National average rates fell to 81% from 90% in 2016 and from 82% last autumn.
The aviation regulator said passengers’ dissatisfactions included the poor handling of complaints by airlines and airports and a lack of communication and information provided by airlines when flights are delayed.
A lack of accessibility for passengers with reduced mobility was also cited.
From the CAA’s research of 3,500 UK adults surveyed between 8 April and 1 May, passenger satisfaction was lowest in Northern Ireland (67%) and south-west England (76%), while travellers in the north east reported the highest levels of satisfaction (90%).
Other regions to score highly for satisfaction included Yorkshire and Humber, and the East Midlands, with 85% of recent air passengers from each region expressing satisfaction with their flying experience.
According to the CAA, only 56% of recent flyers who made a complaint to an airport or airline were satisfied with how it was handled, while 56% of those who describe themselves as having a disability or health condition said this made accessing and using airports or flying difficult.
Only 54% of UK adults said they found it easy to understand and compare the cost of travelling with different airlines – and only 52% found it easy to find and compare other important information.
Meanwhile, 69% of UK adults agreed that they had “confidence in the safety of airlines and airports”, with only 9% disagreeing with the statement.
When assessing the environmental impact of aviation, the CAA found the proportion of those surveyed saying they think about the impact of flying on the environment had risen from 21% in autumn 2016 to 31% now.
There was also a similar rise in the proportion of UK adults saying they would be willing to pay more to reduce the environmental impact of flying 31%, up from 22% in Autumn 2016.
Tim Johnson, CAA policy director, said: “The numbers show a positive story overall, but it is important for the industry to continue to work to improve areas where consumers are less happy, including complaint handling, transparency and provision for those who benefit from more support.
“These are particular areas where we support the Government’s proposals in its Aviation 2050 strategy to make improvements for consumers.
“The research also revealed that an increasing proportion of consumers are aware of and are considering the environmental impact of flying. This will be an important issue for passengers, the Government and the industry to consider in the context of the UK’s commitment to net zero carbon by 2050.”
