In the hours after the security alert emerged, the Civil Aviation Authority began handing out clear bags for the limited hand luggage still being allowed. (Phil Coomes/BBC)
From 6am queues were growing in all of Britain's airports. This Stansted passenger was 500m from the main security post with no end in sight. (Phil Coomes/BBC)
At 8am, the queues at Heathrow were stretching back through the terminals as people waited to be checked in and approach security. (Ashley Highfield/BBC)
Passengers watched the departure boards anxiously for more information. (Phil Coomes/BBC)
But air traffic controllers and carriers had no option in many cases but to cancel flights. (Phil Coomes/BBC)
Shortly before 9am, Heathrow was partially closed to flights other than those already in the air.
Families planning their summer break found their expectations dashed - with parents doing their best to explain to their children what was happening. (Phil Coomes/BBC)
And with the security alert focusing on liquids, mothers were told that they would be required to taste baby milk before it would be allowed on to a flight.
Many passengers settled down to get what rest they could, hoping that they would be able to get in the air eventually. (Phil Coomes/BBC)
Every step of the way to departure gates, police watched passengers.
But for many, it was proving too much.
Queues continued to build at Heathrow, stretching outside terminal four by late afternoon.