Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
General Flight Cancelled / Delayed; General Maintenance Action
Aircraft
I stepped onto Aircraft X. I don't have the registration number for this airplane. I immediately smelt something foul when I stepped onto the airplane. I thought it smelled like someone had thrown up in the flight deck. It was really bad on the flight deck and first class galley. I took a walk through the cabin and it seemed to me to dissipate as you went further back in the cabin. Both the First Officer and #1 Flight Attendant could smell it as well. The APU was off and we had not ground air connected. The remainder of the flight attendants boarded and they immediately started boarding after. I started the APU hoping that would clear the smell as I still thought maybe it was from some garbage the cleaners had just taken off the airplane. With the APU running you could still smell it and it was becoming more musky gym locker type of smell. I used only one pack at a time and that did not make a difference. The flight attendants working in the rear of the cabin called the flight deck and said passengers noticed the smell and they could smell it all the way in the rear of the cabin. I then turned the bleed off and called Ops to stop boarding. A few minutes later I made the call to have the passengers deplane. I called Dispatch and the Chief Pilot to keep them updated on the situation. After the passengers got off the airplane; I told our flight attendants and my First Officer to pack up and get off the airplane. Eventually Maintenance showed up took the airplane out of service. Suggestion: More routine maintenance on PACKs and bleed systems; making sure everything is clean and clear of contaminates.
A321 First Officer reported a musky gym locker" smell was noticed during passenger boarding that resulted in maintenance removing aircraft from service."