Narrative:

While deploying the landing gear; we noticed that we had both green and red lights indicating an abnormal gear situation. This occurred shortly before landing; at or near the outer marker. Both the captain and I were flying and; as such; were directly involved. We saw both 3 green and 3 red lights above the landing gear lever. The normal display for 'gear down' is only 3 green lights. We believe the event occurred because the landing gear lever (or gear handle) was unusually slow or sticky when operated. We both noticed this condition upon activation of the handle. With a normal deployment force the lever would hang up or stop short of the detent -- this resulted in the red lights that indicate that the handle is not in the same position as the gear. On our return flight in the same plane; the other pilot (the captain) noticed the same behavior. We wrote up the handle after landing. We discussed recycling the gear and the captain decided against this course as it was possible there might be damage that would only make the situation worse. The checklist did not have a procedure that described our condition. I (copilot) coordinated with maintenance at our departure and arrival stations to see if either team had further guidance since we didn't have appropriate checklist guidance. They suggested we check circuit breakers and hydraulic pressure as well as the nose wheel viewing port. We found nothing out of the ordinary for the gear down status we believed we had. We had also heard the airflow sounds of gear deployment at the time of the handle deployment. We accomplished all of these suggestions while the captain flew a box pattern back to the airport. Beyond this advice; maintenance did not have further guidance or suggestions and concurred that the gear was down and locked. We also took advantage of a nearby traffic helicopter for visual confirmation of the gear's status as down. We also found a supporting note in the 'manual extension' checklist that emphasized that the red lights did not subtract from our down and locked condition. Although the checklist was not written for our situation; it did convey valuable aircraft systems knowledge about the warning lights we were seeing at the time. Tension or friction in landing gear lever for that particular plane needs to be adjusted. It's possible that a checklist describing this condition could be incorporated if other aircrews are likely to be in the same situation.

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Original NASA ASRS Text

Title: Both red and green lights in a B737-400's landing gear handle were illuminated on final. The crew discovered that the gear handle not fully in the down detent position will cause this even though the gear is properly down and locked.

Narrative: While deploying the landing gear; we noticed that we had both green and red lights indicating an abnormal gear situation. This occurred shortly before landing; at or near the outer marker. Both the Captain and I were flying and; as such; were directly involved. We saw both 3 green and 3 red lights above the landing gear lever. The normal display for 'gear down' is only 3 green lights. We believe the event occurred because the landing gear lever (or gear handle) was unusually slow or sticky when operated. We both noticed this condition upon activation of the handle. With a normal deployment force the lever would hang up or stop short of the detent -- this resulted in the red lights that indicate that the handle is not in the same position as the gear. On our return flight in the same plane; the other pilot (the Captain) noticed the same behavior. We wrote up the handle after landing. We discussed recycling the gear and the Captain decided against this course as it was possible there might be damage that would only make the situation worse. The checklist did not have a procedure that described our condition. I (Copilot) coordinated with Maintenance at our departure and arrival stations to see if either team had further guidance since we didn't have appropriate checklist guidance. They suggested we check circuit breakers and hydraulic pressure as well as the nose wheel viewing port. We found nothing out of the ordinary for the gear down status we believed we had. We had also heard the airflow sounds of gear deployment at the time of the handle deployment. We accomplished all of these suggestions while the Captain flew a box pattern back to the airport. Beyond this advice; Maintenance did not have further guidance or suggestions and concurred that the gear was down and locked. We also took advantage of a nearby traffic helicopter for visual confirmation of the gear's status as down. We also found a supporting note in the 'Manual Extension' checklist that emphasized that the red lights did not subtract from our down and locked condition. Although the checklist was not written for our situation; it did convey valuable aircraft systems knowledge about the warning lights we were seeing at the time. Tension or friction in landing gear lever for that particular plane needs to be adjusted. It's possible that a checklist describing this condition could be incorporated if other aircrews are likely to be in the same situation.

Data retrieved from NASA's ASRS site as of April 2012 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.