The shortage of aircraft-parts threatens further disruption to air travel

The resurgence in air travel has also threatened aircraft manufacturers and their supply chains, preventing automakers from ramping up production quickly, not only for new aircraft but also for reconditioned aircraft.

Supply chain bottlenecks that have delayed everything from car production to furniture deliveries during the pandemic now collide with renewed demand for flights. As a result, airlines are scrambling to find replacement parts to keep planes in the air, which industry officials say has sometimes led to delays, cancellations and groundings.

“It’s becoming increasingly difficult for us to get our hands on the parts,” said Steve Ross, CEO of Florida-based Silver Airways LLC, which flies primarily to Caribbean destinations.

Mr. Rossum said one or two of the airline’s roughly 20 planes were grounded on any given day because of air-conditioning-related issues. One plane was grounded for more than a week with a broken axle because special equipment was difficult to find, he said.

German airline Deutsche Lufthansa AG

Some aircraft were forced to stop because the source was taking too long to find. While the airline team was previously able to find missing items from Europe, it had to expand its search for parts around the world, particularly rare items such as panels on the interior of the cabin, one of the people said.

Qatar Airways is taking the unusual and expensive step of keeping its planes on standby, including one of its eight Airbus A380 superjumbos, to avoid disruption if planes cannot fly due to a lack of parts, Chief Executive Akbar Al Baker said.

The airline is battling long turnaround times at engine repair shops due to labor shortages, the executive said, adding that Qatar Airways is operating aircraft a few hours a day to limit the impact of maintenance delays and avoid disruptions seen in the industry. And especially in Europe.

“It’s very difficult,” said Mr. Al Baker. “I have issues in the cabin, I have issues with the avionics,” he added.

Airlines are also operating with low inventory. Geoff Murray, a partner at the Chicago-based consulting firm Oliver Wyman, said that in the wake of the airline pandemic, carriers have found a variety of assets to sell to raise cash, including their spare parts warehouses.

Parts shortages are increasing the time it takes to move aircraft through critical maintenance checks. For some engine types, upgrades that normally take 60 days can take up to 100 days. On airframes, critical maintenance checks are now about seven weeks instead of four, Oliver Wyman said.

Competition for space at repair shops is intensifying as airlines return aircraft to service after the outbreak, with long wait times. Some carriers are taking parts from grounded planes to keep others from flying, people familiar with the matter said, in part to avoid maintenance delays.

Engines are a big bottleneck. Engine makers such as CFM International, a joint venture between General Electric Co.

and saffron SA,

According to people familiar with the matter, deliveries of the new engines have been delayed by about two months, with Pratt & Whitney and Rolls-Royce Holdings Plc, company officials said.

CFM said it is working with its suppliers to expedite engine deliveries to aircraft makers. Rolls-Royce said it is working with its customers to support their operations. A spokesman for Pratt & Whitney’s parents quoted Raytheon Technologies Corp. CEO Greg Hayes as saying the company is managing the delays and that engine supplies will increase significantly later this year.

Guillaume Faury, chief executive of Airbus SE, said: “There are spare parts shortages, including engines, that are impacting our customers’ ability to operate efficiently,” adding that there is no immediate solution to the problem. “It’s going to take time,” he said.

In addition to airline operations such as Lufthansa, Airbus has about 30 “gliders,” the industry term for newly manufactured planes without engines, the European plane maker said. The company on Wednesday cut its shipment guidance for this year and delayed its ramp-up plan as suppliers struggled to supply enough components to meet targets.

GEE CEO Larry Culp said the engine maker is working to keep its airlines up and running amid the severe downturn and sudden recovery caused by the pandemic. “In any manufacturing business, it’s a lot of adjustment in both directions in a relatively short period of time,” he said.

Russia’s invasion of Ukraine has also contributed to the anxiety. For example, the part used to cool hot engine air, called a heat exchanger, is becoming harder to find, industry officials said. Airlines, in some cases, extend the life of spare parts by repairing them instead of replacing them, he said.

Collins Aerospace, which makes heat exchangers for some aircraft, used to rely on Russia but is now shifting production to the US and UK, said Rayton, a spokesman for the parent company. The manufacturer said he expects normal production levels to return next year.

Boeing Co.

Stan Dale, the planemaker’s chief commercial officer, said customers of the planemaker’s airline have so far seen little disruption, with a significant number of planes out of service due to a shortage of parts. “That’s why our caution—for both Airbus and Boeing—[with] The supply chain is now critical to help the industry recover,” Mr Dell said at a news conference in London earlier this month.

Delta Air Lines Inc.,

The Atlanta-based carrier has not experienced significant disruption due to the shortage and is working with manufacturers to increase parts flow, Chief Financial Officer Daniel Jankey said on a call with analysts this month. “But it’s day by day,” he added.

— Alison Sider contributed to this article.

Write Andrew Tangel at Andrew.Tangel@wsj.com and Benjamin Katz at ben.katz@wsj.com