Vietnam Airlines (VN, Hanoi Noi Bai International) has grounded its fleet of sixteen ATR72-500s after an incident involving a tire falling from one of the turboprops in mid flight. Vietnamese state media report that VN-B219 (c/n 886) landed at Da Nang from Haiphong on Monday night after an uneventful flight, only for one of the aircraft's front nose wheels to be discovered missing. Tien Phong reported Tuesday that Vietnamese authorities asked ATR - Avions de Transport Régional (EVX, Toulouse Blagnac) to join the investigation into the incident which comes just days after a Lao Airlines (QV, Vientiane) ATR72-600, RDPL-34233 (c/n 1071), slammed into the Mekong River on the downwind approach leg into Pakse killing all on board.