Regulators, insurers and experts are warning airlines to take extra care when reactivating planes left in extended storage during the COVID-19 pandemic, citing potential pilot rustiness, maintenance errors and even insect nests blocking key sensors.

This picture taken on Monday shows a view of the Soviet-built Antonov Airlines Antonov An-225 Mriya strategic airlift cargo aircraft, the world's largest cargo plane, upon landing at Israel's Ben Gurion International Airport in Lod, east of Tel Aviv, Israel. Photo: AFP

The unprecedented number of aircraft grounded as coronavirus lockdowns blocked air travel - at one point reaching two-thirds of the global fleet - has created a spike in the number of reported problems as airlines return them to service.

The number of "unsterilized" or poorly handled approaches has risen sharply in 2020, according to the International Air Transport Association (IATA). Such mishaps can result in hard landings, runway overshoots or even crashes.

Worried by IATA's data, insurers are questioning airlines about whether they are doing extra pilot training to focus on landings, said Gary Moran, head of Asia aviation at insurance broker Aon PLC.

"They want to know about the circumstances of the training," he said.

Approaches and landings place significant demands on crew for which training and regular experience are seen as vital. According to aircraft maker Airbus SE, the largest category of fatal accidents can be traced back to the approach to an airport.
Newspaper headline: As jets return airlines warned over safety