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The portions of the software that need to be restarted have to do with avionics, not with the vehicle management computers that actually control the aircraft an

The portions of the software that need to be restarted have to do with avionics, not with the vehicle management computers that actually control the aircraft and keep it in the sky. The VMCs are triply redundant and are extremely reliable. The stuff that's making the news and causing all the problems has nothing to do with actually keeping the plane in the air.

natch 10y ago
Citation needed. And I'm not only concerned about the plane staying in the sky. I also want the jet fuel and the weapons to stay in the plane, to name a couple other items that are pluses. Nor do I have any confidence that a plane that stays in the sky today will do so tomorrow, given the record of this team. All kinds of things can go wrong[1]. Focusing on one aspect and claiming (without evidence) that this aspect is safe doesn't help a bit. And triply redundant means very little (as with a famous bomb accident example, sometimes all those redundancies are shown to still be cutting it very close)[2]. This is especially the case when the entire system is a poster child for projects going wrong[3]. 1. http://catless.ncl.ac.uk/Risks/ http://catless.ncl.ac.uk/Risks/ 2. http://www.theguardian.com/world/2013/sep/20/usaf-atomic-bomb-north-carolina-1961 http://www.theguardian.com/world/2013/sep/20/usaf-atomic-bom... 3. https://www.google.com/#q=f-35+failed+project https://www.google.com/#q=f-35+failed+project
- engi_nerd 10y ago
  The split between the F-35 vehicle systems and mission systems is described in [0]. "This new design approach breaks avionics into two categories: mission systems and vehicle systems. The former includes tools that help the aircraft do its job, such as sensors, displays, and weapons. The latter are subsystems that help the aircraft function correctly, such as power generation, cooling, and flight control." For more on the Vehicle Managment Computers, see [1], particularly: ""Each F-35 will have three boxes, making it a triple-redundant system," said Tom Burbage, executive vice president and general manager of the Lockheed Martin JSF program. "Each box 'votes' and compares its decision with that of the others before executing a command -- a process that takes place in much less than the blink of an eye. If one or even two boxes were to be damaged or malfunction, the aircraft would continue to operate normally." The all-digital VMCs, which save weight and space while improving precision, are at the heart of the distributed F-35 Vehicle System." When we say "Block 3i" we are talking about the mission systems hardware[2] and software that are all about "sensors, displays, and weapons". All I intended was to point out this difference, and to point out that the vehicle systems are controlled by physically distinct components and simply saying "The F-35 software" isn't completely accurate. You'll note I made no claim about safety, nor do I intend to do so. Future performance of the system does not necessarily depend on its past performance. Allow me to point out,though, that through 50,000+ flight test hours, no F-35 has been lost through a flight control failure (again, no guarantee that there isn't some latent failure case awaiting discovery!) And, as an engineer who is struggling to tame some complexity on a rather bothersome flight test instrumentation system, I'm well aware of risks (I love Risks Digest!). Heck, check some of my post history, I'm often exhorting people to read John Gall's Systemantics and heed its lessons. Discuss technical failings of the program if you wish, but remarks about the "record of this team" and a google search to "f35 failed project" are rather offputting and are, in my humble opinion, needlessly negative. [0]: http://www.militaryaerospace.com/articles/print/volume-14/issue-5/features/special-report/f-35-jet-fighters-to-take-integrated-avionics-to-a-whole-new-level.html http://www.militaryaerospace.com/articles/print/volume-14/is... [1]:http://www.prnewswire.com/news-releases/first-lockheed-martin-f-35-joint-strike-fighter-vehicle-management-computer-delivered-55707452.html http://www.prnewswire.com/news-releases/first-lockheed-marti... [2]: http://www2.l-3com.com/displays/pdfs/redesign/ICP(2011)_LR.pdf http://www2.l-3com.com/displays/pdfs/redesign/ICP(2011)_LR.p...

natch 10y ago

Citation needed. And I'm not only concerned about the plane staying in the sky. I also want the jet fuel and the weapons to stay in the plane, to name a couple other items that are pluses. Nor do I have any confidence that a plane that stays in the sky today will do so tomorrow, given the record of this team. All kinds of things can go wrong[1]. Focusing on one aspect and claiming (without evidence) that this aspect is safe doesn't help a bit. And triply redundant means very little (as with a famous bomb accident example, sometimes all those redundancies are shown to still be cutting it very close)[2]. This is especially the case when the entire system is a poster child for projects going wrong[3]. 1. http://catless.ncl.ac.uk/Risks/ http://catless.ncl.ac.uk/Risks/ 2. http://www.theguardian.com/world/2013/sep/20/usaf-atomic-bomb-north-carolina-1961 http://www.theguardian.com/world/2013/sep/20/usaf-atomic-bom... 3. https://www.google.com/#q=f-35+failed+project https://www.google.com/#q=f-35+failed+project

engi_nerd 10y ago
The split between the F-35 vehicle systems and mission systems is described in [0]. "This new design approach breaks avionics into two categories: mission systems and vehicle systems. The former includes tools that help the aircraft do its job, such as sensors, displays, and weapons. The latter are subsystems that help the aircraft function correctly, such as power generation, cooling, and flight control." For more on the Vehicle Managment Computers, see [1], particularly: ""Each F-35 will have three boxes, making it a triple-redundant system," said Tom Burbage, executive vice president and general manager of the Lockheed Martin JSF program. "Each box 'votes' and compares its decision with that of the others before executing a command -- a process that takes place in much less than the blink of an eye. If one or even two boxes were to be damaged or malfunction, the aircraft would continue to operate normally." The all-digital VMCs, which save weight and space while improving precision, are at the heart of the distributed F-35 Vehicle System." When we say "Block 3i" we are talking about the mission systems hardware[2] and software that are all about "sensors, displays, and weapons". All I intended was to point out this difference, and to point out that the vehicle systems are controlled by physically distinct components and simply saying "The F-35 software" isn't completely accurate. You'll note I made no claim about safety, nor do I intend to do so. Future performance of the system does not necessarily depend on its past performance. Allow me to point out,though, that through 50,000+ flight test hours, no F-35 has been lost through a flight control failure (again, no guarantee that there isn't some latent failure case awaiting discovery!) And, as an engineer who is struggling to tame some complexity on a rather bothersome flight test instrumentation system, I'm well aware of risks (I love Risks Digest!). Heck, check some of my post history, I'm often exhorting people to read John Gall's Systemantics and heed its lessons. Discuss technical failings of the program if you wish, but remarks about the "record of this team" and a google search to "f35 failed project" are rather offputting and are, in my humble opinion, needlessly negative. [0]: http://www.militaryaerospace.com/articles/print/volume-14/issue-5/features/special-report/f-35-jet-fighters-to-take-integrated-avionics-to-a-whole-new-level.html http://www.militaryaerospace.com/articles/print/volume-14/is... [1]:http://www.prnewswire.com/news-releases/first-lockheed-martin-f-35-joint-strike-fighter-vehicle-management-computer-delivered-55707452.html http://www.prnewswire.com/news-releases/first-lockheed-marti... [2]: http://www2.l-3com.com/displays/pdfs/redesign/ICP(2011)_LR.pdf http://www2.l-3com.com/displays/pdfs/redesign/ICP(2011)_LR.p...