Delta to take up London Heathrow slots for Boston and Miami. Pretty aggressive route development


The grant of anti-trust immunity across the Atlantic for the oneworld group,stipulated that the alliance must surrender slots from Heathrow to both Boston and Miami. At the time there was speculation about who might claim these slots and commence operations. The answer is now known: Delta, using them to improve service to Boston and Miami. This move bears the stamp of a large, confident carrier. But is is good strategy?

The SkyTeam alliance's US anchor, Delta,  has announced that as of Summer 2011 it will inaugurate two daily roundtrips between LHR and Boston and a daily operation to/from Miami according to the following schedules:




DL 270

BOS   1900

LHR   0645+1

DL 271

LHR   1030

BOS   1325

DL 144

BOS   2150

LHR   0935+1

DL 145

LHR   1330

BOS   1625

DL 260

MIA   1730

LHR   0730+1

DL 261

LHR   1020

MIA   1525

Boston, perhaps unexpectedly, is a major city of the US northeast that has no dominant alliance carrier. JetBlue is a powerful force in the domestic market and has recently entered into a codesharing relationship with American, a oneworld affiliate that was looking to expand its reach without expanding its presence. As a consequence, it has increased its feed at the airport.

Miami, meanwhile, is truly an American fortress hub, supplying most of the domestic and International lift in South Florida. Members of other alliances bring little to the party in Miami.

No shortage of lift, but not so much SkyTeam (or Star)

Both Boston and Miami also already have considerable service to London, as demonstrated by the following chart.

At Boston, flights are dominated by the oneworld group and operate from early morning until late evening.

Boston and Miami-LHR daily schedules







BA 238

BOS   0815

LHR   1940

BA 213

LHR   1125

BOS   1330


BOS   0905

LHR   2045

AA 109

LHR   1135

BOS   1405

BA 212

BOS   1800

LHR   0515+1

VS 11

LHR   1505

BOS   1735

AA 108

BOS   1915

LHR   0650+1

AA 125

LHR   1515

BOS   1810

VS  12

BOS   1945

LHR   0720+1

BA 215

LHR   1625

BOS   1835

BA 214

BOS   2130

LHR   0845+1

AA 155

LHR   1805

BOS   2055

AA 124

BOS   2200

LHR   0935+1

BA 239

LHR   1930

BOS   2145

AA 56

MIA   1705

LHR   0635+1

AA 113

LHR   0820

MIA   1250

BA 206

MIA   1715

LHR   0635+1

BA 207

LHR   0940

MIA   1350

AA 182

MIA   1855

LHR   0825+1

AA 57

LHR   0955

MIA   1430

VS 6

MIA   1925

LHR   0905+1

VS 5

LHR   1115

MIA   1545

BA 208

MIA   2045

LHR   1000+1

BA 209

LHR   1340

MIA   1750

The same carrier grouping is present at Miami, as well as oneworld’s Iberia with its links (along with American’s) to Madrid. So not only does American dominate Miami, but regular travellers also have strong incentives and ties to that alliance’s loyalty programs.

How do Boston and Miami fit into Delta's strategy?

This raises the question of how Delta hopes to find traffic for these new operations. Clearly Heathrow, as BA’s primary base, provides a vast array of connecting flights to both oneworld carriers, British Airways and American Airlines, at the airport.

The same is however not true for Delta, whose European partners essentially connect London to their own hubs. With Air France-KLM as its major partners, it is improbable that a Paris-Miami or Amsterdam-Miami passenger would travel via LHR, given the availability of nonstop services between those cities.

So perhaps Delta is looking to the US cities for feed and de-feed traffic. Unfortunately, that, too, looks an unlikely gamble - as shown by the next table, which lists nonstop Delta services from Boston and Miami.

Delta domestic nonstop services from Boston and Miami

Boston to

Miami to

















New York






Salt Lake


The cities shown in bold already have nonstop links to London, many supplied by Delta.

And, especially for those Delta services to/from Boston, there already exist multiple connections between those points and/or Atlanta and Detroit so that through service on Delta is already available.

From Miami the choice is even more limited, as Delta flies only to its own hub cities, except for Salt Lake City which has only one-stop service.

Justifying the new capacity - with transfer traffic unlikely

In brief, this is hardly a banquet waiting to be served to travellers. The corporate press release is interestingly worded and is not fully supported by reality;

“As Florida's largest carrier offering international service, and the second-largest carrier in Miami, Delta and its SkyTeam partners are well-positioned to enhance competition between Miami and Heathrow. If approved, Delta would operate one daily flight on the route using Boeing 767-300 aircraft.”

While interpretations may vary, it is difficult to parse the claim that the airline is “Florida’s largest carrier offering international service” since this will be the carrier's first direct international venture from the state. Perhaps the meaning is that, as the nation’s largest carrier and offering international service (albeit from elsewhere), such a statement reflects reality.

The second point, about being the second largest in Miami, is true. However, the difference in seat offer between first and second place is significant: American Airlines supplies nearly 75% of the airport’s seats; Delta’s share is less than 10%. And all of that 10% goes to other Delta hub cities.

An even more intriguing statement in the Delta press release is the following:

Boston is one of the largest markets between the U.S. and Heathrow, with more than 270,000 passengers annually. The route is popular with business travellers in the financial services and technology industries.”

This is undoubtedly true, but a quick look at existing capacity on the two routes follows.

The first chart depicts the configurations of the aircraft operating the routes, and the second breaks that into availability as of Summer 2010 - without Delta. (Note that some aircraft operate in multiple configurations, but those variations are minimal.)

Operating carrier seating configurations between LHR and the US

DL B763


BA B777


BA B747


VS 747


AA 777


AA 763


AA 757


Summer 2010 schedule, Boston and Miami-LHR




7 x B763


14 x B757


14 x B747


7 x B777


7 x B747

Total weekly





8 x B777


14 x B747


7 x B747

Total weekly


The addition of all those seats likely to provoke wide discounting

Totaling those figures for Boston and multiplying the sum by 52 weeks yields a present total seat offer of over 668,000 seats per year. The Delta 270,000 figure is not obviously substantiated, but probably represents O&D traffic.

As the airport is a transit point for many passengers, the overall traffic is enhanced. Nonetheless, the market already supplies nearly 400,000 seats in excess of O&D demand, making its difficult to understand the need for an additional 78,000+ seats generated by the Delta aircraft.

In an aviation marketplace fraught with difficulty and, in the US, contraction, it is always good to see carriers taking bold initiatives in the face of adversity. This move however, challenges not only logic but also loyalty patterns and raw numbers as well. But in this case, just how additional traffic, independent of existing loyalties and travel patterns, will be generated without massive discounting is unclear at best.

Or is it just the foot in the door to a wider argument....

Perhaps however Delta is considering the operations as a way to capture the available slots, with an eye to subsequently appealing for a change of routing sometime in the future.

If this slot surrender solution, mandated as a condition for oneworld’s ATI approval can be shown to be unworkable, Delta may then argue that, in a market dominated by alliances, it is the viability of networks - rather than individual destinations - that creates true competition.

This might then lead to the argument that the intent of the slot release might be more effectively achieved if the slots were transferable and used to bolster an existing, competing alliance system, rather than just transferred within existing service patterns.

So, for yet another indeterminable period, Heathrow will remain a focus of transatlantic travel and upheaval. The attempt by Delta either to gain traction at these gateways, or repurpose the slots, would in any event create waves.

But, if, as some of the carrier's competitors argue, it is another example of the gorilla approach to route development, it could, in the absence of continued solid trans-Atlantic growth, be simply another avenue for diluting the yields of an already highly competitive market.

Want More Analysis Like This?

CAPA Membership provides access to all news and analysis on the site, along with access to many areas of our comprehensive databases and toolsets.
Find Out More