Some days at British Airways can involve some pretty rough times for customers and the flight operations staff often take the brunt of the feelings from the customers. By asking this question, your interviewer is looking to gauge your understanding of the potential downsides to a role in a customer facing role at British Airways, and that you've put thought into how you would handle these days. As you answer this question, be sure to highlight the importance of always maintaining a positive attitude no matter what is happening during your day. Also be sure that you don't sound like you are complaining about any days you've had like this in the past, as that will reflect poorly on your ability to handle this aspect of the job. In the end, keep your response customer focused by highlighting your ability to work with customers in this mindset.