George Best Belfast City Airport is working “around the clock” to make it as safe as possible for travellers, its chief executive has said.
Aer Lingus is to carry out a review after pictures emerged of an almost full flight with no apparent evidence of social distancing measures.
The airline said any changes required would be implemented as a “matter of urgency”.
Pictures were shared from inside the cabin of a Belfast to London Heathrow flight on Monday morning showing row after row filled with passengers.
Airport chief executive Brian Ambrose said Monday saw the first big influx of passengers since the virus outbreak, with 154 on the flight.
He told the BBC’s Stephen Nolan Show: “Measures yesterday were not up to our usual standards.
“The people at the airport will not be found wanting to find solutions.”
He said no-one has yet found a solution to keep people two metres apart on an aeroplane.
“How could you?”
The airline has said the safety and security of Aer Lingus’s customers and crew is its top priority.
Mr Ambrose added: “As soon as we were alerted yesterday to problems … We are working around the clock to make sure Belfast City Airport can provide the safest environment possible.”
He said one of the “pinch points” happened when customers took their hand luggage to re-pack it after clearing security.
Alternative aircraft boarding methods could meaning dividing passengers between an “air bridge” from the terminal to the front of the plane and using the rear doors from the tarmac.
Mr Ambrose said he is still reviewing whether measures put in place around social distancing on Monday were inadequate or whether not enough staff were present to ensure passengers adhered to restrictions.
Until Monday only 30 or 40 passengers had been using the Heathrow flight and were mainly medical workers.
The chief executive added: “I don’t want to jump to any conclusions.
“The pinch points had not emerged until yesterday.”
It is expected to be late summer before the airport begins opening some of its cafes or restaurants and stemming its significant losses.