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Aviation: London's airports are full(-ish)

It's a commonly held belief that London's airports are full; that is, there are no runway slots available which can be used to start new services. Five of the UK capital's six airports - Heathrow, Gatwick, Stansted, Luton and City - are IATA Level 3 coordinated, which means that demand for landing and takeoff slots outstrips supply. Only Southend, until a couple of years ago a sleepy backwater, has capacity aplenty but its short runway restricts movements to aircraft with fewer than around 180 seats.

Surprising then that ACL (Airport Coordination Limited), the independent organisation that manages slot bids and allocations for many airports around the world says that there's still some capacity available at London's big five. Indeed the firm goes on to point out that the total number of slots available next summer has actually increased by 31 compared to this year. Unfortunately these new slots aren't distributed across the capital - Heathrow, Gatwick and Luton will be able to handle only the same number of arrivals and departures as summer 2018 while 16 extra movements will be possible at London City, along with 15 more at Stansted. If all of the vacant slots are requested by airlines, four of London's airports will reach their daily take off and landing limits. Heathrow on the other hand cannot use all of the slots its two runways enable, as it is also constrained by a yearly movements limit. Even so with this new capacity, year-on-year increases across the capital will be 1.5%, representing 11,000 more seats and 26 additional take-offs and landings in the London area every day.

London City is getting busier and is constrained by aircraft parking space.

With slots at a premium and being leased or exchanged for millions of pounds, its not surprising that airlines are finding others ways to provide extra capacity. ACL notes that many operators are already using bigger aircraft, and that will continue - there will be 3.4m more seats on offer at London's airports next summer, an increase of 2.5% over 2018. This is particularly the case at London City, where next summer the average will be 91.5 seats per flight versus 85.6 this year.

Taking a closer look

Intrigued, The Aviation Oracle decided to examine the slot situation in London next summer more closely, choosing at random the week ending Sunday August 4, 2019. A tip for anyone reading beyond here: if you're not really interested in the detailed figures just look at the colours - red is bad, orange is not good, green is great when it comes to slot availability.

London Heathrow

The week ending August 4, 2019 at Heathrow is shown below, and its typical of the entire summer period from late March through to late October. The figures in the grid indicate the number of slots being used and the number available (allocated / available), each hour of every day of the week. Red means no slots are free, orange means just one slot is available, and green indicates that there more capacity free. Clearly any new entrant to the market - or an airline wanting to start a new service or increase frequency - would stand a fair chance of be allowed to operate if it only wants to operate on a Saturday, and in particular on a Saturday afternoon. There's also a little bit of wriggle room on Sunday morning if inbound / outbound turn times aren't too tight, but not much. But in the middle of the week there's pretty much no chance. And in particular launching a new daily operation to Heathrow based around slots that are available would be almost impossible. However, even though there are a few runway slots available at the weekend, that does not guarantee there is capacity within the terminals - that too can constrain demand. And don't even think about the green at the top and the bottom of the charts because pre-04:00 and post 22:00 noise rules place severe constraints on movements.

All charts:

Gatwick Airport

South of London things don't look much prettier. The good news is that there's a lot more orange and a bit more green, particularly during the afternoon and evening. But wouldbe airlines will need to be quick - there's a lot of orange which means only one slot is available during an hour.

Moving beyond those two though, things become a little more rosy.

London Stansted

At the moments airlines can take their pick almost throughout the day. Clearly a newcomer would not be able to launch a daily operation that leaves between 08:00-09:00, 12:00-13:00 or 15:00-16:00 but otherwise

London City

Similarly there is capacity at London City for a good part of the day, as long as an airline does not want to introduce a new service in the morning and evening peaks. However this airport has limited aircraft parking spaces in front of the terminal, and a runway slot being available is not indicative of there being room on the apron where unloading and loading will take place. The docklands airport is also restricted to aircraft that can safely take off and land on is rather short runway, and are certified for the steep approach path. Note too that London City is closed on Saturday afternoons and Sunday mornings, a situation that is unlikely to change in the foreseeable future.

London Luton

Finally there's Luton. There's no chance if an airline wants to depart in the morning peak when most of the low-fare and holiday flights leave, and likewise getting a daily arrival slot in the late evening is going to be challenging. Otherwise though, a newcomer could almost have the run of the place. The sea of green does mean that the corporate jets, shunned by London's other main airports, should also be able to get a look-in although with constraints appearing at the start and end of each day they increasingly use Farnborough and Biggin Hill.

Room for a bit more

So what does it all mean? As far as The Aviation Oracle can tell there's still a fair bit of room available at some of London's airports, as long as airlines and their customers are not picky and don't insist on Heathrow or Gatwick. Any operator wanting new slots at either of the big two will almost certainly have to pay through the nose to lease or exchange slots with an airline that already holds a good portfolio. Clearly these two airports urgently need boosts from the proposed third runway and the prospective permission to use the emergency runway respectively.

There is only one way an airlines can get extra slots, and that is to trade with another carrier that has capacity available. ACL shows a number of transactions involving Heathrow slots have already been completed ahead of the Summer 2019 season. The deals involved British Airways, Aer Lingus, Air Canada, Alitalia, American Airlines, Austrian Airlines, Delta Air Lines, Finnair, Iberia, Japan Airlines, Lufthansa, Qatar Airways, SAS Scandinavian, Virgin Atlantic and Vueling - as well as the defunct Cypriot operator Cobalt Air. Almost all of the arrangements involved daily slot pairs, enabling the recipient to operate in and out across the week. Clearly it is a lively trade that will bring with it some changes London's busiest airport, although not all of it involves money changing hands - some of it involves partner cooperation.

London City will always be a niche market with its steep approach, short runway and limited opening hours, especially at weekends. Meanwhile there are opportunities for growth at Stansted and Luton. The UK government says that it wants the best use to be made of existing airfield infrastructure, so in the short to medium term at least this is almost certainly where any additional demand will have to go.

Text © The Aviation Oracle

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