Russia’s aviation industry has defied predictions it would slowly grind to a halt after western sanctions barred access to vital spare parts and maintenance expertise.

Domestic air travel has rebounded close to levels last seen before the Covid-19 pandemic, triggering concerns among western executives that safety may eventually be put at risk.

Since Russia lifted all pandemic-related travel restrictions in the summer, the number of domestic flights has surged and was up 4 per cent on 2019 levels in October this year, according to data from IBA, the aviation consultancy.

International travel remains far below 2019 levels as most western countries banned Russian airlines from their airspace following its invasion of Ukraine. Travel has continued to certain countries, such as China, Turkey and former Soviet Union states.

The domestic rebound, however, has triggered fears over the long-term safety of the fleet. Airbus and Boeing in March suspended the supply of spare parts and services and removed their regular maintenance support. Engine makers, including Rolls-Royce, also stopped support.

Before the start of the war, the two aerospace groups accounted for 70 per cent of Russia’s commercial fleet of roughly 880 aircraft, according to data from consultancy Cirium.

The market is dominated by western lessors, which had more than 500 planes leased to domestic airlines but that have failed to retrieve most of them.

“We think the Russians have a reasonable pedigree in maintaining aircraft but their problem is going to grow and grow over time,” said an executive at one western lessor.

Guillaume Faury, chief executive of Airbus, told reporters last month: “We are worried about the conditions for maintenance as actually the planes are flying a lot.

“Because of the sanctions, we cannot really monitor and support as we do with our customers in normal times. And that’s something that is indeed creating some concerns on the safety side.”

Phil Seymour, president of IBA, said most western-made aircraft would be able to operate without too much maintenance in the short term, stressing that “Russian authorities would not want planes to fly in an unairworthy condition”. 

“The maintainability of aircraft has improved significantly over the past few years. So long as the physical aircraft is not overdue for a scheduled check, you don’t need to do a lot.”

For those due a “major six-year or 12-year check, then the operator will have a problem. Spare parts, tooling and equipment are all quite specialist,” he added.

Industry executives said that as time runs on, Russian airlines would be forced to either cannibalise parts from some aircraft, source components from other countries or manufacture their own.

The Kremlin’s decision to deregister the western-owned aircraft has complicated the future of the planes.

Under western regulations, each aircraft has its own “maintenance planning document”, akin to a servicing guide that details every modification made and that needs to be kept up to date.

“There is a difference between whether the aircraft can still fly OK and whether it meets international safety standards,” said the leasing executive.

Several lessors have in recent weeks launched legal action to secure billions of dollars from their insurers after failing to retrieve their aircraft from Russia.

IBA’s Seymour said that even if the planes were offered back to their owners, there was a question over whether they would want them.

“These aircraft have now gone out of a ‘controlled’ environment, according to western regulators, and going back to square one is not a simple case.”