With the move to the new Al-Makhtoum International Airport still far in the future, Dubai International is struggling to accommodate the escalating amount of traffic. The goal of allowing unlimited growth is at risk.

The airport has just opened what is now called Concourse A, a 20-gate facility to be exclusively used by Emirates. That will take the airport's capacity to 75 million passengers annually. In addition, initial work has been started for Concourse D, another large terminal which will bring the airport's capacity to around 90 million passengers. While these numbers look impressive, it is already clear that the Emirates home base will reach the limit of its envisioned design capacity well before 2020. And another issue needs urgent attention: Terminals may be relatively easy to add, but runways present a far more convoluted and difficult challenge.

Dubai International was used by 57 million passengers in 2012, and operator Dubai Airports expects this number to rise to 66 million this year.

The airport has two parallel runways, which are staggered somewhat, but cannot be used independently. The field is currently at a maximum capacity of 65 movements per hour—about half of what Paris and Frankfurt can handle. But with Dubai's traffic being predominantly widebody operations and the average aircraft size much larger, the airport can take the same number of passengers with much fewer movements. Emirates does not operate narrowbodies, although low-fare airline FlyDubai is rapidly increasing its Boeing 737 fleet.

On the other hand, the share of Airbus A380 traffic is growing significantly. Emirates currently has a fleet of 31 A380s, but an additional 59 are yet to be delivered. And Emirates President Tim Clark has made it clear that he sees markets for around 30 more, provided the home airport can find ways to accommodate them. The additional spacing between A380s and other aircraft could be a further burden to runway capacity.

According to a July 2008 State Letter, the International Civil Aviation Organization (ICAO) recommends 2 mi. of additional spacing for aircraft that follow A380s. For jets falling into the heavy category that would lead to a separation of 6 mi., however Dubai already assumes 5 mi. to get to the current design maximum.

“Our aim is to go above 65 movements,” Dubai Airports CEO Paul Griffiths tells Aviation Week. But whether and when that is achievable depends on a number of factors. Because of the airport's layout, parallel approaches and takeoffs are not possible, although Griffiths is hoping that sequenced parallel operations will soon become feasible.

This would require reduced separation standards that are not yet approved. The airport has launched a “big exercise to gather data” about what separation can be achievable and hopes to also be able to introduce the ground based augmentation system to allow more precise navigation close to the airport. Griffiths says Dubai Airports plans to present ICAO with “a view of what makes sense.” He stresses that there is a huge incentive to achieve closer separations because of the high density of A380 operations.

Airbus says it is already working with Eurocontrol as part of the Single European Sky ATM Research Program (Sesar) to re-categorize wake-turbulence separation minimums and believes this could lead to reduced separation behind A380s. The manufacturer conducted its last wake vortex data collection campaign in 2010.

Dubai International has to handle three concentrated peaks daily—between midnight and 2 a.m.; 8-10 a.m.; and noon-2.30 p.m.—which is when Emirates connects most of its flights. Airport capacity has been strained even further by the advent of low-fare carrier FlyDubai operating out of Terminal 2. There has been talk about moving FlyDubai to al-Makhtoum International, the first stage of which is already operational. But Griffiths says this does not provide an overall solution,” although it would give Emirates approximately 18 months of additional growth.

Emirates, which is vehemently opposed to splitting its hub, does not plan to move to the new airport until the facility can accommodate the entire operation. Strategically, the city's airport challenge is therefore becoming bigger everyday: The old airport needs to expand further and the new one has to be expanded in parallel—with no adequate use in the interim—before the big switch can be made sometime in the next decade. It is also hard to justify the billions in further investment at Dubai International for only a relatively short period of time.

One option would be to add a third runway at Dubai International, which would allow the airport more growth over an extended period and enable it to better amortize the huge investment. But where could it be placed? The field is surrounded by residential areas and business districts; the old town center of Deira is nearby. The only viable location is toward the northeast on the other side of the Emirates Engineering hangars. But even there, massive relocations would be needed and, Griffiths says, it is not a very likely option.