Final answer:
In the twenties and thirties, those flying on planes included pioneers like Charles Lindbergh, Bessie Coleman, and groups such as the Tuskegee Airmen. The era also marked the growth of the commercial airline industry, as air passenger numbers significantly increased.
Step-by-step explanation:
The groups of people who were flying on planes in the twenties and thirties included pioneering individuals such as Charles Lindbergh, who made history with his solo flight across the Atlantic, and trailblazers like Bessie Coleman, an African American stunt pilot. This era also saw combat pilots like the Tuskegee Airmen, a group of African American pilots who trained in Tuskegee, Alabama as part of an Army Air Corps experiment. These men proved that African Americans could excel as pilots and other roles within the military, eventually helping to pave the way for the integration of the armed forces. Additionally, during the thirties, the airline industry began to flourish, and by the end of the decade, the number of domestic air passengers in the U.S. had grown from just over 450,000 annually to nearly two million.