It was on 13 March this year that the US Government ordered the grounding of Boeing’s 737 Max aircraft, the final stage in a series of rulings by regulatory agencies around the world halting flights with the type.

The grounding followed the 10 March crash of an Ethiopian Airlines 737-8 and the October 2018 crash of a Lion Air aircraft of the same type. Those crashes killed a combined 346 people.

ethiopian crash debris c Mulugeta Ayene AP Shutter


Ethiopian Airlines 737-8 crash debris

Mulugeta Ayene / AP / Shutterstock

Six months on, the type remains grounded and there is no certainty as to when the Max will return to service.

September is the month Boeing flagged as when it intended to submit 737 Max certification materials to US regulators for approval.

Boeing may meet that goal, and the company continues sticking to its expectation that regulators will lift the grounding in the fourth quarter.

But as October approaches, the return-to-service path remain muddled amid open investigations and signals suggesting some of the world’s civil aviation regulators will approve the Max on differing schedules.

abu-p07-Max-parked-c-Elaine-Thompson AP Shuttersto

737 Max 8s parked

Elaine Thompson / AP / Shutterstock

On 11 September, Boeing chief executive Dennis Muilenburg told attendees to an investor conference that Boeing has been “working through” delivering certification materials to the Federal Aviation Administration as part of an “iterative process”.

Those materials relate to 737 Max flight control software, training materials and “other certification documents”, he said.

“All of that work supports our timeline for an early fourth quarter return to service,” Muilenburg said.

But in the same week, news arose that highlighted the continued unsettled nature of the entire 737 Max affair.

Boeing 737 Max test flight

737 Max test flight


On 12 September, the US House of Representatives’ transportation committee disclosed it wrote Muilenburg a letter “to formally request interviews with several Boeing employees”.

The committee made the request ahead of another planned, and newly disclosed, hearing related to its investigation into the 737 Max. The date of that hearing has not been set.

“The committee believes certain employees may be able to shed light on issues central to the committee’s investigation, including information about the design, development and certification of the 737 Max,” the committee says in a media release.

The company already “provided substantial documents to the committee over the past several months and shared its senior management’s perspective with the committee”, the committee release adds.

But, certain Boeing employees “can provide unique insight into specific issues and decisions in a way that senior Boeing management simply cannot”, says the release.

The committee declines to provide FlightGlobal with a copy of the letter to Muilenburg or to specify the names or titles of the employees it seeks to interview.

Asked to comment, Boeing says: “We’re deeply disappointed the committee chose to release private correspondence given our extensive cooperation to date. We will continue to be transparent and responsive to the committee.”

Boeing has been criticised by some observers for lack of transparency and for not adequately addressing the role its systems played in two crashes.

The first, a Lion Air 737 Max 8, went down in October last year. Then an Ethiopian Airlines 737 Max 8 crashed in March, prompting China, and then the rest of the world, to ground the Max aircraft family. Investigations have suggested the 737 Max’s manoeuvring characteristics augmentation system (MCAS) – technology created for the Max by Boeing to make the aircraft fly and respond similar to the earlier-generation 737NG – played a central role in both crashes.

Earlier this year Boeing had insisted it updated MCAS in a way that would prevent wayward MCAS activation.

But then last summer came news that regulators found additional, non-MCAS related issues, including a software problem, which pushed certification back further.


Meanwhile, airlines have removed 737 Max flights from their schedules in incremental chunks, with many carriers now hoping for an early January return.

The European Union Aviation Safety Agency confirmed this week that it intends to scrutinise the 737 Max itself, and to conduct its own test flights, rather than rubber stamp the FAA’s approval.

EASA said it is reviewing numerous concerns about the aircraft, including those related to the angle-of-attack indicator (specifically, the fact that the 737 has only two indicators), manual horizonal trim and flight crew responses to emergencies.


Muilenburg addressed EASA’s intentions at the 11 September investor conference, saying Boeing is working closely with that agency but conceding a “phased ungrounding” may play out.

In such a scenario, the FAA might approve the aircraft first, followed by regulators in Europe, China and possibly elsewhere. When approval from China, the country that was first to ground the aircraft, might come remains unknown.

Michel Merluzeau, director of aerospace consultancy AIR, thinks the likelihood of a fourth quarter return-to-service will become clearer next month.

“I think it’s safe to say that by the end of October we should have a much better understanding of the timeline,” he says.

Much remains uncertain, but Merluzeau sees a path by which the FAA lifts the grounding in the fourth quarter – possibly in November or December.

Only a small number of Max – those coming off Boeing’s production line – will likely be flying immediately after the grounding lifts. Months may pass before the aircraft currently in storage return to service. Indeed, Air Canada chief financial officer Michael Rousseau said on 12 September that a year might pass before that airline gets its 50 planned 737 Max’s back in service.

The airline has about 400 trained 737 Max pilots – enough to operate its pre-grounding fleet of 24 aircraft, but not enough to operate additional, newly-manufactured 737 Max that will be available when the grounding lifts, he says.

That pilot shortage is exacerbated for Air Canada because it flies no earlier-generation 737s, meaning it has no pilots that can undergo a conversion course and fly the Max.

“We will have to work with Boeing as to when we bring those planes in, because we have no pilots to fly those planes, at this point,” Rousseau says.