Which Car seat to use on board EasyJet, Ryanair, Aer Lingus etc?

[user1469193349]

I want to purchase a seat for my 18mth old but I am finding it difficult to get a carseat to fit the plane seat / arm rest dimensions of the major budget airlines.

Anyone any recommendations or anyone use a car seat on board lately?

( Virgin = 43cm, EasyJet = 42cm, Ryanair = 42.5cm, Aer Lingus = 43cm ).

Can I ask why you want to?

Using a car seat takes up a lot of space which is in short supply anyway! We didn't bother and tbh I fly a lot and have never seen a car seat in use on a plane.