From closing thousands of window shades to keeping out tiny insects, the work does not stop for aircraft engineers just because their planes are out of work. The show Grounded uncovers some interesting facts about what is required.
At airports round the world, the bustle of travellers and constant sound of planes taking off have been replaced by silence and perhaps the occasional bird chirping on the runways.
The COVID-19 pandemic has all but decimated commercial passenger flights. And with nowhere to go, thousands of planes are out of work.
But while these planes are grounded, work goes on for the army of engineers whose job it is to keep an eye on the aircraft and make sure they remain in good shape.
As the show Grounded finds out, many things need to be considered: From where to park the planes, to how to keep out birds (and the tiniest of insects) and even what would happen if window shades are not closed. (Watch it here.)
Here are some interesting facts about protecting grounded planes.
Parking Planes At Airports Is Like Solving Jigsaws
Think of where to find planes, and the instinctive response would be the airport. But airlines have run out of the usual space to store them.
“Airports are designed to keep aircraft in constant motion rather than stationary,” said aviation industry expert Simin Ngai from travel data and analytics company Cirium.
For example, there is not enough space for AirAsia, with Malaysia’s biggest fleet, to park all its planes at Kuala Lumpur International Airport 2, said AirAsia aircraft maintenance engineer Yap Sheng Lin. Some must be parked at the cargo terminal.
“In Bangkok, they’re even parked in the taxiways, and some of them are sent to Phuket and Pattaya International Airports,” he added.
Taxiways, which connect runways to terminals, are being used in Singapore too.
“In the history of Changi, the only other time we’ve parked planes on the taxiway was during Sars in 2003,” said Singapore Airlines engineering division quality manager Abel Li.
“But it was only for a short while and for a few aircraft, unlike 2020, when we have more than 90 per cent of our fleet being grounded.”
Finding the space is one challenge, but positioning the planes can be another. Extra precautions must be taken when parking them on the taxiways, said Li, because there is no clearly demarcated location to put the aircraft.
They also need to be kept 25 metres apart so that when the engines are started up, dust or exhaust is not blown onto the aircraft behind.
Like a jigsaw puzzle, fitting planes into a crowded space not meant for parking planes requires a real team effort and co-ordination on the ground, particularly when the wingspan of some planes can be the width of a football field.
The Best Place To Store Planes Is The Desert
Humidity can wreak havoc on grounded planes. The jet fuel planes use, for example, can absorb moisture, resulting in water forming in the fuel tank.
“Water can breed microbes, and these contaminants can cause damage to the fuel tank and to an aircraft, which then impacts safety,” said Li.
This is why the arid desert environment is the best place to store planes. SIA, for example, stores some of its largest planes at Alice Springs Airport, which Ngai described as “one of the key choices in the region”.
“It’s dry, so it’s better for maintaining the equipment,” she said. “By putting it in a more conducive environment for long-term storage, you’re looking at less damage eventually, when the aircraft returns to service.”
One facility in Arizona, Ascent Aviation Services, has seen a 600 per cent increase in its storage business since COVID-19 began. Its president, Dave Querio, said it currently has more than 400 aircraft in storage, from six continents.
Grounded Planes Mean Silica Gel Bags Are In Demand
For planes that remain parked at boarding gates, taxiways and runways, particularly in humid Southeast Asia, the most important part to protect from moisture is the engine, which can cost more than US$25 million (S$34 million) each.
“When the aircraft is on the ground for an extended period, these engines aren’t turned on as frequently as we want,” said Li. Humidity could then corrode the engine’s parts.
This is why SIA, for example, runs each grounded plane’s engine periodically — every month or every three to six months, depending on the aircraft, engine type and the plane’s mode of parking.
“Running the engine burns any water content that’s in the oil,” said Li.
“This is what drives the aircraft, so it’s very important to protect the engine, to make sure it’s rust free, it’s well-oiled … in good condition and safe to fly.”
Between engine runs, other measures are in place to keep engines safe from moisture and rust.
Aircraft engineers use silica gel bags, which Yap described as “the same as those tiny silica gels that we find when we unpack our household items”, but larger. At least 15 packs are needed per plane, he said.
These packs are also needed for the plane’s cabin. With cabin doors closed, humidity can rise, and moisture can cause mildew to damage leather on plane seats, carpets, curtains and the galleys, according to Li.
With so many planes grounded round the world, these bags are in great demand. “Every airline needs this for corrosion prevention, so it’s very hard for us to procure,” said Yap. “We’re working day and night trying to procure (them).”
Even The Tiniest Pest Can Pose A Serious Threat
Even though grounded planes are not in service, the to-do list for maintenance is long. If he were to print out the manual, said Yap, it would “easily run to over a hundred pages”.
Of the many guidelines, one of the key ones is to keep wildlife out of the planes. With airports quieter than ever, planes have become a perfect nesting ground for creatures of all shapes and sizes.
In Bangkok, some AirAsia engineers found a bird’s nest under the wings of one plane, Yap recalled. “We had to safely remove the bird’s nest so that the birds weren’t harmed,” he said.
Besides the wings, engineers must check spaces like the landing gear — and even crawl into them to ensure that no creatures have made a home there.
“You may find birds or maybe small rodents crawling in here, which may damage all these electronics and the hydraulic lines in the aircraft,” said Philippine Airlines senior aircraft technical specialist Manuel Quizon Jr.
Overlooking even the tiniest of pests could prove catastrophic. He pointed to a 1996 plane crash: The pilot had received inaccurate information from one of the plane’s tubes for measuring airspeed — because nest debris from an insect was stuck inside.
So even “the littlest things”, such as small sensors, must be taken care of and covered. “We need to always ensure that these covers are in place and … not blown away by the wind,” said Quizon.
“We have programmes in place to have them inspected on a daily basis.”
There are also numerous other little tasks to be done, such as closing the thousands of window shades on all the planes. This, said Li, blocks sunlight and UV rays, preventing damage to the interior furnishings.
Most SIA planes, he added, have window shades that can be pulled down easily. But the 787 Dreamliner planes used by its subsidiary Scoot uses dimmable windows instead, which work only when the plane is powered up.
“We actually apply black plastic sheets to cover the windows because they don’t have the manual window shades,” said Li. “In this unprecedented situation, we had to be creative and think on our feet to find solutions to these problems.”
The tasks may be simple but also time-consuming. Seat checks, for example, are done every month, said Li. It includes checking every seat’s recline, leg rest, footrest, meal table and the overhead reading lights.
“These are really small things that might seem insignificant, but they’re really important because if you find problems early enough, you can fix them,” he said.
Checking just one plane with 300 seats could take around five hours to complete.
Strapping Cargo Into Passenger Seats Takes Effort
With so many planes grounded, airlines like SIA have transformed some passenger planes to carry cargo instead, which Ngai described as a “good way for them to bring in some revenue and deploy aircraft that are otherwise idle”.
But to make this transformation happen and carry goods not just in the cargo hold, a lot of work must go on behind the scenes.
For example, bubble wrap is placed on passenger seats to protect them, before a plastic covering is applied, Li cited.
“Just like a passenger needs to have his seatbelt fastened … we also want the cargo to be fastened at all times, so we use ropes to strap them in,” he added.
SIA also protects inflight entertainment screens by using pillows with cling wrap, to prevent any damage during the loading of the cargo.
As the pandemic goes on, however, revised travel restrictions have led to some planes being reactivated for passenger service. This means the job of an aircraft engineer is now more complicated.
“We have to do inspections, remove the covers and run the engines, so that everything’s working fine,” said Yap. “The reactivation depends on our aircraft storage duration; we need around one to three weeks to get it back to life.”
But beyond the technical checks, passenger cabins prepped for travel amid a pandemic have to be different from the pre-COVID era.
Philippine Airlines’ cabin crew, for example, have to wear a mob cap, face mask, gloves as well as a personal protective suit. Magazines in seat pockets have been removed, and blankets are available only for passengers who really need one.
Meals are served in disposable bistro boxes, and instead of getting drinks poured into a cup, passengers are now served drinks in bottles.