“This is not just an airport. It’s a monument to victory,” is how posters around the terminal describe Istanbul’s colossal new airport.

That remains to be seen. After starting on Friday, Turkish Airlines will have a 45-hour window to complete one of the most complex logistical projects in history, as it switches its entire operation to the new Istanbul airport from its existing hub at Atatürk international airport.

Planners are calling this weekend move “the Big Bang”: a total of 10,000 pieces of equipment, from planes to huge aircraft-towing vehicles to fragile security sensors, will be moved from Atatürk to the new airport’s location, 30km north on the Black Sea. In just two days’ time, all Turkish Airlines flights will be expected to arrive and depart from the new site.

Facebook Twitter Pinterest When finished in 2027, Istanbul’s new airport will have six runways and four terminals capable of accommodating 200 million passengers a year. Photograph: Istanbul new airport/www.igairport.com

The stakes could not be higher. President Recep Tayyip Erdoğan’s 16 years in office have been characterised by his fondness for infrastructure megaprojects: new highways, mosques, ports and bridges – built to showcase the greatness of both Turkey and the president himself – have transformed the country. Though supposedly the engine of the economy, these projects are often finished at enormous cost to the taxpayer.

Erdoğan calls them his “crazy projects” and the new airport might be the biggest and craziest of all. When completed in 2027 at a projected cost of £6bn, it should be the busiest airport in the world by a large margin: six runways and four terminals will be able to accommodate 200 million passengers a year, dwarfing Turkey’s aviation hub rivals in the Gulf.

The project has long frustrated Istanbullus, however, who accept that the existing airport is at capacity but fear the new one’s spiralling costs are helping to bankrupt a country already on the brink of financial collapse.

It comes at a fraught time for Erdoğan, too. At the same time that the grandest of his projects is supposed to open its doors, last week voters for the first time looked to have rejected Erdoğan’s Justice and Development party (AKP) in local elections, putting the president on the back foot in the city where he grew up and where as mayor he became a political star. The ruling party is appealing the result of the Istanbul poll, delaying the official outcome.

The opening date has been pushed back three times, but authorities insist that the main terminal building and two runways will be fully operational by Sunday, in what critics say it is a rushed and dangerous attempt to stay on schedule.

Originally, every airline at Atatürk was supposed to move this weekend, but authorities eventually decided to limit it to Turkish Airlines, the country’s national carrier, when the daunting scale of the operation became clear. The timetable for the other airlines to move is unknown, as is the date for the closure of the old airport, located on a prime piece of real estate that has been earmarked for a “people’s garden” and luxury retail and housing developments.

The mammoth switchover is just the first of many challenges facing the new airport. A handful of routes already operate there, but several flights have been suspended or cancelled. Reports say cargo and catering services hangars are not finished. The airport has been built at 60 metres above sea level, rather than the recommended 105 metres, in what detractors say was an attempt to save time and money.

Facebook Twitter Pinterest ‘I am afraid it is going to be chaos,’ said a former Turkish Airlines pilot of the move. Photograph: Anadolu Agency/Getty Images

At least 27 deaths during construction have been reported since 2015. Work was briefly halted at one point due to protests over unpaid wages, and accommodation with bedbugs.

“The pressure to open on time sped up the work and caused a lapse in control and security measures,” said Özgür Karabulut, the head of a workers’ union active at the site.

“An electric mains board exploded, and many people fell from heights during high winds we shouldn’t have been working in.”

Neither Turkish Airlines nor IGA, the consortium building and operating Istanbul Airport, responded to requests for comment.

Aside from the hurry to open its doors, many of the new airport’s problems can be attributed to an original sin: its location, on a wetland by the Black Sea.

Ever since the project’s inception in 2009, aviation experts have insisted that the unstable ground, the local bird population and the Black Sea’s changeable weather – including strong winds and fog – pose a safety threat to air traffic.

“I am afraid it is going to be chaos,” said a former Turkish Airlines pilot, on condition of anonymity. “There’s no one with previous experience landing there. Every pilot is going to be learning the winds for the first time.

“The logic was: ‘We are going to build a new airport in this location’, rather than ‘Where should we build a new airport?’”

Turkish Airlines has expanded rapidly in the last decade, helped by Istanbul’s location at the crossroads of Europe, Africa and the Middle East, which allows it to fly shorter-haul and more fuel-efficient planes than other carriers. But its success has stretched Atatürk to capacity, and there is no room to build more runways.

The new Istanbul airport, together with a third bridge across the Bosphorus completed in 2016 (substantially over budget) and ambitious plans for an Istanbul canal to rival those in Panama and Suez, are supposed to kickstart development north of the existing city, which is already home to at least 15 million people.

Facebook Twitter Pinterest A Turkish Airlines plane touches down on Friday morning at the as yet unfinished Istanbul airport. Photograph: Anadolu Agency/Getty Images

The cost so far has included 1.5m trees, as vast swathes of the region’s northern Bosphorus forest are cut down to make way for the new projects without proper environmental impact research, said Aisha Yikici, an urban planner who is part of a campaign to protect the forest.

“The northern forest is essential for giving Istanbul clear air and water, and of course is home to a lot of wildlife,” she said. “There will be new thermal and carbon dioxide emissions. None of that has been accounted for. It’s the same story with so many of these big projects.”

As with all of Turkey’s controversial megaprojects, the new airport is driven by the promise of profits generated through public-private partnerships. But government tenders have largely been given to a group of five companies whose foreign currency debt is spiralling thanks to the lira crash last year.

How Turkey’s lira crisis was written in Istanbul's skyline Read more

Loans of at least £13.4bn to the consortium have been guaranteed by state banks, creating what Bahadır Özgür, an economist, described as a “black hole” in state finances – particularly worrying given that Turkey officially entered a recession in February.

Projections are based on initially 150 million and then 200 million passengers a year, even though Istanbul has another airport (the smaller Sabiha Gökçen) and despite the fact that Turkish Airlines’ passenger count has dropped by 10% since the lira crash, making it unlikely that the estimates will soon be met.

“Regardless of all the other issues, the math just doesn’t add up,” Bahadır Özgür said. “This airport is a perfect symbol of modern Turkey.”

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