Swiss International Airlines has been named the best short-haul carrier by a consumer watchdog.
Singapore Airlines came number one in the long-haul category
The airline scored an overall satisfaction rating of 76 per cent in a survey of over 8,000 Which? members. Aer Lingus came second with 67 per cent.
Thomas Cook Airlines was named as the worst short-haul carrier, scoring the lowest ratings for overall customer satisfaction and the likelihood of being recommended to a friend.
Which? members gave the airline a rating of 37 per cent, while Ryanair scored just 38 per cent.
The cabin environment of Thomas Cook Airlines was given one star out of five, and Ryanair got the same rating for the quality of its boarding process.
Both airlines were given two stars for their value for money.
In the long haul category, Singapore Airlines came number one with 89 per cent. Air New Zealand was second (88 per cent) and Emirates third (80 per cent).
Rochelle Turner, head of research at Which? Travel, said: “The airline you choose can have a big impact on your trip, making the difference between arriving feeling tired or refreshed.
“The top-rated airlines all score highly for both the cost and value for money of the flight and most still include free hold luggage, plus onboard drinks and snacks in the ticket price – something clearly prized by travellers.”
The survey questioned 8,277 Which? members about their most recent return flight. Some 2,179 had travelled long-haul, and 6,048 short-haul.
Ian Ailles, chief executive officer of the mainstream travel division which deals with many of the package holidays organised by Thomas Cook UK and Ireland, said: “The Which? Airline Satisfaction Survey results are in stark contrast to the high levels of satisfaction our customers tell us about.
“From our own survey – which is 84 times larger than the Which? report – customer satisfaction scores with 89 per cent of our customers rating their flight as either excellent or good for their holiday last summer.
“It’s impossible to see how this offers consumers a like-for-like comparison when Which? is comparing airlines with completely different product offerings that appeal to completely different customers.
“If Mrs Smith wants to fly with her family to Spain, a smaller scheduled airline with restricted flying programme is not going to be able to help her.”
He added: “Unlike scheduled airlines, for most of our customers our flights form part of their package holiday with us.
“An important factor is about getting them to their holiday destination on time and we came first in the Civil Aviation Authority’s on-time per-formance table last year, and expect to perform similarly well when the new report is out.”
Thomas Cook said it questioned 510,000 customers in its 2011 annual survey.