Narrative:

It started out as a normal layover. Captain and I discussed how we had such a good night's sleep and were ready for the long day home ahead of us. In the car ride to the airport we discussed the flight plan; weather and aircraft. We got to the gate ahead of schedule. We settled in and we started our normal routines. I did the walk around while the captain briefed the flight attendants and started setting up the cockpit. We loaded up and pushed back early. There was a little congestion but we made it to the runway prior to our flight planned departure time. Everything was normal and checklists were complete. We started the takeoff roll uneventfully. I was the flying pilot. We accelerated through V1; rotate; positive rate; gear up. Shortly after we were told to contact departure. At 800 feet I began to accelerate and asked for flaps 1 and then up. We were both wearing noise cancelling headsets so things are usually pretty quiet. I mentioned to him that the airplane was not climbing very well and he said that we were heavy. I know that departure likes altitude over airspeed so I was trying to climb as fast as possible. That is when I noticed the red and green gear lights. I believe that I mentioned that to the captain but really could not believe it. The gear handle was up and we had all the lights. It took me a minute to think about in and then I had a sinking feeling. I thought that I for sure did not see a gear pin installed in one of the gear assembly; probably the nose gear; because it is difficult to get up in the nose well to get a good look at it. Pulled out the checklist and proceeded through it. ATC wanted a fast climb and we initially told him we had a gear issue and would need vectors. We made the crossing restriction over the VOR and then were given a heading after that. The captain finished the checklist and then asked if I would take the radios and the aircraft and he would contact dispatch and maintenance. I put the autopilot on and took over the radios. While he was on the #2 radio the flight attendants called up front because of the noise and fact that we did not turn off the sterile light and chime. I told them too much; but I said we were dealing with a landing gear issue and that we were probably going back to the departure airport. The captain overheard some of the conversation and told me to tell them that we would get back to them when we had a plan. After that conversation with the flight attendants; ATC inquired about our intentions and that is when I said that we would probably need to return. ATC gave us another heading. I began to set up both radios and the FMC for the ILS. The captain came back from talking to maintenance control touched the alternate gear door so that it is completely closed and the switch was activated and then raised the gear and all was good and quiet again. Then he looked at me and asked if I was good to continue. I thought about and said yes if we have the gas for it. He then said; worst case scenario we make a fuel stop. I programed the route back in and the FMC said we would land with about 5900 lbs of gas. We were scheduled to land with 7;100 lbs so we burned an extra 1000 lbs dealing with the issue. This was acceptable but we would monitor as we proceeded. We continued to our filed destination uneventfully.

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Original NASA ASRS Text

Title: B737 flight crew reported the landing gear would not retract after takeoff. Following a discussion with Maintenance; it was discovered that the Manual Gear Extension Door was not completely closed.

Narrative: It started out as a normal layover. Captain and I discussed how we had such a good night's sleep and were ready for the long day home ahead of us. In the car ride to the airport we discussed the flight plan; weather and aircraft. We got to the gate ahead of schedule. We settled in and we started our normal routines. I did the walk around while the Captain briefed the flight attendants and started setting up the cockpit. We loaded up and pushed back early. There was a little congestion but we made it to the runway prior to our flight planned departure time. Everything was normal and checklists were complete. We started the takeoff roll uneventfully. I was the flying pilot. We accelerated through V1; Rotate; positive rate; gear up. Shortly after we were told to contact departure. At 800 feet I began to accelerate and asked for flaps 1 and then up. We were both wearing noise cancelling headsets so things are usually pretty quiet. I mentioned to him that the airplane was not climbing very well and he said that we were heavy. I know that Departure likes altitude over airspeed so I was trying to climb as fast as possible. That is when I noticed the Red and Green gear lights. I believe that I mentioned that to the Captain but really could not believe it. The gear handle was up and we had all the lights. It took me a minute to think about in and then I had a sinking feeling. I thought that I for sure did not see a gear pin installed in one of the gear assembly; probably the nose gear; because it is difficult to get up in the nose well to get a good look at it. Pulled out the checklist and proceeded through it. ATC wanted a fast climb and we initially told him we had a gear issue and would need vectors. We made the crossing restriction over the VOR and then were given a heading after that. The Captain finished the checklist and then asked if I would take the radios and the aircraft and he would contact Dispatch and Maintenance. I put the Autopilot on and took over the radios. While he was on the #2 radio the flight attendants called up front because of the noise and fact that we did not turn off the sterile light and chime. I told them too much; but I said we were dealing with a landing gear issue and that we were probably going back to the departure airport. The Captain overheard some of the conversation and told me to tell them that we would get back to them when we had a plan. After that conversation with the flight attendants; ATC inquired about our intentions and that is when I said that we would probably need to return. ATC gave us another heading. I began to set up both radios and the FMC for the ILS. The Captain came back from talking to Maintenance Control touched the Alternate gear door so that it is completely closed and the switch was activated and then raised the gear and all was good and quiet again. Then he looked at me and asked if I was good to continue. I thought about and said yes if we have the gas for it. He then said; worst case scenario we make a fuel stop. I programed the route back in and the FMC said we would land with about 5900 lbs of gas. We were scheduled to land with 7;100 lbs so we burned an extra 1000 lbs dealing with the issue. This was acceptable but we would monitor as we proceeded. We continued to our filed destination uneventfully.

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.