for security for Trump arriving at Stansted, why didn't he fly in to one of the American Air Force bases at Lakenheath or Mildenhall then get a helicopter to London?
That's a mystery to me.All the state visits I have attended the principal has always arrived at the VIP suite Terminal at LHR and on a couple of occasions at LGW. They were then given a motorcycle escort to Horse Guards Parade to meet the Queen and inspect the Guard of Honour. A carriage drive followed down the mall and into Buckingham Palace.
On one occasion the principal landed at LGW and was supposed to travel by special train into London to be met at the appointed railway station by the Queen or her representative.The locomotive broke down but a SEG team were at the airport to escort the Royal Corps of Transport baggage vehicles to Buckingham palace so they escorted the principal by road in the limos that were meant to carry the entourage. Went like clockwork and the principal got his carriage drive from Admiralty Arch to BP escorted by Mounted Branch.
Perhaps for security reasons it would be too obvious for the US security teams to let POTUS land at the same VIP suit at the same London Airport as his predessors.
The link provided by' mushroom 25' is self-explanatory.The staff have regular training in security checks. The layout provides for the planes to be placed well away from the terminal buildings which would be helpful in a hi-jack scenario. Barrack Obama used this airport on at least three occasions.