China is set to keep a tight restraint on overseas flights well into 2022, according to analysts who have heard from Air China. This could spell trouble for tourism businesses around the world because Chinese travellers play an outsized role. Last month China’s aviation regulator said weekly international flights were still only at 2 percent of 2019 levels. Now the country’s three biggest airlines have all said restrictions could last through the first half of 2022. Analysts say Air China, China Southern, and China Eastern all said as much during earnings calls. February’s Winter Olympics in Beijing are reportedly one factor, with the government wanting to maintain a preventive approach to COVID-19 infections. Air China management told analysts recovery would be slower than in Europe or the U.S. One analyst told Reuters that a full recovery for Chinese air travel won’t come until 2024. Others have been cutting their forecasts …