We think of war and we think of airplanes.

But when Orville and Wilbur Wright invented the airplane a century ago, they did not envision massive aerial bombardments of "shock and awe."

In fact, the Ohio brothers once thought their invention would become the great deterrent to warfare.

It was an idea shared by many after the inception of flight. War would become practically impossible, the brothers thought, because the scouting done by aircraft would equalize opposing nations with information on each other's movements, preventing surprise attacks.

"We thought governments would recognize the impossibility of winning by surprise attacks," Orville said in 1917, "and that no country would enter into war with another of equal size when it knew that it would have to win by simply wearing out its enemy."

Two years before, he had declared: "The aeroplane will prevent war by making it too expensive, too slow, too difficult, too long drawn out."

Yet eight years after the bicycle mechanics first flew across the sands at Kitty Hawk, N.C., the airplane was used to make war deadlier.

In 1911, an Italian pilot on an observation mission reached over the side of his airplane and dropped four grenades on Turkish targets during the Italo-Turkish war. Assault by air had become a reality.

Shortly before his death in 1948 and three years after American B-29 Superfortresses dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki, Orville Wright was asked by interviewer Leland D. Case if he and his brother ever thought their invention would be used for bombing.

The smile under Orville's gray mustache disappeared.

"Yes, we thought it might have military use - but in reverse," said the 76-year-old inventor, whose brother had died at age 45 in 1912. "Because the men who start wars aren't the ones who do the fighting, we hoped that the possibility of dropping bombs on capital cities would deter them."

Case noted that that same idealism persuaded dynamite inventor Alfred Nobel that his explosive creation would make war so catastrophic that men would turn away from it.

"The day when two army corps will be able to destroy each other in a second, all civilized nations will recoil in horror and disband their armies," Nobel said.

"We talked and we thought that way too," Orville said. "We dared to hope we had invented something that would bring lasting peace to the earth. But we were wrong. We underestimated man's capacity to hate and to corrupt good means for an evil end."

Little could he have imagined the deadly technology that would turn aircraft into the chief instruments of war. The aerodynamic principles pioneered by the engineering duo not only redefined the boundaries of the traditional battlefield, but gave birth to planes responsible for some of history's most horrific acts of carnage.

From the World War II strategic firebombings of Germany and Japan that killed hundreds of thousands of people with hurricanes of flames, the power of flight has often been measured with human lives.

"Technology is neither good nor bad; nor is it neutral," said historian Melvin C. Kranzberg, and the Wrights always recognized their technology was a double-edged sword.

"The Wrights were well aware that flying machines would likely drop explosives on their journey to the millennium, and they were not pacifists enough to let that prospect keep them from selling the machine to soldiers," James Tobin points out in To Conquer the Air: The Wright Brothers and the Great Race for Flight.

Still, the first client for their would-be instrument for peace was none other than the U.S. Army. Under contract in 1909, the Wrights built the two-seat, 735-pound Wright Military Flyer, the world's first military airplane. It was designated Signal Corps Airplane No. 1 and cost the Army $30,000.

Wright brothers historian Tom D. Crouch says the military sales were driven by the fact that, in the beginning, there was a limited market for airplanes.

"The Wright brothers were geniuses in business terms as well as engineering terms and they saw there was no market for this thing," said Crouch, senior curator of aeronautics at the Smithsonian National Air and Space Museum. "They recognized at the outset that sales to governments were going to be their primary market because the military had things you could do with it."

Reconnaissance missions were one, and in 1915, Orville said such missions explained why fighting had dragged on in Europe during World War I.

"Each side has such complete knowledge of the other's movements that both are obliged to crawl into trenches and fight by means of slow, tedious routine rather than by quick, spectacular dashes," he told Collier's Weekly. "War will become prohibitively expensive. And the scouting work in flying machines will be the predominating factor in bringing this about. I like to think so anyhow."

But in the end, Orville adopted a far more pragmatic view of the airplane's impact.

"He would say something like the invention of the airplane was sort of like the invention of fire," says Crouch. "Fire has done enormous damage to human civilization over the centuries, but when you add everything up, it's still a good thing that we had fire."

Information about centennial activities can be found at www.countdowntokittyhawk-.com, www.wrightexperience- .com. and www.centennialof-flight.com.