Dirty tray tables, seats full of crumbs and toilets with wet, sticky floors – is there anything worse than being confined to a grubby plane? Don’t answer that, there isn’t.

Now, consumer advice service Which? is dishing the dirt on the filthiest flight operators – and Ryanair has come out on top (or bottom, depending on which way you look at it). Fewer than half of passengers surveyed rated the airline as ‘good’ for cleanliness.

Almost 8,000 flyers were surveyed in total – rating several different airlines – and Ryanair’s grubbiness seemed to be significantly worse than others. Almost one quarter of the 1,161 Ryanair passengers surveyed rated cleanliness on the airline’s flights as ‘poor’. 

When a Which? investigator later boarded a Ryanair flight to check out the cleanliness for themselves, they apparently spotted greasy tray tables, soiled headrests and dusty window sills. An ultraviolet light also showed up stains on the tray table that could not be seen with the naked eye.

Cleanliness is important to prevent illness – and we all know what germ pits planes can be. In 2015, a microbiologist collected bacteria samples from four flights and found the drop-down tray tables were the dirtiest places on planes – with eight times the number of bacteria than the toilet flush button. Overhead air vents were also found to be pretty grubby.

In the Which? survey, Wizz Air, Vueling and EasyJet didn’t rate that well for cleanliness, either: 10% of passengers rated Wizz Air and Vueling’s cleanliness as ‘poor’, dropping slightly to 8% of passengers for EasyJet.

It’s worth noting there’s quite a disparity in sample sizes between the airline passengers surveyed. On top of the 1,161 Ryanair passengers, the consumer brand spoke to 69 Wizz Air passengers, 75 Vueling passengers and 2,099 EasyJet passengers.

The number of passengers surveyed from other airlines can be seen in the tables below. 

Almost all of the passengers who flew with Air New Zealand (97%), Singapore Airlines (96%), Emirates (95%), Qatar Airways (95%), Cathay Pacific (94%) and Swiss (94%) told Which? that they found the cleanliness onboard to be ‘good’.

Which’s travel editor, Rory Boland, said: “Faster and faster turnarounds are one thing but it is unacceptable for some airlines to be cutting corners when it comes to cleaning out their cabins properly – no matter how cheap the airline ticket.”

Boland urged flyers to take steps to avoid a hygiene nightmare: “Either choose your next flight on an airline that has a good track record for cleanliness or equip yourself with some antibacterial wipes.”

He added: “If you are flying Ryanair though, a biohazard suit might be more appropriate.”

In a statement to HuffPost UK, a spokesperson from Vueling said the airline is “constantly working on improving the quality of cleanliness in the cabin with our teams and suppliers, aiming to provide customers with the best possible experience when travelling with us”.

HuffPost UK has also contacted Ryanair, Wizz Air, and EasyJet for comment.