A320
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Time Pressure
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Weather / Turbulence
General None Reported / Taken
Aircraft; Human Factors
We discussed as a crew that in the future when we get pressured by time constraints and environmental pressures (i.e. raining hard during the walk around) that we won't allow ourselves to be hurried and in a rush. That is when things get missed.I missed the cowl latch key left in the Number One Engine on the preflight walk around. It was dark and raining hard and we were running a little bit late due to an excessively long line at the KCM (Known Crewmember) checkpoint.
We discussed as a crew that in the future give us more time to get to the airplane in ZZZ with the long train ride and busy departure time. And no matter never get caught rushing any procedure. Get down on your knees and check those cowl keys! Long line at KCM (Known Crewmember) Checkpoint and we were rushing to get the flight out on time. Rainy cloudy morning in ZZZ FO (First Officer) missed cowl latch key during walk around. Proper keys and pins located on the [Aircraft] during our interior cockpit preflight. Only informed of our mistake by the outbound crew in ZZZ1. Captain called Crew Scheduling to get my number.
Flight Crew reported being informed that they missed the cowling door latch key still installed in the engine cowl latch and departed.