Boeing 737 aircraft used by HNA has been widely used in the past decades and is considered as one of the relatively safe models. Boeing 737 series aircraft operate well in the world, providing reliable transportation services for the global aviation industry.

However, the accidents of Ethiopian Airlines Flight 302 and Indonesian lion air Flight 6 10 last year caused people to worry about the safety of Boeing 737 Max series aircraft. These two accidents are thought to be related to the aircraft's automatic driving system MCAS. Therefore, in order to ensure the safety of the aircraft, Boeing has taken a series of improvement measures, including major modification of MCAS, and closely cooperated with relevant institutions and airlines to ensure the safe operation of the aircraft.

At present, Boeing Company and relevant institutions are conducting strict examination and testing on Boeing 737 Max aircraft to ensure its safety meets the highest standards. As one of the airlines, HNA will follow the relevant regulatory requirements to ensure the safe operation of the aircraft.

Although all risks in flight cannot be completely ruled out, flight safety has always been an important area of concern for airlines and manufacturers. HNA will take a series of measures to ensure passenger safety, including regular inspection and maintenance of aircraft, pilot training and cooperation with aviation regulatory agencies.

To sum up, the Boeing 737 aircraft used by HNA is relatively safe, but flight safety is still a complex problem, which needs many efforts and continuous attention.