Medevac From Luzon
A small band of helicopter pilots risked their lives to rescue wounded soldiers during World War II.
- By Roger Connor
- Air & Space magazine, July 2010
38TH DIVISION PHOTOGRAPHER
(Page 3 of 4)
By the standards of Korea and Vietnam, Carle’s workload seems trivial, but the R-4B was a far more demanding machine than its successors. The R-4B’s blades were constructed of wood ribs around a steel spar and covered with doped fabric. They were difficult to keep in track (rotating in the same plane) and vibrated excessively. The pilot’s cyclic stick made continuous small orbits, never staying completely stationary. There was no governor to control rotor speed, and the pilot had to correlate the throttle continuously with collective pitch inputs. In one of the only instances of public coverage given to the Ivory Soap helo pilots, a June 21, 1945 Chicago Tribune article reporting on Carle’s initial efforts noted: “Driving the ‘eggbeater’ is hard work. The control stick shakes like a jackhammer, and the pilot must hold it tightly at all times. Should he relax for even a minute the [helicopter] falls out of control. Pilots of regular planes say it’s easy to identify a helicopter pilot—he has a permanent case of the shakes.”
Besides wrestling with the helicopters, the pilots had to load and unload the wounded without assistants, which only added to the job’s stress. Not all of the pilots assigned to the aircraft repair units were suited to the medical evacuation missions. First Lieutenant Harold “Pappy” Greene walked away from helicopters after flying only two evacuations, swearing he would “never fly another helicopter—ever.”
Carle and Cowgill found their evacuations becoming more difficult. The pilots continued to discover unanticipated limitations on these first-generation production rotorcraft. Cowgill recalled that though the R-6 was intended as an improvement on the hastily designed (and perhaps overbuilt) R-4, it seemed to have numerous defects and was an even trickier machine to fly. “They had the fuel tank in front of the center of lift…so when you ran [low] on fuel, the nose began to rise and you would run out of forward stick if you [were] alone,” said Cowgill. “I had to stop once and put a stone up in the front to trim it up enough. It was just a completely stupid goof.”
Carle’s final disastrous evacuation demonstrated just how far beyond the design limits of the R-4B the pilots were going. With the heat, humidity, and altitude characteristic of central Luzon, the payload of the R-4 was essentially zero. To get off the ground, Carle had to employ a dangerous technique: the jump takeoff. In an article he wrote for the January 1947 issue of American Helicopter magazine, he recalled that he deliberately oversped his engine and rotor rpm past redline to “2,600 [engine] rpm and [pulled] 7.5 degrees pitch to start the takeoff,” causing the helicopter to leap into the air. The technique had numerous hazards, including the helicopter settling back onto the ground. Another danger was that either stress or the increasing air pressure at the blade tips would cause the blades to fail structurally. Over-revving did the engine no favors either, but Carle later instructed future helicopter pilots that “such a high rpm may shorten the life of the engine, but it will lengthen the life of the pilot.”
The high-torque maneuver also overwhelmed the R-4B’s tail rotor, and the “torque caused the tail to swing almost 90 degrees to the left.” The helicopter was then in an awkward position to depart the tight clearing, but Carle made the best of it. As his helicopter moved sideways, the rotor began to enter what is now known as “effective translational lift,” in which a forward influx of airflow increases rotor efficiency, providing just enough improvement in performance to keep the helicopter from settling onto the ground. Carle then noted that “as the ship picked up speed, the action of the wind swung the tail partially behind me…[but], as I started it soon became apparent that the 210 pounds of my passenger, plus the altitude of 1,500 feet were going to make it impossible to clear the high trees. The rpm was dropping rapidly, and the airspeed was near zero. I was at the limit of my climb and still the tops of the trees were above me. I couldn’t turn back without dropping straight in, probably killing the passenger and myself, so I jerked the pitch control as high as it would go and luckily we cleared the trees by inches, but the effort had cost [rotor rpm] and all of my airspeed.
“As soon as I realized that we were clear of the trees, I dropped the pitch to 4 degrees and held full throttle, at the same time pushing forward on the stick. As the rpm came back within the green, I increased the pitch and fortunately missed dropping into the jungle. Again, the rpm dropped, and again I lowered the pitch enough to bring it back. The airspeed was building slowly and we began to climb to safety. What had actually been a few seconds seemed an eternity. My clothes were drenched with sweat, and I was so weak that I could hardly move the controls.”
Carle’s experiences presaged those of countless combat helicopter pilots in the Korean and Vietnam wars, who were forced to master flying overloaded aircraft into tight landing zones; his recollections vividly illustrate just how risky these early operations were. On June 21, Carle and Cowgill both ran out of luck. Carle’s rotor tip hit a tree, and almost simultaneously, Cowgill, flying an equally treacherous approach in the R-6A, clipped a tree with the tail rotor. Fortunately, the troops at his landing zone were well positioned, and were able to post a guard to watch the aircraft (recovered a week later). Cowgill marched out of the jungle with an escort on a harrowing four-day journey in which he too encountered determined Japanese opposition.
The two crashes ended the Fifth Aircraft Repair Unit’s participation in the operation, as their ship was preparing to support the newly captured airfields on Okinawa. After Carle deployed with his vessel to Okinawa, the war ended. He went back to Luzon to fly R-6As with the Second Emergency Rescue Squadron, which was adding helicopters to an extensive stable of fixed-wing rescue aircraft. After returning to the United States, he suffered persistent pain from the rotor fragment in his skull and never flew helicopters again.