Boeing is in crisis. Airbus is struggling to power ahead.

The plane maker had just smashed its record for annual orders, airlines were still clamoring for more jets and production was ramping up. The company’s only significant rival, Boeing, had been flung into a fresh and escalating crisis after a door-size panel blew off the side of a 737 midflight.

Since then, Airbus has been dogged by delays, prompting the company to cut its annual delivery guidance and defer a long-heralded production target. Orders during the first half of the year were less than a third of the intake in the same period of 2023, and the company’s stock is now down more than 20% since it hit a record high in March.

It is a frustrating change in fortunes for the world’s biggest jet manufacturer, which was confident it could capitalize this year on a postpandemic surge in demand. Instead, Airbus is mired in supply-chain issues.

“I thought we were going to be in a better place," Scherer, a company lifer who for years has been focused on ramping up production, said in an interview. “There’s the whole future to prepare, but now there’s also the present to manage much more than we thought."

Airbus said late last month that it had been blindsided by some of the new delays, which span engines, landing gear, seats and toilets, all of which were holding back production. These components are meant to arrive just in time for the company to install on newly built jets, limiting its ability to react to last-minute snags.

Separately, on Friday, a 14-year-old plane made by Airbus’s joint venture with Italy’s Leonardo fell from the sky in Brazil, killing all 62 on board. Officials are investigating the cause of the crash. Aviation experts have pointed to the possibility of ice buildup on the plane’s wings.

The company’s challenges come as Boeing is working to get past its struggles with the start of Kelly Ortberg, a new chief executive. Ortberg is well-versed on the aerospace supply chain, having spent much of his career running the predecessor to RTX, one of Boeing and Airbus’s biggest suppliers.

“Boeing will never be a weaker competitor than it was at the beginning of this year," said Sash Tusa, an analyst at Agency Partners.

The next few years could be critical to how the balance of power between Boeing and Airbus might shift as the industry looks toward a new generation of aircraft programs, which typically cost billions of dollars to develop. Airbus, which is sitting on close to $9 billion in cash, has a big head start, with Boeing’s total debt reaching nearly $58 billion in its latest update.

Project Lead

Much of the aviation industry is being hindered by delays, with airlines complaining of monthslong waits for aircraft from Airbus and Boeing. The plane makers and their suppliers have been contending with the loss of swaths of seasoned workers who left during the pandemic and who they have had to replace with new, inexperienced recruits.

“You need to train those people, you need to retrain them, you need to double check their work. It’s just extra effort," Scherer said. At Airbus, the level of seniority required for an employee to sign off on work has been increased to mitigate risk.

The European plane maker has launched an internal program called Project Lead to focus teams on the supply-chain challenges and cut out some of its own smaller side projects that might distract from the core goal of boosting production.

Airbus has also increased the number of staffers it has working at its biggest suppliers’ manufacturing sites to help navigate bottlenecks and track progress, including at Safran of France, Honeywell, Pratt & Whitney and CFM International. CFM is a joint venture between Safran and GE Aerospace.

While the so-called joint improvement plan teams don’t necessarily mean Airbus will get the parts it needs on time, the company says it is helping to boost transparency and cooperation.

Scherer said he doesn’t know how long it will take for the industry to get over these latest delays. Airbus has indicated it might not get all the parts the company needs to meet end-of-year targets.

“This is an issue that will be prolonged—three years, four years, five years, maybe 10 years, I don’t know," said József Váradi, CEO of Wizz Air, an all-Airbus operator that had aimed to double its fleet to 500 aircraft by 2030. It now expects to reach that milestone in 2032.

Váradi said he expects to receive compensation from Airbus for each delayed aircraft.

‘We’ve been preaching’

Airbus’s supply-chain struggles are frustrating for Scherer, who joined the company in 1984 and previously led its sales team as chief commercial officer for five years.

Scherer had spent much of the pandemic trying to persuade Airbus’s biggest suppliers that they needed to be ready for an inevitable scramble for aircraft when passengers returned to the skies. They didn’t heed his warning, he said.

“I’m disappointed," Scherer said. “We’ve been preaching out there, saying ‘Guys, here is the curve.’ That some of the large, sophisticated players who have their hands on the pulse of this industry would question that is disappointing."

As Covid-19 decimated air travel, Airbus pushed airlines to take aircraft they didn’t want so it could keep production ticking along at a high-enough rate that it would be able to quickly bounce back once demand recovered.

In 2021, Airbus announced plans to return production of the A320neo, its bestselling rival to Boeing’s 737 MAX, to prepandemic levels in 2023, and move to a rate of 75 a month by 2025. That production rate would be the highest ever for a commercial airliner, and help supercharge the company’s market share lead over its U.S. rival.

In January this year, Airbus said its backlog had surged to a record 8,598 aircraft in 2023 and that its A320 was sold out until early into the next decade. The company has said it turned some customers away because of the lack of availability.

Before this year, Airbus had struggled to work through orders as rapidly as it wanted, partly because of its own manufacturing challenges. At the start of 2024, the company was confident its production was on a firmer footing, until sidetracked by the recent supply issues.

In June, Airbus deferred for a second time to the 75-a-month target, with the company now expecting to reach that rate in 2027. It also cut back its goal for this year from about 800 aircraft deliveries to 770. That number compares with 735 delivered in 2023.

“Our trajectory is ambitious," Scherer said. “We’re on it, but our supply chain is not. We’ve got to whip the supply chain into shape."

Write to Benjamin Katz at ben.katz@wsj.com