Date: 202003
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: A319
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
Aircraft component: APU
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Human factors: Workload; Communication Breakdown; Time Pressure
Second reporter function: Instructor
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Attendant; Person Flight Crew
Result: General Flight Cancelled / Delayed; General Maintenance Action; General Work Refused
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: After doors were closed but before engines were started the aft flight attendant called the cockpit and said there was a strong 'dirty sock' smell in the rear of the airplane. We ran the QRH Smoke/Fumes procedure and that didn't seem to solve the issue. I made a passenger announcement and had gate personnel deplane the aircraft. I called Maintenance and they had me fill out the Cabin Odor/Fumes report which I did. Contract maintenance was called and eventually the mechanic found an oil leak in the APU. Around this time I went up to the gate area to discuss the issue with the First Officer. He said he had recently been down to the plane and the fumes were still too strong for him to return to the aircraft. I told him I would not take the aircraft until the fumes were removed. I then called Maintenance and they said the next step was to do an engine run at idle power to remove the odors from the air conditioning system. I looked in the FOM for guidance on doing an engine run at the gate and was having trouble finding the relevant section. I then called the Dispatcher and she put me in touch with the Chief Pilot. I explained the situation to him regarding the First Officer and he said that I would be fine if the mechanic was with me and we were towed to the remote location instead of taxiing out on our own power. The mechanic then called [Airport Operations] and they said a two engine run at idle would have to be done at remote location. I arranged for the tow; and did the engine run up with the mechanic per guidance from maintenance. After the run was complete we were towed back to the gate. I shut the airplane down and turned the aircraft over to the mechanic to complete the Cabin Odor maintenance action. I then found out the First Officer and the Flight Attendants had been placed on the next flight to ZZZ. I boarded that flight with a jumpseat listing and returned to ZZZ as the wait to talk to crew tracking was quite long and the flight to ZZZ was about to leave. I assumed since the rest of the crew had been booked on this flight that they had cancelled [flight] and had overlooked me in booking a seat back to ZZZ. In addition; I had a redeye to ZZZ1 the very next evening so I thought crew tracking would want me back in town for that. In hindsight I should have sent Crew Tracking a message from [system].It started with cabin odors caused by an APU oil leak that required deplaning the aircraft and going through the cabin odor maintenance process. The essence of the event is that I probably felt rushed to complete the cabin odor procedures so I could get the crew and the passengers back to ZZZ that evening. I didn't know at the time there was another flight to ZZZ so soon after ours or I would have handled things a little differently. I have learned a good lesson about self induced time pressures. You think you know all about get-there-itis and then it sneaks up on you. I thought I was being prudent by seeking guidance from the Chief Pilot and Maintenance but in retrospect I should have called my own Chief in ZZZ in the middle of an unfamiliar situation.


Second narrative: A few seconds after I called for push from [gate]; the Captain received a call from the aft Flight Attendant and was informed there was a 'dirty sock' smell in the rear of the cabin. At the same time; I also smelled it in the cockpit. The Captain asked me to go to the back of the plane and see if I could smell the odor. As I got towards the rear of the plane; I could definitely smell the dirty sock odor. I went back to the cockpit and told the Captain I did smell the odor and we both pulled out the QRH for fumes. As He was doing the QRH; I called OPS and told them we might need to de-plane; which we did a couple minutes later. After all the passengers were off the plane; the flight attendants and I also left the plane except for the Captain who was on the phone with Maintenance and Dispatch I believe. About 30 minutes later; the Captain came out to the gate area where I was sitting and started talking about doing an engine run-up when maintenance was done to remove the smell. I asked him who was going to do the run-up as I said I will not do that. It was a maintenance function I assumed and I also didn't want to go back to the fumes (the reason the contract maintenance needed assistance was because they weren't qualified to do the run up). About 30 minutes after that; the Captain came back out from the plane to the gate area and said that I didn't need to be on the plane with him to do the run-up since there was no taxiing involved (they got pushed/pulled to a location about 100 ft. away from the terminal and did the run up there. When I went back to the plane to remove my belongings; the smell was really strong and I asked him if he could smell it. I didn't really get a yes or no response. As the Captain and maintenance were doing the run-up / pack-burn for about 30 minutes; I called the on duty Chief Pilot and told him that I didn't feel safe flying with the Captain and requested a deadhead back to ZZZ since the Captain had been in the plane most of the time with the fumes.


Synopsis: A319 flight crew reported they were notified by a Flight Attendant of a dirty sock" smell in the rear of the cabin prior to gate pushback resulting in a maintenance delay; and eventual flight cancelation."