Marine Medium Tiltrotor Training Squadron 204 was activated 1 May 1972 at Marine Corps Air Station New River, North Carolina as Marine Helicopter Training Squadron 204 (HMT-204). In the wake of the Vietnam War, Marine Aircraft Training Group 40 was deactivated, and Marine Medium Helicopter Training Squadron 401 and Marine Heavy Helicopter Training Squadron 402 were combined to form HMT-204.
HMT-204 was originally a composite training squadron, training both CH-46 and CH-53 helicopter crews. In June 1988, Marine Helicopter Training Squadron 302 (HMT-302) assumed responsibility for CH-53 training, and CH-53s departed HMT-204. Shortly thereafter, HMT-204 received the Meritorious Unit Commendation for its support of the Fleet Marine Force during 1987.
In October 1993, HMT-301 was deactivated and HMT-204 became the sole Fleet Replacement Squadron for the Marine Corps CH-46 community. This made HMT-204 the largest CH-46E squadron in the Marine Corps.
Also in October 1993, the Fleet Replacement Enlisted Skills Training (FREST) program was established. The HMT-204 FREST provided comprehensive technical training for officers and enlisted in the operation, maintenance, and repair of CH-46E aircraft and associated equipment.
For its efforts in 1998 and 1999, HMT-204 was awarded its second Meritorious Unit Commendation for production of pilots and crew for the Fleet Marine Force. By that time, HMT-204 had trained over 1800 CH-46E pilots, over 275 instructor pilots, and over 450 crew chiefs. It also had amassed over 95,000 class A mishap-free flight hours, earning the Chief of Naval Operations Safety Award in 1977, 1994, and 1997.
On 10 June 1999, HMT-204 turned a new page in Marine Aviation history when it was redesignated VMMT-204. It was named the model manager for the MV-22 Osprey. The unit rapidly began training pilots and supporting operational evaluation of the aircraft. Unfortunately, two mishaps in 2000 led to the grounding of the Osprey and of VMMT-204. While the Osprey program was undergoing restructuring, VMMT-204 was reduced in size. A small cadre of dedicated Marines laid a foundation for the eventual return to flight in the form of developing maintenance and flight training, as well as working on transition planning.
On 7 October 2005, years of hard work inside and outside of VMMT-204 culminated in the squadron's return to flight. Since that time, aircraft with “GX” on the tail have flown over 2000 hours toward making a tiltrotor medium-lift force a reality.
Meritorious Unit Citation with bronze star
National Defense Service Streamer with bronze star