B737 CREW WAS UNABLE TO RETRACT THE LNDG GEAR AFTER TKOF.

Narrative

AFTER TKOF FROM RWY 1L AT SFO ENRTE TO LAX; WE WERE UNABLE TO RAISE THE LNDG GEAR. AFTER CONSIDERING THE WX; FUEL BURN; FUEL QUANTITY AND ALTERNATES; WE DECIDED IT WOULD BE JUST AS SAFE TO CONTINUE TO LAX AS IT WOULD TO RETURN TO SFO. WE ATTEMPTED TO CONTACT DISPATCH AND MAINT THROUGH COMMERCIAL RADIO. HOWEVER; WE WERE UNSUCCESSFUL. WE EVENTUALLY MADE CONTACT OVER ACARS WITH BOTH DISPATCH AND MAINT. THEY WERE BOTH INFORMED OF OUR INTENTIONS. WE LANDED AT LAX WITH OVER 5000 LBS OF FUEL. TAXI IN AND SHUTDOWN WERE UNEVENTFUL. OUR BIGGEST PROB WAS COMMUNICATING TO DISPATCH. AFTER REPEATED ATTEMPTS OVER THE DURATION OF THE FLT WE WERE STILL UNABLE TO ESTABLISH CONTACT WITH COMMERCIAL RADIO. THE COMMERCIAL RADIO SYS NEEDS TO BE BETTER MONITORED AND MAINTAINED. SUPPLEMENTAL INFO FROM ACN 412215: WHEN THE FLAPS WERE RAISED; THE TKOF WARNING HORN SOUNDED. THIS IS A CLASSIC INDICATION THAT THE AIR-GND SWITCH HAS FAILED IN THE GND POS. WE ALSO HAD OTHER INDICATIONS THAT THE AIR-GND SWITCH WAS INDEED IN THE GND POS (XPONDER; ACARS; CABIN PRESSURE CTLR; ETC). THIS IS A COMPLETELY SAFE CONDITION. IT JUST MEANS THAT THE AIRPLANE THINKS IT IS STILL ON THE GND. WE DID A FUEL CALCULATION AND DETERMINED THAT WE HAD MORE THAN ENOUGH FUEL TO FLY TO LAX AT 210 KTS WITH THE GEAR DOWN. I INFORMED THE ATC CTLR THAT THIS WAS OUR INTENTION AND HE CLRED US APPROPRIATELY. LET ME EMPHASIZE THAT THE WX IN BOTH SFO AND LAX WAS CLR WITH UNLIMITED CEILING AND VISIBILITY AND NO ATC DELAYS. SUPPLEMENTAL INFO FROM ACN 412577: I RECEIVED A CALL FROM THE ACR MAINT CTLR ASKING WHAT I KNEW ABOUT FLT XXX FLYING FROM SFO-LAX WITH THE GEAR DOWN. I KNEW NOTHING ABOUT THAT SIT AT THE TIME. THE FLT HAD BEEN AIRBORNE FOR APPROX 30 MINS. MAINT SAID LINE MAINT IN ABE HAD TALKED TO THE FLT OVER THE LCL FREQ AND THE FLT WAS CONTINUING TO LAX. MAINT HAD TROUBLESHOOTING INSTRUCTIONS FOR THE CREW AND ASKED ME TO SEND THE INSTRUCTIONS TO THE CREW. I SENT THE INSTRUCTIONS OVER ACARS AND ASKED THE CREW TO VERIFY FLYING GEAR DOWN. WHILE WAITING FOR A RESPONSE; I LOOKED UP THE FUEL BURN AND TIME TO LAX WITH THE GEAR DOWN TO MAKE SURE THE FLT HAD ENOUGH FUEL ON BOARD. THEY DID; THEY WOULD LAND IN LAX WITH 5000 LBS. WHEN I RETURNED TO MY DESK I CHKED TO SEE IF THE CREW HAD RESPONDED TO MY MESSAGE. IF THEY HAD NOT I PLANNED TO CALL THEM OVER THE RADIO. THEY DID NOT RESPOND; BUT I COULD SEE OVER MY PRINTER THAT THE CREW AND MAINT WERE SENDING MESSAGES TO EACH OTHER; SO I CHOSE TO NOT CALL AND INTERRUPT THEM. AFTER DISCUSSING THE SIT WITH MAINT THE CREW DID SEND ME A MESSAGE SAYING THEY DISCUSSED THE SIT WITH MAINT OVER ACARS AND WERE CONTINUING TO LAX; AND HAD ENOUGH GAS. I AGREED. BY THIS TIME THE FLT WAS AT LEAST 1/2 WAY TO LAX. I THEN SENT AN IRREGULARITY MESSAGE. THE CREW LANDED WITH 5000 LBS. THERE WAS EMER EQUIP WAITING; WHICH NEITHER I NOR THE CREW REQUESTED. IF MAINT HAD NOT CALLED ME I WOULD HAVE NEVER KNOWN THE CREW WAS FLYING GEAR DOWN.