Hop Harrigan is the son of Colonel A. Harrigan, a renown mail plane pilot and a pioneer in aviation. The colonel's wife left him to return to her native Columbia with their daughter, and the colonel made a flight from which he never returned and was declared dead.
Now alone, the young Harrigan inherited his father's farm and a considerable sum of money. However, a farmer named Silas Crass, who falsely claimed to be Hop's legal guardian and who mistreated the boy, stole the money and sold the farm, keeping the profits for himself.
Hop idolized such famous pilots as Charles Lindbergh and Corrigan, and taught himself how to fly his father's antique "Jenny" biplane. One day, Crass found the teenager by the plane and was so enraged that he tried to chop up the plane with an axe. Hop struck Crass and flew off in the plane.
While flying near an airport, Hop saw that a man's parachute had caught on the tail of another man's plane, thereby endangering both men. Hop lowered a knife to the man with a parachute, who turned out to be a top aviation mechanic, Ikky Tinker. After cutting himself free, Tinker descended on an emergency parachute. Both Tinker and the plane's pilot, Prop Walsh, were grateful to Harrigan and highly impressed with his flying ability. When Tinker said about Harrigan's flight, "Some Hop, Harrigan," Walsh decided to make "Hop" the teenager's nickname.
Walsh got hop a job at the airport, taught him about flying, and eventually became his legal guardian. Hop quickly became a superb pilot and soon met Gerry, a millionaires' daughter who became his girlfriend. Hop, Walsh and Tinker formed the All American Aviation Company, which built planes for military and civilian use.
Harrigan had many World War II adventures, at first taking part in spying missions. Later the three men joined the US army corps and Hop fought the Nazi's in South America and Asia. All three men returned to civilian life after the War.