On 15 February 1944, the Squadron activated at Quantico, Virginia as Marine Observation Squadron (VMO) 5, the “Black Aces.” The operational aircraft at the time was the OY-1 Piper Cub. VMO-5’s primary tasks were providing aerial fire support spotting and observation in support of ground forces. Following several months of training in Camp Pendleton, California and Ewa, Hawaii, the Squadron deployed with the 3d Marine Aircraft Wing (MAW) to the Pacific Theater. It split into two groups, staging in Saipan and Guam in preparation for the Iwo Jima Campaign. On 19 February 1945, elements of the Squadron went ashore and remained on Iwo Jima until the end of the campaign. After this campaign, the Squadron redeployed to Hilo, Hawaii and attached to Marine Observation Group 1, 2d MAW. Following victory in World War II, VMO-5 deployed to Sasebo, Japan for occupation duty from September 1945 to January 1946. Upon completion of this tour, VMO-5 returned to San Diego and deactivated on 31 January 1946.
With the looming Vietnam War, the subunit of Headquarters and Maintenance Squadron 30 (H&MS-30) at Marine Corps Base Camp Pendleton was redesignated as VMO-5 on December 15, 1966 becoming a full-fledged training squadron. They originally fell under the command of Marine Helicopter Training Group 30 under the 3rd Marine Aircraft Wing and were equipped with a complement of UH-1E Hueys and OV-10 Broncos. In March 1968, the squadron was redesignated HML-267 and remained at alert status and training replacement pilots and crew for the rest of the war.
