Date: 202009
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Aircraft: A319
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
ATC / advisory: Ground ZZZ
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Human factors: Troubleshooting
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Attendant
When detected: Pre-flight
Result: Flight Crew Overcame Equipment Problem; General Maintenance Action; General Flight Cancelled / Delayed
Contributing factors: Airport; Aircraft
Primary problem: Ambiguous

Narrative: Post Shutdown checklist at ZZZ1; Flight Attendant (FA) #1 advised me that she smelled a burning rubber odor after landing during the beginning stages of taxi-in. According to her input; this was the same odor that [the] Captain; First Officer; FA#1; and [the] Gate Agent smelled in ZZZ prior to gate departure. In ZZZ prior to gate departure; Maintenance (MX) was called. After consultation; MX techs believed that the source of the odor was external to the aircraft. They surmised that the source was landing aircraft on RWY XXL. Our aircraft was just south of the touchdown point with a north wind. The jetbridge door was open. The odor was distinct but not sustained. It was definitely a burning rubber odor and not a sweaty sock odor. After consulting with MX techs on the scene; I concluded that the MX explanation was plausible. That is; the source was external and not aircraft related. I had no other evidence to refute their assessment at the time. After making inquiry of the crew; no adverse symptoms were reported by anyone. No AML entry was made. I decided to depart for ZZZ1 as planned. No odors or adverse symptoms were noticed or reported during flight. Since FA#1 reported the same smell as described above after landing in ZZZ1; Additionally; we were more than 5 miles in trail of the preceding aircraft (a King Air). Based on the new evidence; I now believed the odor was aircraft-related and not precipitated by an external source.  Therefore; I made an AML entry and contacted Dispatch. I also spoke with the Chief Pilot and the Dispatcher for [our] flight. I completed a safety report.[Caused by] task saturation. Compressed timeline due to inbound aircraft disruption. (Change of planned aircraft.) Station ZZZ wanted the flight to depart for customer satisfaction. Station managers should be instructed to not suggest possible causes for a mechanical discrepancy (ground air conditioning as the odor source... 'happening all week'). I rejected that input as the ground AC was not connected while the aircraft was at the gate. Had the ground AC been connected; I may have falsely factored that input into the go/no-go decision.


Second narrative: After shutdown; (Flight Attendant) FA#1 advised us of a burning rubber smell in the forward cabin; this was the second time the smell occurred and we expected it might be from the APU. Earlier; prior to departure in ZZZ; we also smelled the burnt rubber smell. The smell came and went. ZZZ Maintenance personnel convinced myself and the Captain that due to our proximity to Runway XXL touchdown zone and multiple aircraft landing; that the smell was being pushed by a north wind through an open jet bridge door and into the forward entry door. The General Manager was on the bridge and claimed they've had complaints of that smell all week. Feeling that this explanation made sense and because it came and went; we decided to continue onto ZZZ1. However after landing we found out that the smell had returned and we then felt it necessary to write the aircraft up for a burnt rubber odor. Pressure to get an already delayed flight on its way by ZZZ Maintenance and General Manager that didn't want further delays. I believe that it would've been handled in ZZZ properly if we had just put it in the book before Maintenance ever showed up. Once the General Manager and Maintenance staff realized we weren't completely sure of the problem; they found plausible reasons that the smell was coming from outside sources rather than our aircraft.


Synopsis: A319 flight crew reported a cabin fumes event post flight during engine shutdown at gate. Discrepancy was referred to Maintenance and Dispatch as a repeat anomaly.