It Might Be A Kludge

I’m an engineer. Or used to be, but once an engineer, always an engineer. It’s a way of thinking, a way of looking at the world. And the two recent MAX 8 airliner crashes got me to thinking.

Engineers have a word they sometimes use: kludge (or kluge). It’s pronounced like ‘klooj’. Here’s how Wikipedia defines it:

A kludge or kluge is a workaround or quick-and-dirty solution that is clumsy, inelegant, inefficient, difficult to extend and hard to maintain. This term is used in diverse fields such as computer science, aerospace engineering, Internet slang, evolutionary neuroscience, and government.

Jackson W. Granholm, in his 1962 article "How to Design a Kludge", defined it this way:

‘An ill-assorted collection of poorly-matching parts, forming a distressing whole’; a machine, system, or program that has been improvised or 'bodged' together; a hastily improvised and poorly thought-out solution to a fault or 'bug'. ...

Back to the airliners. When Boeing designed the MAX, they started with a model 737. One of the changes they made was to install bigger engines. Ground clearance was already limited, so the engineers redesigned the engine attachment pylons, moving the engines forward and higher. This gave the engines more ground clearance, but it also had the unfortunate side-effect of causing the jet’s nose to pitch up under certain conditions. This nose-up condition could cause an aerodynamic stall, in which the wings no longer generate enough lift to keep the plane in the air. So, problem.

Engineers addressed this problem by adding to the flight-control software something called the Maneuvering Characteristics Augmentation System (MCAS). When MCAS detects a nose-up condition, it takes over the flight controls and pushes the nose down. The current working theory about the two crashes is that, due to a faulty sensor, MCAS pushed the nose down when it wasn’t supposed to and flew the plane into the earth.

To my engineer’s eyes, it looks like Boeing engineers created a problem when they moved the engines, and in order to compensate they installed a “fix” that came with its own potential problem. If MCAS isn’t a kludge, I think it skirts the definition uncomfortably closely. That’s my opinion, of course. I’m sure Boeing would vehemently deny that it was anything like a kludge. And yet two MAX airliners have crashed within about five months.

To be fair to the Boeing engineers, MCAS can be turned off from the cockpit. If the air crews had done that, the crashes could probably have been avoided. But the crews were apparently not aware of why the plane kept nosing down, or not aware that they could turn off MCAS, or both.