A300
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Flight Crew Last 90 Days 50; Flight Crew Total 6000; Flight Crew Type 965
Troubleshooting; Workload
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Returned To Departure Airport; Flight Crew Landed in Emergency Condition
Aircraft
On climb out from ZZZ and per our procedure; we delayed putting the landing gear up. On the after takeoff checklist; I placed the landing gear lever to OFF and that is when we received an ECAM message that stated ' Landing gear door not closed' We decided to level off at 8;000 ft. and maintain a safe speed of 220 kts. The Captain who was the Pilot Flying maintained radio control with ATC while I ran the QRH for the proper procedure which said 'not to cycle the landing gear'. After the QRH and the AOM; we called flight control to informed us to perform a diversion. The Captain used his discretion and [advided ATC]. I hit the divert key on the center pedestal; changed the airport destination and started the process of setting up our approach for Runway XXR in ZZZ. We had two jumpseaters onboard with us and the Captain elected to call [jumpseater] to help us in every possible way and ATC was extremely helpful which was beneficial to our safety. We landed safely and taxied to our ramp.
A300 pilot reported a landing gear door malfunction after takeoff; resulting in a return to the departure airport.