Parts and Materials - In the selection of parts and materials,
fulfillment of major design objectives shall be the prime consideration. In
so doing the following shall govern:
(1) Parts and materials requirements shall conform to
(2) Nonrepairable subassemblies, as outlined in MIL-T-21200,
Shall be used when practicable. The general size of the subassembly and the
amount of circuitry to be included therein shall be approved by the procuring
activity. Nonrepairable subassemblies must be reliable (See 6.4).
(3) When previously produced models of the equipment did
not use nonrepairable subassemblies, the design shall not be changed to employ
nonrepairable assemblies without the approval of the procuring activity.
Nonstandard Parts and Materials Approval - Approval for the
use of nonstandard parts and materials other than microelectronic devices shall
be obtained as outlined in MIL-T-21200.
Electronic Devices - Electron tubes and semiconductor devices
shall be in accordance with MIL-T-21200 or MIL-STD-454, Req. 30.
Modules, Maintenance - The electronic portions of the equip-
ment shall be divided into maintenance modules as specified In AR-10 (See
MIL-S-23603) . Modules shall normally be considered repairable.
Design and Construction - The equipment shall conform with
-21200 for design, construction and
all the applicable requirements of MIL-T-
workmanship except as otherwise specified herein,
3.3.1 Total Weight - The total weight of the equipment shall be
a minimum consistent wit, good design and shall not exceed 90 pounds including
Operational Stability - The equipment shall operate with
satisfactory performance, continuously or intermittently for a period of at
least 1,000 hours without the necessity for readjustment of any controls which
are inaccessible to the operator during normal use.
220.127.116.11 Operating Life - The equipment shall have a minimum total
operating life of 10,000 hours with reasonable servicing and replacement of
Reliability in Mean Time Between Failure (MTBF ) - The equip-
ment shall have a minimum of 5,000 hours mean (operating) time between failures,
This requirement shall be verified by mathematical analysis in accordance with
the provisions of MIL-STD-756 and MIL-HDBK-217.