London Heathrow is by far the UK's busiest airport. It handles nearly twice as many passengers and aircraft movements as second-placed Gatwick. In fact, it has consistently been ranked as the busiest airport in the whole of Europe by passenger traffic.

However, to facilitate such figures, the airport operates at full capacity. This makes preferable slots at the airport difficult to obtain. But which airlines have been the winners and losers from the latest round of slot allocations?

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Congestion in the capital

An airfield has existed on the site of Heathrow since 1929. However, it did not become a commercial airport until after the Second World War, in 1946. Despite this slow start, it has since become a major hub of international air travel. Over the course of its history, Heathrow has been home to such iconic aircraft as British Airways' supersonic 'Concorde' airliners.

According to the Civil Aviation Authority, 2019 saw the airport handle almost 81 million passengers (1% annual increase) over nearly 480,000 aircraft movements. However, these record figures have led to the airport becoming increasingly congested. This has prompted the airport to propose a significant expansion, including a new, third runway. However, this has been met with strong opposition by both environmental groups and the local community.

Heathrow runway queue
Most mid-air collisions happen near airports where planes are taking off and landing. Photo: Getty Images

Interestingly, the ongoing coronavirus pandemic has caused a rethink regarding the necessity of the proposed expansion. Indeed, earlier in the year, Heathrow operated using just one of its two existing runways. Nonetheless, the slot allocation process for the summer 2021 schedule has proved fiercely competitive. Indeed, the aforementioned capacity issues have prevented some airlines from obtaining their desired slots. But who exactly has been the most successful?

Slot allocations - the winners

Airport Coordination Limited (ACL) recently published its data concerning slot allocations at Heathrow for summer 2021. In total, 299,642 slots have been allocated across the next financial year (April 2021-April 2022). This represents a 1% increase over the previous year (298,483), and 87.5% of the total requested slots for this period (342,558).

Air Mauritius, Administration, Voluntary administration
The costs are mounting for the carrier. Photo: Getty Images

Several airlines have been very successful in obtaining their desired slots for this period. Some have even had 100% of their requests met. These were generally smaller airlines. Such carriers could be given more flexibility due to having applied for fewer slots. They included the likes of Air Mauritius (186 slots) and Shenzen Airlines (310 slots).

However, compromises had to be made to facilitate this allocation. One sixth of Air Mauritius' slots are 15-25 minutes outside the requested times, and a further 1/6 are more than two hours off. Ten percent of Shenzhen Airlines slots are also over two hours outside the requested times. On the other hand, larger carriers such as American Airlines (9,548 slots) and Lufthansa (15,368 slots) were able to get all their slots at the requested times. Perhaps this shows the influence of flag carrier airlines on the slot allocation process.

American Airlines Boeing 777 Landing At London Heathrow
International airports where passengers have been able to take advantage of American Airlines' Five Star Service include London Heathrow, Buenos Aires Ezeiza, Tokyo Narita, and Sao Paolo Guarulhos. Photo: Getty Images

The losers

However, the allocation rate of 87.5% does mean that some 42,916 requests had to be turned down. As such, several airlines did not obtain any of their requested slots. These included regional carriers such as Eastern Airways (2,108 requests) and Loganair (4,278 requests). However, the airport's long-haul slots were also subject to significant levels of refusal.

A lot has been made of JetBlue's proposed launch of flights from New York and Boston to London. However, while Heathrow was the airline's desired airport, it could not obtain any slots (1,302 requests) there for the coming summer. Instead, its new transatlantic flights will serve Gatwick and Stansted. Other long-haul carriers with a 0% success rate included China Airlines (310 requests) and Canadian hybrid carrier WestJet (1,680 requests).

JetBlue A320 take-off
JetBlue is cutting summer capacity by 8-10% to address staff shortages and scheduling problems that are disrupting holiday traffic. Photo: Getty Images

At first, LOT Polish Airlines appears to have lost out, having only obtained 50% of its requested slots (1,300/2,602) for the next financial year. However, 1,300 represents the same amount of slots that it had last year. As such, it could be the case that airlines apply for more than they need as a contingency measure.

A curious example to end on is Uzbekistan Airways. This carrier obtained all of the 124 slots that it requested for the coming financial year. However, all 124 of these were more than two hours outside the carrier's requested times! Overall, it seems that, in the slot allocation business, one certainly has to be willing to compromise.