Why a half-empty plane from the UK still has to take off

On the right day, at the right airport, an aircraft will push back from its stand, taxi to the runway and climb away with almost no one aboard.

It has not been misrouted. No emergency has emptied the cabin. The flight is doing precisely what the rules ask of it, which is simply to exist.

The reason sits in a system most passengers never see. At Britain’s most congested airports, led by Heathrow, a slot is permission to land or take off at a particular time, and there are only so many to go round.

That scarcity turns slots into assets of startling value. A pair of prime early morning slots at Heathrow was reported to have changed hands for around $75 million in 2016, a sum that explains a great deal of airline behaviour that otherwise looks irrational.

What governs those assets is a single, deceptively simple rule. Under the regulation that has long applied, an airline must operate a slot at least 80% of the time across a scheduling season to keep its historic right to it the following year, the so called 80:20 or use it or lose it rule.

Fall short, and the slot drops back into a pool where a rival can claim it. In ordinary times this keeps scarce capacity moving and discourages hoarding.

It also creates a perverse incentive. When demand falls away, the cheapest way to protect something worth millions can be to fly the aircraft anyway, passengers or not. The industry has a quiet phrase for it: keeping a slot warm.

The pandemic dragged the practice into daylight. With travel grounded in 2020, the usage rule was suspended outright for several seasons before being phased back in stages, and the full 80% threshold returned only for the summer 2023 schedule.

Even with relief in place, the spectre of empty jets returned. The Lufthansa Group warned it could be forced to operate the equivalent of 18,000 unnecessary flights across a single winter to hold on to its slots. The phenomenon predated Covid, too.

One British carrier once shuttled an Airbus between Heathrow and Cardiff after abandoning a route to Tashkent, and Qantas at one point ran a chartered regional jet on a daily round trip between Heathrow and Manchester, each flight a placeholder at an airport with no room for newcomers.

What the new bill actually does

This is the backdrop to clause 7 of the Civil Aviation (Consumer Protection and Regulatory Reform) Bill, which received its second reading in the House of Lords on Tuesday (2 June).

The clause rewrites the slots regime wholesale. It inserts a new power into the Airports Act 1986 letting the Secretary of State make rules on how slots are allocated, transferred, withdrawn and, above all, how regularly they must be used.

The bill gives ministers a standing power to disapply or modify the usage requirement in the event of a significant threat to public health, or for any other substantial reason.

The emergency waiver that had to be improvised during the pandemic, under separate temporary legislation, becomes a permanent fixture of the law. The bill repeals the older slot power in the Air Traffic Management and Unmanned Aircraft Act 2021 and folds the whole question into the Airports Act instead.

A waiver of the usage rule would count as excluded regulations, exempt from the requirement for a debate and vote in both Houses and left to the lighter negative procedure.

A future government could switch the rule off faster, and with less scrutiny, than the Covid waivers ever attracted.

The clause also severs another tie to Brussels, restating or replacing the retained EU regulation that has governed UK slots since long before the referendum, along with the domestic rules built on top of it.

Sitting alongside are provisions for new entrants and a power to retaliate when UK carriers face discriminatory treatment at airports abroad.

Who wins and loses?

For campaigners, the bill is a chance missed. A parliamentary petition organised by Flight Free UK, which gathered thousands of signatures, called for the usage requirement to be cut to zero as a permanent measure, on the grounds that flying empty aircraft during a climate emergency cannot be justified.

The bill does close to the opposite of abolishing the rule. It preserves it, and makes it easier to suspend when a crisis demands.

Airlines, for their part, insist the ghost flight is largely a caricature. They argue that many near-empty flights have nothing to do with slots, and instead reposition aircraft, carry cargo, or meet maintenance and crew requirements.

Regulators have sometimes taken their side. At the height of the disruption a senior European Commission official dismissed the alarm as unnecessary fuss, and said there was no evidence of carriers flying empty planes to satisfy the rule.

The deeper issue the bill leaves largely intact is the one passengers feel in the fare.

Slots at Heathrow are so scarce, and so closely held by the incumbents with historic rights to them, that breaking in is close to impossible, which dulls competition on exactly the routes where it would matter most. The new entrant provisions gesture at the problem.

Whether they move it is a question for the regulations that follow, and the bill itself sets out none of them.

So the half empty plane survives, for now.

The bill does not dismantle the logic that puts it in the sky. It tidies the rulebook, brings it home from Brussels and gives ministers a cleaner switch to flip when the next shock lands.

On an ordinary day, at a constrained airport, an aircraft with almost no one aboard will still have somewhere it has to be, because the alternative is to surrender something worth far more than the fuel it burns getting there.

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