Stirling enlisted the Smithsonian as sponsor and the Dutch government as a partner. To make it past the perilous rapids that had blocked previous attempts to penetrate the interior, he was counting on two modes of transport. Seventy Dayak tribesmen from central Borneo, terrifically skilled canoeists, would negotiate the treacherous stretches of river in 10 boats. And a modified World War I-era Breguet14 B2 bomber would ferry supplies upriver and scout the route.
The Breguet was one of the first aircraft with a corrugated-metal skin, developed to get around the weakness and weightiness of wood skins. Stirling bought his from the Yackey Airplane Co., which had added pontoons so the craft could make water landings, replaced the original engine with a more powerful 400-horsepower Liberty, and added a few accessories to the cockpit, including a collapsible two-person boat, a camera mount, and a small "frigid air plant" to keep the film chilled. The airplane was christened the Ern, a popular crossword term for a sea eagle. Two Yackey employees, pilot Hans Hoyte and mechanic Albert (Prince) Hamer, joined the crew, and Richard Peck became the expedition's backup pilot and photographer.
Stirling exuded confidence as he set sail from Batavia (now Jakarta), Indonesia, toward New Guinea on April 7, 1926, the Ern tied to the deck of the steamship Fomalhout. Speaking to the press while a regimental band played what one report described as "American airs," Stirling said, "I have the utmost confidence in our plane's motor to fly and keep flying over the jungles and mountains."
Which it did, admirably. In two months of ferrying supplies upriver-two or three round trips every day, typically with 700 pounds of cargo on each trip-the engine never failed once. But there were plenty of nervous moments. Stirling's notebook from the expedition-written in a neat, flowing hand that fills nearly every inch of every page-is in the Smithsonian's National Anthropological Archives in Suitland, Maryland, looking amazingly fresh, considering all it must have gone through 77 years ago. The daily entries include this description of a harrowing May 15 encounter with natives, which took place as Stirling and Hoyte returned to the airplane after leaving a cache of supplies far up the Rouffaer River:
The air was fairly ringing now with shouts and cries, and five or six canoes with about 25 men were paddling out into the river about 400 yards above us, armed with bows and arrows and gesticulating wildly. In a couple of minutes we saw an equal number of canoes on the river below paddling vigorously upstream toward us.
There being only two of us, we decided that it was high time to evacuate. At this crucial juncture, we saw that the radiator was leaking, so I filled a five-gallon kerosene tin with water while Hans climbed up on the engine and poured it into the radiator. We did not dare put in more as the canoes were slowly working nearer to us.... After closing the radiator cap, Hans started priming the engine and in his haste burned his arm on the exhaust pipe. We then let loose our line and threw it with the anchor into the cockpit.
Now the problem of taking off! With the line off, I had to hold the wing of the plane inshore, while Hans got on the wing to crank the engine. As the Liberty was still hot from her long pull, this was no simple task, and as is usual when in the biggest hurry, the engine refused to start. It is heavy work and Hans, already tired, was soon almost exhausted...
In the meantime the Papuans above began shooting arrows at us, some of which bounced off the aluminum side of The Ern. I fired my 45 into the air, and the Papuans dove into the water from their canoes and the arrows stopped coming. On reflection, I think they were shooting at the plane rather than us.
It was probably about five minutes, though it seemed an hour, when the engine caught. The welcome roar of the Liberty at that moment was one of the sweetest sounds I ever heard in my life. I swung the nose of the pontoon into the stream as Hans gunned the engine and made a dive for the end of the wing as the plane headed into the stream, her tail barely clearing the tree below us....