Edinburgh Airport has been rated the worst in the UK for assisting disabled passengers.
The Civil Aviation Authority (CAA) said it was the only one of 30 to be in the bottom rank, with a “poor” performance in the year to March.
The CAA said improvements were also needed at Aberdeen, Inverness and Prestwick airports.
Glasgow was the only airport in Scotland to be rated “good”. The CAA said it had consulted widely with a number of disability organisations and consistently had good service.
Assistance for disabled passengers includes for checking in, transferring to boarding gates and on to aircraft, and helping arriving passengers reach onward transport.
At Edinburgh, the CAA criticised Amey, which was responsible for helping 50,000 disabled passengers a year before the firm lost the £3 million contract.
But the regulator also rebuked airport managers for failing to check Amey’s performance.
Amey had promised “best in class” service when it was awarded the contract three years ago, but the CAA said it was terminated in March.
The CAA said it had raised concerns with Edinburgh Airport last November, including over of its “lack of proper oversight” of Amey’s performance.
The regulator said the airport had since replaced the company with OmniServ and significantly increased the budget for new equipment and more staff.
The airport also appointed a new manager to ensure the service improved.
When Amey won the contract in 2013, its then chief executive Mel Ewell had said: “Building on our proven expertise in airport management, we will introduce innovations and best practice to deliver efficiencies for the client as well as a best in class service for airport passengers.”
The CAA said: “We welcome the steps Edinburgh Airport has taken and we will continue to monitor the airport’s performance closely.”
An airport spokesman said: “Since the findings of this report were collected six months ago, we have taken great steps to improve in this area, including bringing in OmniServ.
“Edinburgh Airport is absolutely committed to continuing to improve the passenger experience of everyone who uses the airport, including those with a disability and those with reduced mobility.”
A spokesman for Amey said its contract was ended two weeks early, by mutual consent, so the new operator could take over before the busy Easter period.