As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PHL-YYZ - FLT 1633 - AT ROTATION THE STALL WARNING SYSTEM ACTIVATED AND THE FLIGHT CREW FIREWALLED THE ENGINES IN RESPONSE. THE AIRCRAFT RETURNED TO THE FIELD AND LANDED WITHOUT INCIDENT. MAINTENANCE RESET THE STALL WARNING CIRCUIT BREAKERS AND THE SYSTEM CHECKED NORMAL. ALL ENGINE PARAMETERS STAYED WITHIN LIMITS. THE ENGINES WERE INSPECTED AND CHECKED OK. (M)