Date: 201510
Local time of day: 1201-1800
Location: PHL.Airport, PA
Flight conditions: VMC
Light: Daylight
Aircraft: Airbus 318/319/320/321 Undifferentiated
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class B PHL
ATC / advisory: Tower PHL
Second aircraft: Helicopter
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Distraction; Situational Awareness
Second reporter function: First Officer; Pilot Flying
Anomaly: Aircraft Equipment Problem Less Severe; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Unstabilized Approach
Detector: Automation Aircraft TA; Person Flight Crew
When detected: In-flight
Result: Flight Crew Became Reoriented
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: [We] departed on schedule for our non-stop flight to PHL. Weather was not a factor and visibility was excellent and winds were light. We were flying the BOJID ONE RNAV Arrival. Towards the end of the arrival; we were given vectors to the final approach course for Runway 27R at PHL. PHL Approach Control pointed out company traffic for us that was approaching from the South. We called traffic in sight and were cleared for the visual approach behind company for 27R. We contacted the PHL Tower and we received landing clearance. At this point the autopilot was on with Flaps 2. Somewhere near the JALTO FAF; traffic was issued to us. It was a helicopter over the river; south of the final approach course at 800 feet. Our attention to getting a visual on the traffic contributed to both of us scanning for that traffic and neglecting our duty to the aircraft configuration. A Traffic Alert (TA) was then issued and contact with the traffic was confirmed in the cockpit. As we approached 1;000 AGL; as I reached for the checklist and started to ask the FO (Pilot Flying) if we had run the landing checklist the landing gear unsafe warning was triggered. I immediately reached over and placed the landing gear lever to the down position; Flaps 3 and Managed Speed. The aircraft was barely in the landing configuration at 500 AFL and target speed was approximately 15 KTS above target. Touchdown; spoiler deployment and rollout were normal.Why did this event occur? I have asked myself this question over and over and over. I have flown this approach a million times into one of our most familiar airports and runways. Our attention to detail was terrible and the search for the nearby traffic only exacerbated the situation. Poor handling of the landing checklist and earlier aircraft configuration would have eliminated the entire event.As I mentioned; earlier detection and awareness would avoid a repeat of this situation. We are trained to 'Multi-task' and the Flying Pilots responsibility to detail is imperative. The Non Flying Pilot has the task of monitoring his actions or inactions; as in this case. If it occurred again; a go around would be the procedure to follow. In the heat of the moment; I felt it safe to continue with enough altitude and time remaining. The continuous repetitive chime accelerates the need to silence the warning as soon as possible by lowering the landing gear lever and positioning the aircraft in the proper configuration for landing. A go around would buy some time to reassess the chain of events. As a personal note; I will try to get in the habit of physically holding the checklist in my hand commencing with the Flying Pilots request for 'Flaps 1'. Perhaps this new technique will create a new barrier and better safeguard.


Second narrative: I believe encountering the helicopter at such a critical point on the approach diverted my attention away from flying the aircraft. The aircraft was still on autopilot; however my routine of the approach was interrupted. Also; the perfect weather conditions in PHL; flying a very familiar approach at a very familiar airport; led me into a sense of complacency.


Synopsis: A320 series flight crew reported they were distracted by helicopter traffic on approach to PHL and did not meet stabilized approach criteria.