What was found
THIS MALFUNCTION LEAD TO A NOSE GEAR UP LANDING. THE NLG APPEARS TO HAVE RETRACTED IN AN OFF-CENTER POSITION. INSPECTION POST INCIDENT REVEALED A CRACKED ALIGNMENT GUIDE, WHICH IS FIXED TO THE TOP OF THE NLG STRUT. THIS PART IS RESPONSIBLE FOR ENSURING THE GEAR IS RETRACTED IN TO THE WHEEL WELL IN A CENTERED POSITION. THE CENTRAL ALIGNMENT BEARING, WHICH CONTACTS THE ALIGNMENT GUIDE JUMPED OVER THE RIGHT SIDE CHANNEL, RESULTING IN THE GEAR RETRACTING AT ABOUT A 25 DEGREE RT TURN POSITION. THE NLG TIRE SIDEWALL CONTACTED THE FIREWALL CUT OUT, NOT ALLOWING A FULL RETRACTION. WHEN THE CREW ATTEMPTED EXTENSION OF THE LANDING GEAR, THE OFF CENTERED NOSE GEAR EXTENDED TO A POINT, UNTIL THE NLG STEERING HORN ON THE RT SIDE OF THE NLG STRUT CONTACTED THE MUFFLER SHROUD. THIS PREVENTED THE GEAR FROM EXTENDING TO A FULL DOWN AND LOCKED POSITION. PROBABLE CAUSE HIGH TIME ON A PART HIGHLY SUSCEPTIBLE TO METAL FATIGUE WHICH LEAD TO EVENTUAL WEAKENING OF THE MATERIAL AND A CRACK. RECOMMENDATIONS TO PREVENT RECURRENCE: SPECIAL AIRWORTHINESS INFORMATION BULLETIN (SAIB) TO ALERT OPERATORS OF POSSIBLE FAILURES OF THIS PART. AIRWORTHINESS DIRECTIVE MANDATING RECURRING INSPECTIONS OF THIS PART. APPLYING A LIFE LIMIT TO THE PART IN FLIGHT HOURS/YEARS.