The number of passengers at the airport will be capped at 100,000 per day this summer because the airport has been unable to keep up with the recovery of air travel.
Airlines have been told by the airport to stop selling summer tickets.
There is a capacity cap in place.
"Our assessment is that the maximum number of daily departing passengers that airlines, airline ground handler and the airport can collectively serve over the summer is no more than 100,000," John Holland- Kaye wrote in an open letter to passengers.
According to the latest forecasts, the daily departures will average 104,000, giving a daily excess of 4,000 seats. We are asking our airline partners to stop selling summer tickets in order to limit the impact on passengers.
The rebound from Covid-19 has led to 40 years of passenger growth at Heathrow. It has been a challenge to meet the needs of the airport. He thinks that the pre-pandemic level of security workers will be reached by the end of July.
According to Holland- Kaye, the airlines have had problems with staff.
The ground handler who is contracted by airlines to provide check-in staff, load and unload bags and turn around aircraft is one of the critical functions in the airport which is still under resourced.
This is a significant constraint to the airport's overall capacity because they are doing the best they can with the resources available.
There have been long security lines, bags not traveling with passengers and late-arriving bags at the airport.
Willie Walsh, the former British Airways CEO, said in an interview that he should have prepared better. Walsh is the director general of the International Air Transport Association.