A PIC ALLOWS A TKOF ON AN LTT AFTER THE FO HAD OVERTORQUED BOTH ENGS. THE PIC DID NOT KNOW THE HIGHER LIMITS OF THE OVERTORQUE BUT THEN RETURNED TO DEP ARPT AFTER DUE REFLECTION.
Synopsis
A PIC ALLOWS A TKOF ON AN LTT AFTER THE FO HAD OVERTORQUED BOTH ENGS. THE PIC DID NOT KNOW THE HIGHER LIMITS OF THE OVERTORQUE BUT THEN RETURNED TO DEP ARPT AFTER DUE REFLECTION.
Narrative
VERY INEXPERIENCED FO WAS PF. CLRED POS AND HOLD FOR SEVERAL MINS WHILE TFC LAUNCHED OFF XING RWY. WHEN WE WERE CLRED FOR TKOF I REACHED UP TO TURN ON LNDG LIGHTS. BEFORE I COULD LOOK BACK DOWN; I WAS SURPRISED TO HEAR ABNORMAL ENG AND PROP SPOOL UP SOUNDS. GOT MY EYES AND HAND DOWN TO THROTTLE QUADRANT AS RAPIDLY AS POSSIBLE AND FOUND FO HAD PUSHED UP THROTTLES INSTEAD OF CONDITION LEVERS. WE BOTH PULLED THROTTLES BACK QUICKLY. BY THE TIME I GOT MY EYES ON THE ENG GAUGES; TORQUE WAS HIGH; BUT SPINNING DOWN TOO RAPIDLY TO READ. IT WAS DEFINITELY BELOW THE LIMITATION VALUE. LINE-UP CHK WAS COMPLETED AND FO MADE THE TKOF. AT THAT POINT; I CONSIDERED IT TO HAVE BEEN A MINOR AND MOMENTARY MISTAKE. AFTER A FEW MINS REFLECTION; HOWEVER; I REALIZED I HAD NO IDEA HOW HIGH THE TORQUE SPIKE MAY HAVE BEEN. CALLED MAINT CTL AND DISCUSSED WHAT WE HAD SEEN. AFTER A FEW MINS RESEARCH THEY PRODUCED A VALUE HIGHER THAN THE PLT LIMITATION; BUT I HAD TO TELL THEM I COULDN'T BE SURE IF THAT VALUE HAD BEEN EXCEEDED. THEY DECIDED THAT WE HAD BETTER BRING IT BACK FOR INSPECTION. SHOULD WE HAVE NOT MADE THE TKOF? HINDSIGHT MIGHT SUGGEST THAT. AT THE TIME I WAS MORE CONCERNED WITH CREATING AN ENVIRONMENT THAT WOULD ENCOURAGE FO TO RELAX -- SETTLE DOWN -- GET HIS MIND ON FLYING RATHER THAN WORRY ABOUT HAVING MADE THE MISTAKE. WHEN I DECIDED TO CALL MAINT IT WAS NOT BECAUSE I ACTUALLY THOUGHT WE HAD EXCEEDED A LIMIT; IT WAS A REALIZATION THAT SINCE I DIDN'T KNOW (AND GAUGE RATE OF CHANGE SEEMED TO IMPLY A PROBABILITY THAT IT HAD BEEN MUCH HIGHER) IT WAS NO LONGER MY DECISION TO MAKE AS TO WHETHER TO CONTINUE OR GIVE IT BACK TO MAINT.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.