Sophia Kuo says she still hears the whispers as she walks through international airports in her EVA Airways Corp. pilot's uniform: “ 'Wow, we have female pilots.' 'How does she fly an airplane?' 'She must be really smart!' ”

More than eight decades after Amelia Earhart's solo flight across the Atlantic, women like Kuo, a 35-year-old copilot on the Taiwanese carrier's Boeing 747s, remain the exception in the cockpit. Only about 5 percent of pilots globally are female, according to Liz Jennings Clark, chairwoman of the International Society of Women Airline Pilots. And just "a tiny" percentage of them are captains.

Now, airlines are being forced to balance the scale because a rapid escalation in air travel in Asia may leave the industry desperately short of pilots. The region is transporting 100 million new passengers every year, said Sherry Carbary, vice president of flight services for Boeing Co., which assists airlines in training new pilots. To fly all those aspiring new middle class passengers, Asia is going to need another 226,000 pilots in the next two decades, according to Boeing.