AN F100 ABORTS TKOF AT IAH BECAUSE OF A LIFT DUMPER EICAS MESSAGE THAT OCCURRED IN THE RANGE OF 80-100 KTS.

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ON TKOF AT IAH AT 100 KTS RECEIVED A LIFT DUMPER FAULT ANNUNCIATION ON MFDU AND INITIATED AN ABORT. RETURNED TO GATE WHERE MAINT PERFORMED LIFT DUMPER DEACTIVATION OF SYS. THIS HAD PREVIOUSLY BEEN PERFORMED IN CHICAGO PRIOR TO FLT #BB JUN/XA/98. IT WAS FOUND THAT LAST ITEM ON LIST WAS NOT PERFORMED WHICH WAS TO TURN OFF LIFT DUMPERS IN COCKPIT. THIS WAS AN ITEM I HAD ASKED MAINT ABOUT IN ORD AND TOLD DID NOT NEED TO BE TURNED OFF. MAINT RECHKED PROC IN IAH AND TURNED SYS OFF AS APPROPRIATE. MEL WAS COMPLIED WITH AND WE DEPARTED TO ORD LATE. THIS WAS THE 2ND ABORT OF THE DAY FOR MY CREW IN THIS ACFT AND 6TH OR 7TH ABORT IN PREVIOUS 2 WKS FOR LIFT DUMPER FAULTS IN THIS ACFT. TUL TECHNICIAN SAID ACFT WOULD BE PULLED FROM SVC WHEN RETURNED TO ORD AND REPAIRED. EVERYTHING ELSE WAS OKAY EXCEPT CREW WAS REMOVED FROM REMAINDER OF TRIP DUE TO ARR AT DEP TIME OF NEXT LEG OF TRIP. THUS MISCONNECT WITH NO RECOURSE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THIS ABORTED TKOF OCCURRED BECAUSE OF LIFT DUMPER FAULT LIGHT ON THE EICAS. THIS MEANS THE LIFT DUMPER COULD ACTIVATE AT ANY TIME. LIFT DUMPER IS VERY SIMILAR TO SPOILERS. IN THIS CASE; THE MESSAGE WOULD INDICATE THAT THE LIFT DUMPERS COULD DEPLOY AT AN UNEXPECTED TIME. THIS MESSAGE OCCURRED AT 80-100 KTS; SO THE FLC ABORTED. IT TURNS OUT THAT ACFT HAD BEEN IN MAINT FOR A 'C' CHK. THERE IS A SWITCH THAT MAINT USES TO DEPLOY LIFT DUMPER ON THE GND FOR THEIR TESTING. THIS SWITCH WAS LEFT ON SO THEY WERE SUBJECT TO DEPLOY DURING TKOF AND FLT. THE SWITCH IS THE LAST ITEM ON THE CHKLIST USED BY MAINT; BUT; FOR SOME REASON; THE SWITCH WAS NEVER TURNED OFF. AFTER THIS ABORT; PLT RETURNED TO GATE AND MAINT TURNED OFF THE SWITCH WHICH DEACTIVATED LIFT DUMPER ACTIVATION ON THE GND.