The United States' aviation giant had hoped to see the 737 MAX return to the skies by the end of the year. But with regulators apparently in no hurry to give the green light, there is little clarity when flights may resume.

The jet was grounded worldwide following two deadly crashes in the space of less than five months. The first, Lion Air flight 610 near Jakarta in October 2018, and the second, an Ethiopian Airlines jet in March this year. In total, the two crashes claimed the lives of 346 people.

Since then, more than 380 737 MAX aircraft owned by airlines around the world have been grounded. Hundreds more jets are reportedly being stored by Boeing at its facilities; fresh off the production line but unable to be delivered to their customers.

For airlines, the grounding has meant reshuffling flight schedules, extending leases on aircraft, delaying the transfer of older planes and paying expensive storage and maintenance costs for aircraft that are not permitted to fly.

But securing regulatory approval is just one step in getting the 737 MAX back in the sky. The real challenge will be winning back confidence among airlines, pilots and, of course, passengers.

There have been incidents of grounded aircraft before, but the case of the 737 MAX is in a different league: a challenge not just of restoring trust in the jet but navigating the complicated process by which that trust was lost in the first place.

In the immediate aftermath of both crashes, Boeing was quick to point to pilot error as the likely cause. The Federal Aviation Administration (FAA), the US regulator, backed Boeing, insisting the 737 MAX was safe to fly — only backtracking after other regulators issued their own orders grounding the plane.

What has subsequently emerged, however, is a troubling picture of a close relationship between regulator and manufacturer, with the FAA effectively outsourcing much of the aircraft’s testing and certification process to Boeing itself.

It’s a story that has its roots in the design and development stages of the 737 MAX and the intense competition between US-based Boeing and Europe’s Airbus.

In its fierce rivalry with Airbus, Boeing was determined to make its latest iteration of the 737 as competitive as possible. In terms of units sold, it is the most successful commercial passenger aircraft ever built, yet much of its basic design and control system dates back to the late 1960s.

In part this is what has made the 737 so successful. Familiarity keeps pilot training costs down and makes servicing and maintaining the aircraft easier and cheaper.

In order to maximize fuel efficiency, Boeing focused on updating the 737s engines. Because these are larger, they have to be positioned further forward from the wings, which affects the balance of the aircraft.

However, in order to appeal to airlines, the jets flight controls were designed to require minimal retraining for pilots who were familiar with flying earlier models of the 737.

To bridge the gap, engineers developed special software to manage the way the larger engines altered the jet’s handling and to prevent stalling.

This meant Boeing was able to build a training program that would see most pilots transferring from other 737 models spending only a few hours doing a course on an iPad, rather than in a costly simulator, in order to fly.

Such an approach makes sense when looking at numbers on accounting spreadsheets. But after two deadly crashes it isn’t hard to see why some observers have seen this as cutting corners on safety.

Compounding this have been further revelations; for example, that a system for alerting pilots to problems with information from the plane’s angle-of-attack sensors was made an optional feature on the 737 MAX.

Investigators believe that faulty information from these sensors caused the anti-stall software to repeatedly override pilot commands, ultimately forcing both jets into a fatal dive. However, because the optional warning indicator was not installed, the theory is that pilots were either unaware of what was triggering the software or that Boeing’s training had not been rigorous enough for them to know how to override it.

As it tries to get the 737 MAX flying again, Boeing has pledged to earn back the trust and confidence of airlines and flying public. Its engineers are working on a software overhaul of the aircraft’s systems and a revised training plan for pilots.

But the Chicago-based firm will find it hard to shake off the perception that it has tried to deflect responsibility and been arrogant in its approach to safety. Critics, including some major shareholders, have been pressing Boeing to restructure its senior management and how its board oversees operations.

Meanwhile the FAA, following criticism that it had been unduly close to Boeing, is pledging to take a tougher line, promising it would take “as long as it takes” to ensure the jets are safe. It has also said it will work with other international regulators to evaluate Boeing’s fixes, but that it won’t try to force them to agree with its findings.

With more than 30 other regulators involved though, building consensus will be vital. If the FAA recertifies the 737 MAX as safe to fly but another regulator elsewhere in the world disagrees, confidence in the jet will only be further undermined.

Ultimately, when regulators do eventually give the green light, returning the 737 MAX to flight will depend on the confidence of passengers and — crucially — pilots.

Pilots take safety extremely seriously and, as a community, talk with other pilots — particularly in online forums. In the wake of the two crashes, many complained they felt betrayed and misled by Boeing.

Airlines and regulators will need to work closely with pilots to ensure all questions are answered and residual doubts overcome. Any impression that pilots are being coerced to fly the 737 MAX or are otherwise misinformed will only do further damage.

***

Professor in the department of marketing and vice dean of graduate studies at the National University of Singapore (NUS) Business School. The views expressed are his own.