The Boeing 737 MAX uses 16-bit computers

“The Ancient Computers in the Boeing 737 Max are Holding Up a Fix”:

A brand-new Boeing 737 Max gets built in just nine days. In that time, a team of 12,000 people turns a loose assemblage of parts into a finished $120 million airplane with some truly cutting-edge technology: winglets based on ones designed by NASA, engines that feature the world’s first one-piece carbon-fiber fan blades, and computers with the same processing power as, uh, the Super Nintendo.

The Max has been grounded since March 2019, after some badly written software caused two crashes that killed 346 people. And while Boeing has received plenty of scrutiny for its bad code, it’s the Max’s computing power — or lack thereof — that has kept it on the ground since then.

Boeing took [the ethos of proven tech] to heart for the Max, sticking with the Collins Aerospace FCC-730 series, first built in 1996. Each computer features a pair of single-core, 16-bit processors that run independently of each other, which reduces computing power but also keeps a faulty processor from taking down the entire system.

Even by late-’90s consumer tech standards, the FCC-730s were behind the curve. By the time they went to market, Nintendo had already replaced its 16-bit SNES console with the Nintendo 64 (the first game console to use — you guessed it — a 64-bit CPU), and IBM had created the world’s first dual-core processor.

In other words, your washing machine or dishwasher from 2006 may have a more powerful processor than the B737 MAX (“Fujitsu Introduces New 32-bit Microcontroller for Home Appliances”).

22 thoughts on “The Boeing 737 MAX uses 16-bit computers

  1. Meh, men were sent to the moon on less computing power. Seems like the Max has fundamental geometry problems that can’t be fixed by software, regardless of how powerful the CPU that software runs on.

  2. The CPU on the MAX is not news, its basically an Intel 80286 processor. All of the B737 NG series have the same CPU, its kept for backward compatibility with the older FCCs. The common type rating is the criterion that undermines this whole mess.

  3. Electronic components are always far behind bleeding edge in aviation. Seems the author is making more of this than he should.

    Of course, it’s possible that like the airframe, 737 avionics are reaching their limits of expansion, but just criticizing a 16-bit processor seems over-reaching.

  4. I like Elon’s idea. Use cheap and up-to-date hardware and just make it very very redundant. For what Intersil charges for a rad-hard 1980’s CPU you can buy 100 up-to-date 64-bit CPUs.

    • How did it work for people killed by the Autopilot?

      (And, yes, rad-hardening is HARD. And expensive.)

  5. Feels like Boeing is all retro computing fans who just do it to keep history alive. Mars rovers are using more powerful computers. Based on the statistics, there’s absolutely no merit in using the obsolete parts & the obsolete cockpits with humans in the loop that they use. The mass of all that lead would buy a few millimeters of leg room.

    • As has already been stated, the big issue that a major change means a whole new certification. Boeing should have taken that step ages ago. When it came to Max, there was too much time and cost pressure. And in summary, Airbus aircraft are designed ground-up to be software intensive, Boeing not so. Each has its advantages, but Boeing hit the ‘keep it manual’ limit at just the wrong time.

  6. Obama always says if you like your 16 bit processors you can keep your 16 bit processors!

  7. The only difference modern computer power would have made given the same marketing and engineering team is that a modern chip would have made the decision to fly the plane into the ground a split second faster.

  8. If the Boeing engineers don’t know enough to install more than a single sensor and compare their outputs, in case of a single sensor failure, I don’t think increased computing power is going to help the situation. Sheesh!

    I really hope I’ve misunderstood what I’ve read about this. I can’t believe they’d do this.

  9. There is a reason for using older hardware, they are simpler all around and thus less prone to cause problems. And because they are simpler, they can withstand a tougher environment in which an airplane endures.

    Take your home appliances, what part goes out the most and first? The newer electronics such as touch surfaces, fancy sensors, etc. Same is true for luxury/comfort features in newer model cars.

  10. @Phil, have you been following Microsoft Flight Simulator 2020? If so, can you tell us what you think of it?

    I used to be a big fan of its original release up to some 20 years ago when I stopped flying them. Based on the videos out there [1], this just one, I cannot wait to try out this latest release once it comes out.


    • I am not a simulator hero! I do think MSFS 2020 is an interesting example of terrible timing. Imagine the sales if they could have released it back on March 1! How many consumers will want another excuse to stay indoors if this thing becomes available in the fall?

  11. Remember, the Max had been flying just fine for years prior to the two Third World accidents.
    And since the B-737 seldom has to make atmospheric entry calculations a 16 BIT processor was working just fine.

  12. Hi I’m a 23,000 hour pilot on private jets. . third world pilots don’t have the skills set. And I’m not saying all .but it’s a known factor. Of the lesser regulations in other countries. And putting 200hr pilots in ..cockpits. I fly learjets. That have systems that if you didn’t pass getting that system off in the stimulator. You failed .. My pilots and passengers died because of weak pilots. There’s one quik disconnect button in all jets. They had one to disconnect the system. Unskilled pilots panic. I see it every 6 month when I go to school. They wash up and need extra training. . don’t get me wrong we see it in the USA. But you must become a good commander ..Thanks

    • Yeah, there’s been several articles saying pretty much that, as nicely as possible. William Langewiesche’s was one, IIRC. Puts Boeing in a tough place.

      That still doesn’t excuse the atrocious Boeing engineering.

      Of course, you could find plenty of folks in the U.S. who had no business being in a cockpit. I wonder if for some cultural reason some of these third-world countries don’t filter so well for pilot candidates? Is it a result of the different training path?

    • Some of them you think they were the only one in the room. The instructors at the top flight schools say the same

    • Runaway trim has killed good pilots as well as bad ones. And the scenario these guys faced in the air was not one that was ever presented in the sim.

    • I agree with you. But there is a master disconnect. That I see for years was taught. And these guys still panic.. We see it more and more .

    • Long story short is if things are so bad you put a 300hr pilot in a 737. That’s bad management and pilot management.. Just doesn’t work.

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