6 ms·
With all due respect, this sounds too much like the kind of armchair quarterbacking that routinely appears on HN when avionics/politics/astronomy is mentioned,
by yongjik 8y ago
With all due respect, this sounds too much like the kind of armchair quarterbacking that routinely appears on HN when avionics/politics/astronomy is mentioned, where a lone programmer feels competent enough to criticize an industry for missing "something obvious".
I mean, this particular change might have saved the particular 737, but I'd rather hear it from someone who actually knows how 737s fly.
- gowld 8y agoDo you think the analysis is invalid? Do you think that an autopilot response to "AOA > 15 degrees" should be the same regardless of whether AOA is 20, 40, 60, or 80 degrees?
- astrodust 8y agoIs there an industrial coding standard that makes recommendations here? What does NASA do?
- itronitron 8y agoa common practice is to limit the number of bits in the data value which will limit the range of values it can have
- deleted 8y ago[deleted]
- gamache 8y agophilg's been flying and writing about it for years: https://philip.greenspun.com/flying/ https://philip.greenspun.com/flying/
- noxryan 8y agoI agree that we frequently see this on HN in regards to aviation. However, I don;t think it applies to Greenspun. He's a knowledgeable and active pilot himself.
- bilbo0s 8y agoLots of people are, that doesn't mean they aren't armchair quarterbacking. I know how to fly airplanes and helicopters, does that make me an expert on the flight dynamics of 737 MAX?
- starpilot 8y agoAccording to Wikipedia he flew for Delta Airlines/Comair https://en.wikipedia.org/wiki/Philip_Greenspun https://en.wikipedia.org/wiki/Philip_Greenspun. That still doesn't mean he knows anything about writing code for flight control systems in commercial environments. Maybe he's written some toy code in MATLAB demonstrating some things, that's never undergone testing on a real airframe.
- VBprogrammer 8y agoI think it's fair to say that his knowledge of aircraft plus his knowledge of software and electrical engineering qualify him to speculate. Its quite likely he has greater knowledge of both subjects than the person who physically implemented MCAS. Sadly, no speculation is necessary. Had that change been included in MCAS the Ethiopian crash wouldn't have happened.
- tzs 8y agoAre there any airliners for which a sustained 60-70 degree angle of attack over a span of several minutes is not overwhelmingly likely due to sensor failure?
- joezydeco 8y agoHowever, any programmer that's been around the block a few times knows when they see a phrase like "all of the problems on the Ethiopian flight could potentially have been avoided by changing....about 10 characters of code" It's a sign that things are never as simple as they seem on the surface.
- js2 8y agoPhilip Greenspun is a highly experienced pilot: https://philip.greenspun.com/flying/milestones https://philip.greenspun.com/flying/milestones
- fixermark 8y agoHe doesn't seem to be an experienced owner of a home outdoor thermometer though. Or if he is, I need to know where he found one that goes to 452 degrees and why he even needs that much range. ;)
- navila17 8y agoDigital thermometers usually have triple digits to be able to display numbers in the low 100's. I could see one of them failing in a weird way and displaying 452.
- lepton 8y agoBBQ lid? Many have thermometers that go higher than this (say, 700F), and they're often outdoors.
- squarefoot 8y agoThe thermometer sensor and circuitry might be perfectly ok, still the 452 number might be a single digit gone bonkers in the panel, so that data being transmitted (maybe also recorded?) is ok while the readout is plain wrong. A human acting according data being shown there might react very differently from someone reading the temperatures log. Sometimes software problems can be awfully subtle.
- deleted 8y ago[deleted]
- darkpuma 8y agoHow else would you know there is a wildfire outside?
- depressed 8y agoI was as confused as the other commentators by this post until I realized that fixermark is thinking of analog thermometers with a physical dial, while we (and probably the author as well) are envisioning electronic thermometers with digital displays.
- Zak 8y agoPhilip Greenspun is, in fact a pilot. He is not a 737 pilot, but probably has a better idea of how a 737 works than the average HN armchair quarterback.
- phdp 8y agoPhilip Greenspun is not a no one when it comes to aviation. https://philip.greenspun.com/flying/resume https://philip.greenspun.com/flying/resume While he doesn't have 737 experience, he's far from an armchair quarterback.
- ronilan 8y agoDown by 4 at the Super Bowl, 2nd & Goal, 27 seconds on the play clock, Lynch in the back field. Run the ball About 10 characters of code. Sometimes armchair quarterbacking has a point.
- greedo 8y agoAs a Hawks fan, that hurt. Really hurt.
- ronilan 8y agoThe agony: https://www.youtube.com/watch?v=U7rPIg7ZNQ8 https://www.youtube.com/watch?v=U7rPIg7ZNQ8
- aidenn0 8y agoEven there though, the fact that the Pats scout team ran that exact play twice in practice with the backup nickelback in was something that the coach perhaps could not have anticipated? Any result other than an INT means Lynch still has a chance to run.
- sesteel 8y agoThis seems equivalent to "it is just a button, how hard can it be?" People outside of software rarely see the complexity they are suggesting or asking for.
- salawat 8y agoThis type of elitism has no real place in hopefully constructive conversation. I'm not going to ignore a well thought out point because someone doesn't have a PhD in the exact question under rumination. And "armchair quarterbacking" tends to translate to "Request For Comment" in my book. I.e. a coming together of disparate ideas and areas of expertise to more fully render the extent of a problem.