10 ms·
That sounds like adding a heuristic which works most of the time which is something I can see myself doing to cover some pathfinding issue in a game where it's
by aurelwu 7y ago
That sounds like adding a heuristic which works most of the time which is something I can see myself doing to cover some pathfinding issue in a game where it's sufficient if it works 99,9% of the time or when working on a simulation where I can look on the result data afterwards and can see if something looks highly unusual despite the heuristic and improve it iteratively - a luxury you don't get with air planes, at least not without casualties. Additionally given the very limited computing power of the hardware in the 737 adding even more software to it might create even more problems.
- thelittleone 7y agoWasn’t aware the compute power was low on the 737. Interested if you have some more info? Always thought they would spec a substantially more processing capability than required. I understand economics are a factor but surely it’s not through necessity to save power?
- Maakuth 7y agoHere's an article about it. According to this piece, 737 avionics run on a pair of 80286s. https://www.moonofalabama.org/2019/06/boeings-software-fix-for-the-737-max-problem-overwhelms-the-planes-computer.html https://www.moonofalabama.org/2019/06/boeings-software-fix-f...
- seymore_12 7y agoThe should at least get 1202 error..
- tyingq 7y agoIf true it uses a 286, for some relative comparison, the fastest 286 is 1.5 MIPS. A run of the mill current Arduino is probably 20 MIPS, and a Raspberry PI3 is 2451 MIPS.
- robin_reala 7y agoCan’t find the exact MIPS estimate for the Harris CS80C286 25Mhz 286, but given that the 1.5MIPS was quoted for the 10Mhz Intel one I’d guess it’s substantially faster. Although still slower than an Arduino :)
- ethbro 7y agoI love how HN is taking umbrage in the rest of the comments about Boeing being too aggressive with MCAS et al. redesign. Then taking umbrage here that they were too conservative and possibly froze the hardware spec.
- tyingq 7y agoNo umbrage here. Just interesting to me. My Commodore 64 was half a MIP.
- CydeWeys 7y agoThe general consensus I've seen here on HN is that Boeing should have done a clean sheet design rather than trying to shoehorn increasingly ill-fitting features into a decades-old design. You're not accurately representing that view.
- ethbro 7y agohttp://news.aa.com/news/news-details/2011/AMR-Corporation-Announces-Largest-Aircraft-Order-In-History-With-Boeing-And-Airbus-07202011/default.aspx http://news.aa.com/news/news-details/2011/AMR-Corporation-An... "American also intends to order 100 of Boeing's expected new evolution of the 737NG, with a new engine that would offer even more significant fuel-efficiency gains over today's models. American is pleased to be the first airline to commit to Boeing's new 737 family offering, which is expected to provide a new level of economic efficiency and operational performance, pending final confirmation of the program by Boeing. This airplane would be powered by CFM International's LEAP-X engine." When a customer demands...
- aurelwu 7y agoThe issue is (from what I understand as layman) that to avoid recertification they kept their old computer hardware from earlier 737 generations, and added more and more tasks to do for it. https://www.nytimes.com/2019/06/26/business/boeing-737-max-faa-test.html https://www.nytimes.com/2019/06/26/business/boeing-737-max-f... (somewhere in the middle: "The issue discovered last week is linked to the data-processing speed of a specific flight control computer chip, according to the two people with knowledge of the matter. In the test, the F.A.A. pilot encountered delays in executing a crucial step required to stabilize an aircraft." )
- jacobush 7y agoThat's surreal - avionics should run on hard real time. (Whether it's offline scheduled and thus "impossible" to miss a deadline, or if it's "soft" realtime and merely testing ensures this, is not the important part. The important part is that it should never miss a deadline.)
- raverbashing 7y agoI can understand it looks weird but it isn't. A faster processor has no more real time guarantees than a slower processor from the 80s Of course, the faster one can do more stuff in less time, but for flying an airplane (or going to the moon) the amount of computing power needed is much less than people imagine. The issue here is adding more computing into an aging platform. But there's nothing inherently wrong into using an older platform into the flight computer. Now I'm not sure if for certification purposes they would be allowed to replace it with modern hardware but just keeping the functionality the same, I believe the answer would be yes, that they are allowed (but they probably didn't want to rewrite the sw and recertify the hw)
- wiz21c 7y agois it me or the certification looks at the hardware but not at the software ?
- 7y ago
- paulie_a 7y agoNASA supposedly bought 386 chips from eBay The lesson is real engineers do not need row hammer afflicted processing power, they are not running crappy JavaScript. They built something that works and over engineered the hell out it. Ford in Detroit once lost a mainframe. For 20 years
- paulie_a 7y agoTo the person that consistently downvoted and admitted to stalking me. Hi fuck yourself Edit I shared some info and got downvoted. I have been stalked on this website. The mods need to get their shit together. Apparently I pissed off the shitty mods and someone that works at Facebook.
- taneq 7y agoYeah, it’s a nice way of saying “this is a hack”.
- mtgx 7y agoMove fast and kill things. At least that seems to be the motto of self-driving carmakers, too.
- LifeLiverTransp 7y agoHey, just add a "I-the-User-m-Responsible" dead-men-switch to the plane, that the pilot has to press and you will be fine. Regards the Lawyers department for engineering & software hacks