The Rise of the Helicopter During the Korean War

The Navy bought four of the improved Sikorsky aircraft in 1942 for evaluation but soon handed the responsibility for helicopter development and pilot training to the Coast Guard. The Navy resumed its own helicopter programs after WWII ended, forming Experimental Squadron 3 (VX-3) on December 28, 1945. Pilots and support personnel from that unit staffed Helicopter Utility squadrons HU-1 and HU-2 as training and fleet support squadrons.

Postwar atomic bomb tests forced the Marines to reconsider their traditional form of amphibious landings. As a result, Marine Helicopter Developmental Squadron 1 (HMX-1) was created on December 1, 1947, to test the use of rotary wing aircraft to move troops from ship to shore. When North Korean forces invaded South Korea on June 25, 1950, four HO3S-1 helicopters and 37 Marines were transferred from HMX-1 to VMO-6, which departed for Korea in July aboard the escort carrier Badoeng Strait.

The squadron’s four helicopters and eight Stinson OY-1 (the U.S. Navy designation for the L-5) fixed-wing spotter planes flew into the Pusan perimeter on August 2, as the Provisional Brigade’s ground troops were arriving. The helicopters quickly proved their worth, helping General Craig and his battalion commanders overcome their lack of familiarity with their operating area. “Helicopters were a life saver in this connection, as they provided the means for even commanders of small units to get into the air quickly from almost any point and identify roads, villages and key points prior to moving their troops,” Craig recalled.

The helicopters added pilot rescue to their duties on August 3 when an HO3S carrying Craig diverted to pick up a Marine Vought F4U-4 Corsair pilot who had been shot down during a close air support mission. Marine choppers would assume that role scores of times in the coming months. Major Robert J. Keller, a commander of VMF-214, the famous “Black Sheep” fighter squadron, said later, “The helicopters have done a wonderful service in rescuing downed pilots under the very guns of the enemy.”

As the choppers’ roles diversified, their crews implemented a variety of field modifications. When asked to carry casualties to the rear, the Marines found that a stretcher would not fit inside the HO3S’s small cabin. So they removed the rear window on one side and stuffed the wounded man’s litter in headfirst, leaving his feet exposed to the weather. On occasion, innovative helicopter crews also supported the infantry by laying field telephone wires between units, putting down lines over rugged terrain within minutes that would have taken men on foot days to cross.

Equipped with only the most basic instruments, the helicopters were not actually certified for night flying. But with so many lives at stake, Marines soon found themselves evacuating casualties after sundown. Pilots from the other services also defied the ban on night flying. In the end, chopper crews would conduct hundreds of dangerous nighttime medevac missions.

To meet the increasing demands for their services, additional Marine helicopters and pilots were sent from Japan in August. General Craig called for larger helicopters that could carry heavier loads, and Marine headquarters responded within a year. VMO-6 helicopters had no immediate role in the 1st Marine Division’s daring amphibious landing at Inchon on September 15, but choppers got into the action the next day when one of the squadron’s helos flying off an LST (landing ship, tank) rescued a Corsair pilot who had ditched in the harbor. Many of the rescue missions proved dangerous, and VMO-6’s helicopter units suffered their own losses. Two choppers were shot down, and one pilot was killed while trying to rescue other fliers during the advance from Inchon to Seoul.

The choppers played key roles during the Marines’ advance to the Chosin Reservoir and their fighting withdrawal from the massive Chinese offensive, maintaining contact among the widely separated units. And they also continued flying medical supplies and critical materiel in and carrying casualties out of small landing spots in the narrow valleys of North Korea. Two more choppers were shot up and another pilot killed during that precarious withdrawal.