Date: 201401
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: Haze / Smoke
Light: Daylight
Aircraft: A319
Operator: Air Carrier
Operating under: Part 121
Mission: Passenger
Flight phase: Initial Climb
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Door Warning System
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Human-Machine Interface
Anomaly: Aircraft Equipment Problem Less Severe
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Returned To Departure Airport
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: On initial climbout...at approximately 5;000 FT; an ECAM message alerted us to FWD Cargo Door. We then asked ATC for a level off at 10;000 FT to troubleshoot and vectors to keep us close...in case of air return. The pilot flying was the First Officer. I took control and ATC and had the First Officer perform ECAM actions and consult the [QRH] procedure. The [QRH] procedure had us verify proper pressurization. The aircraft though was not at a substantial altitude to verify the pressurization. We then decided that based on the indication; we could not visibly verify if the door was actually closed; to air return to [departure airport]. We then sent messages to Maintenance and Dispatch via ACARS to alert them of the air return; in addition to calling...Operations as well. Our landing would be an overweight landing at 148;000 LBS. We performed the [QRH] procedures and I (Captain) performed the landing with no further incident. Reasons for the air return: 1. ECAM message stating we had a possible cargo door open. 2. Close proximity to [airport]; runway length; [with] maintenance availability. 3. At such a low altitude and speed we could not verify if the pressurization would hold at 35;000 FT at 0.78 Mach for 3 hours and 40 minutes to [destination]. 4. We decided that based on these factors; it was safer to make the air return with overweight landing in order to not test whether the door indication was faulty at altitude and speed with an approximate 8.0 PSI pressure differential that could further stress a possible unlatched door and create a much larger emergency and possible structural damage. Upon landing and speaking with Maintenance Control and Dispatch; I had to defend my actions for the air return. I felt that was inappropriate and would go against [the airline's] culture of safety. I was repeatedly asked if I had a pressurization problem; insinuating that we should have continued to climb to our cruising altitude and on to our destination 1;400 miles away. I explained that we never climbed high enough to see a proper PSI differential to verify that; and that I would not experiment with the structural integrity of the aircraft with an unverified possible cargo door open; and 150 souls onboard.After the air return...the Mechanic found the indication to be [due] to a loose cannon plug on the door sensor. This event was possibly due to the constant loading and unloading of bags; hitting against this sensor and its cannon plug.




Synopsis: A319 flight crew observed ECAM FWD Cargo Door warning on climbout at 5;000 FT. Captain elected to perform an air return rather than continue climb to check for pressurization problem.