In 1942 there were no helicopters in US military service. Sikorsky had just introduced its R-4 “Hoverfly” which would become the first helicopter employed by US armed forces. Under the nomenclature HNS-1, Navy and Marine units spent two years proving the Hoverfly concept. During this time, L-birds were used for air ambulance duties. Allegorical to hover-and-fly, the low-and-slow L-birds proved reliable and effective for such purposes.
The US Navy ordered 100 Piper HE-1 ambulance aircraft in 1942 for use in the Pacific Theater. The HE-1 was based on the civilian J-5 Cub Cruiser, specifically, the J5C model with a Lycoming O-235-B engine (military designation O-235-2). It included an electrical system and other Navy specified modifications.
The Piper J-5 was a 3-seater, using the same wing, tail surfaces and controls as the J-3. With a widened fuselage, it could accommodate two passengers (albiet cramped) in the rear seat. The engine was enclosed in a metal pressure cowling, further distinguishing it from the J-3.
Specific to the HE-1, the aft fuselage, or so called “turtledeck,” opened allowing the aircraft to carry consignment of some length. For the purpose of air ambulance, the HE-1 could accommodate the pilot plus one standard Stokes litter—a wire basket conforming in shape to the human body into which an injured person can be safely strapped. Minor changes were made in the aircraft’s structure and control systems to support the litter.
Those built from 1944 to 1946 included further design changes developed for the US Navy. Notable are the bungees on the landing gear placed inside the fuselage. Early versions, of which 783 were built between 1940 and early 1942, have external, exposed bungees. Also, the designation for the HE-1 changed to AE-1 (A for ambulance, H previously being hospital) when the Navy took delivery of its first helicopter in 1943. This applied retroactively to all.
Dimensionally similar to the J-3, with its wider cockpit and larger engine, the AE-1 weighs 906 lb empty with a 1,426 lb GTOW, roughly 200 lb greater than the J-3. The Navy maintained the bright yellow Cub color of the civilian J-3 adding blue roundel military insignias on the wings and red crosses on the fuselage sides.
In US Navy service, the AE-1 aircraft were usually based at small, remote air stations located some distance from major medical facilities, e.g., Naval Auxiliary Air Stations (NAASs) Brown Field and Holtsville, California; Chase Field (Beeville), Texas; Martha’s Vineyard, Massachusetts; Oceana, Virginia; Vero Beach, Florida, etc.
The U.S. Marine Corps accepted their first in 1943. By August of that year, the Marines were operating seven aircraft assigned to the Base Air Detachments (BADs) at Marine Corps Air Stations (MCASs) Cherry Point, North Carolina (2); El Centro (1), El Toro (1) and Mojave (1), California; Quantico, Virginia (1); and Parris Island, South Carolina (1).
As helicopters began to dominate the air ambulance role, the AE-1 became superfluous and all were discarded soon after the war ended (Sept. 1945).
Note: Though based also on the J-5, the Piper L-4F and L-4G were not ambulance versions.
Like its civilian predecessors (and the lighter Aeronca, Interstate, Piper and Taylorcraft L-birds), the Stinson L-5 was constructed of a tubular steel fuselage, wood framed wings and tail surfaces, with a fabric covering. Its unique leading edge slots and aileron design gave the aircraft superb, stable slow flight characteristics.
The Stinson L-5 too served as an air ambulance during WWII and in Korea. By putting a deck into its aft fuselage, the heftier L-bird could easily accommodate a wounded passenger on a stretcher. A large “dutch” door, combined with the rear seat observer’s door, on the right side of the fuselage, allowed easy access. In the days before medevac helicopters, an aircraft that could take off and land in small fields meant the difference between life and death of an injured soldier. Used as an air ambulance, L-5B and later model Sentinels could carry a passenger-litter up to 250 pounds.
In total 3,591 were built for the US armed forces, making the L-5 the second most widely used light observation aircraft of the war behind the Piper L-4. An additional 31 units of the L-5 were completed and sold post-WWII on the civil market.