What was found
JFK - FLT 253 - AFTER TAKEOFF, LANDING GEAR WOULD NOT RETRACT AND LANDING GEAR UNSAFE LIGHTS ILLUMINATED. PLACED LANDING GEAR SELECTOR TO DOWN AND ALL DOWN, AND LOCKED INDICATION ILLUMINATED. VERIFIED LANDING GEAR DOWN. FOUND LANDING GEAR BYPASS VALVE IN THE BYPASS POSITION. STOWED AND LATCHED LANDING GEAR BYPASS VALVE. GROUND CHECKS OF LANDING GEAR CHECKED NORMAL. CHECK C-1D - 11-14-94 - MCI.