The new route will see the national flag carrier fly twice a day to the central London airport. This brings the number of destinations the airline travels to in the British capital up to three, alongside Gatwick and Heathrow. TAP said in a statement that air traffic between Lisbon and London has shown strong growth in 2017, with passenger numbers up 28 percent. Estimates are that 700,000 passengers will fly on TAP between the two cities during the course of this year.