Not back in the air yet, but Boeing is paddling hard to ensure smooth MAX return

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Sunday, 22 September 2019

US plane maker Boeing hopes that by end October, it will have US approval to return its 737 MAX jets to the skies after their world wide grounding.

All 387 of the planes in service were ‘parked’ in March this year following two crashes that killed all 346 passengers and crew. Another 250 jets manufactured since the grounding are being stored by Boeing.

Both crashes - Lion Air Flight 610 in October 2018 and Ethiopian Airlines Flight 302 in March 2019 -have been linked to flaws in anti-stall flight software known as the Maneuvering Characteristics Augmentation System (MCAS). 

MCAS was developed because the new, larger CFM International LEAP-1B engines chosen for the MAX had to be located further forward and higher on the wings than the engines used on earlier 737 types. This affected the jet’s handling characteristics.

Put simply, if the ‘angle of attack’ (AoA) air flow/speed sensors on the outside of the jet indicated the plane was attempting to climb too steeply and/or too slowly, MCAS activated and automatically forced the plane’s nose down (into a dive). 

Unfortunately for Boeing and the passengers and crew on the two crashed jets, in dive mode MCAS was ‘almost physically impossible’ for pilots to correct manually.   Boeing’s own engineers probably did not know how difficult it would be for pilots to overpower the activated dive setting during a real-life crisis. 

And while many pilots claimed not to know MCAS even existed, others believed MCAS used two AoA sensors (one acting as a failsafe if the first malfunctioned) when in reality only one of the two on each jet was active as a default setting. If that one active sensor misfired, as some reports said may have happened as a result of a bird strike in the Ethiopian Air crash, then MCAS could start repeatedly, activating every few seconds.

(The Lion Air MAX crash jet suffered what is believed to have been a MCAS malfunction on the day before its fatal accident, but the flight deck crew on that earlier flight were able to switch the system off - and the jet was repaired after landing safely. The pilots on the same jet’s next outing, Lion Air Flight 610, were not able to disable MCAS when it ‘went rogue’ - or perhaps they did not how to turn it off and didn’t have time to find out. One can only speculate whether the crew on the Ethiopian jet knew there was an ‘off switch’ for MCAS but failed to find it. Following the earlier Lion Air crash, Boeing had issued an advisory on how to address erroneous cockpit readings.) 

Disaster control

After the fleet was grounded globally, Boeing went into disaster control mode. 

Ceo Dennis Muilenburg said the safety systems on its 737 MAX jets were properly designed, but added that Boeing would ‘make them safer’.

He also said the pilots did not completely follow Boeing’s procedures to prevent the kind of malfunction that probably caused the Ethiopian Airlines crash. 

He stopped short of saying the crashes were purely pilot error, but his comments encouraged pilots on other airlines to come forward with their own MAX MCAS stories. Those claims in turn gave weight to law suits lodged later by crash victims’ families, Boeing’s own shareholders and its airline customers’ pilots. 

Later still, the United States Department of Transportation (DoT) ordered an audit into the 2017 regulatory process that led to the aircraft’s initial certification. The audit came after allegations were made that Boeing had (to an extent) been allowed to self-certify the MAX so the MAX would better compete with the (then new) Airbus A320neo. 

That DoT investigation is ongoing.

Adding to Boeing’s troubles, during a set of ‘fixed’ MAX MCAS simulator tests in June, the FAA’s test pilots discovered a separate issue that affected pilots’ ability to quickly and easily follow Boeing’s recovery procedures for runaway stabiliser trim and stabilising the aircraft.

Boeing immediately started work on a solution and so far, no other issues have surfaced.

Boeing’s challenge now

To ensure the MAX fleet is back in action safely and as soon as possible, Boeing engineers currently are working on an aviation logistics program that dwarfs almost anything done outside times of war. Boeing Commercial Airplanes chief engineer John Hamilton says as well as retrofitting the 387 grounded jets with new MCAS software, the work includes synchronising inputs from 680 component suppliers. 

The program also involves assembling tool kits for technicians who will install the software updates plus procedures for other staff tasked with checking jets that have been idle for months, many of them at airports/countries far from their home bases. Estimates are that each jet will need 100-150 hours to make it comply with whatever the Federal Aviation Authority (FAA) demands.

At the same time, the manufacturer has other teams working with customers to decide on the order in which each airline’s grounded jets will be returned to service. And of course which airline’s jets will be repaired first.    

These commercial/technical teams are working hand-in-glove with other Boeing staff who are negotiating compensation agreements with airlines that had to cancel flights, cut capacity, drop routes and in some cases, find other planes to fill MAX slots - and find pilots qualified to fly them.

There’s also a legal team charged with defending the company against multiple law suits connected to the two disasters. As mentioned, these are by the families of the 346 victims, plus a pilots action and one from Boeing’s own shareholders.

The lawsuits accuse Boeing of ‘greed and misconduct’ and also claim Boeing did not fully inform its customers’ pilots about MCAS. The suits have been filed in the US, Indonesia, Kenya, France and Ethiopia, all of which have different laws and compensation limits.

To add to the complexity of the repair program, as well as the 387 grounded customer jets, there are two different ‘new MAX’ categories: The hundreds of jets produced and parked by Boeing since March, all of which will be retrofitted with new MCAS software (and any other mandated improvements/repairs) prior to their delivery to customers - and the jets that will be produced after authorities give the Boeing fix/es the green light. 

Cancelled orders

Of the new jets already built, about a dozen belong to lessors and haven’t yet been assigned to airlines, while some were built (and branded) for carriers including India’s now-bankrupt Jet Airways. Also, some airlines that bought the MAX have since tried to delay deliveries and two, Indonesian flag carrier Garuda Indonesia and Saudi carrier Flyadeal, have cancelled orders for 49 and 30 MAX jets respectively.

Other airlines have said they are concerned their customers will be reluctant to fly on the MAX for some time after it returns to service - although studies and surveys indicate most airline customers either have forgotten that the MAX was the plane involved in the two disasters, or they don’t know and don’t care. ‘Customer concern’ at those airlines doubtless will convert to added compensation demands.

Regardless of what happens to the new jets, the 387 aircraft in service before the grounding will be returned to service by a mix of airlines’ own engineers and Boeing teams that already are deployed around the world in order to assist its customers.

These already-complex preparations are taking place despite a number of aviation authorities including the European Aviation Safety Agency (EASA) that say regardless of any FAA decision to green light the MAX, they will make their own decisions concerning a time frame for the MAX’s return to service in their airspace. 

Boeing ceo Dennis Muilenburg has conceded this will be the case, saying: “We don’t control the time line.” 

As well as timing, Boeing also doesn’t control the weather where the grounded jets sit. Jets in colder regions may need aircraft anti-freeze treatments, while others in warmer areas may have suffered humidity/condensation damage to sensitive electronics and fuel lines. 

In a nutshell, every grounded plane will have to be checked nose-to-tail, inside and out. 

Another challenge will be finding enough pilots to conduct any on-ground and flight tests, though Boeing may already have contacted aircrew and training providers for temporary staff.

Estimated cost to Boeing so far? About US$8 billion and counting.

How it all began …

THE BOEING 737 MAX was expected to require a ‘new aircraft type’ certification by US authorities, but instead was accepted as an ‘upgraded B737’ - and therefore avoided the more-lengthy process. 

Its airline customers benefited from this in two ways: Their new and more-ecomical jets were delivered sooner and they didn’t have to put their 737 pilots through expensive and time-consuming retraining.

It was a popular decision. The new series was announced on August 30, 2011 and gained FAA certification in March 2017. The first delivered was a MAX 8 in May 2017 to Indonesia’s Malindo Air. 

As of June 2019  Boeing had received 4,934 firm MAX orders.

The 737 MAX is offered in four variants, the MAX 7, MAX 8 and MAX 9 plus the upcoming stretched MAX 10 (originally scheduled to be delivered by July 2020).