Airlines are being warned to take extra care before reactivating mothballed planes, which have been gathering dust during the COVID-19 pandemic, according to a report.
Regulators, insurers and experts cite a variety of possible problems — ranging from pilot rustiness, maintenance errors and even insects blocking vital sensors – that could pose a challenge to getting the planes back to the skies, Reuters reported.
At one point during the global outbreak, which has decimated the airline industry, two-thirds of the global fleet was grounded as coronavirus lockdowns canceled air travel, according to the outlet.
And when airlines gradually resumed service, the number of “unstabilized” approaches – during which a pilot does not maintain a constant glidepath to the runway – rose sharply, the International Air Transport Association said.
Such approaches, involving an incorrect speed, descent rate or flight path, may result in hard landings, runway overshoots or even crashes.
Gary Moran, head of Asia aviation at insurance broker Aon PLC, told Reuters that insurers are questioning airlines about whether they are providing pilots with extra training to focus on their landings.
“They want to know about the circumstances of the training,” he said.
According to plane maker Airbus, the largest category of fatal accidents can be traced back to an approach, while the largest number of non-fatal incidents happen during landings.
In May, 97 people were killed when a Pakistan International Airlines plane crashed after an unstabilized approach. Three months later, 18 people died in an Air India Express crash after a similar approach.
Meanwhile, the European Union Aviation Safety Agency also has reported an “alarming trend” in the number of reports of unreliable airspeed and altitude readings during the first flight after a plane leaves storage.
In most cases, the problem was traced back to undetected insect nests inside pitot tubes, pressure-sensitive sensors on the fuselage that provide key data to an avionics computer, Reuters reported.
In June, the pilot of a Wizz Air jet with no passengers were on board aborted the take-off after noticing that the airspeed was reading zero.
The plane, which had been parked for 12 weeks, was found to have insect larvae buried in one of the pitot tubes, the UK’s Air Accidents Investigation Branch said last month.
Kate Seaton, an aerospace partner at the HFW law form, told Reuters that flight crews must be aware of possible defects that might not have been identified properly as planes return to service.
“We are in new territory — the industry must take steps to mitigate the risks but need to be prepared for the unexpected,” she told the news agency.
Last month, the European Union Aviation Safety Agency said that issues found after extended parking included an engine shutdown in flight after technical problems, fuel contamination, reduced parking brake pressure and emergency batteries losing their charge.
“We’ve got people returning to work who are quite rusty, which is a big issue,” Moran said.
Carriers have developed training programs for pilots re-entering service ranging from refresher courses to simulator sessions and supervised in-flight checks, depending on how long they were grounded.
Cockpit crews also need to make an honest assessment of their skills and confidence upon resuming work, International Federation of Air Line Pilots’ Associations rep Peter Meiresonne said.
They may need to turn down offers like shorter landing approaches from air-traffic controllers if they do not feel ready, he said during a recent webinar.
“Maybe now is a good time to say, ‘We are not able today’ or ‘Give us a six- or 10-mile lineup rather than a four-mile lineup’, which you might accept when you are more proficient and (flight experience is) more recent,” he said.