The Paris Air Show opened on Monday with last-minute negotiations over aircraft orders and supply chain headaches vying for attention with rows of missiles, drones and futuristic transports.

The largest air show in the world, which alternates with the British one in Farnborough, is held in Le Bourget for the first time in four years after the 2021 edition fell victim to the pandemic.

French President Emmanuel Macron has flown by helicopter to the crowded aerospace bazaar and witnessed a flight demonstration that included Airbus’ latest jet development, the A321XLR, and air power, including the French Rafale fighter.

Later, the flight of the American F-35 fighter is scheduled.

Belgium announced its intention to participate as an observer in the Franco-German-Spanish FCAS fighter project, a possible successor to the Rafale and the multinational Eurofighter, despite differences between the industrial partners on the advisability of expanding the project.

The air show is being held under the shadow of the conflict in Ukraine, with no Russian presence in the chalets and exhibition pavilions, unlike the last event held four years ago.

Some Ukrainian officials and aerospace companies were expected to attend the hall. The French Thales announced a contract with Indonesia for the acquisition of 13 long-range aerial surveillance radars.

On the commercial front, aircraft manufacturers came with expectations of demand growth as airlines scramble to get capacity to meet demand and help meet industry goals of net zero emissions by 2050.

But they also face the challenge of meeting that demand as suppliers battle rising costs, part shortages and a lack of skilled labor in the aftermath of the pandemic.

Barring last-minute unforeseen events, Airbus is expected to announce a record order for 500 narrow-body aircraft from Indian giant IndiGo later this Monday.

Industry executives say that in a resurgent market for commercial aircraft, as many as 2,000 aircraft orders worldwide are at stake, in addition to those already tentatively announced, as airlines try to fill the void left by the sharp drop in price activity during the pandemic.

They said that only a fraction of these potential new deals would be ready in time for this week’s airshow, which could see a mix of new and repeat announcements.

Airbus was going to confirm that Qantas is going to exercise its purchase options on a further nine A220s, as the airline announced earlier this year.

“The year-end order book matters,” said Sash Tusa of Agency Partners.

Airbus is also close to landing a potentially large order for narrow-body jets from low-cost Mexican airline Viva Aerobus, industry sources said on Sunday. The number of plans being discussed was higher than 100, they said, although some sources said the number in the final deal could be set closer to 60.

The Mexican airline has long been a fierce battleground between Boeing and Airbus.