航班因机械故障备降宜昌的海航：几天前有航班因机械故障返航

Group 1 - The core issue is that Hainan Airlines experienced mechanical failures on two flights, leading to emergency landings and delays [2][3] - On February 9, flight HU7696 from Qionghai to Shijiazhuang made an emergency landing at Yichang Sanxia International Airport due to mechanical issues, landing safely at 17:47 Beijing time [2] - The airline expressed apologies for the inconvenience caused to passengers and assured that they would provide proper service and support to ensure safe arrival at the destination [2] Group 2 - On February 6, flight HU492 from Brussels to Beijing also returned to Brussels due to mechanical failure, landing safely [3] - Hainan Airlines arranged for a replacement flight, HU492D, which departed Brussels on February 7 and was scheduled to arrive in Beijing on February 8 [3]