What was found
LAX - AIR TURN BACK OF FLT 505 - CREW REPORTED SEVERE VIBRATION FROM NOSE AREA, AFTER LANDING GEAR RETRACTION VIBRATION INCREASED AS AIRSPEED INCREASED. LOWERED LANDING GEAR AND RETURNED TO LAX, LANDED WITHOUT INCIDENT. FOUND NLG DOORS OPEN, CLOSED NLG DOORS AND ACCOMPLISHED RETRACTION/EXTENSION TEST AND OPERATED NORMALLY. (M)