Airlines face at least half of a second summer without the use of the Boeing 737 Max.

An admission last night by the US manufacturer that the troubled new generation aircraft will not return to service before the summer peak will affect carriers in Europe such as Norwegian Air, Ryanair and Tui.

Boeing revealed that the 737 Max, which has been grounded since March following two fatal crashes killing a total of 346 people, would not resume flying until “during mid-2020”.

The disclosure dashed airline hopes that the aircraft would be ready to start operating again ahead of the busy summer period.

Tui’s share price slumped by as much as 6.5% in early morning trading today in response to the news before staging a slight recovery.

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Optimism had previously been raised by Boeing about the 737 Max being ready to resume operations by the end of 2019.

But Boeing announced plans to halt production in December and then confirmed a new software problem had been discovered.

The US manufacturer said its updated guidance on the 737 Max return to service was “informed by our experience to date with the certification process”.

Boeing added:  “It is subject to our ongoing attempts to address known schedule risks and further developments that may arise in connection with the certification process.

“It also accounts for the rigorous scrutiny that regulatory authorities are rightly applying at every step of their review of the 737 Max’s flight control system and the Joint Operations Evaluation Board process which determines pilot training requirements.

“Returning the Max safely to service is our number one priority, and we are confident that will happen.

“We acknowledge and regret the continued difficulties that the grounding of the 737 Max has presented to our customers, our regulators, our suppliers, and the flying public.

“We will provide additional information about our efforts to safely return the 737 Max to service in connection with our quarterly financial disclosures next week.”

Podcast: Is the aviation sector in turmoil? [2019]