As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF DURING POWER REDUCTION, RIGHT THROTTLE WOULD NOT DECREASE BELOW 20 INCHES MANIFOLD PRESSURE. AIRCRAFT RETURNED TO BASE UNEVENTFULLY. INSPECTION REVEALED THROTTLE CABLE SEIZED AT ENGINE SIDE WHERE CABLE EMERGES FROM OUTER SHEATH. THE OUTER SHEATH HAD SEPARATED AT FLEXIBLE SWEDGE THAT ALLOWED INCREASE OF THROTTLE POSTION BUT LIMTED RETARDING TO 20 INCHES MANIFOLD PRESSURE. CABLE REPLACED AND AIRCRAFT RETURNED TO SERVICE. (SUBMITTED BY FAR-FSDO FROM INFORMATION ON FORM 8010-4 SUPPLIED BY OPERATOR). (X)