The Marine Corps MOS 6116 is for tiltrotor mechanics who work on the MV-22. They inspect and maintain tiltrotor airframes and components, and may also perform flight line operations. They are trained to repair and maintain systems and components associated with helicopter blades, motors, hydraulics, and landing support gear.
The first two numbers of the MOS code designate the three primary positions:
60 - Mechanic
61 - Helicopters
62 - Fixed wing aircraft
Here are some other Marine Corps MOS codes:
6113 - Helicopter Mechanic CH-53
6114 - Helicopter Mechanic A/UH-1
6122 - Helicopter P/P Mechanic T-58