What was found
ON FLT NR 550, ATL-ATL, AIR RETURN, AFTER TAKEOFF THE TAKEOFF WARNING HORN SOUNDED DURING FLAP RETRACTION. THE FLAP SLAT WERE RE-EXTENDED TO 5 DEGREES, DID NOT GET AIR MODE. AUTO SPOILER ' DO NOT USE' LIGHT WAS ON FOR LANDING. MAINTENANCE FOUND THE GROUND SHIFT MODE OUT OF RIG. RIGGED NOSE GEAR GROUND SENSE MECHANISM, OPS CHECK GOOD. SECURED TURNBARRELS MM 32-23-1. (M)