Narrative:

We were on approach to runway at ZZZ. When the landing gear was selected down; the left main gear did not show down and locked (the red gear unsafe light was illuminated and there was no green indication on the left main gear). We informed the tower and continued the approach so that the tower could look at the gear and then make a missed approach. The tower said the gear appeared to be down. While being vectored we ran the unsafe gear/manual extension checklist and was unable to make any changes to our indications. We informed the flight attendants of what was going on and had them check the viewfinder for the left main landing gear. They were not sure if the gear was down and locked. The a flight attendant came to the cockpit and I went to look through the viewfinder and found that the gear appeared to be down and locked. After I returned to the cockpit the captain told me he had talked to the flight attendant about a possible evacuate/evacuation. During this whole time he had also been talking with operations and dispatch about our situation and what to do. After finding that the gear appeared to be down and locked we decided to make another low approach and let the tower look at the gear again. This time the ZZZ airport police shined a flood light on the gear and made it more visible. Once again it was found to be down. We coordinated with the flight attendants to prepare the cabin for an emergency landing and a possible evacuate/evacuation (worse case scenario). In the meantime we were being vectored back around for another approach to runway. The captain and I accomplished the first 3 steps of the partial or gear up landing checklist and reviewed the rest. We also reviewed the emergency evacuate/evacuation checklist. We declared an emergency; requested the crash; fire and rescue trucks; and informed approach that we were ready to fly the approach and land. When the flight attendants had the cabin prepared; we started the approach to runway. The approach was flown flaps 40 degrees; an uneventful normal landing was made and the aircraft was brought to a complete stop on the runway. After the aircraft was inspected by the rescue personnel; the right engine was shut down; I threw the gear pins out my window to a company operations agent and all 3 landing gear were pinned. After receiving clearance to taxi to the gate; we did so with no further incident. After arriving at the gate the captain contacted dispatch; the chief pilot and made an entry into the logbook. After all of the passenger were deplaned; the aircraft was shut down and we went to the hotel. This was the first time I had ever looked through the viewfinder at the landing gear down and locked indications. I think it would be beneficial to everyone if this could be done during training so the crew members will be more familiar with what they are looking for. I was able to see what I needed to see; but it would have been nice to have seen it before instead of the first time being during an emergency.

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Original NASA ASRS Text

Title: B737-300 CREW HAS UNSAFE GEAR INDICATION AND LANDS SAFELY.

Narrative: WE WERE ON APCH TO RWY AT ZZZ. WHEN THE LNDG GEAR WAS SELECTED DOWN; THE L MAIN GEAR DID NOT SHOW DOWN AND LOCKED (THE RED GEAR UNSAFE LIGHT WAS ILLUMINATED AND THERE WAS NO GREEN INDICATION ON THE L MAIN GEAR). WE INFORMED THE TWR AND CONTINUED THE APCH SO THAT THE TWR COULD LOOK AT THE GEAR AND THEN MAKE A MISSED APCH. THE TWR SAID THE GEAR APPEARED TO BE DOWN. WHILE BEING VECTORED WE RAN THE UNSAFE GEAR/MANUAL EXTENSION CHKLIST AND WAS UNABLE TO MAKE ANY CHANGES TO OUR INDICATIONS. WE INFORMED THE FLT ATTENDANTS OF WHAT WAS GOING ON AND HAD THEM CHK THE VIEWFINDER FOR THE L MAIN LNDG GEAR. THEY WERE NOT SURE IF THE GEAR WAS DOWN AND LOCKED. THE A FLT ATTENDANT CAME TO THE COCKPIT AND I WENT TO LOOK THROUGH THE VIEWFINDER AND FOUND THAT THE GEAR APPEARED TO BE DOWN AND LOCKED. AFTER I RETURNED TO THE COCKPIT THE CAPT TOLD ME HE HAD TALKED TO THE FLT ATTENDANT ABOUT A POSSIBLE EVAC. DURING THIS WHOLE TIME HE HAD ALSO BEEN TALKING WITH OPS AND DISPATCH ABOUT OUR SITUATION AND WHAT TO DO. AFTER FINDING THAT THE GEAR APPEARED TO BE DOWN AND LOCKED WE DECIDED TO MAKE ANOTHER LOW APCH AND LET THE TWR LOOK AT THE GEAR AGAIN. THIS TIME THE ZZZ ARPT POLICE SHINED A FLOOD LIGHT ON THE GEAR AND MADE IT MORE VISIBLE. ONCE AGAIN IT WAS FOUND TO BE DOWN. WE COORDINATED WITH THE FLT ATTENDANTS TO PREPARE THE CABIN FOR AN EMER LNDG AND A POSSIBLE EVAC (WORSE CASE SCENARIO). IN THE MEANTIME WE WERE BEING VECTORED BACK AROUND FOR ANOTHER APCH TO RWY. THE CAPT AND I ACCOMPLISHED THE FIRST 3 STEPS OF THE PARTIAL OR GEAR UP LNDG CHKLIST AND REVIEWED THE REST. WE ALSO REVIEWED THE EMER EVAC CHKLIST. WE DECLARED AN EMER; REQUESTED THE CRASH; FIRE AND RESCUE TRUCKS; AND INFORMED APCH THAT WE WERE READY TO FLY THE APCH AND LAND. WHEN THE FLT ATTENDANTS HAD THE CABIN PREPARED; WE STARTED THE APCH TO RWY. THE APCH WAS FLOWN FLAPS 40 DEGS; AN UNEVENTFUL NORMAL LNDG WAS MADE AND THE ACFT WAS BROUGHT TO A COMPLETE STOP ON THE RWY. AFTER THE ACFT WAS INSPECTED BY THE RESCUE PERSONNEL; THE R ENG WAS SHUT DOWN; I THREW THE GEAR PINS OUT MY WINDOW TO A COMPANY OPS AGENT AND ALL 3 LNDG GEAR WERE PINNED. AFTER RECEIVING CLRNC TO TAXI TO THE GATE; WE DID SO WITH NO FURTHER INCIDENT. AFTER ARRIVING AT THE GATE THE CAPT CONTACTED DISPATCH; THE CHIEF PLT AND MADE AN ENTRY INTO THE LOGBOOK. AFTER ALL OF THE PAX WERE DEPLANED; THE ACFT WAS SHUT DOWN AND WE WENT TO THE HOTEL. THIS WAS THE FIRST TIME I HAD EVER LOOKED THROUGH THE VIEWFINDER AT THE LNDG GEAR DOWN AND LOCKED INDICATIONS. I THINK IT WOULD BE BENEFICIAL TO EVERYONE IF THIS COULD BE DONE DURING TRAINING SO THE CREW MEMBERS WILL BE MORE FAMILIAR WITH WHAT THEY ARE LOOKING FOR. I WAS ABLE TO SEE WHAT I NEEDED TO SEE; BUT IT WOULD HAVE BEEN NICE TO HAVE SEEN IT BEFORE INSTEAD OF THE FIRST TIME BEING DURING AN EMER.

Data retrieved from NASA's ASRS site as of January 2009 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.