The Airplane - Jay Spenser [50]
Born in 1859, Hugo Junkers grew up in Rheydt, today an industrial suburb of Mönchengladbach in west-central Germany. Not interested in his family’s textile business, Junkers took degrees in mechanical and electrical engineering. A hardworking entrepreneur, he helped design products and created companies to bring them to market. One of his firms manufactured diesel ship engines. Another produced steam boilers and water heaters that he had designed.
In 1906, Junkers traded the pressures of industry for a teaching post at Aachen, in his home state of North Rhine–Westphalia. Romans had walked Aachen’s historic streets, and Charlemagne had made the town his capital. But the Aachen of Junkers’ day looked to the future because of its famed technical university.
Two years after joining the university’s staff, Hugo Junkers accidentally entered the field of aviation when a colleague asked him for engineering help with an airplane he was designing. Had that professor called on an established aviation expert, history would have taken a different turn. But instead he asked Junkers, a complete neophyte when it came to flying machines.
Junkers had little reverence for the paths others had taken. What’s more, he knew and cared little about bird wings and had no wish to emulate them. Instead, at his age and being a forceful personality, he saw flight as a chance to apply hard-won knowledge to benefit a new field. It was a challenge he relished.
All of this predisposed Junkers to think in unconventional terms. Being experienced in steel fabrication, he immediately considered all-metal construction. Never mind that others had ruled out steel as being too heavy for more than sparing aviation use. And while Junkers didn’t really seek to make a water heater fly, as some suggested, there was unquestionably boiler DNA in his Junkers J 1 of 1915, the first all-metal airplane to fly.1
Significantly, the structural engineer in Hugo Junkers couldn’t help wondering whether thick wings would work. If the answer was yes, it meant that wings could be designed robust enough to carry all the loads of flight internally. If so, they would need to be supported only at one end, like the span of a cantilever bridge; there would be no need for external bracings.
Of course, such wings would have to be considerably thicker than any in existence. Consequently, when Junkers began his aerodynamics research in 1913–14, his wind tunnel studies focused on one burning question: could fat cambered airfoils sustain an airplane in flight the way thin ones do?
The answer turned out to be yes. In fact, as the world would soon discover, fat wings performed better than thin ones.
Thin airfoils are inherently dangerous. With their sharp nose profiles, they stall with little or no warning to the pilot.
An aerodynamic stall is what happens when the angle between the wing and the air it is passing through becomes too great for the airplane’s speed, weight, and available power. The airflow separates from the wing, causing the airplane to quit flying and start falling.
Junkers employees demonstrate the strength of the Junkers G.23’s fully cantilevered wing in 1924.
Museum of Flight, Seattle
To recover from a stall, the pilot ceases to pull back on the stick, allowing the airplane to regain flying speed and continue on its way after a loss of altitude. If the airplane falls off on one wing when the stall breaks, the pilot may also have to counteract a spin by applying opposite rudder as part of the stall recovery.
All of this is simple enough if you have enough altitude to complete a successful recovery when the airplane stalls. If not, you’re out of luck. That’s why advance warning of incipient stalls is so important.
As it turns out, thick wings with their blunt noses do provide this warning. Instead