If you want a job with BA then saying you love to travel or being in the air isn't going to get you far in an interview at all, every man and woman and their dog comes out with those lines. Come up with something different that will make you stand out from the rest.
They are looking for answers that show how you are going to be in a cabin environment.
i.e
- I LOVE helping and meeting people from different walks of life
- I LOVE working as part of a team
- I LOVE a challenge and solving problems straight away
In all fairness though my interviewers (when I met them on line after I got the job) said I got the job mainly because I was enthusiastic, didn't have to think about answers (this shows you may be lying or making something up). And one which shocked me; they could see me in the uniform as I was in a suit and well groomed.
Hope this helps