Zit Seng's Blog

A Singaporean's technology and lifestyle blog

Aircraft Must Not Fly Like Magic

Modern passenger aircraft are extremely complex machines. There are all sorts of automated computer systems which help pilots fly their aircraft safely to their destination. While these systems are really cool, we should not forget that the pilots, ultimately, need to know how to fly, and how their aircraft work.

The two recent crashes of Boeing 737 MAX 8 aircraft, within five months of each other, are extremely worrying. They happened under similar circumstances, and the leading theory for the cause of crash points to faulty sensor input that led a computer system to force the aircraft into a dive, despite pilots’ struggle to grapple control of their aircraft.

Prior to the earlier crash of Lion Air flight JT610 in October last year, it seems that pilots were unaware of the Manoeuvring Characteristics Augmentation System (MCAS) design to force the nose of the aircraft down. Boeing, in their infinite wisdom, believed that pilots did not need to know about the system.

As a techie, and working with IT infrastructure, I always make it a point to understand the technology that I use. It is absolutely important. Some people may see technology as something magic. We also often joke about how things work, not just automatically, but automagically. Or joke about how gadgets have magic smoke in them that make them work.

However, in all seriousness, I absolutely want and have to know how the technology I use work. I don’t necessarily have to understand them entirely from first principles, but I need to understand them enough so that I can trust the technology.

A modern passenger aircraft has a lot of computers and automation built into them. For the most part, that’s a good thing. Humans make mistakes, and computers can help to spot, flag out, and correct those mistakes. However, we should be be mindful that computers can fail, and faulty computers should not be allowed to override pilots.

I often think of pilots as troubleshooters of technology problems in the sky. I don’t mean to diminish their profession. Pilots have great responsibilities; their jobs definitely require tremendous knowledge, skills, expertise, and experience. However, with the amount of technology and automation in modern passenger aircraft, and computers often doing most of the flying, it is not surprising that pilots are mostly just monitoring that technology and fixing problems that crop up mid-flight.

That means it is absolutely essential for pilots to know their aircraft in and out. They need to know about every system in the aircraft. They do, for the most part.

The problem with the Boeing 737 MAX 8 is that there is magic installed in the aircraft that pilots don’t know about. Boeing thinks that’s just fine, and worse, the United States’ Federal Aviation Authority (FAA) agrees.

The 737 MAX series is Boeing’s response to Airbus’ A320neo family of aircraft. Boeing was caught by surprise, and they scrambled to modify their hugely successful 737 aircraft design to compete with the A320neo. Boeing needed the 737 MAX to woo airline customers away from the A320neo.

Compared to the 737-800 which the 737 MAX 8 is designed to replace, the latter is heavier and its larger engine is mounted higher and more forward. This difference causes a shift in the centre of gravity, and causes the 737 MAX 8 to have a tendency to pitch up. The flight handling characteristics of the 737 MAX 8 have changed, but Boeing tried to compensate for that through software, in order to avoid costly pilot retraining. In fact, this is part of Boeing’s marketing strategy for the 737 MAX 8.

It is just crazy that Boeing should put out a new aircraft and have pilots believe that it’s basically the same as the old one. The aircraft is different, and it should have been pertinent for pilots to know everything they needed to know. Unlike aircraft technicians who have time to troubleshoot problems when the aircraft is on the ground, pilots don’t have that luxury mid-flight.

Can you imagine if, in the future, you had a fancy self-driving car that would one fine day auto-brake and auto-accelerate for reasons you cannot understand? Perhaps a faulty LIDAR is forcing an emergency brake due to a phantom obstruction that doesn’t exist? It would be scary, to say the least. However, in the worst case scenario, you could stop the car and step out.

You can’t do that with an aircraft.

In the first place, whatever system you put in an aircraft must be designed to be as fault tolerant as possible. Then, you had better tell the pilots all about the system. They need to know exactly what the aircraft is doing, what the computers are up to. You don’t want magic.

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