LHR - London Heathrow Airport, which is mentioned in the text as the location of British Airways' First Wing.
PEK - Beijing Capital International Airport, which could be a potential destination airport for a flight deal from London Heathrow.
LGW - London Gatwick Airport, which could also be a potential departure airport for a flight deal.
It's worth noting that the text does not explicitly mention any specific airfare deals, so it's possible that no airport codes are relevant to this text.