101–110 of 173 posts
F-35 looks like it's the most ambitious software project ever attempted. - Lots of system integration for the final product from multiple suppliers (usually nightmare). - Autonomic Logistics Information System (ALIS) is critical for the maintainability and it's millions of lines of code. Failure rate of large projects like this is typically 40-60% and ALIS looks like it's more advanced than most bean counting systems…
"Abort, retry or fail?"
F-35 looks like it's the most ambitious software project ever attempted. - Lots of system integration for the final product from multiple suppliers (usually nightmare). - Autonomic Logistics Information System (ALIS) is critical for the maintainability and it's millions of lines of code. Failure rate of large projects like this is typically 40-60% and ALIS looks like it's more advanced than most bean counting systems…
"Abort, retry or fail?"
Earlier quoted context omitted.
Because, for all their software and development delays, they significantly outperform 4.5th gen offerings and (the A, at least, which is the majority of what people are buying) don't cost nearly as much (~85-95 million for an F-35A flyaway vs. 110-120+ million for a Eurofighter or Rafale).
Wasn't the F35 spanked by an obsolete F16 recently? Which means modern MiGs are going to eat it for breakfast.
There's also currently no missile for S-300/400 SAM capable to intercept F35, although there's a hectic R&D effort in that direction.
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Maybe it is an example of the sunk cost fallacy. But ruminate on this for a moment: if we were having this conversation in 1996, you could have easily said something like, "The F-22 is a $800 billion black hole; a stark lesson on the sunk cost fallacy. The F-15 exists, and works..." Maybe the F-35 is what you say it is, but when you look at the history of fighter development, I don't think the F-35 is significantly d…
Yes, to a degree, several modern fighter aircraft have run into significant cost and schedule overruns due to the additional complexity born of new advanced capabilities. However, the F-35's woes are particularly bad because of some disastrous decisions made early on with the project. First, the government decided not to start out with drafting detailed requirements for the JSF like they have for previous aircraft (a…
On requirements: as an engineer I know how disastrous it is to write bad requirements. But having a thorough set of bad requirements is better than not having requirements at all. Without requirements, just about anyone is free to make them up as they go along. As you said, the government did decide that it didn't know how to build planes and the defense contractors did.
But, also, the government has, by and large, shifted its engineering focus away from systems design and more towards systems engineering and integration. Also, in general, the government cannot pay the same kinds of salaries that contractors do. So, even if the government had wanted to take a more active role in systems design, it would have found itself lacking the right people to do so effectively.
This doesn't excuse the lack of requirements, but it does offer an explanation as to why the government didn't take a more active role in design.
> There was also a large reliance on computer simulation in lieu of real world testing. Predictably there were some sizable problems simulation did not catch, which resulted in major revamps and retrofits.
Most notably, the government provided an incorrect computer model of the dynamics of the arresting gear found on aircraft carriers. The initial F-35C arrestment hook was designed against this incorrect model. When testing revealed this deficiency, the hook had to be redesigned.
> But with the F-35 the government approved "concurrent production" which meant that production F-35's were getting built before all of the testing was complete.
Yes, in large part because the government believed that improved computer simulation would eliminate the need for a separate engineering and manufacturing development phase. We've seen how that worked out.
> Right now there are about 170 production F-35's out there
From different production lots, so not even all production aircraft are the same. Later production lots include fixes that must be retrofitted on earlier lots.
> and operational testing is far from finished.
What the government calls Operational Testing (OT, what is also known and talked about in the linked document as Initial Operational Test & Evaluation, or IOT&E) is different than a layman's interpretation of the term.
Traditionally, once the government completed a very detailed set of specifications and the contractor built a few prototypes, these prototypes were flight tested by the contractor (with government oversight, of course). Once the developmental testing was done, the completed aircraft and all its test results and paperwork were handed over to the government. "Here's your plane, it meets all your requirements." Then the government would conduct testing in environments representative of actual deployments and combat conditions. Operational Testing. The OT force for F-35 just stood up last year. OT has really barely even started.
> Put all of these facets together and it's a much worse situation than what we had with the F-22.
An amplification of previous trends, as I said earlier.
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This is what so many non-software people trying to make decisions on software fail to realize - every constraint added increases the complexity of software by an order of magnitude.
Maybe you can explain it to them this way - if they know what a function is. If you have a function that does something, foo, and it takes one boolean parameter, that's two test cases. If you add a second boolean parameter, now you have at least four total test cases. And so on.
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Harrier design concept is limited by the massive frontal cross section that Pegasus type engines imposes on the craft - this limits aero efficiency, and especially the ability to go supersonic. Harrier design is also completely not low observable. An F-35 could splash any harrier derivative from afar, and could probably beat out an Harrier in anything but the lowest altitude, lowest speed confrontations. F-35 is full…
F-35 could splash any harrier derivative from afar And an X-wing could take out an F-35, I mean, if we're talking complete hypotheticals. The Harrier is battle-proven everywhere from the Falklands to Afghanistan. Marry it up with modern radar and air-to-air missiles and you will have a very capable platform - one that the F-35 - if it ever flies in combat - which it won't because no-one will risk those mind-bogglingl…
This doesn't translate into a tactical capability today: Falklands: Harriers fighting Mirage III, which were 20 years old, 34 years ago. Afghanistan: dropping dumb bombs on adversaries who didn't have a SAM capability
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This is what so many non-software people trying to make decisions on software fail to realize - every constraint added increases the complexity of software by an order of magnitude.
well, a binary order of magnitude maybe
When viewing the F-35 through the lens of a defense project, it looks silly. You must also realize that this is also an indirect federal jobs program. When the F-35 would replace other aircraft and their roles, the bases, parts suppliers, and ...sub contractors those people had to be kept employed. No member of congress wanted to say don't add that or build that if it would hurt their district. So much backroom deali…
Army: We need 3 different planes Government: Why not build one plane that can do 3 things? it will be cheaper. ... it turns out it isn't.
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The F-35 is becoming the definitive example of how scope creep destroys a project Or an example of how we don't learn from history, for the same exact thing happened with the '60s TFX, except the F-35 substitutes S/VTOL for air superiority. 5 models of it were planned, two for the Navy, all but what ended up as the F-111 were canceled, and we resumed building focused planes like the F-14 through F-16, and the A-10 I…
>>Or an example of how we don't learn from history Of course we learn from history. The thing you have to understand is that everything is working as intended. F-35, and programs like it, are a way to use public money to create private sector jobs. They aren't meant to be efficient or even effective means to develop and manufacture military hardware. You can see a direct analogy of this in the space sector, where Spa…
Earlier quoted context omitted.
Fagan-style code review is likely a net productivity gain over no-reviews-at-all. Sure, scope creep is a killer, but I'd imagine it's a herculean task to create software for a new fighter. The expectation would likely be that software could control and/or monitor many features that would not have been software-controlled in previous generations. Safety requirements for flight (active life support) and armaments would…
IIRC, the F-22 has the equivalent of a Harris Night Hawk computer onboard. That was a big deal 20 years ago , but computationally outclassed by a $100 smartphone today. My memory, faulty as it may be, seems to recall a two page ad in AW&ST touting the Night Hawk "supercomputer" that would be in each F-22.
This processing capacity could be replaced with a couple of high density MILSPEC FPGAs. Its likely they'd use a 64-bit PowerPC processor augmented by FPGAs. The combined solution would be flexible and probably offer 1000x what the F-22 (Block 5 airframe) went into service, at a fraction the cost of the CIP [1]
As for the reference to the $100 smartphone, the latest "$100" smartphones could probably handle MegaPixel cameras for Augmented Reality and with connected sensors, more commonly known as "Sensor Fusion" [2]
Note: A failure of a $100 smartphone doesn't usually result in a pilot pulling the ejection handles on a $185m (unit cost) fighter. Avionics has to meet higher standards. There are MILSPEC versions of some of these processors. FPGAs are available with MILSPEC qualification.
[0] https://en.wikipedia.org/wiki/Intel_i960#i960_variants
[1] http://www.f22fighter.com/avionics.htm#2.1 Common Integrated Processor (CIP)
[2] http://www.f22fighter.com/avionics.htm#4.0 Software