What was found
DURING A SCHEDULED PILOT TRAINING FLIGHT THE GEAR WAS RETRACTED TO UP AND LOCK. A LOUD POP/BANG WAS HEARD AND THE NOSE LANDING GEAR (NLG) INDICATED NO UP AND LOCKED. HOWEVER THE MAIN LANDING GEAR (MLG) WAS UP AND LOCKED. THE MAIN GEAR SYSTEM WAS RECYCLED WITH SAME RESULTS. AIRCRAFT LANDED WITH MLG DOWN AND LOCKED AND NLG NOT DOWN AND LOCKED AFTER INSPECTION THE BELLCRANK IDLER WAS BROKEN. IT SUSPECTED THAT FATIGUE COULD BE THE CAUSE. INSPECTION OF SUSPECTED PART FOR CRACKS.