MIL-DTL-24784 / 21B (SH)
b.
Overall and FBDs and descriptions.
c.
Logic principles shall be described beginning with an introduction to the basic digital logic
symbology used in the manual. Each logic function shall be described and supported by
Boolean equations, truth tables, simplified logic diagrams, and timing diagrams.
d.
Functional description of power distribution, power supplies, and regulators shall be in
accordance with 3.6.4.1c.
3.6.4.4 Preparation of FBD associated keyed text. This section describes the requirements and
method of presentation of the keyed text associated with each FBD.
a. Keyed text presents brief descriptions of each block on the FBD. The short (generally one to
three sentences) paragraph is "keyed" to the FBD by a circled number. The first text
paragraph shall describe the total FBD sheet. Each subsequent paragraph (circle one, circle
two, circle three, and so forth) shall describe what that block does within the operation of the
system.
b. The keyed text shall discuss, at an overview level, the purpose of each block (why it exists,
and what it does). The keyed text shall not discuss circuit implementation, or how it works.
When the same block appears on many levels of the FBD, the keyed text relating to the block
shall be identical at all levels. See figures 21-34 through 21-36.
3.6.4.5 Equipment function directory. An equipment function directory shall tabulate operation
control functions and the signal data described in the detailed level of functional analysis. The
tabulation shall include the following information, as applicable:
a. Official name of the function, colloquial name, and symbol.
b. Type of control or signal (ac frequency and voltage, dc polarity and voltage, hydraulic
pressure, mechanical motion, synchro, and so forth).
c. The origin and termination of the control or signal.
d. Identify components (relay transmitters, coordinate converters, distribution boxes, switches,
and the like) between the origin and termination of the output control or signal.
e. Figure numbers of illustrations on which the function is illustrated, including the fault-isolation
diagrams in Chapter 5.
3.6.5 Chapter 4, Scheduled maintenance. Chapter 4 shall contain all scheduled maintenance
procedures, together with necessary explanations and illustrations. It is intended that the
engineering effort required to develop preventive maintenance data be expended only once and
that the data be used both in this chapter and in Logistic Support Analysis (LSA) or Maintenance
Requirements Cards (MRC) where one or more of these data items is required by the contract
(see 6.2). The preparation of this chapter of the manual should therefore be delayed until
completion of the LSA, or MRC. If LSA data is not available when required, the submissions of
the review draft copy (RDC) should be marked "TO BE SUPPLIED UPON COMPLETION OF
LSA". When the approved LSA or MRC data is available, it shall be referenced in the manual.
When included in the manual, such LSA or MRC data shall be integrated with other technical data
required by this specification to be in this chapter. Chapter 4 shall comprise the following:
22
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business