Almost 17,000 aircraft now sit idle at airports and storage parks around the world as airlines wait for a signal that travel restrictions are being lifted and borders re-opened.

They’re not holding their breath. At American Airlines, which carries more passengers than any other airline, the talk among the maintenance crews is still about taking planes out of the sky rather than putting them back in.

IATA forecasts a tentative pick-up in travel demand in the third quarter which will strengthen in the final three months.  Getting back to post-coronavirus levels of demand could be years away. For airlines, that degree of uncertainty is creating a major logistical challenge of grounding the fleet while keeping it flight-ready for when the situation improves.

It’s difficult enough for airlines which have room to park their grounded fleet. For carriers where space is limited the challenge is formidable.

“It can be a logistical nightmare,” admits Paul Longhurst, General Manager of Maintenance at Hong Kong-based  HAECO, which carries out engineering and maintenance on sister company Cathay Pacific’s fleet of more than 150 aircraft. “There is limited space to park and we’ve ended up with aircraft on taxiways which ends up with a problem of aircraft blocking aircraft when we have to do periodic maintenance and engine runs,” he told an Aviation Weekly Week and Space Technology webinar. 

Even airlines with the luxury of space grapple with maintenance issues and a strategy for a restart. American Airlines has parked almost 400 aircraft out of a fleet of about 950 across several locations including Tulsa, OK, Pittsburgh, PA, Mobile, AL, and Roswell, NM.

American knows better than most about how to store and reactivate aircraft. It has one of the biggest fleets of Boeing 737 MAX aircraft, now grounded for more than a year.

“Good or bad, by virtue of having a lot of MAXs on the ground for past year we have learned a lot about storing the aircraft and how to build a better program and incorporate that into other fleets,” says Stacy Morrissey, American’s Managing Director of Fleet Engineering.

American divides its 400 grounded aircraft into actively parked, short-term storage, and long-term storage. Nearly half are actively parked—treated as if on an overnight layover with visual inspections and basic checks including tires, hydraulics and oil as well as the standard additional deep cleaning in the cabin.  These aircraft can be reactivated pretty much instantly.

Another 100 planes are in short-term storage and require more work before they can fly again. The remainder are older aircraft earmarked for early retirement that are being prepared for long-term storage.

Essential systems
Aircraft are not built to sit on the ground. They are made be in near-continual use, which means that maintenance on a parked aircraft quickly starts to ramp up.

“After 96 hours all of a sudden there’s additional things we need to do,” says Erik Olund, Managing Director and of Base Maintenance at American Airlines. 

Engines and sensors are covered and sealed. Essential systems are then regularly checked and tested. This involves running the engines every 10 days and turning tires to avoid flat spots. If the aircraft is blocked in, it is hoisted on jacks to rotate them.

During short term storage, cockpit windows are wrapped, fuel and water are drained and, in some cases, special liquid added to fuel lines and exposed areas covered to protect against weather and unwanted guests. “If a plane sits for a long time, they become great places to nest and you find all sorts if the plane isn’t stored properly,” says Olund.

Putting an aircraft into storage takes “enormous effort” over about three days, he said. Bringing it back to airworthiness, under the carrier’s FAA-approved maintenance program, takes about the same time.

With FAA approval, American took one of its MAX aircraft out of storage late last year to move it to another airport for extra maintenance and it took two days to get it back in the air.
“Despite being stored for eight months it flew clean and was perfect,” says Morrissey. “That speaks to fact if you have well designed and well executed storage program you can get your fleet back up quickly.”

HAECO’s Longhurst says manuals written by the airframe and engine manufacturers are being adapted to streamline the preservation and restoration of an aircraft. “The whole maintenance manual right now is tailored for longer-term mothballing of aircraft but we are in a situation where different areas of world may want to reactivate fleets more quickly, and they don’t want to face a large re-activation package. We have been working with OEMs on this and they have been very supportive,” he said.

Pilots needed

Aircraft reactivation is only half the story, though. There needs to be up-to-date pilots available to fly them.

To maintain active flying status pilots must perform at least three landings in 90 days and complete an annual proficiency test in a simulator, according to Captain Jack Netskar, President of the International Federation of Air Lline Pilots’ Associations (IFALPA).  

Along with the majority of his peers worldwide, Captain Netskar is now furloughed from his job at Scandinavian carrier, SAS.

“The challenge is the amount of time we spend on the ground,” he said. “If I am grounded for two months, I will feel rusty about getting back in the cockpit even though I am cleared to fly. But what happens after three months or six months?”

IFALPA is working on a submission to ICAO explaining how to get pilots back into the air with minimum disruption. It will examine whether three landings in three months will remain fit for purpose.

“I think if the time on the ground is extended to four months most pilots would be more comfortable spending time in a simulator before getting into the cockpit,” said Netskar. “And that of course brings up the question of whether there are enough simulators.”

That access to training, combined with the process of getting qualifications revalidated, has been recognised by IATA as a key issue. It has advocated for the license and qualification validity period to be extended for pilots, cabin crew, and maintenance personnel and has proposed alternative solutions for their recurrent training to ensure the quality of instruction via a virtual classroom.

With pilots and crew facing the likelihood of severely limited flights this summer, IATA has also designed a refresher pilot training session following the principles of competency-based training and assessment (CBTA).

“The main objective of the CBTA session is to validate that pilots are competent and confident for a safe and efficient return to operations by ensuring that recent experience is recovered,” said Gilberto Lopez Meyer, Senior Vice-President of Safety and Flight Operations at IATA.

The assessment puts emphasis on flight path management-manual control, situational awareness, workload management, and application of procedures that are success critical in the context of the return to operations.

IATA recommendations accessible here: