Eric M. Johnson and Aishwarya Nair

(Reuters). Despite pointing out that there is strong demand for its most popular models of jets as travel recovers after the pandemic, Air Lease Corp warned Thursday about potential threats to production due to stretched global supply chains.

After reporting a quarter-end loss, the Los Angeles-based leasing company issued these remarks following a $800 million writeoff on jets left behind in Russia due to sanctions.

The global aircraft leasing firms have struggled to reclaim more than 400 Russian jets valued at almost $10 billion. Most of these jets have not been responsive to requests to surrender them.

After posting the results, Air Lease (NYSE) Chief Executive John Plueger stated that he was aggressively seeking insurance coverage. He also believed that there were valid claims.

Steven Udvar Hazy, Chairman of Air Lease, stated that aircraft with Russian customers have been placed at comparable or higher rates with European and American airlines.

Air Lease stated that air travel demand is driving new and used aircraft. This supported higher lease rates, and increased the fleet’s value.

However, they warned that a rising demand in medium-haul planes following a pandemic as well as certification and industrial risks for top aircraftmakers Boeing (NYSE) and Airbus could lead to a possible shortage of jets.

Plueger stated that he believes this to be a probable outcome, which will occur in 2023 or beyond.

Plueger said Boeing faced problems throughout its jet portfolio. He noted that 787 deliveries were frozen and there was delay in certification for the 777X mini-jumbo, 737 MAX 10 and 777X mini jumbo. In addition to shortages in parts and materials, the industry also faces uncertainty due to the conflict in Ukraine.

“Any one of these challenges alone would prove burdensome, but to have all at once is clearly taxing for the organization,” Plueger said.

Plueger’s remarks came just hours after Domhnal Slattery from Avolon Ireland, who said that Boeing “lost their way” at a conference and would need new leadership.

Airbus and Boeing both sell planes to leasing firms to help them stay afloat in times of economic uncertainty that might prevent airlines from buying.

Hazy indicated that Boeing might offer new-built aircraft at a reduced price to those whose delivery was delayed by cancellations or setbacks in certification.

Hazy stated that there may be opportunities to fly brand-new aircraft on the market with existing airlines with which Hazy has a great relationship.

Air Lease posted a net loss of $479.4million, or $4.21 per shares, for the three-months ended March 31. This compares to an $80.2 million profit, or 70c per share, one year ago.

Air Lease reported that its adjusted net earnings before income tax rose 72% to $201 million, excluding the jet write-off.

Quarterly revenue increased 25.7%, to $596.7million