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‘Ghost Flights’ and the Spectre of Climate Change

22nd February, 2022

What are ‘ghost flights’?

The danger of ‘ghost flights’ may sound like something from the world of espionage, but the term also applies to the phenomenon of thousands of empty, or near empty, planes crossing our skies. In the aviation decarbonisation debate, it is unsurprising that these spectres of inefficiency have become a flashpoint in the discussion. 

Ghost flights arise because of the ‘use it or lose it’ rule that forms part of the system of ‘slot management’. Slots are defined times when an airline can use the runway at a particular airport. So an airline can plan for and advertise a departure at, for example, 8:30 am because it holds that slot. Airlines retain the right to use a slot if they use it on a regular basis. If demand dips, as it did during the financial recession of 2007 when ‘ghost flights’ were first exposed in the media, or as it has done as a result of the Covid pandemic, some airlines will choose to operate loss-making low-occupancy flights just to retain their slot rights for future use. 

Before the pandemic, airlines were required to use their slots at least 80 per cent of the time. While this was initially suspended during the pandemic and then increased to 50 per cent for the current winter season, it is now set to return to around 70 per cent in the UK as air travel resumes.

At congested airports such as Heathrow, slot rights can be lucrative commodities, particularly at popular times of the day. Airlines are assumed to have ‘grandfather’ rights to slots they have used historically. Slots they no longer need can be leased or sold to other airlines for large sums of money. Air New Zealand sold a single slot in 2020 for $27 million, while British Airways’ 2018 financial accounts list the asset value of its landing rights at £693 million. 

How much do ghost flights matter?

The effect of ghost flights on the environment is very real. A Boeing 737-800, for example, can emit as much as 18 tonnes of CO2 on a 1,500km flight, and that excludes the additional climate impacts associated with contrail formation and NOx emissions.

In February 2022, Alex Sobel MP asked the Government how many departures from UK airports took off with less than 10% of their seats occupied. The answer was nearly 15,000 since March 2020. There was no breakdown of whether these were short- or long-haul flights. However, even if they were exclusively short-haul, this could equate to 270,000 tonnes of CO2. Based on data from the Lufthansa group, Greenpeace estimated that the scale of the problem in Europe could translate to 2.1 million tonnes of CO2, or the equivalent of yearly emissions from 1.4 million average diesel or petrol cars.  

This is, of course, a relatively small proportion of the total emissions from aviation in Europe, which came to 151.8 million metric tonnes of CO2 in 2019. Nevertheless, the notable contention surrounding ‘ghost flights’ is part of the larger debate about regulation and efficiency within the aviation industry, and the seeming lack of agreement over how complex systems should be reformed to meet net zero in 2050. 

IATA, the International Air Transport Association, has argued that the perceived problems with the current approach to slot allocation “are disproportionately focused on a small number of super-congested airports, such as London Heathrow, Amsterdam Schiphol and Hong Kong International” and that the focus should be more in increasing capacity by growing airports than on inefficiencies in how scarce capacity is allocated. Conversely, low-cost carriers typically say that they don’t operate ghost flights, and when Lufthansa recently complained about being forced to operate ghost flights, Ryanair responded by saying that they should simply sell their spare seats at low fares. 

Calls for reform 

Since Brexit, the UK is now free to set slot allocation rules that differ from those of the EU. In a draft aviation strategy published in 2018, The UK’s Department for Transport argued that the “current allocation system is not designed to stimulate a competitive market environment and has no means of taking into account broader objectives”. Many acknowledge the need to overhaul – or at least improve – this system, yet meaningful change remains to be seen. DfT’s proposals to date, such as auctioning or renting of slots as an alternative to grandfather rights are expressed primarily with a view to allocating new slot capacity at an expanded Heathrow rather than to reform the existing system.

In the short term, the easiest way to avoid ghost flights would be to continue to apply a lower usage percentage for the slot allocation rule. A ghost flights petition created by Flight Free calling for the percentage to be cut to zero has now gained thousands of signatures. 

However, keeping such an arrangement in place longer-term could allow incumbent airlines to keep their slots (and prevent competitors from making use of them) even if they were not really needed. This situation could potentially even strengthen calls for airport expansion as a way of creating new capacity in the system. 

AEF’s view

At less than 1% of UK aviation emissions, ending ghost flights won’t do much to help the industry decarbonise. That being said, ‘ghost flights’ are such an obvious example of wastage that the need for slot reform can’t be ignored. Solutions aren’t necessarily straightforward but the Government should take this opportunity to act. It is clearly an unsustainable practise resulting from outdated rules that were not designed with the current climate challenge in mind. 

The current policy not only encourages inefficiency, but also gives a false impression that existing capacity is being fully utilised. The Government should rule out airport expansion and instead focus on slot reform and other efficiency improvements. 

Regulators should also make it easier to monitor progress. This information has been hidden from public view, with airlines avoiding scrutiny by claiming the data is proprietary. No doubt airlines fear reputational damage, especially where they’ve made commitments to net zero, but the public and consumers should be informed. It shouldn’t take a parliamentary question to expose the scale of this wasteful practice.