The UK's busiest airport has operated a full flight service for the first time since the terror alert 10 days ago.
Some 1,200 flights left or arrived at Heathrow on Saturday
Heathrow Airport was among the airports worst hit by disruption to schedules after details of an alleged plot to blow up flights emerged on August 10.
On Saturday, 1,200 flights - carrying 172,000 people - arrived and departed with no severe delays or cancellations.
Gatwick Airport also said Saturday was the first day new security measures had not caused severe scheduling problems.
There, 831 flights carried about 67,000 passengers in and out.
One flight was cancelled, but a spokeswoman said this was due to the high number of passengers travelling on one of the busiest weekends of the year.
A spokeswoman for Heathrow said it as "a typical busy Saturday afternoon in August".
"The flight schedule has been running as normal. It has been busy but we are getting back to normal."
Airports and airlines have criticised the new security measures for increasing their costs and their workload, but on Friday, the Department for Transport insisted that these would remain at UK airports for now.
The spokeswoman for Gatwick said the only way its passengers could be processed was through the huge efforts of its staff.
"The longer it goes on the harder it becomes for people," she said.
Low-cost airlines Ryanair and Easyjet, which largely operate out of smaller airports, have run a full schedule since Tuesday.
But Ryanair said it would sue the government for compensation for delays unless usual security arrangements resumed within a week.
A DfT spokesman said: "We have no intention of compromising security levels nor do we anticipate changing our requirements in the next seven days."