The Boeing 737 MAX – how does it affect me?

The second fatal crash of Boeing’s latest aircraft, the 737 MAX 8, in Ethiopia on March 10th has reverberated around the world.

The MAX is the latest iteration of Boeing’s classic 737 design that first flew in 1967 and is the world’s best-selling jet airliner, with over 10,400 built. (This is exceeded only by the legendary Douglas DC-3, a long-obsolete 1930s propeller-driven aircraft.)

Who flies the 737 MAX?

SriLankan Airlines has an all-Airbus fleet, so does not use the MAX. Regionally, SpiceJet, Fly Dubai, Jet Airways, SilkAir and Oman Air have this version of the Boeing 737, but they are all grounded at the moment. The largest MAX operators are the US giants, Southwest, United and American.

An effective duopoly

The Boeing Company (NYSE:BA) is the world’s oldest and largest aerospace company, having been founded in 1916. With a market cap of over USD 200 billion and revenue of over $101 billion, Boeing reported an operating profit of $7.9 billion in FY 2018. Company shares reached an all-time high of $440.62 on March 1st 2019.

Boeing’s only rival is the European Airbus Industrie conglomerate (NASDAQ:EADSY), and the two giants command 98% of the world’s airliner market. However, Boeing is much more profitable, as it has a robust defence business as well.

While Boeing dominates the large ‘wide-body’ market with the 777 and 787, the venerable 737 was gradually losing market share to Airbus’ A320 family in the ‘narrow-body’ market. This accelerated in 2011, when Airbus decided to upgrade the engines on the A320 family with more advanced and fuel-efficient power plants, marketed as the Airbus 320neo (for New Engine Option).

The Airbus ‘neo’ left Boeing with a dilemma. Should they invest in a long and probably very expensive development program to build a new ‘fly by wire’ version of the 737, or try to upgrade the existing model with new engines and a few tweaks to keep it current?

What is ‘fly by wire’?

Aircraft control surfaces located on the wings, the rudder, and horizontal stabilizer at the rear of the aircraft were originally connected to the pilots by a series of cables and pulleys. Pilot action on the control wheel or stick would move the control surface, which was some distance away, by means of the mechanical linkage between the two.

Airbus became the first manufacturer to remove this mechanical linkage, replacing it with an electronic interface between pilots and control surfaces. The pioneering A320 aircraft eliminated mechanical linkages, with pilot input being converted to digital electrical signals that were relayed to the control surfaces via electrical circuits, the ‘wires’ in ‘fly by wire’ or FBW.

The allowed a great deal of weight-saving while permitting increased use of computer-controlled techniques to optimize flight. The popularity and reliability of the system forced Boeing to follow suit, with the 777 being the first of their products to incorporate fully digital FBW controls. The 787 Dreamliner uses a similar system, as does the entire stable of Airbus aircraft.

The dilemma faced by Boeing

The 787 Dreamliner, which Boeing had launched in 2009 but only delivered in 2014, had cost an estimated $32 billion in development and manufacturing. Prolonged delays and technical problems affected the company greatly, and profit-hungry executives were not eager to engage in a similar expensive program.

It was decided to avoid developing an all-new aircraft, but instead to upgrade the 737 with similar engines to what the A320 would have (the CFM International LEAP) and make a few more modifications to keep the aircraft competitive. By doing so, Boeing executives hoped to save costs and get the aircraft to market much sooner. Critically, it also allowed Boeing to market the aircraft as a ‘variant’ of the 737, thus keeping the same ‘type-rating’. There would not be the lengthy certification process that every new aircraft type must undergo to prove that it is safe as well as efficient. Pilots who were currently flying the 737 could fly the MAX – as the new sub-type was dubbed – with only a self-study course, and no expensive simulator training and conversion required.

This represented a huge saving for the airlines, particularly the US giants who had fleets of 737s numbering in the hundreds. Pilots could fly the MAX and earlier versions of the 737 interchangeably, reducing the cost of introducing the aircraft, while at the same time enjoying a 15-20% fuel saving for the new type.

A runaway sales success

The MAX proved to be a winner. Sales were astonishing, with over 4,000 sold in a short period since launch of the type. But behind the scenes Boeing engineers were facing an impossibly tight deadline.

The MAX was launched in 2011, offered for sale in 2012, and the first completed aircraft rolled out in 2015. By the standards of the aviation industry, this was incredibly fast. It certainly saved Boeing a lot of money and also meant that Airbus did not dominate the narrow-body market with their ‘neo’. In fact, Boeing maintained a roughly equal market share to the Europeans’.

The MAX was one of the factors that led to Boeing being Wall Street’s darling, with the high price of shares pushing the whole NY Stock Exchange to record highs.

The hidden threat

But as we now know, the MAX had at least one fatal flaw. The bigger and more powerful LEAP engines were positioned further forward than on older 737s. This meant that in an extreme case of nose-up aircraft attitude, the MAX was in danger of entering into an unrecoverable stall. In order to prevent this, Boeing’s engineers used software they labelled MCAS (Manoeuvring Characteristics Augmentation System) to push the airplane’s nose down automatically, in response to a dangerously nose-high attitude, or angle, being detected.

Crucially, this system was certified without the pilots being aware that it even existed. The Federal Aviation Administration (FAA) and European Aviation Safety Authority (EASA) did not require that MAX pilots were informed about MCAS and its functionality. The only dissenting voice was that of Brazil’s National Civil Aviation Agency (ANAC), who insisted that MAX aircraft registered in that country specifically addressed MCAS and made pilots aware of it. This will go down as a tragic failure on the part of not only Boeing, but also the FAA which was hitherto the most respected aviation regulator in the world.

Fatal consequences

On October 29th 2018, Indoesian carrier Lion Air’s flight JT 610, operated by a Boeing 737 MAX 8, took off from Jakarta and crashed into the Java Sea shortly thereafter. The preliminary accident report released last week showed that the MCAS caused an excessive nose-down control input, even though the aircraft was nowhere near an aerodynamic stall. In part because they were not aware of the system and what it did, the crew was unable to correct this before the aircraft dived into the sea, killing all on board.

The accident of a practically brand-new aircraft caused shock waves throughout the aviation industry, and initial analysis centred on the little-known MCAS addition. However, the 737 MAX type was not grounded but continued to be manufactured and flown all over the world.

That was until the tragically similar accident to Ethiopian Airlines’ flight ET 302, which also crashed just after takeoff, in eerily similar circumstances to that of the Lion Air MAX 8. This immediately prompted first the Chinese civil aviation regulator to ground the aircraft, followed not long after by an almost worldwide grounding of the MAX airplanes in operation and those about to enter service. Sadly, the USA’s FAA, the most respected of aviation regulators, were the last to ground the MAX, a fact that has further sullied their reputation.

What’s next?

Boeing continues to manufacture the 737 at the rate of almost 54 aircraft a month. The integrated supply chains and ‘just in time’ manufacturing techniques mean that production cannot be stopped in the short term.

The worldwide grounding of a new aircraft type is a very rare occurrence. Airbus suffered two crashes of the then new A320 in June 1988 and February 1990. As a result of the second accident, India’s regulator (the crash involved an Indian Airlines aircraft in Bangalore) grounded the fleet in that country, but other regulators declined to follow suit, despite claims that the aircraft’s fly-by-wire control system was fundamentally flawed.

A number of changes were subsequently made to the A320’s systems, and the type has become a best seller for Airbus, along with smaller and larger derivatives of the original model which have proved equally popular with operators, engineers, pilots and passengers alike in many parts of the world. There have been other crashes of the A320 ‘family’ of airplanes since, but no fatal system error has been identified, with most accidents being attributed to ‘pilot error’ or extraneous factors.

The FAA and Boeing are now working hard to fix MCAS issue and will probably release a software update in a few days’ time. This will probably allow the MAX to start flying again; but recovering passenger confidence is going to take a long time. With over 300 already built and 4,000 more on order, the airline industry, and not least Boeing, desperately needs the MAX to become airworthy as soon as possible, certainly before the peak summer travel season begins.

The fundamental issue

At the heart of the problem is that the Boeing 737 is still a ‘mechanical’ aircraft. An overlay of modern instruments and software obscures the fact that underneath the aircraft floor, steel wires and pulleys are at the heart of the flight control system.

Thirty years after the introduction of fly-by-wire airliners, there has been an exponential growth of the industry, with a superb safety record. There are less than 100 fatalities per trillion kilometres in the worldwide industry, an astonishing record that has been improving year on year.

This commendable statistic, the benign behaviour of newer aircraft, and the rapid growth in airlines has, however, led to some compromises. Pilots have adapted slowly to the new technology, becoming increasingly focused on following Standard Operating Procedures and the automated failure identification systems that are integrated in the design of today’s airplanes.

For the Airbus fleet, which is entirely fly-by-wire, these systems work very well. As already noted, Boeing’s wide-body products, the 777 & 787 Dreamliner, are also fly-by-wire. The venerable 747, the original ‘jumbo jet’, is not; but with production diminishing, this type will become obsolete soon.

The issue is, of course, the Boeing 737 MAX. No amount of software fixes can change the fundamentals of the mechanical flight control system, which is at the heart of this type.

To draw an analogy with the automotive industry, most of today’s airliners are like a Toyota Prius or perhaps a Tesla. The electronic systems are an integral part of the design and the operator (or pilot/driver) has little ‘visibility’ of how they interact with each other. One has to accept that they are well designed and will function flawlessly, as they do.

The MAX, however, may look like a Prius, but under the sophisticated veneer it is actually an old Corolla with a manual transmission. The electronics may resemble those of a more modern aircraft, but the basic fundamentals of the system date from the 1960s when the 737 was first designed.

The writer, a pilot with experience on 12 different types of jet aircraft, feels it is time the industry reverts to basics as well. In the case of the Boeing 737 MAX there will have to be a large and dedicated investment in training pilots to fly it again, without their reliance solely on automated systems to keep them and their passengers safe.

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