Boeing Culpable in Lion Air Crash!
by John Lawrence, February 5, 2019
Last October a Lion Air 737MAX manufactured by Boeing crashed off the coast of Indonesia. All indications were that the pilots had struggled to keep the plane in the air while at the same time the plane's computers were forcing the nose down causing the plane to dive head first into the ocean. Now that the crash has been thoroughly investigated, it has been learned that a few lines of computer code added to the plane's software without the pilots' knowledge was the culprit in causing the crash. It is a case of too much technology turning the plane's functions over to a computer and taking the pilots' ability to fly the plane literally out of their hands.
It all started when Airbus announced a new version of their best selling A320 that was more fuel efficient. Boeing scrambled to come up with a competitive version of their 737. In doing this they redesigned the planes engines making them larger. This required the engines to be repositioned on the plane's wings, and, consequentially, there was a concern among Boeing engineers that this might lead to a stall under certain conditions. They chose to insert a few lines into the computer code that would automatically lower the plane's nose if the plane was about to stall. In order to to keep the price down so that the 737MAX would be price competitive with the new Airbus, Boeing didn't require any pricey pilot retraining as a result of the upgrades.
The New York Times reported:
Understanding how the pilots could have been left largely uninformed leads back to choices made by Boeing as it developed the 737 Max more than seven years ago, according to statements from Boeing and interviews with engineers, former Boeing employees, pilots, regulators and congressional aides.Those decisions ultimately prompted the company, regulators and airlines to conclude that training or briefing pilots on the change to the flight control system was unnecessary for carrying out well-established emergency procedures.
The story of the change to that system, and how it came to play a central role in the Lion Air crash, shows how safety on modern jetliners is shaped by a complex combination of factors, including fierce industry competition, technological advances and pilot training. It illustrates how, in the rare instances when things go awry, the interplay of those factors can create unintended and potentially fatal consequences.The crash has raised questions about whether Boeing played down or overlooked, largely for cost and competitive reasons, the potential dangers of keeping pilots uninformed about changes to a critical element of the plane’s software.
There was a malfunction of the so-called maneuvering characteristics augmentation system, known as M.C.A.S. due to faulty data being fed to it by the angle of attack sensors which are devices on either side of the fuselage that measure how much the plane’s nose is pointing up or down. Preliminary findings from the investigation suggested that the sensor on the pilot’s side of the plane was generating erroneous data. So erroneous data triggered the M.C.A.S. system taking control out of the pilots' hands and forcing the plane's nose downward.
Again from the New York Times article, Behind the Lion Air Crash, a Trail of Decisions Kept Pilots in the Dark:
The bottom line was that there was no regulatory requirement for Boeing or its airline customers to flag the changes in the flight control system for its pilots — and Boeing contended that there was no need, since, in the company’s view, the established emergency procedures would cover any problem regardless of whether it stemmed from the original system or the modification.
At least as far as pilots knew, M.C.A.S. did not exist, even though it would play a key role in controlling the plane under certain circumstances.
However, pilots were concerned about the lack of knowledge regarding the M.C.A.S. system. “I would think this is one of those systems that the pilots should know it’s onboard and when it’s activated,” said Chuck Horning, the department chairman for aviation maintenance science at Embry-Riddle Aeronautical University.
The faulty design of the Boeing 737MAX, in my opinion was that there was no intuitive way fro the pilots to take control of the plane away from the plane's computer once the M.C.A.S. system was activated. There was a way, however, if the pilots had been trained on it which was entirely too convoluted and unintuitive. The centerpiece of that procedure is to switch off two “stabilizer trim cutout” switches on the central console of the cockpit, and then flip open the handles on wheels near the knees of the captain and first officer. By cranking those wheels, the pilots can adjust the stabilizers manually in an effort to keep the plane from pitching up or down.
However, older 737s had another way of addressing certain problems with the stabilizers: Pulling back on the yoke, or control column, one of which sits immediately in front of both the captain and the first officer, would cut off electronic control of the stabilizers, allowing the pilots to control them manually. This is how it should have been done on the 737MAX.
In a car the driver can take over from cruise control just by stepping on the brake or the accelerator. It should have been as simple and intuitive for the pilots to take control of the plane as that, but it wasn't. In their haste to get a version of the plane on the market, Boeing and the FAA screwed up. It's as simple as that. So the fact that Boeing didn't require any pilot retraining and a faulty design was responsible for the death of 189 people. It was all about Boeing's profits. Newer isn't always better, and too much technology can be worse than simpler technology.