the development
phase of an equipment item, a development indicator like (XN-1) may be appended
to the basic equipment designation (or, for groups and units, inserted between
the designator and the slant bar). The letter combination always starts with
"X" and indicates the organization responsible for the development,
and the number is a sequential series number (using separate series for each
combination of equipment designator and developing organization). Examples
include the A/E24T-189(XN-1), the first developmental model of the basic
A/E24T-189 by the US Navy, and the WGU-15(XCL-1)/B, the first developmental model
of the WGU-15/B by the US Naval Weapons Center, China Lake. The organization
indicators are identical to those used by the Joint
Electronics Type Designation System.
[Note: Up to and
including MIL-STD-875, the indicators were different to those used by JETDS,
but I don't have a listing of these original indicators.]
ANA Bulletin 440a
introduced the option to use suffix numbers to differentiate between different
versions of aircraft instruments. This option was limited to indicators for
aircraft instruments (e.g. AAU, ABU, etc.), and was dropped in MIL-STD-1812. An
example is the AAU-31/A altimeter with versions AAU-31/A-1 and AAU-31/A-2.
General notes for the
designation lists:
I have only very few
ASETDS equipment designations in my lists. All I have will eventually be
provided on this site, but don't expect it to be anywhere near complete.
To view the designation
listings in a frame with a separate navigation bar, click here.
A/Annx
- Aerospace Vehicle Installed Equipment
A/Bnnx
- Aerospace Vehicle Installed Equipment (Mission Expendable)
A/Cnnx
- Ground/Airborne Combination Equipment
A/Ennx
- Ground Equipment (Not Fixed)
A/Fnnx
- Fixed Ground Equipment
A/Mnnx
- Movable Ground Equipment
A/Nnnx
- Aircraft/Missile Transported Equipment
A/Pnnx
- Personal Equipment
A/Snnx
- Self-Propelled Ground Equipment
A/Unnx
- Multi-Installation Equipment
A/Wnnx
- Water/Shipborne Equipment
The listings for xxU,
xxK and xxG designations are organized alphabetically, one file
per initial letter:
Axx,
Bxx,
Cxx,
Dxx,
Exx,
Fxx,
Gxx,
Hxx,
Jxx,
Kxx,
Lxx,
Mxx,
Nxx,
Pxx,
Rxx,
Sxx,
Txx,
Vxx,
Wxx
To view the designation
listings in a frame with a separate navigation bar, click here.
The navigation bar lists also those equipment types, for which there is no
listing yet available. If the type designator is shown in light gray, I don't know a single designation for
that type. For the other entries without link, at least one designation will be
eventually provided.
The following index shows
all designation listings sorted by the following general categories:
Aircraft
Armament
Other
Munitions and Related Equipment
Other
Air-Dropped or Aircraft-Carried Equipment
Aircraft
and Flight Instrumentation
Other
Aircraft Equipment
Missile
Components
Fuel
Handling Equipment
Cargo
Handling Equipment
Other
Ground Support Equipment
Clothing
and Flight Gear
Miscellaneous
Personal Equipment
Electrical
Equipment
Other
Equipment
If an equipment type is
listed below, but has no link, a listing is definitely planned (equipment
types, for which I don't know a single designation, are not listed below). If a
type designation covers items in several of the above categories, the type
appears under several headings.
BDU -
Simulated Bombs
BLU -
Bombs
BRU/BRK
- Bomb Racks and Shackles
CBU -
Cluster Bombs
CDU -
Clustering Devices
GAU/GAK
- Airborne Guns
GBU -
Guided Bombs
GDU -
Dummy Guided Missiles
GPU -
Gun Pods
GTU -
Weapon Turrets
LAU/LAK
- Vehicle Installed Launching Mechanisms
MDU -
Miscellaneous Simulated Munitions
MLU/MLK
- Miscellaneous Live Munitions
RBU -
Rocket and Launcher Units
RDU -
Simulated Rockets
SUU -
Stores Release and Suspension Units
Other Munitions and Related Equipment
BBU -
Explosive Items
BSU/BSG
- Munitions Stabilizing and Retarding Devices
CCU/CCK
- Cartridges
CXU -
Impact Marking Smoke Charges
DSU -
Target Detection Devices
FMU -
Munitions Fuzes
FSU -
Munitions Fuze Safety Arming Devices
FZU -
Munitions Fuze-Related Items
GFU/GFK
- Gun-Related Items
JAU -
Cartridge Actuated Initiators
KMU/KMK
- Miscellaneous Kits
LMU/LMK
- Ground Launching Mechanisms
MAU -
Miscellaneous Armament Items
MHU/MHK
- Munitions Handling Items
MJU -
Munition-Countermeasures
PGU -
Gun Ammunition
Other Air-Dropped or Aircraft-Carried Equipment
CTU -
Aerial Delivery Containers
FPU -
Pylon-Mounted Fuel Tanks
LUU -
Illumination Lights
PAU -
External Dispensers
PDU -
Printed Data for Dispensers
PWU -
Internal Dispensers
RMU/RMK
- Reels and Reeling Mechanisms
TDU/TDK
- Target Devices
WMU -
Weather Devices
Aircraft and Flight Instrumentation
AAU/AAK
- Altitude Indicators
ABU/ABK
- Flight Instruments
AEU -
Engine Instruments
AGU/AGK
- Pressure Indicators
ALU -
Position Indicators
AQU -
Navigational Instruments
ARU -
Attitude Indicators
AVU/AVK
- Speed Indicators
EFU/EFK
- Fuel Measuring Instruments
EAU -
Engine Performance Indicators
EGU/EGK
- Engine Pressure Measuring Instruments
EHU/EHK
- Engine Temperature Measuring Instruments
ERU/ERK
- Engine Tachometers
APU -
Miscellaneous Autopilot Components
ASU/ASK
- Signal Amplifiers
CKU -
Aircraft Ejection Seat Catapults
CPU/CPK
- Computers
FNU -
Internal Fuel Tanks
GEU -
Electrical Generators
GGU -
Gas Generators
HBU -
Harnesses and Safety Belts
LRU -
Life Rafts
LTU -
Aircraft Lights
PTU -
Auxiliary Power Units
RAU -
Canopy Removers
SBU/SBK
- Stabilizing Devices
SEU -
Seats
SJU -
Ejection Seats
SKU/SKK
- Seat Kits
STU -
Engine-Installed Starters
SVU -
Servomechanisms
TRU/TRK
- Instrument Transmitters
WAU -
Warhead Sections
WBU -
Vehicle Body Sections
WCU -
Vehicle Control Sections
WDU -
Explosive Warheads
WGU -
Vehicle Guidance Sections
WNU -
Vehicle Nose Sections
WPU -
Vehicle Propulsion Sections
WTU -
Training and Dummy Warheads
EFU/EFK
- Fuel Measuring Instruments
FFU -
Fuel Filters
FNU -
Internal Fuel Tanks
FPU -
Pylon-Mounted Fuel Tanks
FTK -
External Fuel Tanks
GRU/GRK
- Ground Refueling Items
RFU -
Inflight Refueling Items
TMU -
Miscellaneous Tanks
CGU -
Cargo Tiedown Items
CNU/CNK
- Containers
HCU -
Cargo Handling Items
Other
Ground Support Equipment
ACU/ACK
- Air Compressors
AHU/AHK
- Handling Items
EAU -
Engine Performance Indicators
ETU/ETK
- Engine Transportation or Handling Devices
FEU -
Fire Extinguishers
FRK -
Refrigerators
GLU -
Ground Engines
GSU/GSK
- Miscellaneous Ground Support Items
HDU/HDK
- Heaters
HLU/HLK
- Hoists
LEU -
Ground Lights
MMU/MMG
- Vehicle Maintenance Items
MSU/MSK
- Maintenance Stands
NRU -
Miscellaneous Nitrogen Handling Items
SGU -
Ground Starters
SHU/SHK
- Shelters
THU -
Target Handling Items
CMU/CMK
- Miscellaneous Clothing
CSU/CSK
- Special Clothing
CWU -
Warmth Clothing
EDU -
Eye Protection Devices
EEU/EEK
- Eye Protection Devices for Headgear
FWU/FWK
- Footwear
HAU/HAK
- Handwear
HGU/HGK
- Headgear
MBU -
Breathing Oxygen Masks
Miscellaneous Personal Equipment
BGU -
Bags
CQU -
Breathing Air Items
CRU/CRK
- Oxygen Items
CHU -
Cushions
DTU -
Timers
FLU -
Inflators
GUU -
Guns
HBU -
Harnesses and Safety Belts
LPU -
Life Preservers
LRU -
Life Rafts
MCU/MCK
- Breathing Air Masks
MPK -
Protective Masks
PCU -
Parachute Components
PRU/PRK
- Protective Items
SRU -
Survival Items
BCU - Battery
Chargers
ECU/ECK
- Electrical Converters
EMU -
Ground Electrical Power Supplies (with prime mover)
EPU -
Ground Electrical Power Supplies (without prime mover)
HRU/HRK
- Electrical Harnesses and Cables
JEU/JEK
- Electrical Distribution, Junction and Connection Items
PEU/PEK
- Electrical Panels
RGU -
Electrical Regulators
RYU/RYK
- Electrical Relays
SWU/SWK
- Electrical Switches
TEU/TEK
- Electrical Transformers
ADU/ADK/ADG
- Adapters
ATU/ATK
- Actuators
BAK -
Aircraft Arresting System Components
BNU -
Buoys
CAU -
Miscellaneous Cabinets
CLU -
Calibrating Items
CVU/CVK
- Covers
DCU/DCK
- Vehicle Control Devices
DEU -
Dehumidifiers
DHU -
Detectors
DTU -
Timers
GCU -
Gaseous Converters, Chargers and Rechargers
GMU/GMK
- Miscellaneous Gages
KMU/KMK
- Miscellaneous Kits
LBU -
Lubricating Devices
LNU -
Navigation Lights
MTU -
Mounts
MXU/MXK/MXG
- Miscellaneous Items
NCU -
Nonstereo-Charting Items
PJU -
Projectiles
PLU -
Plotting Devices
PMU/PMK
- Pumps
PVU -
Primers
REU -
Rescue Devices
RMU/RMK
- Reels and Reeling Mechanisms
RVU -
Dummy Re-entry Vehicles
SDU/SDK
- Signal Devices
SMU/SMK
- Simulators
SPU -
Mine-Sweeping Items
SXU -
Scoring Devices
TAU -
Training Aids
TCU -
Cartridge Actuated Thrusters
TLU -
Tools
TMU -
Miscellaneous Tanks
TTU/TTK
- Test Items
VAU/VAK
- Valves
VSU -
Viewing Devices
WMU -
Weather Devices
[1] Department of
Defense: MIL-HDBK-1812 "Type Designation, Assignment And Method For
Obtaining"
[2] Department of Defense: MIL-STD-875A "Type Designation System for
Aeronautical and Support Equipment"
[3] Department of Defense: MIL-HDBK-505 "Handbook For Definitions Of Item
Levels, Item Exchangability, Models And Related Terms"
(The designation listings were compiled using a wide variety of sources, not
the least of which were the Internet and contributions by fellow researchers.)
Comments and corrections to: Andreas Parsch
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Last
Updated: 9 May 2003