Travelling abroad with kids: what to do about car seats?

Can you bring a car seat on board? 

There are two factors here. First the car seat generally needs to be TUV or FAA approved for use on board an aircraft (see list at end of blog post of car seats that are TUV approved).
Second the airline needs to accept car seats on board. Each airline has different rules and while it can be very frustrating trying to get answers, we recommend contacting your airline as soon as you have booked your flight to clarify with them in writing (this is important to have as the flight crew on board your actual flight may differ on this). We have included the two main Irish airlines, below, Aer Lingus and Ryanair: 

Aer Lingus
Infants aged 0-5 months old must sit on an adult’s knee and be restrained by an infant loop belt.
Car type safety seats may be used by children aged more than six months and less than 36 months. (In order to accommodate a child aged 36 months or older in a car seat, the child must be within the size and weight limits for that seat and special Irish Aviation Authority (IAA) approval is required). 

The car seat must be restrained on the aircraft seat by the normal aircraft lap strap. Aer Lingus don’t permit rearward facing car seats. The seat must be a purpose-designed children's car seat with a 5-point harness, and must be of a type approved for use in motor vehicles and aircraft and bearing labels to this effect:

USA

• This must display an Federal Aviation Administration (FAA) sticker which must display the words "Certified for use in motor vehicles and aircraft".

European

• This must display a CE sticker, with the words "Certified for use in motor vehicles and aircraft".
• In order to ensure the car seat will fit into the aircraft seat, please ensure the seat width doesn't exceed 17 inches (430mm).
• Infants aren't permitted to occupy exit rows or the rows immediately before or after an emergency exit row.

Children aged 2 - 11 years must travel in their own seat.

(We contacted Aer Lingus several times to get more clarity on the above with no response)

Ryanair

Infants aged 8 days to 23 months inclusive must sit on an adult's lap.

If you bring a car seat for an infant under 2 years of age and wish them to sit in this car seat for the duration of the flight, you will need to book an extra seat for them. You may bring a car seat on board for an infant or child if it is approved for flying and has a 5-point harness.
(You can bring 2 items of carry-on baby equipment for free, this can include a pushchair / buggy, car seat, booster seat or travel cot).

Type of car seats:
The list of TUV approved seats are mostly infant carriers but these are rear facing and what if your airline doesn't allow rear facing seats? There is an alternative: the Amsafe CARES harness.