If World War I showed the nations of the world how the airplane could vault over ground emplacements to strike at an enemy, the combatants also came to appreciate the efficacy of using aircraft as ambulances to surmount obstacles and save precious time flying away from the fray.
During that war, U.S. Army aviation devised ways to put a litter patient in the aft fuselage of a Curtiss JN-4 Jenny biplane, as well as in the modified fuselage of a larger deHavilland DH-4.
The French and British also used airplanes on a number of occasions in combat areas to hasten the removal of injured men to hospitals during World War I.
By World War II, the fundamentals of Army Air Forces airlift had codified the concept of using larger inter-theater or intra-theater transports to bring troops and supplies to the battle, and to take injured soldiers away on the return flight.But the concept of a small air ambulance remained viable for getting the wounded out of sometimes-rustic airstrips unsuited for larger C-46s, C-47s, and C-54s.
Some liaison aircraft included modifications for service as forward air ambulances in World War II. The Piper L-4 could serve as a medical evacuation airplane in some configurations, and the Stinson L-5 had an ambulance variant with a large door for a litter on the right side of the fuselage behind the pilot. The L-5 pilot’s manual includes the admonition: “Never spin the airplane when it is being used as an ambulance or cargo airplane.”
A real attention-getter was the conversion of drop tanks by installing removable Plexiglas nose caps and making rudimentary accommodation for one passenger. These now non-drop tanks could be mounted one under each wing of a P-38 Lightning fighter or its F-5 photo reconnaissance version for speedy evacuation.
After the war, the Canadian deHavilland L-20 (later U-6) Beaver could be rigged with two litters, one over the other, along the right side of the cabin. The Beaver was large enough to accommodate the pilot, a medical attendant, two ambulatory seated patients and two litter patients.
The first known medical evacuation by helicopter took place during World War II with a Sikorsky R-4. By the time of the Korean war in the 1950s, R-5 and H-13 helicopters were providing rotary-wing medevac sorties.
The use of UH-1s and other helicopters for medical evacuation since the war in Vietnam is a story in itself. Helicopters came to own the important task of battlefield medical evacuation.