A B727-200 ON TKOF ROLL AT 80-90 KTS EXPERIENCES A PACK TRIP FAILURE WARNING. CAPT DECIDES TO CONTINUE TKOF DUE TO SPD.

Narrative

DURING A NORMAL TKOF ROLL THE 'AUTO PACK INOP OFF ARMED LIGHT' FAILED TO ILLUMINATE AFTER THROTTLES WERE ADVANCED TO TKOF PWR. AS SO; I ANNOUNCED THE MALFUNCTION; TESTED THE LIGHT BULB; AND RECYCLED THE ARMING SWITCH. THE CAPT LOOKED BACK AT THE SO PANEL WHILE I WAS TESTING THE LIGHT; POSSIBLY CAUSING HIM TO BELIEVE THE SYS HAD STARTED FUNCTIONING PROPERLY. AFTER TESTING THE SYS; I ANNOUNCED THAT IT STILL WAS NOT WORKING. BY THIS TIME WE WERE ACCELERATING PAST 80 KIAS. THE COPLT ASKED IF WE SHOULD CONTINUE THE TKOF AND THE CAPT AND CREW DECIDED TO CONTINUE THE TKOF ROLL DUE TO THE RELATIVELY HIGH SPD VERSUS LOW DANGER CAUSED BY THE MALFUNCTION. (OUR GROSS WT WAS UNDER THAT WHICH WOULD REQUIRE THIS SYS TO BE OPERATING.) NORMAL PROC IS TO REJECT THE TKOF; BUT THE CAPT AND CREW DECIDED THE REJECTED TKOF AT NIGHT WAS MORE DANGEROUS THAT THE MALFUNCTION. AS A FURTHER SAFETY MEASURE; I PLACED MY HANDS NEAR THE AIR CONDITIONING PACK SWITCHES SO I COULD ACT AS THE 'AUTO PACK TRIP OFF' SYS IF WE LOST AN ENG ON TKOF. THE REST OF THE FLT WAS NORMAL AND WE WROTE UP THE MALFUNCTION.