Heathrow Terminal 5
 

We are arriving on a BA flight at Terminal 5 from New Orleans, and connecting to a BA flight to Nice, also departing from Terminal 5. Do we need to go through airport security again after Customs?

Actually, I found the answer on the airport planner. We will need to go through the security checkpoint before boarding the connecting flight.

Just to round out the picture... you will clear security but not customs. Lines can be long, but I’ve only missed one T5 connection in at least three dozen trips. Unless you land and are basically immediately departing from a satellite pier, you will need to go to the main terminal to clear security. Follow the crowd if you have one hour+ And you’ll end up in the right spot. If you have elite status or are in a premium cabin, look for the expedited security lanes to shave a bit of hassle.

For anybody with similar questions - the LHR website has a tool that gives step by step instruction for any connection. Go here and enter your flight info: http://www.heathrow.com/flight-connections

You won't have to bo theough Passport Control if you cahnging flights.

Thanks for the responses. We will have 2 hours and 45 minutes, so time is not the issue. I have an external medical device, and I wanted to mentally prepare myself for going through that hassle again.