Narrative:

It was the end of a 14-hour duty day. The captain and I had been dodging WX all day and were running 4 hours behind schedule. It was the captain's leg and the two of us were tired at this point. We were on about a 2 mi final for runway 18L at tpa when the tower controller told us to 'go around.' another aircraft landing on the crossing runway exited on our runway and was not able to get clear in time for our landing. The captain brought the thrust levers to toga and called for 'go around flaps.' the rest of the flaps and gear were retracted on profile and the captain began a climbing turn toward the tower-assigned heading and an altitude. The plane had just passed 210 KTS when I noticed we were still accelerating rapidly. I suggested to the captain that he 'start slowing down for the pattern.' we were approaching 230 KTS when I repeated the suggestion. The captain responded that he wasn't able to slow the plane down and had both thrust levers in the idle detent. He 'dialed down' the speed selector to 190 KTS with no effect. I suggested that he disengage the autothrust and try manual control. He responded that it 'wasn't working' and asked that I give it a try. At this point; we were passing 250 KTS at the tower-assigned altitude of 2600 ft in a right crosswind leg for runway 18L. I 'matched up the doughnuts' on the EPR gauges and clicked the autothrust disconnect buttons on the thrust levers. Manual thrust control was restored and I handed the thrust levers back to the captain. He brought the thrust back to idle; slowed the plane back to 210 KTS and entered the downwind leg. After things had 'settled down' we decided to give the autothrust another try and re-engaged it. From that point on; the autothrust functioned normally so I left frequency to make a quick PA announcement to the passenger and notified the flight attendants that we were in the process of a go around and would be landing shortly. We reconfigured for landing and touched down in tpa uneventfully. During our debrief; the captain and I tried to reconcile why the autothrust behaved the way it did. The best explanation I could think of was that somehow; the captain inadvertently put the system into a thrust lock situation during the initial phases of the go around and it refused to respond to command inputs from that point on. Unfortunately; I didn't get a chance to check the FMA during the initial go around stages; so I can't verify whether the autothrust went into thrust lock or not.

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Original NASA ASRS Text

Title: AN A319 FO RPTS THE ACFT ENTERED A 'THRUST LOCKED' CONDITION DURING A GAR AS THE ACFT ACCELERATED THROUGH 250 KTS. CREW DUTY TIME 14 HRS.

Narrative: IT WAS THE END OF A 14-HR DUTY DAY. THE CAPT AND I HAD BEEN DODGING WX ALL DAY AND WERE RUNNING 4 HRS BEHIND SCHEDULE. IT WAS THE CAPT'S LEG AND THE TWO OF US WERE TIRED AT THIS POINT. WE WERE ON ABOUT A 2 MI FINAL FOR RWY 18L AT TPA WHEN THE TWR CTLR TOLD US TO 'GO AROUND.' ANOTHER ACFT LNDG ON THE XING RWY EXITED ON OUR RWY AND WAS NOT ABLE TO GET CLR IN TIME FOR OUR LNDG. THE CAPT BROUGHT THE THRUST LEVERS TO TOGA AND CALLED FOR 'GAR FLAPS.' THE REST OF THE FLAPS AND GEAR WERE RETRACTED ON PROFILE AND THE CAPT BEGAN A CLBING TURN TOWARD THE TWR-ASSIGNED HDG AND AN ALT. THE PLANE HAD JUST PASSED 210 KTS WHEN I NOTICED WE WERE STILL ACCELERATING RAPIDLY. I SUGGESTED TO THE CAPT THAT HE 'START SLOWING DOWN FOR THE PATTERN.' WE WERE APCHING 230 KTS WHEN I REPEATED THE SUGGESTION. THE CAPT RESPONDED THAT HE WASN'T ABLE TO SLOW THE PLANE DOWN AND HAD BOTH THRUST LEVERS IN THE IDLE DETENT. HE 'DIALED DOWN' THE SPD SELECTOR TO 190 KTS WITH NO EFFECT. I SUGGESTED THAT HE DISENGAGE THE AUTOTHRUST AND TRY MANUAL CTL. HE RESPONDED THAT IT 'WASN'T WORKING' AND ASKED THAT I GIVE IT A TRY. AT THIS POINT; WE WERE PASSING 250 KTS AT THE TWR-ASSIGNED ALT OF 2600 FT IN A R XWIND LEG FOR RWY 18L. I 'MATCHED UP THE DOUGHNUTS' ON THE EPR GAUGES AND CLICKED THE AUTOTHRUST DISCONNECT BUTTONS ON THE THRUST LEVERS. MANUAL THRUST CTL WAS RESTORED AND I HANDED THE THRUST LEVERS BACK TO THE CAPT. HE BROUGHT THE THRUST BACK TO IDLE; SLOWED THE PLANE BACK TO 210 KTS AND ENTERED THE DOWNWIND LEG. AFTER THINGS HAD 'SETTLED DOWN' WE DECIDED TO GIVE THE AUTOTHRUST ANOTHER TRY AND RE-ENGAGED IT. FROM THAT POINT ON; THE AUTOTHRUST FUNCTIONED NORMALLY SO I LEFT FREQ TO MAKE A QUICK PA ANNOUNCEMENT TO THE PAX AND NOTIFIED THE FLT ATTENDANTS THAT WE WERE IN THE PROCESS OF A GAR AND WOULD BE LNDG SHORTLY. WE RECONFIGURED FOR LNDG AND TOUCHED DOWN IN TPA UNEVENTFULLY. DURING OUR DEBRIEF; THE CAPT AND I TRIED TO RECONCILE WHY THE AUTOTHRUST BEHAVED THE WAY IT DID. THE BEST EXPLANATION I COULD THINK OF WAS THAT SOMEHOW; THE CAPT INADVERTENTLY PUT THE SYS INTO A THRUST LOCK SIT DURING THE INITIAL PHASES OF THE GAR AND IT REFUSED TO RESPOND TO COMMAND INPUTS FROM THAT POINT ON. UNFORTUNATELY; I DIDN'T GET A CHANCE TO CHK THE FMA DURING THE INITIAL GAR STAGES; SO I CAN'T VERIFY WHETHER THE AUTOTHRUST WENT INTO THRUST LOCK OR NOT.

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.