The authority’s latest UK Aviation Consumer Survey, its sixth over the past two years, found consumer satisfaction has fallen from 83% to 82% since April, and is down from 90% since 2016.
Moreover, the latest survey found a growing divide in attitudes between those living in the north of England and Northern Ireland and those in London, the south east and West Midlands.
Among those having flown in the past 12 months, people from Northern Ireland (87%), the north west (86%) and north east (86%) were the most likely to be positive about their recent flying experience.
By comparison, Londoners (76%) and those in the West Midlands (80%) were bottom of the table, with the overall rate for the UK coming in at 82%.
Tim Johnson, CAA policy director, said: “While the numbers show a positive story overall, it is important for the industry to continue to improve in areas where consumers are less content, such as complaint handling.
"This is particularly important given new findings in this survey showing how poor complaint handling can make many consumers think twice about flying with an airline again.”
The survey found waiting at the boarding gate to be the "low point" of customers’ pre-flight journey at a rate of 74% satisfaction and ease of navigating around airports (85% satisfaction) the high point.
In total, 78% were satisfied with access to information to compare airlines and airports.