If it is rearward facing such seats are not permitted for use during the flight. How wide is the seat too?. I ask as it may well not fit into the aircraft seat. If that happened it would need to go into the hold. Economy seats on VA are 17 inches wide.
From their website:-
"An infant is a child less than two years old. (Children aged 2 and over are not permitted to use an Infant car seat onboard)
If you would like to use your own car seat, it must:
Be designed to be secured by means of a normal aircraft single lap strap
Have a separate 5-point restraining harness
Not exceed the dimensions of the aircraft seat, and should fit into an area of 43cm x 43cm (17.ins x 17ins)
Must be secured to its host seat at all times of the flight
Must not require the use of a three-point harness to secure it to the aircraft seat.
AFT facing car seats are not allowed
If for any reason your car seat cannot be fully secured, it may have to be placed in the hold. In these circumstances, your infant will have to be secured to your lap whenever the seat belt sign comes on"
It must also have EU approved labelling
Approved for use in motor vehicles according to the UN standard ECE R 44, -03” or later
OR
‘Qualification Procedure for Child Restraint Systems for Use in Aircraft’ (TÜV Doc.: TÜV/958-01/2001)
flywith.virginatlantic.com/gb/en/on-the-flight/cabin-and-seats/seats-for-children.html