The walkout is a severe blow to Boeing and an embarrassment for Mr Ortberg, who had made a last-ditch plea to workers before the vote, warning that a strike would put the company’s “recovery in jeopardy”.

The question now is how long it will go on for. Boeing seems ready to get back to the table.

But there is an obvious breakdown in trust between management and the workforce – and equally between the workforce and the union leadership, who had said this was the best contract it had ever negotiated and had urged members to accept the deal.

As well as a 25% pay rise over four years, the preliminary agreement that workers rejected included a commitment from Boeing to build its next commercial plane in the Seattle area if the project started during the lifetime of the contract.

The union had initially targeted a number of improvements to workers’ packages, including a 40% pay rise.

Mr West said it was clear there had been a “disconnect” and that Mr Ortberg was “personally” involved with finding a compromise.

On the face of it, it is hard to see a quick solution unless Boeing capitulates.

Analysts say an extended shutdown could cost the company and its suppliers billions.

On Friday, shares in the firm fell as Moody’s warned that the situation could lead to a downgrade of Boeing’s credit rating, an action that would make it more expensive for the firm to borrow.

The current contract between Boeing and the unions was reached in 2008 after an eight-week strike.

That walkout cost the company about $1.5bn (£1.14bn) a month, according to credit rating agency Moody’s.

In 2014, the two sides agreed to extend the deal, which expired at midnight on Thursday.

“It’s never a good time for a strike, at least from the perspective of management, the current situation makes it even more problematic,” said Greg Waldron, Asia Managing Editor at aviation news website FlightGlobal.

“Still, a great deal will depend on how long the strike lasts. Airline CEOs with 737 Maxes on order will be watching this closely,” Mr Waldron added.