What was found
PA44-180 PIPER SEMINOLE MADE A LANDING WITH THE NOSE GEAR RETRACTED. THE INSTRUCTOR-PILOT CLAIMED THAT, AFTER EXTENDING THE LANDING GEAR HANDLE, HAD A 'NOSE GEAR UNSAFE' INDICATION....'. AFTER SEVERAL ATTEMPTS TO NORMALLY AND MANUALLY EXTEND THE NOSE GEAR, THE AIRCRAFT LANDED WITH THE NOSE GEAR RETRACTED. THE STUDENT/PILOT STATED THAT THE '..GEAR DOOR LINKAGE FELL OUT WHEN (THE) NOSE WAS LIFTED'. THE OWNER/OPERATOR STATED THAT THE NOSE GEAR FOLLOW-UP ROD FAILED JAMMING THE NOSE GEAR IN THE WHEELWELL. REPORTEDLY, THE PART HAD OVER 5,000 HOURS OF TIME IN SERVICE, AND THERE IS NO LIMITING TIME PUBLISHED FOR THE PART.