A319
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Total 0
Situational Awareness
Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Illness / Injury; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Air Traffic Control Provided Assistance; Flight Crew Returned To Gate; General Maintenance Action
Aircraft
After taxi out and after both engines were started and APU shut down we started smelling a very noxious odor. We checked with the flight attendants and they and the passengers also smelled the odor. We followed the appropriate checklist and decided to return to the gate. Once we started heading back to the gate we had a medical situation due to a passenger having a seizure. We notified maintenance; ATC; the company and the ramp. After returning to the gate we talked to the maintenance personnel and they informed us that this was the fourth time this had occurred [in the previous 10 days]. Something toxic is leaking into the air conditioning system. Find the cause of the smell and leak.
A319 First Officer reported during taxi for departure 'noxious odor' were detected throughout the aircraft. Flight crew executed a ground gate return in which Medical and Maintenance met the aircraft.