Modern flight is a software problem wearing an aluminium shell.
05, Technology
Every aircraft and spacecraft flying today is a piece of software with a shape around it, and the software is held to standards the rest of the industry does not use.
Every vehicle in the other four fields is now defined as much by its code, sensors and compute as by its structure. Flight control laws, sensor fusion, redundancy, simulation, autonomy. This is also the fastest route into the industry for someone who already likes building things on a laptop.
What almost everybody thinks
“Autopilot flies the aircraft, so the pilots are mostly along for the ride.”
What is actually going on
Autopilot holds what it was told to hold. Deciding what to tell it (and noticing when what it is doing is no longer what the situation needs) is the job, and it is the part that gets people killed when it goes wrong.
Machines that show it
- Triple-redundant flight computersThree answers, a vote, and a plan for when one of them disagrees.
- Inertial reference unitsKnow where they are with nothing outside to look at, until the drift catches up.
- ADS-BAircraft broadcasting their own position, which is why anyone with an aerial can track them.
- Model-based developmentThe specification IS the code, because a specification nobody can execute is a specification nobody can test.
How it got here
- 1969The Apollo Guidance ComputerRoughly 72 kilobytes of rope memory, priority scheduling, and a landing it did not abort.
- 1972Digital fly-by-wireNASA flew an F-8 with no mechanical link between stick and surface, the computer became the aircraft.
- 1988Fly-by-wire in the airlinesThe A320 put envelope protection in front of hundreds of passengers a flight.
- 1992DO-178BThe standard that decides how airborne software is allowed to be written, and how much evidence it takes.
- 2000GPS, unblurredSelective availability was switched off, and civil positioning went from a hundred metres to a handful.
What you can learn here
Topic pages are being written, these are the first five
- 01
Software that cannot crash
How is flight software different?
Determinism, redundancy, formal verification, and why a flight computer is often slower than your phone on purpose.
- 02
Knowing where you are
How does an aircraft know its position?
Inertial measurement, GNSS, air data, and the filter that fuses disagreeing sensors into one answer.
- 03
Autonomy and control loops
How does autopilot work?
Feedback, gains, stability margins, the same loop whether it is holding altitude or landing a booster.
- 04
Testing in a computer first
What is a digital twin?
Models, hardware-in-the-loop, and how much of a vehicle is flown thousands of times before it is built.
- 05
What the data says afterwards
What happens to flight data?
Telemetry rates, flight test instrumentation, and turning a terabyte of signals into one engineering conclusion.
Where this leads
Everything on Mach 9 is connected in both directions. A concept leads to the people whose job it is, and a job leads back to what you would need to learn.
- CareerFlight Software EngineerWrites the code that has to work the first time, every time.
- CareerGuidance, Navigation and Control EngineerDesigns the loops that decide where the vehicle points and goes.
- CareerFlight Data EngineerTurns terabytes of test and flight signals into engineering answers.
- CareerSoftware EngineerBuilds the systems everything else runs on, in any industry that needs one.
Flickr / reivax, CC BY-SA 2.0ExplainerOne bad update, 8.5 million broken computersThe largest IT outage in history came from one file that was missing a single field.- Photo essayA humanoid robot just finished an eleven-month shift on a real production lineNot a demo video, an actual BMW factory, ten-hour shifts, for almost a year.
- BriefingAn AI system broke into a company while being tested for exactly thatOpenAI was testing whether its models could find and exploit security flaws. One of them escaped the test environment entirely and spent four days inside a real company’s production servers.
