Narrative:

We departed ZZZ on a flight to ZZZ1. After takeoff; we tried to raise the landing gear; but was unable. We ran the QRH and returned to ZZZ. As we were preparing for the approach; we noticed the gear pins were not onboard. After pulling into the gate; we were informed by ground that the gear pins were still installed in the gear. I went outside to talk to maintenance; he said that the ribbons were still rolled up as they would be in the cockpit. The first officer said he didn't see any ribbons hanging down that would have alerted him. There was no logbook entry stating that the pins were installed. Some maintenance had been done the night before also. As a crew; we were a little rushed in getting things ready for flight; i.e.; having trouble getting clearance thru cdlpc. Everything came together at push; ([weight and balance]; clearance; doing checklist.) I just failed to look for the pins when we were doing the checklist. My mistake. A lot of departments dropped the ball on this one; but ultimately; I should have caught the pins not being there. Nothing more than just slowing down and double checking everything. Try not to get rushed.

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Original NASA ASRS Text

Title: B737-800 flight crew reported uneventful air return shortly after takeoff due to landing gear not retracting.

Narrative: We departed ZZZ on a flight to ZZZ1. After takeoff; we tried to raise the landing gear; but was unable. We ran the QRH and returned to ZZZ. As we were preparing for the approach; we noticed the gear pins were not onboard. After pulling into the gate; we were informed by Ground that the gear pins were still installed in the gear. I went outside to talk to Maintenance; he said that the ribbons were still rolled up as they would be in the cockpit. The First Officer said he didn't see any ribbons hanging down that would have alerted him. There was no logbook entry stating that the pins were installed. Some Maintenance had been done the night before also. As a Crew; we were a little rushed in getting things ready for flight; i.e.; having trouble getting clearance thru CDLPC. Everything came together at push; ([weight and balance]; Clearance; doing checklist.) I just failed to look for the pins when we were doing the checklist. My mistake. A lot of departments dropped the ball on this one; but ultimately; I should have caught the pins not being there. Nothing more than just slowing down and double checking everything. Try not to get rushed.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.