The Marine Corps Military Occupational Specialty (MOS) 6174 is for helicopter crew chiefs who maintain and operate Marine UH-1 “Huey” helicopters. Crew chiefs are flight crew members who perform duties related to the maintenance and operation of these helicopters.
The average salary for a crew chief in the United States is $55,205 per year, which is 13% higher than the average US Marine Corps salary of $48,525 per year.
You can find more information about the Marine Corps MOS in the official Department of the Navy Headquarters Marine Corps MOS Manual.