HRH the Prince of Wales met security personnel, observed a demonstration by air traffic controllers and enjoyed a tea party aboard a BA Dreamliner.
The visit and tour, highlighting the work of Heathrow staff and security to keep the airport safe, came 10 years after The Queen officially opened the new terminal.
The Prince was greeted by specialist Metropolitan Police officers, Border Force and immigrations officials, and Heathrow staff.
But it was trainee sniffer dog Ned who seemed to capture the Prince’s imagination when the cocker spaniel pup affectionally licked at HRH’s hand as he was stroked.
Air traffic controllers then gave a demonstration of how they keep the skies over the UK’s busiest airport safe.
His Royal Highness also learned more about the Border Force’s bio security measures before boarding a British Airways 787 Dreamliner for tea with BA chairman and chief executive Alex Cruz.
The Prince, a long time advocate of encouraging young people into STEM (Science, Technology, Engineering and Mathematics) subjects, later met apprentices and other young people involved in providing a wide range of services throughout the airport.
John Holland-Kaye, Heathrow chief executive, said: "It was an honour and a privilege to be able to show His Royal Highness some of the great work being done here by our colleagues and partner agencies that keep our airport safe. Security will always be our priority and investing in people and technologies to ensure this happens on a continual basis.
"Heathrow... is protected by leading intelligence services, a designated police force and dedicated security colleagues that work 365 days a year. It is a real boost for them to meet The Prince who thanked them all for their work.
"Some of the most advanced passenger security and technology in the world can be found here at Heathrow and it was fantastic to show these to The Prince of Wales as we know he is the Royal Patron of Intelligence Services also."