TM 1-1520-240-10
1-1-2
1-1-13. Aircraft Designation System.
1-1-14. The designation system prescribed by AR 70-50
is used in aircraft designation as follows:
Example CH-47D
C - Mission symbol (cargo)
H - Basic mission and type symbol (Helicopter)
47 - Design number
D - Series symbol
1-1-15. Series and Effectivity Codes.
Designator symbols listed below are used to show limited
effectivity of airframe information material in conjunction
with text content, paragraph titles, and illustrations. Des-
ignators may be used to indicate proper effectivity, un-
less the material applies to all models and configuration
within the manual. Designator symbols precede proce-
dural steps Designator symbols listed below are used to
show limited effectivity of airframe information material in
conjunction with text content, paragraph titles, and il-
lustrations. Designators may be used to indicate proper
effectivity, unless the material applies to all models and
configuration within the manual. Designator symbols
precede procedural steps in Chapters 5, 8 and 9. If the
material applies to all series and configurations, no des-
ignator symbol will be used.
DESIGNATOR
APPLICATION
SYMBOL
712
CH-47D aircraft equipped
With T55-L-712 engines.
714A
CH-47D aircraft equipped
with T55-GA-714A engines
1-1-16. Use of “Shall, Should, and May”.
Within this technical manual, the word “shall” is used to
indicate a mandatory requirement. The word “should” is
used to indicate a nonmandatory but preferred method
of accomplishment. The word “may” is used to indicate
an acceptable method of accomplishment.
1-1-17
