Force-Navy Aeronautical (ANA) Bulletin No. 306M.
The other system, MIL-STD-1812 designation system,
includes all newly developed (Air Force, Army, and
Navy) gas turbine engines.
These designation systems use standard symbols to
represent the types and models of engines now used in
ANA BULLETIN NO. 306M DESIGNATION
The following paragraph describes the ANA
Bulletin No. 306M designation system. This system
has no provisions for Army designation. T56-A-14 is
an example of this systems designation number.
The first part of the designation system is a letter
(or letters) that indicates each basic engine type. Table
6-1 shows the letter symbols that identify engine types.
A number follows the first letter symbol. The using
armed service assigns the number used in conjunction
with the letter symbol as follows:
! The number 30 for the Navy. The Navy has
! The number 31 for the Air Force. The Air
Force has odd numbers.
The designation of odd or even numbers does not
restrict the use of the engine to the sponsoring service.
Aircraft engines, regardless of type designation, are
applicability for a particular aircraft. In some instances,
engines are made interchangeable for a particular
The second part of the designation is a dash and a
letter symbol that indicates the engine manufacturer.
Some of the manufacturers are listed in table 6-2.
Internal combustion, air-cooled,
radial engine (reciprocating)
Aviation gas turbine (turboprop and
Table 6-1.Aircraft Letter Symbols and Engine Types
Allison Division, General Motors Corp.
Bell Aircraft Company
Continental Aviation and Engineering Corp.
United Aircraft of Canada Ltd.
AiResearch Division, Garrett Corp.
General Electric Company
Lockheed Aircraft Company
Lycoming Division, Avco Corp.
McDonald-Douglas, Aircraft Company
Pratt and Whitney Aircraft Division, United Aircraft Corp.
Rolls Royce, Ltd.
Westinghouse Electric Company
Table 6-2.Engine Manufacturers