As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EMERGENCY DECLARED. FLIGHT RETURNED TO DEPARTURE DUE TO A NR 2 ENGINE SPEED CARD FAILED. LANDING UNEVENTFUL. REMOVED AND REPLACED RIGHT ENGINE N3 TACHOMETER GENERATOR TRANSMITTER IAW AMM 77-12-02. OPS CHECKED GOOD. AIRCRAFT WAS GROUNDED.