Final answer:
Checking wheels and wheel nuts to ensure that they are secured is a safety check.
Step-by-step explanation:
In TM 9-2330-357-14 P (SEMITRAILER FLATBED: RADAR SET AND LAUNCHING STATION), checking wheels and wheel nuts to ensure that they are secured is classified as a safety check.
It is important to regularly inspect the wheels and wheel nuts of a semitrailer to prevent accidents caused by loose or damaged components.