Date: 202107
Local time of day: 0001-0600
Location: ZZZ.TRACON, US
Aircraft: A319
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Takeoff / Launch
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Coalescer Bag
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Time Pressure; Troubleshooting; Workload
Second reporter function: Pilot Flying; First Officer
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Weight And Balance; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Illness / Injury; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Landed in Emergency Condition; Flight Crew Overcame Equipment Problem; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Returned To Departure Airport; General Maintenance Action; General Flight Cancelled / Delayed
Contributing factors: Aircraft; Human Factors
Primary problem: Aircraft

Narrative: This was a fumes event. On takeoff; we noticed an oily odor. I thought this was something transient and continued takeoff. At about 4;000 feet the smell was not going away. I said we need to return to ZZZ. We [requested ATC priority handling for an air return] and put our O2 masks on. I called the Flight Attendants (FA's) and asked if they smelled anything. They said yes. We made an approach and overweight landing to Runway XXL. Prior to landing; I called on another radio for a gate. By this time at least one FA was on portable O2. I asked the Tower to send paramedics to Gate. I began the fumes checklist on the QRC. Once those initial actions were complete I stopped because we were getting close to a landing. Two AML entries were made. One for the fumes event and another for an overweight landing. According to the AML; the aircraft hit a bird the day before and an engine was bore scoped. When we arrived at the gate; Maintenance was powering hydraulic systems and testing reversers. When we got to the gate; I told the passengers to exit out the forward door quickly. After a couple of minutes of securing the flight deck; I opened the door and no one had gotten off. There was a fireman testing the air just inside the aircraft door.


Second narrative: SOF Event during departure with an immediate return to the departure airport (ZZZ). First Officer (FO) was the pilot flying. Ground Ops and taxi out to runway XXL were uneventful. As soon as the engines reached FLEX power; a slight burning metal smell began. This smell; experienced from time to time when the engines run up; normally dissipates in a matter of seconds. This time it remained throughout the entire takeoff roll. All other aircraft indications were normal during rotation and clean up. The smell persisted and a dirty sock smell was now prevalent; intensifying somewhat as we made a turn to a 230 heading with a climb up to 12;000 feet. At 4;000 feet we elected to stop the climb; don oxygen masks; and [advised ATC the need of an air return]. As a side note; it was hard to hear ATC and ICS with the loud noise of breathing with the masks on. At this point I remained the Pilot Flying and the Captain informed ATC of our intention to return for an immediate landing on runway XXL. The Captain was also made aware by the #2 Flight Attendant that the #1 Flight Attendant was on oxygen and still feeling very sick. I loaded the FMS for arrival and began a descent/vectors for the ILS runway XXL approach. At this time the Captain completed the Smoke/Avionics Smoke/Fumes QRH Quick Action procedure and informed the passengers and flight attendants of our intention to land. We were over maximum landing weight by roughly 4;000 lbs.; but elected to proceed with the descent checklist and land instead of working through the QRH procedure for Overweight Landing due to time. The approach; landing; and taxi in were uneventful.This aircraft; Aircraft X; had a birdstrike in the #1 Engine on the preceding flight. The maintenance actions were signed off. It is possible that the fume event could be related to this event. Fume events are a recurring issue across most fleets and airlines. I know there is a lot of attention from multiple organizations on this issue and that should certainly continue.


Synopsis: Air Carrier flight crew reported an air return during initial climb due to a fume event.