What was found
DURING CLIMBOUT ON FLIGHT 2987, LT ENGINE WAS FIREWALLED FROM 17000 TO CRUISE ALTITUDE 22000. RAN APPROX 5 - 6 PERCENT LESS THAN CHARTED TORQUE. ITT WAS APPROXIMATELY 830-840. AIR RETURN TO MSP AS PER MXC, AND DISPATCH UNABLE TO MAKE CHARTED TORQUE POWER LEVER SPLIT NOTED AT MOST SETTING LEFT PL 3/4 AHEAD OF RIGHT PL. MAINTENANCE FOUND LT ENGINE OUT OF RIG. RERIGGED LT ENGINE PER SAAB AMM 76-10-00. PERFORMED GROUND RUN, FOUND NO POWER LEVER SPLIT. PERFORMED GPA, FOUND MARGIN TO BE ACCEPTABLE.