quantity production. Samples shall be inspected and pass the preproduction tests specified in 4.4.
After preproduction approval is granted, any change in formula, material, or manufacturing
procedure shall void approval. Product, with changes incorporated shall be examined and tested
in accordance with, and shall pass preproduction inspection specified in 4.4.
3.1.1 Initial production inspection. Unless otherwise specified (see 6.2), an initial production
semitrailer to be furnished under this specification shall be produced after award of contract. The
initial production samples shall be selected by a Government representative from the first
production units manufactured. The samples selected shall be inspected and pass the tests
specified in 188.8.131.52. After initial production approval is granted, any change in formula, material,
or manufacturing procedure shall void approval. Product, with changes incorporated shall be
examined and tested in accordance with, and shall pass initial production tests specified in 4.4.l.l.
3.2.1 Reliability. The trailer shall meet a reliability requirement of 6,000 Mean Miles
Between Failure (MMBF) to be demonstrated when coupled with suitable towing vehicle in
accordance with the operational profile (184.108.40.206) during test (see 220.127.116.11) (see 6.6 for definition
and classification of a failure.).
18.104.22.168 Operational profile. An 8,000-mile operational profile test shall be apportioned as
shown in table II.
TABLE II. Operational profile test.
High-speed paved road
Improved gravel road
Level, substantial road
bed, moderate cross-country
Hilly secondary road
3.2.2 Maintainability. Total maintenance, excluding driver and crew checks and services,
shall not exceed 12 man-hours during the first 8,000 miles of specified operation. This equates to
a maintenance ratio (MR) of 0.030 at 20 operational miles equivalent to one operational hour.
The scheduled maintenance interval shall be 8 months or 8,000 miles, whichever comes first