After an active athletic career in swimming, which included a reign as U.S. national 200-meter breaststroke champion from 1936 to 1939, she was accepted into the University of Southern California's first Civilian Pilot Training Program in 1939.

After racing aeroplanes competitively during the 1950s, Cummings and her husband, Howard Critchell founded the Bates Aeronautics program at Harvey Mudd College in 1962.

A long-time certified FAA Pilot Examiner, she was the recipient of several international aviation awards and was a member of the National Flight Instructors Hall of Fame.

In her later years, she remained active as a lecturer, consultant, and curator of the Aeronautical Library Special Collections at Harvey Mudd.

Iris attended the 1932 Summer Olympics as a spectator and began competing in swimming the following year, winning numerous local and regional tournaments.

[1] Cummings joined the Los Angeles Athletic Club (LAAC) in 1934 and received her first financial support in 1935, helping her attend that year's Far Western Championships.

[2] She was required, however, to raise her own funds for travel to the Games and spent much of her time leading up to the tournament collecting money rather than training.

[4][5] Following her unit's deactivation, she married military pilot Howard Critchell, whom she had met at a base that was used as a ferry stop for the WAFS and WASPs.