Connecting at London Heathrow (LHR) in just one hour is considered an extremely "tight" window and is generally only feasible under very specific circumstances. Heathrow is a massive, multi-terminal hub where distances between gates can be substantial. If you are arriving and departing from the same terminal (e.g., both flights are in Terminal 5) and your first flight lands on time, sixty minutes is the "Minimum Connection Time" (MCT) set by many airlines. However, this leaves zero margin for error. You must still clear a security re-screening, which is mandatory for almost all connecting passengers at Heathrow, and these queues can be unpredictable. If your connection requires a terminal change (e.g., arriving at Terminal 2 and departing from Terminal 5), one hour is almost certainly not enough, as the transfer bus alone can take 15 to 20 minutes, not including wait times or the walk to the gate. In 2026, with increased security protocols and high passenger volumes, most travel experts recommend a minimum of 90 minutes for same-terminal connections and at least 2 to 3 hours for inter-terminal transfers to ensure you don't miss your onward flight.