What was found
AFTER TAKEOFF APPROX 1.5 MINUTES FOLLOWING GEAR RETRACTION, NOSE GEAR DOOR OPENS AND SHUTS. NO ECAM INDICATION OF FAULT. COMPLIED WITH CRITICAL ALERT REF LP 9501148. REMOVED AND REPLACED LANDING GEAR SAFETY VALVE (TT 0046159). REPLACED RELAYS 28GA, 48GA, AND 53GA. OPS CHECK GOOD RELAY M AND E 26-2130-3-0017 26-2700-3-0018/00-0366-3-0017. AIRCRAFT IS ON CRITICAL ALERT, HAS HAD SEVERAL RELATED WRITE-UP SINCE 12 NOV 99..