Avoid this airline
After 3 hours of uncertainty, the flight was cancelled due to a technical defect. They refused to offer an alternative flight with another company 'because they do not have authorization'. The only alternative they had was to arrive 3 days later because this was the first flight they had. They advised to file a claim online themselves. Then, after multiple contacts, they refused to refund the cancelled flight and refused to provide delay compensation without a reason. Never again with Hainan.