A Boeing 737 MAX 8
A Boeing 737 MAX 8 plane at the Boeing plant in Renton, Washington. This past week, Boeing completed test flights of its troubled 737 Max airplane to demonstrate that it can fly safely with new flight control software. Image Credit: NYT

Seattle: This past week, Boeing completed test flights of its troubled 737 Max airplane to demonstrate that it can fly safely with new flight control software. The Max was grounded in March 2019 after a pair of fatal crashes - in Indonesia and Ethiopia - that killed 346 people.

Even as the company began testing the planes for recertification, a federal inspector general’s report said that Boeing had kept information from federal regulators about the flawed computer system that brought down the two jets during the plane’s initial approval process.

The Max is the most recent model of Boeing’s 737, a type of aircraft with many variants over the decades. More than 10,000 737s have been built. The Max was released in 2017 in four lengths to accommodate up to 230 seats. The Max has larger, more fuel-efficient engines than the older models.

If the Federal Aviation Administration is convinced that Boeing has corrected the problems that led to the crashes, the planes will return to service, but no timeline has been announced.

The agency said in a statement that it “will lift the grounding order only after we are satisfied that the aircraft meets certification standards.”

Boeing’s chief executive, David Calhoun, flew on the plane in February. The head of the FAA and longtime Delta pilot, Stephen M. Dickson, told a Senate committee that he would fly the Max himself and must be satisfied that he would put his family aboard before he would lift the grounding order.

Boeing 737 MAX aircraft
About 10,000 Max aircraft were grounded in March 2019 after a pair of fatal crashes - in Indonesia and Ethiopia - that killed 346 people.

Industry experts said that it could still take several months before the agency and its counterparts in Europe, Canada and Brazil give the green light to certify the Max - possibly as late as 2021. All told, this likely means that the Max won’t return to service until this fall at the earliest.

Here’s what travelers who might be contemplating flying again around that time need to know.

What happens when the FAA certifies the aircraft?

The airlines need to ready the planes and their pilots, and the FAA needs to approve a new training regime for pilots.

The grounded planes are parked at airplane storage facilities around the United States. They undergo periodic maintenance even while grounded. When the FAA provides its approval, an airline’s maintenance teams and pilots will fly the aircraft (with no passengers on board) to airline maintenance facilities, said R. Eric Jones, an associate professor of Aviation Maintenance Sciences at Embry Riddle Aeronautical University and an experienced airline maintenance lead. There, the aircraft will undergo extensive evaluations and maintenance of systems, including hydraulics and avionics, and of the wings and landing gear. “Assuming no anomalies are found, it could take as little as two weeks to a month to return a parked Max to operational service,” Jones said.

Boeing has recommended to the FAA that pilots undergo training on flight simulators combined with computer-based training “before returning the Max safely to service.” This training could be similar to the intense annual checks every airline pilot undergoes regardless of what aircraft they fly. It could take several days per pilot on a tablet, coupled with simulation of the new flight control system on a full-motion flight simulator. The details of the training have not been announced. Many pilots who fly the Max have trained on flight simulators every three months since the plane was grounded to maintain their knowledge of how it flies.

Boeing 737 MAX 8
Southwest Airlines was the largest U.S. operator of the Max, with 34 in its fleet. American Airlines has 24 and United Airlines has 14.

What airlines fly the Max?

Since it was introduced, Boeing has delivered 370 Max aircraft to 47 customers worldwide.

Southwest Airlines was the largest U.S. operator of the Max, with 34 in its fleet. American Airlines has 24 and United Airlines has 14. Delta Air Lines is the sole major U.S. carrier not to have ordered the jet to date. While the Max represents a small percentage of the fleets of these carriers, hundreds more were on order before the crashes.

Internationally, dozens of airlines are slated to take delivery of the Max over the coming years. In North America, Air Canada, WestJet and AeromExico fly the aircraft and have orders for more. Ryanair, the European low-cost carrier, will eventually fly more than 100 Max aircraft.

What routes does the Max normally fly?

The Max is the latest generation of Boeing’s 737, which was designed to fly medium-range flights like New York to Austin, Texas, or San Francisco to Chicago. None fly trans-Atlantic.

A Boeing 737 MAX 8
The Max is about 17% more fuel-efficient than its older Boeing 737 siblings. The fuel savings are huge for cash-strapped airlines.

With COVID-19 slowing airline travel, what’s the hurry?

The Max is about 17% more fuel-efficient than its older Boeing 737 siblings. The fuel savings are huge for cash-strapped airlines. Airlines want to deploy the jets as soon as they can, even during this period of depressed travel demand.

How can I tell when I’m booking whether the plane will be a Max?

When you book your ticket online, airlines display the type of aircraft slated to fly the route. You might have to click a link to reveal this information. For example, American Airlines previously listed the Max on its website booking page as the “7M8” aircraft, which stands for Boeing 737 MAX 8. (There are 7, 8, 9 and 10 numbered variants, depending on the seating capacity). Southwest has a webpage that lets you identify what plane you are scheduled to fly on. However, the plane that is scheduled to fly a route can change for myriad reasons, ranging from run-of-the-mill maintenance issues to poor weather causing network delays.

RDS_190317-YT-Letters-Ethiopian-Airlines-1552742550549
Fear of flying. People mourn the Ethiopian crew and passengers who died in the last fatal crash.

Has any other commercial aircraft been successfully rehabilitated?

Aviation authorities grounded the Boeing 787 Dreamliner for four months in 2013 because of smoking lithium-ion batteries in two separate incidents. For a time, passengers were skittish about flying the then-new aircraft. That moment has long passed; the Dreamliner is key to many airlines’ international routes. But the Dreamliner had not been involved in fatal crashes.

How can I tell if I’m flying on a Max?

If you’re waiting at the gate and see your plane, look for large and pointy fins extending above and below the wingtips called winglets. Winglets come in all manner of similar designs, but the Max’s stand out.

Will airlines allow me to rebook or get a refund if I don’t want to fly on the Max?

Rebook? Yes. Refund? No. U.S. carriers have not yet announced policies related to the return of service of the Max. However, in a statement this past week to The New York Times, a United Airlines spokesperson said that the company “will be transparent - and communicate in advance - with our customers who are booked to fly on a Max aircraft, will rebook those who do not want to fly on a Max at no charge.” Expect other airlines to follow United’s lead.