Petty Officer 1st Class Mark Petre, of Kansas City, Mo., an instructor at the Coast Guard's Aviation Technical Training Center, supervises students as they assemble a tail rotor hub fairing for an MH-65 helicopter during advanced Aviation Maintenance Technician training March 18, 2014. Students in the four-week Aviation Maintenance Technician MH-65 Airframe & Powertrain course learn the necessary skills, knowledge and practical experience required to service, maintain and repair airframe and powertrain systems and associated equipment on the MH-65 Dolphin helicopter. AMTs in the Coast Guard may fill a variety of aircrew positions including flight engineer, flight mechanic, loadmaster, dropmaster, sensor-systems operator or basic aircrewman.