The Boeing 737 MAX : a cocktail of a devil in the system, uber-pilots and negotiable safety

The Devil in the System

Mary Schiavo, former Inspector General of the United States Department of Transportation, said in a CNN interview that the Boeing 737 has outlived its useful life but is being kept alive because “Boeing has more clout than the FAA” and that is why it still flies in the US.

It was evident, within minutes of the Ethiopian crash, that there were striking resemblances to the Lion Air crash of 29 October last year. It may be premature to speculate on these crashes in the absence of official findings, but the similarities speak volumes.

Boeing’s 737 has been progressively developed through various generations of models. The engines have become vastly larger compared to the earlier models which had small cigar-shaped engines attached to the bottom of the wings. Later models have big turbofan jets which had to be mounted in front of the wings, and the bottom of the engines needed to be flattened to improve ground clearance.

The MAX uses still bigger engines and these changed the handling characteristics of the MAX compared to the previous generation. To save Boeing from having to re-certify the aircraft because of the handling differences, and to save airlines buying the MAX from having to spend money on expensive pilot training, the FAA agreed to Boeing’s request to install a system called MCAS (a stabilator-trim system) to automatically lower the nose at low speeds to prevent the plane from stalling.

What Boeing omitted to do was to tell the pilots about this new stab-trim system and to build in proper redundancy for its data sources. So the 737 MAX did not need to go through the same certification testing as a clean-sheet aircraft design, as they relied on the ‘grandfather rights’ from the original B737-100 certified in the 1965. This not only saved Boeing a huge amount of time and money in development but also reduces the training requirements for the operators.

But now the MAX has been described by a retired captain as “an old necklace, with too many charms added.” And this may be the root of the devil in the system.

When the Lion Air MAX crashed into the sea off Jakarta the ‘black box’ data recorder showed that the airspeed indication was wrong and this had caused the MCAS to constantly try to lower the nose of the aircraft, despite the pilots’ best efforts to raise it. Eventually the stab-trim forced the nose so far down that the aircraft dived near-vertically into the sea. And judging from the radar and satellite returns, this is also what happened to the Ethiopian MAX 8.

At risk of being sensationalistic, it’s worth reviewing what it must have been like for the pilots and passengers. As the stab-trim system pushes the nose of the aircraft down to increase speed, the pilots pull back on the control column. But the stab-trim continues to push the nose down. In the Lion Air crash, the crew lost control after more than 24 progressively increasing oscillations. And so a tug of war ensues with the aircraft porpoising wildly through the sky. Any unrestrained passengers will be slammed against the ceiling and if the pilots haven’t done up their seat belts properly they will be flung up and down and so find it extremely difficult to hold onto the controls, let alone operate switches. For the final 30 seconds of the flight the aircraft will be screaming almost vertically into the ground. It is too ghastly to contemplate.

The need for uber-pilots

After the Lion Air crash, Boeing recommended a procedure requiring the pilots to use cut-out switches to stop the stab-trim. These switches do not turn off the MCAS system, which is currently believed to be the root of the problem, they merely stop the electric trim working. But if the pilots are properly trained, and sharp enough, at the first sign of the plane trying to lower its nose on its own accord, they can flick two switches to turn the stab trim function off. The passengers should hardly notice the blip.

Shortly after the Ethiopian crash, Donald Trump cast aspersions on the Ethiopian and Lion Air pilots, specifically their failure to cut-out the MCAS programme. Trump is notably close to Boeing, and his Acting Secretary of Defence, Pat Shanahan, worked for Boeing for 21 years. This close relationship between POTUS and Boeing has caused the Ethiopians to distrust the Americans.

But the quality of the pilots in these two crashes nonetheless poses a real question. Boeing argues that simply switching the stab trim off is a basic skill required of all pilots for all 737s, even the fifty year old first generation ones. It is required training for all 737 pilots in the simulator. However no matter how realistic they are, the one thing simulators cannot do is replicate the often violent G forces. When you are porpoising through the sky and being thrown about the cockpit like a rag doll, finding and using small switches requires a cool head.

For passengers, having to hope that your pilot is an unflappable uber-pilot is scant comfort. But in support of the cool head proponents, it is important to note that there have been a number of other incidents reported where the MCAS was successfully neutralised, and these were handled by the pilots applying Boeing’s basic training.

As a side note, for those who reckon that the age of pilotless airliners is imminent, the need for uber-pilots in these instances shows that a ‘fleshware’ pilot will always be required for when the computers run amok.

Profits vs Safety

What these two tragedies have done is shine a spotlight on the age-old conflict between profits and passenger safety. And some airlines have failed the scrutiny.

Understandably, many passengers said that they would refuse to fly in a Boeing 737 MAX until the cause of the two crashes is identified and fixed. The problem passengers face was how to know if you had been booked on a MAX, and what to do if you had been. For those who asked, I attempted to explain the key visual difference between the two, and that is that the MAX has a sawtooth edge to the back of its engines. But naturally, if there was a possibility of them flying on a MAX, many passengers would refuse to fly on any Boeing 737. Despite this, South Africa’s Comair, and most of the American Airlines, initially refused to ground their Max 8s.

It brings things close to home to know that the Ethiopian MAX’s take off immediately preceding its fatal crash had been from OR Tambo Airport, carrying many South Africans. A commentator said; “If this error [with the MCAS] had happened one sector earlier we would have been clearing up aircraft parts, human remains and debris from the eastern suburbs of Pretoria today.” This explains why Australia and then other countries banned all MAX flights from their airspace, not just their local MAX fleet.

What is, however, hard to swallow is that Comair and all the American Airlines initially refused to ground the MAX. For the American Airlines, such as South West with 31 MAX 8s already flying, a grounding is a financial catastrophe. But Comair has only one MAX 8 flying, (with another to be delivered shortly). And yet even with the exposure of a single MAX, being just 4-percent of their fleet, Comair chose to put profits ahead of passenger safety. Uncertain which way to jump, the South African Civil Aviation authority sat on its hands until Comair decided to ground its own aircraft.

Not knowing what the problem buried in the MCAS system is, and relying solely on uber-pilots to be sufficiently cool headed to switch the system off, is simply not good enough, particularly in the age of social media. It was only when the overwhelming opprobrium bubbling through social media impacted Comair that they changed their minds. And perhaps the realisation that if there had been a third crash, it would have wiped out the airline.

This mass of public opinion is almost certainly what finally forced Trump to ground all MAX 8 and 9s. The weight of public opinion indicates that the world simply no longer trusts America, its Federal Aviation Administration and Boeing, to be honest about safety. It is significant that Ethiopia has insisted that the ‘black boxes’ not be sent to the US for analysis.

The fallout from the Trump administration’s grounding of the MAX is profound. As long as the airlines chose to ground the aircraft themselves, Boeing was not responsible for their losses. But a grounding by the FAA makes Boeing responsible for the airlines’ losses for all 371 MAX planes flying worldwide. There is nothing more expensive to an airline (short of a crash) than a brand-new airliner sitting idly on the ground. Norwegian Air Shuttle has already said it will send the bill to Boeing after it was forced to ground its fleet of 18 MAX 8s. The other airlines will no doubt follow suit.

The scale of this disaster for Boeing is colossal. The narrow body MAX's make up much more than half of Boeing’s total airline sales. Boeing has nearly 5,000 737 MAXs on order and they are producing them at the incredible rate of 57 new planes each month. It’s no wonder that $25-billion has been wiped off Boeing’s market cap by the Ethiopian crash.

The war between Airbus, with its A320 family, and Boeing with its heritage 737 design, is intense. These two crashes have shown how far Boeing had to go in its attempts to keep the 737 competitive. Major Boeing MAX orders are mooted to be switching to Airbus, which must be smirking all the way to the bank.

It is also a great loss to Africa’s safety record – after years of being the most dangerous place to fly, Africa cleaned up its act and had not a single fatal airline accident for the past two consecutive years.

But more worryingly, these MAX crashes remind us how both the airframe manufacturers and the airlines are able to pressurise the regulators and make ill-judged decisions about putting profits ahead of passenger lives. DM