Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Flight Crew Overcame Equipment Problem; General Maintenance Action; General Flight Cancelled / Delayed
Aircraft
Prior to pax door closure; when the APU bleed was put into the ON position prior to pushback on Aircraft X; the First Officer (FO) sensed 'dirty socks'; musty smell after a couple minutes of use. Captain concurred with FO odor assessment and APU bleed turned off after 2 - 3 minutes of use. Maintenance was called to [the] aircraft and they concurred with smell assessment and the pax and crew deplaned to a new aircraft. Aircraft X was removed from service for further investigation. Captain submitted Cabin Odor report for Maintenance review and crew reported to new aircraft and continued to ZZZ1.
Air Carrier Captain reported a fume event during preflight at departure gate. Maintenance was requested resulting in an aircraft swap.