The two recent Boeing 737 Max crashes in Indonesia and in Ethiopia have led me to reflect on the risks associated with automated technology. There were undoubtedly many factors behind these tragic crashes but what does it say about society’s zealous belief in automated technology. As someone said “I’d rather be killed by a pilot than an algorithm, at least the pilot is trying to keep me alive”.
Changes to the Boeing Max’s engine position which were introduced to compete with the fuel efficiency of Airbus’s new A320neo meant that the plane had an aerodynamic tendency to nose up. This left it susceptible to stalling during take-off and to compensate for this, an automated angle-of-attack compensation system (MCAS) was created. This system operated automatically while the plane was in manual control i.e. it augmented manual control. While the pilot flew the plane, the MCAS algorithm was in charge of the plane’s nose angle.
In the LionAir 610, the two angle-of-attack sensors, used to inform MCAS, were out by 20o as the plane was taxiing for take-off. It seems obvious now, that the 189 lives would have been spared if, while the plane was on the ground, the on board computer could tell the pilot to turn off MCAS as it cannot be relied upon because its sensors have malfunctioned. You would imagine that Boeing’s failure mode risk analysis (which I presume exists) should have anticipated this scenario. Remember, MCAS will automatically pitch the nose down, over-riding the pilot. It’s like a semi-automatic car where the driver works the pedals but a computer controls the steering wheel. Southwest has since decided to add a pilot notification indicator. Astonishingly, this appears to have been sold as an optional extra, like leather seats.
With the increasing reliance (and reliability) of automatic operations, airlines and pilots have reduced pilot training hours, creating a scenario where pilots are getting less and less time learning the skills of flying and are tending towards being glorified operators.
The changes in design the airline promised were minimal enough to ensure that pilots trained on previous versions of the 737 could switch to the Max with just “2.5 hours of computer based training “. In the fallout since the crashes, a lack of adequate training coupled with a lack of overall flying experience of the flight crew is being examined as a key factor. In the case of the Air Ethiopia plane, Captain Sully Sullenberg (he who safely landed the passenger jet on the Hudson river) said that while the flight crew ‘would have tried to do everything they were able to do to avoid the accident’ the first officer on the flight was ‘woefully inexperienced, he only had 200 hours of flight experience, an absurdly low amount for someone in the cockpit of a jet airliner.’ But even very experienced pilots didn’t know about the MCAS cut-out switches that would have stopped this rogue automat taking charge of the plane as Boeing decided not to include any information about the MCAS system in the on-board pilot manual.
I think their design engineers may have been blinded by their expertise to the extent that they just couldn’t see the risk.