 Following the Vietnam War, Marine Helicopter Training Group 40 (MHTG-40) was deactivated and Marine Medium Helicopter Training Squadron-402 and Marine Heavy Helicopter Training Squadron-401 were combined to form HMT-204.HMT-204 was originally a composite training squadron, tasked with training both CH-46 and CH-53 pilots.In January 1986, the commanding officer of HMT-204 accepted the first fleet model of the CH-46E Survivability, Reliability and Maintainability (SR&M).