Well known as one of the commercial aviation industry's most prolific aircraft salesmen, he made a significant contribution to the increase in Airbus's market share, from 18% in 1993 to 57% a decade later.
His first deal was selling A320s to Northwest Airlines, which was a Boeing customer which was then the risk averse choice.
Similar to loaning four A300B2 to Eastern Airlines for a test run before Leahy, selling 25 A300-600s to American required walk-away leases with little or no penalty at the return, and Boeing had to offer the same to place its 767-300ER.
To feed its New York and Miami hubs, Pan Am replaced its Boeing 727s by A320s but when it collapsed, lessor GPA placed them to Braniff, which then collapsed, America West Airlines took them, went through bankruptcy, and became its largest operator with US Airways and later acquired American Airlines which ordered 400 A320s.
In 1993–1994, Boeing struck exclusive supplier contracts for 20 years to eliminate competition and bind American, Continental, Delta, United and Southwest: the deal was ruled illegal when Boeing and McDonnell Douglas merged three years later, but was honored nonetheless.
He achieved 18% in 1995 and then Boeing Commercial Airplanes president Ron Woodard was determined to crush Airbus by cutting prices and offering early delivery slots: the 737 production rose from 21 a month to 27, unprecedented at the time, but the supply chain couldn't keep up and the line was shut down for 30 days to catch up, causing Boeing's first loss in 40 years as Woodard lost his job.