Narrative:

Flight abc was operated normally until the visual final approach to runway 25L at phx, with first officer at the controls. At 180 KIAS, confign to gear down and flaps 15 degrees was selected whereupon the intermittent nose gear unsafe warning light and horn condition began. We executed the go around, informed the tower of the nature of the problem and asked for vectors to an area to address the problem. The flight attendants were informed of the situation and expected updates to soon follow. The passenger were informed of the general nature of the warning and the contact with our maintenance personnel. We went to the appropriate QRH section, queried maintenance for any ideas and subsequently exercised the landing gear while at 210 KIAS. At 210 KIAS, no warnings followed. We then requested a return to land on runway 26. Advised of a long vector, we elected to retract the landing gear in the interest of fuel savings. Upon our next final approach to runway 26, and again at 180 KIAS, the intermittent nose gear warnings ensued. Again, we requested a 360 degrees back to final, to accomplish the manual gear extension per the QRH. I visually verified the nose gear through the cockpit floor port. Just as a backup, I asked the first officer to do the same visual verification after we xferred aircraft control for that purpose. We both agreed on the visual verification, and xferred control back to the first officer. Landing confign of flaps 40 degrees and speed brake down was used per the QRH. The intermittent nose gear warnings continued until landing. The emergency ground equipment was requested. A normal landing and rollout was accomplished by the first officer and no further warnings occurred. The flight attendants were immediately informed that all was normal and we were taxiing to the gate. Just short of the gate, we requested maintenance personnel to pin the nose gear prior to pulling up to a complete stop at the gate. The first officer should be commended on an outstanding job throughout the process of doing all that was possible, and offering any and all help and suggestions in resolving the problem in a very calm and clear manner. The exemplary performance of the first officer added immensely to superb teamwork.

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Original NASA ASRS Text

Title: A B737 FLT CREW EXPERIENCE 2 LNDG GEAR UNSAFE WARNING HORNS RESULTING IN A MANUAL EXTENSION OF THE GEAR.

Narrative: FLT ABC WAS OPERATED NORMALLY UNTIL THE VISUAL FINAL APCH TO RWY 25L AT PHX, WITH FO AT THE CTLS. AT 180 KIAS, CONFIGN TO GEAR DOWN AND FLAPS 15 DEGS WAS SELECTED WHEREUPON THE INTERMITTENT NOSE GEAR UNSAFE WARNING LIGHT AND HORN CONDITION BEGAN. WE EXECUTED THE GAR, INFORMED THE TWR OF THE NATURE OF THE PROB AND ASKED FOR VECTORS TO AN AREA TO ADDRESS THE PROB. THE FLT ATTENDANTS WERE INFORMED OF THE SIT AND EXPECTED UPDATES TO SOON FOLLOW. THE PAX WERE INFORMED OF THE GENERAL NATURE OF THE WARNING AND THE CONTACT WITH OUR MAINT PERSONNEL. WE WENT TO THE APPROPRIATE QRH SECTION, QUERIED MAINT FOR ANY IDEAS AND SUBSEQUENTLY EXERCISED THE LNDG GEAR WHILE AT 210 KIAS. AT 210 KIAS, NO WARNINGS FOLLOWED. WE THEN REQUESTED A RETURN TO LAND ON RWY 26. ADVISED OF A LONG VECTOR, WE ELECTED TO RETRACT THE LNDG GEAR IN THE INTEREST OF FUEL SAVINGS. UPON OUR NEXT FINAL APCH TO RWY 26, AND AGAIN AT 180 KIAS, THE INTERMITTENT NOSE GEAR WARNINGS ENSUED. AGAIN, WE REQUESTED A 360 DEGS BACK TO FINAL, TO ACCOMPLISH THE MANUAL GEAR EXTENSION PER THE QRH. I VISUALLY VERIFIED THE NOSE GEAR THROUGH THE COCKPIT FLOOR PORT. JUST AS A BACKUP, I ASKED THE FO TO DO THE SAME VISUAL VERIFICATION AFTER WE XFERRED ACFT CTL FOR THAT PURPOSE. WE BOTH AGREED ON THE VISUAL VERIFICATION, AND XFERRED CTL BACK TO THE FO. LNDG CONFIGN OF FLAPS 40 DEGS AND SPD BRAKE DOWN WAS USED PER THE QRH. THE INTERMITTENT NOSE GEAR WARNINGS CONTINUED UNTIL LNDG. THE EMER GND EQUIP WAS REQUESTED. A NORMAL LNDG AND ROLLOUT WAS ACCOMPLISHED BY THE FO AND NO FURTHER WARNINGS OCCURRED. THE FLT ATTENDANTS WERE IMMEDIATELY INFORMED THAT ALL WAS NORMAL AND WE WERE TAXIING TO THE GATE. JUST SHORT OF THE GATE, WE REQUESTED MAINT PERSONNEL TO PIN THE NOSE GEAR PRIOR TO PULLING UP TO A COMPLETE STOP AT THE GATE. THE FO SHOULD BE COMMENDED ON AN OUTSTANDING JOB THROUGHOUT THE PROCESS OF DOING ALL THAT WAS POSSIBLE, AND OFFERING ANY AND ALL HELP AND SUGGESTIONS IN RESOLVING THE PROB IN A VERY CALM AND CLR MANNER. THE EXEMPLARY PERFORMANCE OF THE FO ADDED IMMENSELY TO SUPERB TEAMWORK.

Data retrieved from NASA's ASRS site as of July 2007 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.