Cathay Pacific Boeing 777 above Hong Kong
Pilots flying into Hong Kong have claimed they are stuck "in a perpetual state of quarantine."
The city has some of the toughest restrictions for inbound travellers - including those flying the planes.
One pilot with Cathay Pacific, the Hong Kong flag carrier, reported spending 150 days so far this year in isolation.
"It's almost a certainty that I'll be resigning in the spring... I'm leaving without an actual job and just resigning," another Cathay pilot told the BBC.
"I would say, probably, 80 per cent of those that I fly with are actively looking for work elsewhere. It's all we talk about."
All international inbound travellers, including pilots, have to take a Covid-19 test on arrival and wait until they receive a negative test result before going through immigration procedures.
If they test negative, they can head home - but pilots and crew must remain there for the first three days and are only allowed to leave the house for a maximum of two hours a day for essential activities.
Following that, they must "avoid unnecessary social contact" for 18 more days and take daily Covid tests.
"I don't think this is in any way fair or justified," said one pilot, identified as Clark. "Totally unacceptable."
The other pilot interviewed, given the pseudonym Pierre, described his experience in a government-mandated quarantine facility after testing positive for Covid as being like "solitary confinement".
Quarantine in these facilities usually lasts for 21 days.
Even when abroad, pilots from Hong Kong must adhere to strict rules while on layovers.
"You go directly from your room to the aeroplane," said Pierre. "Fly, and then go directly back to your room and you're locked up in your room until you leave again."
"We are in quarantine from when we show up at work until we get back to Hong Kong," he added.
A Cathay Pacific spokesperson told the BBC: "The safety and wellbeing of our customers, employees and the community remain our absolute priority.
"We regularly remind our aircrew of the critical importance of complying with anti-pandemic measures both in Hong Kong and overseas."
They added of allegations that the harsh restrictions were impacting pilots' wellbeing: "A pilot who feels unfit to fly in any way can express that to the management team without jeopardy and is legally protected in their right to declare themselves unfit for duty."
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