Leading trade body the International Air Transport Association (Iata) originally predicted that flights would recover to 2019 numbers by 2023, but has pushed back its forecast by a year.
One key market that is slowing the recovery is the US, where air travel had been increasing but has recently been knocked off course again by new spikes in coronavirus cases across a number of states.
Although the aviation industry is tentatively restarting after an almost total shutdown in April, Iata chief economist Brian Pearce said that any recovery was “barely visible”, reports Associated Press.
Passenger traffic globally was down 94.1 per cent year-on-year in April; in June, it was still down by 86.5 per cent year-on-year.
A lack of consumer confidence and tighter budgets putting paid to business travel are both contributing to the slow recovery.
“Furthermore, there is little sign of virus containment in many important emerging economies, which in combination with the US, represent around 40 per cent of global air travel markets,” Iata said in a statement.
“Their continued closure, particularly to international travel, is a significant drag on recovery.”
Europe’s biggest budget airline, Ryanair, reported losses of €185m (£167m) – an average of £20 per second – between April and June 2020.
The carrier saw passenger traffic fall by 99 per cent.
In the UK, the Foreign Office blanket warning against international travel, which is still in place for most countries, is thwarting travel plans, alongside the mandatory two-week quarantine for all travelling arriving from all but 62 destinations.
Spain, a favourite with British holidaymakers, was recently removed from both exemptions after a flare-up in Covid-19 cases.