HMMT - 164 Marine Medium Helicopter Training Squadron 164 ( HMMT - 164 ) , is a United States Marine Corps Fleet Replacement Squadron that is based at Marine Corps Base Camp Pendleton . Known as the " Knightriders " , they fall under the command Marine Aircraft Group 39 ( MAG - 39 ) and the 3rd Marine Aircraft Wing ( 3rd MAW ) . History . Vietnam War . Marine Medium Helicopter Squadron 164 ( HMM - 164 ) was activated on July 1 , 1964 at Marine Corps Air Station Santa Ana , California as part of Marine Aircraft Group 36 . In August 1965 the squadron transferred to Marine Wing Support Group 37 at Marine Corps Air Station El Toro , California . The squadron received the first CH - 46 Sea Knight s assigned to West Coast duty six months after activation . HMM - 164 brought the first CH - 46 Sea Knight helicopters into Vietnam when they landed at Marble Mountain Air Facility after transiting from the in March 1966 . HMM - 164 remained in Vietnam for a three and one - half years as part of Marine Aircraft Group 16 ( MAG - 16 ) . During their time in country they operated in and around the following areas : Quảng Trị , Dong Ha , Khe Sanh , Huế , Phu Bai and off the decks of the , the and the " Valley Forge " . While in Vietnam , HMM - 164 supported US forces in all the major operations , most notably in Operation Meade River and Operation Hastings . On July 15 , 1966 while conducting the initial insertion of ground forces during Operation Hastings the squadron lost three CH - 46A Sea Knights in the vicinity of LZ Crow near Con Thien . Two aircraft crashed when their rotorblades intermeshed while trying to avoid Marines on the ground and the third crash was caused by heavy ground fire . In October 1969 , the squadron left Vietnam and relocated to Okinawa , Japan where it joined Marine Aircraft Group 15 ( MAG - 15 ) . From October 1969 through April 1972 , it deployed with elements of the United States Seventh Fleet as part of a special landing force . HMM - 164 supported combat and search and rescue operations off the coast of Vietnam until April 1972 when it deployed aboard the . While aboard the Okinawa , HMM - 164 continued to provide Joint Service combat support in Operation Song Than and Operation Lam Son 719 until returning to Marine Corps Air Station Futenma , Okinawa in 1973 . After the withdrawal of American forces from Vietnam and the squadron ' s subsequent transfer to Marine Aircraft Group 39 ( MAG 36 ) , HMM - 164 participated in numerous peacetime operations aboard naval shipping traveling to Korea , the Republic of the Philippines , and Japan as well as many exercises in Okinawa . A detachment from the squadron participated in the evacuation of Americans from Phnom Penh , Cambodia , on April 12 , 1975 as part of Operation Eagle Pull . On April 30 , 1975 , an HMM - 164 CH - 46D crew lifted the last Americans out of Vietnam when they picked up the Marine combined security force during Operation Frequent Wind . Post - Vietnam through today . With the advent of the Unit Deployment Program , on September 1 , 1978 , HMM - 164 returned home to MCAS Santa Ana , California . In September 1978 , the squadron rejoined Marine Aircraft Group 36 ( MAG - 36 ) at MCAS ( H ) Futenma for a six - month tour beginning in August 1979 and returning to MCAS ( H ) Tustin in February 1980 . On November 1 , 1980 , HMM - 164 became the first unit on the West Coast to receive the " E " model CH - 46 . By March 1981 , the squadron had received its full complement of " Echo " helicopters . During the summer of 1989 , the squadron simultaneously supported oil spill cleanup efforts in Valdez , Alaska and an Air Contingency Force at Soto Cano Air Base , Honduras . In June 1990 , HMM - 164 deployed to the Western Pacific with the 13th Marine Expeditionary Unit ( 13th MEU ) and provided support relief efforts following the July earthquake that devastated the Philippines . In August 1990 the squadron proceeded to Southwest Asia and participated in maritime interdiction operations during Operation Desert Shield and then provided combat support during Operation Desert Storm before returning to MCAS Tustin in April 1991 . The squadron deployed in October 1992 with the 15th Marine Expeditionary Unit ( 15th MEU ) . The squadron provided support to Joint Task Force ( Somalia ) during Operation Restore Hope from December 1992 until February 1993 . HMM - 164 returned to MCAS Tustin in April 1993 . August 1993 found the squadron providing support for units training at the Mountain Warfare Training Center , Bridgeport , California and provided a mission capabilities demonstration for the Secretary of the Navy . In August 1993 , the Marine Corps Aviation Association chose HMM - 164 as the Medium Helicopter Squadron of the year . In June 1995 , HMM - 164 deployed as the Aviation Combat Element with the 11th Marine Expeditionary Unit ( 11th MEU ) . During this time it provided support for the United States Central Command in Operation Vigilant Sentinel in Kuwait as well as Bahrain , Qatar , and United Arab Emirates before returning and relocating to MCAS El Toro , California in December 1995 . In February 1996 , HMM - 164 was called upon to support the President of the United States as he visited the flood - ravaged areas around Portland , Oregon . On August 28 , 1997 , HMM - 164 ( REIN ) deployed again with the 13th Marine Expeditionary Unit . During the month of December 1997 and January 1998 , the squadron ' s AV - 8B Harrier II s and KC - 130 Hercules flew combat sorties in support of Operation Southern Watch over southern Iraq . HMM - 164 ( REIN ) returned to MCAS El Toro on February 26 , 1998 , completing its final deployment before re - designation as a Fleet Replacement Squadron . On January 8 , 1999 , HMM - 164 relocated to MCAS Camp Pendleton , California as part of the Base Realignment and Closure ( BRAC ) move and was attached to MAG - 39 effective January 11 . In February 1999 , the Squadron was re - designated HMMT - 164 and was tasked to become the Marine Corps ’ Fleet Replacement Squadron for the CH - 46E . During March 1999 , the squadron deployed two aircraft to Moffett Federal Airfield to support Operation Urban Warrior and accept its first two student pilots . In May , the Marine Enlisted Aircrew Training Department accepted its first class of new enlisted aircrew . On June 1 , 1999 , the squadron took over the role as Model Manager and Fleet Project Team Manager for the CH - 46E . Since 2000 , HMMT - 164 has trained over 360 new pilots and 460 crew chiefs . On June 28 , 2008 , HMMT - 164 deployed to Naval Air Station Lemoore after California Governor Arnold Schwarzenegger requested military assistance to fight raging wildfires . The helicopters are providing medium lift rotary wing support to United States Northern Command and the National Fire Center .