What has happened at the airport? The airport that confidently laid out expansion plans and charged its customers a hefty premium has been suffering the kind of chaos people pay money to avoid. The airlines have been told to turn away passengers at the beginning of the summer season.

Few places were feeling the heat more than in Britain. As the mercury hit a record 40.2C at the airport, the grass between its runways was a brown color.

The 100,000 daily cap on passengers was announced last week and put thousands of customers at risk. The airport said it was protecting holidays. The airline refused to comply or cancel. Willie Walsh, the director general of Iata and an old enemy from running British Airways and its parent group, IAG, has described Heathrow as a bunch of idiots.

Anxious storm clouds of passengers

There was a thin line inside the airport terminal this week. The airconditioning was working. It did not look like there was a lot of chaos. A staff member at the queueing ropes told them to give it a couple of hours. It's just random.

The airline sector's turmoil is self-perpetuating, with huge lines growing with anxious passengers turning up earlier for flights. One seasoned traveller said he had arrived nine hours before his flight to Australia after warnings that the heat could halt the trains he needed for the airport.

The new Terminal 2 is the most modern addition to the airport and is designed to make it easy for passengers to get to and from the plane. A man in a suit was explaining to customers that even though they check in online, they still have to go through the security line.

Various staff dressed in airline livery, hi-vis vests or pink polo shirts are marshalling incoming groups that appear and dispersed like storm clouds

With corporate travel down, fewer passengers are likely to be mobile and tech savvy. Many here are non-English speaking, with large amounts of luggage, elderly, young, infirm, and needing assistance of all sorts.

The best problems have been airside. The arrivals board now has an additional feature, whether or not bags have been delivered or arrive, as a result of today's delays. The bags haven't made it to the carousels despite the flight landing more than 90 minutes ago.

John Holland- Kaye, the chief executive of Heathrow, said on Tuesday that cutting passenger numbers by just a few thousand can make a huge difference. The cap is being put in place to protect holidays. It is the hottest day we have ever had, and the airport is working well. The action we are taking is working.

Pointing the finger

Holland- Kaye said no one wanted a blame game, but that the main factor was a lack of airline ground handling staff, either directly employed or contracted out. The main effect of the cap will be limiting further ticket sales, but about 1,500 passengers on the busiest summer days will be forced to change their plans, on top of the hundreds of thousands already bumped by mass BA cancellation orders.

If the airport, airlines, or ground handler doesn't have enough capacity, people won't get away on their flights in a worse way. It's the worst of all worlds.

Long background checks for new recruits and competition from other sectors have made the labour shortage worse.

The infrastructure and security officers are the only things that come under the airport's direct purview. There are airlines at the check-in counter. The Border Force and the Home Office are responsible for the immigration hall. The baggage handler who puts the bags in or takes them off is usually employed by an airline.

Direct orOutsourced staff are the people on the tarmac, driving trucks to bring luggage, attaching air bridges or pushing back aircraft.

‘Excessive’ shareholder returns

The unreliability of the baggage system, the understaffed security, and a failure to plan before the cap all contributed to the long queue at Easter. Holland- Kaye is in charge of keeping all of the companies working in tandem at the airport.

The latest standoff has played out to a backdrop of a bitter row over landing charges, with airlines such as BA agreeing and cutting more flights from their schedule to keep the plates spinning. The UK regulators set a price that it can make airlines pay for passengers.

That prompted a furious backlash from carriers who have suffered huge losses and are wondering if the shareholders of Heathrow should be digging deeper after taking billions in dividends in the last decade.

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Investment that directly raises returns the more it builds, under the regulatory system, has been financed by Heathrow's ever increasing debt. The chief executive of Virgin Atlantic said it was using its monopoly position to fleece passengers and deliver excessive returns to shareholders.

At the airshow this week, Walsh claimed that Heathrow was not prepared for the strength of recovery because it was too pessimistic. The demand recovery was downplayed by Heathrow. If airlines expected the bounce back they should have hired more people earlier.

Problems and the blame game seem to have a way to go. It will take at least 18 months for the issues to be solved. He said that the cap might not be lifted for half-term or Christmas.