Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 225; Flight Crew Total 29532; Flight Crew Type 8196
Aircraft Equipment Problem Less Severe
Flight Crew Overcame Equipment Problem; Flight Crew Executed Go Around / Missed Approach
Aircraft
Going into [destination airport]; with the weather around 300 and 2 (lower at times); on the ILS; at the marker I called for gear down FLAPS 15 then 30. At that time we noticed the Amber Leading Edge (LE) FLAPS TRANSIT light on. We then executed a go-around; told ATC of a possible flap problem and then started to run the LE FLAPS TRANSIT checklist from the QRH to include a FLAPS 15 landing and check of the NON-NORMAL CONFIGURATION LANDING DISTANCE TABLE. We then [advised ATC of] emergency and proceeded with vectors back for another ILS. Landing and taxi in to gate [were] without further problem.
On short final to ILS we received a LE FLAPS TRANSIT amber light with an accompanying LE amber light on #5 slat on the overhead LE Devices annunciator panel. Also received an aural 'too low airspeed' caution at normal speed for configuration. I believe this happened when the Captain called for 15-30 flaps. Gear was already extended. Due to the uncertainty of our problem; and the IMC flight conditions on short final the Captain elected to execute a missed approach. On the missed approach I immediately noticed that we were at roughly 1900 feet and were not climbing. I loudly stated that we were not climbing and that we needed to climb immediately. I called positive rate and for gear up. It was later determined that the Takeoff Go Around switch was not properly depressed; which led to confusion on our airspeed delay.
B737NG flight crew reported executing a go-around after receiving a LE FLAPS TRANSIT caution light. Flight landed safely after running the QRH procedure.