The parking stands and runways outside Berlin's new Brandenburg Airport came alive to the sound of jet engines last week. The discovery of an unexploded World War II bomb at nearby Tegel Airport caused chaos, and aircraft diverted to Schönefeld Airport, the site of the new Brandenburg.

Yet in a recent announcement, officials conceded the new airport is now likely to have a late-2019 opening date.

The diverted aircraft sent to Schönefeld used the new runway and some of the parking areas at Brandenburg, but passengers were bussed or flown out once the crisis was averted, with Brandenburg's spotless concourses and jetways remaining unused.

The iconic new airport, which is set to replace all three Berlin airports (one of which, Tempelhof, has already closed), was originally slated to open in November 2011. However, problems with fire safety in the new building discovered at the last minute delayed the opening and set in motion a seemingly endless stream of issues with the quality of the construction, and the contractors put in place to complete it. It led to a corruption trial and many PR disasters.

Now, the present construction company has apparently signed a binding deal to have the work completed by November 2018. This will be followed by months of testing and rectification of any issues before the first passengers are allowed to board any aircraft from the facility.

With the years of delays, experts have led endless speculation over whether it is the right move to completely close the other Berlin airports. Granted, Schönefeld is on the same site, and it makes sense to close the older terminal. Yet Tegel Airport offers an alternative gateway and a chance to cope with any future growth in demand, or to offer an alternative model to airlines.

This is much in the same way as offered in Bangkok, where the modern Suvarnabhumi airport replaced the older Don Mueang, which was in turn reactivated and has become a thriving low-cost alternative. Don Mueang is once again expanding.

However, with the financial woes of local airline Air Berlin revealed last month and its post-bankruptcy future uncertain, the landscape of air travel in Berlin is likely to experience a period of change.

Despite serving Germany's capital, Berlin's airports are only modest facilities on the world stage. The much bigger hub airports at Frankfurt and Munich are far busier, with Berlin unlikely to change in the near term.

Nevertheless, Engelbert Lütke Daldrup, the boss of the new airport, is already planning its expansion. His "Masterplan 2040" sets out modular growth that will take capacity of the airport up to 58 million passengers per year by 2040 through the construction of additional terminals, passenger amenities and ground transportation options.

Considering work began on the new airport 11 years ago — and some have suggested it may never open this plan is being taken with a grain of salt.