Narrative:

During approach with aircraft X; landing gear would not extend normally. Per aom procedures and after consult with maintenance operations center; gravity extended the gear. Made uneventful landing. No emergency declared. Maintenance operations center sent mechanic on next available flight. Maintenance operations center then cleared flight to operate back under MEL 32-3; landing gear retraction system inoperative. Gear was pinned and operated flight gear down as flight with no passenger aboard. Callback conversation with reporter revealed the following information: the reporter stated the cause of the landing gear failure to extend was faulty gear ground sensors or weight on wheel sensors. Alternate gravity extension operated ok. The airplane was maintenance ferried gear down to a maintenance facility for repair.

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Original NASA ASRS Text

Title: AN ATR72 ON APCH COULD NOT EXTEND THE LNDG GEAR NORMALLY. ACCOMPLISHED AOM PROCS. ALTERNATE GEAR EXTENSION OK. CAUSED BY FAULTY GEAR GND SENSORS.

Narrative: DURING APCH WITH ACFT X; LNDG GEAR WOULD NOT EXTEND NORMALLY. PER AOM PROCS AND AFTER CONSULT WITH MAINT OPS CTR; GRAVITY EXTENDED THE GEAR. MADE UNEVENTFUL LNDG. NO EMER DECLARED. MAINT OPS CTR SENT MECH ON NEXT AVAILABLE FLT. MAINT OPS CTR THEN CLRED FLT TO OPERATE BACK UNDER MEL 32-3; LNDG GEAR RETRACTION SYS INOP. GEAR WAS PINNED AND OPERATED FLT GEAR DOWN AS FLT WITH NO PAX ABOARD. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE CAUSE OF THE LNDG GEAR FAILURE TO EXTEND WAS FAULTY GEAR GND SENSORS OR WT ON WHEEL SENSORS. ALTERNATE GRAVITY EXTENSION OPERATED OK. THE AIRPLANE WAS MAINT FERRIED GEAR DOWN TO A MAINT FACILITY FOR REPAIR.

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.