The troubled aerospace giant Boeing says it delivered just 348 aircraft to its customers last year, its lowest output since the pandemic.

Boeing ended the year with a backlog of 5,595 unfilled orders.

Stricter scrutiny of the planemaker’s practices as well as industrial action, have hampered production at what is one of America’s largest manufacturers.

By contrast, its European arch-rival Airbus provided 766 planes.

Boeing said there was “work underway” to improve its culture, and to “restore trust and deliver for our customers”.

The firm’s production was hamstrung in 2024, first by serious concerns over quality control, both in its own facilities and at a key supplier.

Later in the year, a strike by workers in its Washington state heartlands paralysed two of its most important factories.

Together these factors helped bring its output down sharply from the 528 aircraft delivered in 2023.

Boeing’s year began badly. In January 2024, a panel fitted over an unused emergency exit door fell off a brand new 737 Max shortly after take-off.

The incident left a gaping hole in the side of the plane. Investigators later concluded that the panel had not been bolted into place properly.

The affair put quality control standards at Boeing and its primary supplier Spirit Aerosystems under a harsh spotlight.

An audit by the US regulator, the Federal Aviation Administration, found “multiple instances” where both companies had failed to meet required standards.

Boeing had previously been planning to ramp up production of the 737 Max, its bestselling aircraft. Instead, its output was capped by the FAA.

It also faced intense public criticism over its apparent failure to improve safety standards following two previous accidents involving the 737 Max five years ago.

The manufacturer has since faced increased oversight from the regulator, and is in the process of implementing a major safety and quality control improvement plan.

While grappling with the fallout from the January incident, Boeing was also dealing with supply chain problems.

These have been affecting the industry as a whole since the Covid pandemic. Shortages of parts, including engines, slowed output of the 787 Dreamliner and the 777 Freighter.

In September, Boeing suffered another severe blow, when more than 33,000 workers in the US Northwest went on strike.

The dispute, which focused on pay and retirement provisions, was the first major walkout at the company since 2008.

It halted work at Boeing’s major factories in the Seattle region, paralysing production of the 737, the 777 and the 767 freighter.

The strike ended in early November, but disruption continued for several more weeks. The 737 Max production line did not restart until mid-December.

The difficulties Boeing has faced this year have also affected its future plans.

Deliveries of its newest aircraft, the 777X, have been pushed back again from 2025 to 2026, having already faced repeated delays due to problems with the plane and its engines.

The design, a major update of the long-haul 777, was originally scheduled to enter service in 2020.

Boeing’s problems, which have cost the company billions of dollars, have also created headaches for airlines.

Even before the events of the past year, it was struggling to build planes fast enough and the company now has a large backlog of unfulfilled orders.

The 528 aircraft delivered in 2023 fell far short of the pre-Covid era record of 806, set in 2018.

Airbus is in a much healthier position, but still fell narrowly short of production targets last year, as it grappled with its own supply chain issues. Its order backlog now stands at more than 8,600.

With Airbus unable to compensate for Boeing’s shortfall, airlines are struggling to obtain the aircraft they want.

In November, Ryanair’s chief executive Michael O’Leary described delays in getting hold of new aircraft as “a pain in the backside”.

The airline has repeatedly warned that a lack of planes will affect its growth plans, and will limit the number of passengers it can fly this summer.