
Sleeping beauties: The Covid pandemic has brought global aviation almost to a standstill, which means many airplanes have been taken out of service and stored in arid climates, like the Australian outback.

On the ground: About 31% of the global passenger jet fleet are still in storage, according to the aviation analytics company Cirium.

Removing the covers: When planes have been grounded for some time, getting them ready to fly again means starting with simple things like removing the massive number of blanks -- engine protectors -- and tapes covering every hole, port or probe, explains licensed B1 aircraft engineer Steph Smith.

Potential damage: "There is nothing worse than having systems full of bugs, water or debris because, as aircraft accident investigations have shown over the years, blocked pitot-static systems can be catastrophic," says Smith.

Intense effort: Smith estimates that it takes more than 100 man-hours to make a wide-body aircraft airworthy after storage, and around 40 man-hours for a narrow-body aircraft.

Big aircraft, bigger job: "If you've only had it stored short term you can get them turned around quite quickly because you've been doing the maintenance every couple of weeks to keep them airworthy," explains Smith. "Whereas aircraft in long-term storage can take you a long time, and if you're talking something like an A380, it's going to be a lot of work because it's a big aircraft."

By the book: Engineers complete a series of engine runs in accordance with the aircraft maintenance manual. "These are done to ensure the engines are still performing as expected and that the long-term storage hasn't caused any detrimental effects to any of the systems that wouldn't be obvious just by looking at them," says Smith.

Sign off: Once the maintenance is complete and certified, the engineer signs the aircraft off as airworthy.
"They are the final signature that says: 'I'm happy that everything has been done correctly, I'm now releasing the aircraft to service.' That final signature is what the captain will see to then sign the logbook for the aircraft," says Smith.
"They are the final signature that says: 'I'm happy that everything has been done correctly, I'm now releasing the aircraft to service.' That final signature is what the captain will see to then sign the logbook for the aircraft," says Smith.

Big responsibility: Engineers would be among the first people in the firing line if something happened to an airplane, so it's imperative they perform every check to the letter. "That's the thing about getting an aircraft technician license or an engineer's license -- you really need to appreciate how much that little piece of paper actually means in terms of responsibility," adds Smith.

Slow start: According to Smith, it will take a considerable amount of time to get everything flying again when the pandemic ends. The volume of maintenance work that needs to be done and the number of engineers that have been laid off during the pandemic will both be factors in limiting the speed of return.