information on the USAF T.O. numbering system
TO 00-5-18, TECHNICAL MANUAL METHODS & PROCEDURES, AF TECHNICAL ORDER NUMBERING SYSTEM
1.6 TECHNICAL ORDER NUMBERING THEORY.
1.6.1 The basic task of TO numbering specialists is to group similar TO data into categories, systems, equipment series and equipment sub-series by means of an identifying numeric or alpha-numeric TO number.
1.6.2 TO Categories. TOs are grouped numerically by type of equipment covered by the TO Category.
0 - TO Catalog, Indexes and Cross-Reference Table
00 - Methods & Procedures Technical Orders
1 - Aircraft
2 - Airborne Engines and Associated Equipment
3 - Aircraft Propellers and Rotors
4 - Aircraft Landing Gear
5 - Airborne Instruments
6 - Aircraft and Missile Fuel Systems
7 - Airborne Engine Lubricating Systems
8 - Airborne Electrical Systems
9 - Aircraft and Missile Hydraulic, Pneumatic and Vacuum Systems
10 - Photographic Equipment
11 - Armament Equipment
12 - Airborne Electronic Equipment
13 - Aircraft Furnishings and In-Flight Feeding Equipment, Cargo Loading, Aerial Delivery and Recovery Equipment, Aircraft Fire Detection and Extinguishing Equipment
14 - Deceleration Devices, Personal and Survival Equipment
15 - Aircraft and Missile Temperature Control, Pressurizing, Air Conditioning, Heating, Ice Eliminating and Oxygen Equipment
16 - Airborne Mechanical Equipment
21 - Guided Missiles
22 - Aerospace Vehicles
31 - Ground Electronic Equipment
32 - Standard and Special Tools
33 - Test Equipment
34 - Shop Machinery and Shop Support Equipment
35 - Ground Handling, Support, Air and Missile Base Operating Equipment
36 - Vehicles, Construction and Material-Handling Equipment
37 - Fuel-, Oil- and Propellant-Handling Equipment
38 - Non-aeronautical Engines
39 - Watercraft Equipment
40 - Commercial Air-Conditioning, Heating, Plumbing, Refrigerating, Ventilating and Water Treating Equipment
41 - Subsistence and Food Service Equipment
42 - Coating, Cleaning and Sealing Compounds and Fuels, Gases, Lubricants, Chemicals and Materials
43 - Simulator and Training Devices
44 - Common Hardware Equipment
45 - Railroad Equipment
46 - Office, Duplicating, Printing and Binding Equipment
47 - Agriculture Equipment
49 - Optical Instruments, Timekeeping and Navigational Equipment
50 - Special Services Equipment
51 - Automatic Test Systems
60 - Explosive Ordnance Disposal Procedures
1.6.3 Each category of TO data has its own TO numbering pattern. Sufficient flexibility exists within the total numbering system to allow for expansion or contraction within numbering parameters, yet maintain standard application of numbering patterns within each category.
1.6.4 TO numbers are composed of groups separated by dashes, and each group is further divided into parts. The number of parts within any group varies according to the TO data being numbered in a specific category. Each part of a group consists of one or more numeric characters or one or more alpha characters. The numbering patterns used to identify TO data in each category are outlined in Chapters 2 through 41.
1.6.5 A total of seven groups may be used in the TO numbering pattern (see Table 1-1). TO data is identified, in most categories, by using only the first three or four basic groups. The remaining groups are primarily used to extend the TO number to identify specific sections of sectionalized TOs; supplemental manuals; and supplement, checklist and work-card sequence numbers.
