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Status of F-35 – Senate Armed Services Committee Statement [pdf]

armed-services.senate.gov

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Re: Status of F-35 – Senate Armed Services Committee Statement [pdf]

#61

Post by fiatmoney »

coredog64 wrote: post #12
wyldfire wrote: post #7

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.

There are very few functional requirements on that kind of a system that are linearly improved by a faster computer - it's not like they're mining bitcoins in flight. "Doing X in real time" is usually the goal and any faster is superfluous. OTOH, "X percent more robust when pulling G's / subjected to EMP / hit by shockwave" is an excellent property to have, so you stick with simpler systems.

Re: Status of F-35 – Senate Armed Services Committee Statement [pdf]

#62

Post by fiatmoney »

jasonwatkinspdx wrote: post #40
LoSboccacc wrote: post #33

Earlier quoted context omitted.

It is a respunding success according to the amount of porking it generated. Is the f-22 exported? Edit: to clarify: they're not exporting the good one which could change an actual war.

No exports of the F-22. It's apparently got some technology they're not willing to transfer, even to allies.

The politics are a bit more complicated. The DoD would be willing to export to, eg, the UK & Canada, but any exports at all would trigger calls by lobbying organizations to send it to "allies" like Israel & Saudi Arabia, which then immediately finds its way to China / Pakistan / etc.

Re: Status of F-35 – Senate Armed Services Committee Statement [pdf]

#63

Post by engi_nerd »

mozumder wrote: post #58
johngalt wrote: post #8

The F-35 is becoming the definitive example of how scope creep destroys a project. A system designed to do everything for everyone. When it should be designed to do one thing better than everything else. Divide the F-35 into three different attack aircraft. Single engine CAS with STOVL capability. Big/fast/stealthy twin engine bomber. Carrier based attack drone. All three would likely fulfill their roles better for l…

Isn't the F-35's high price due to it already being 3 very different attack aircraft? 1. CAS with STOVL capability (Marine) 2. Light attack fighter (Air Force) 3. Carrier attack plane with bigger wings (Navy) Creating 3 separate programs isn't going to change that. And, if not that, then the software they want is going raise the prices of the 3 different aircraft anyways. The Marines are probably going to want to dev…

They don't have the kind of assembly commonality that the program aimed for initially, but I think it's a stretch to call the three variants "very different" aircraft. There's a pretty high amount of systems similarity. And pilots don't have to go through completely separate training programs for the three variants, just separate qualifications for things like STOVL or CV operations. If you can aviate in an F-35A, you can aviate in the other two variants.

Not sure why you single out the USMC for developing the helmet mounted display, because the HMD is common to all variants and is already a working system.

Re: Status of F-35 – Senate Armed Services Committee Statement [pdf]

#64

Post by engi_nerd »

brohee wrote: post #60
nabla9 wrote: post #20

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…

>> no less than 27 power cycles were required to get all systems functioning between initial startup and takeoff. These power cycles varied in degree – from “cold iron” resets, where the aircraft had to be shut down and then restarted, to component or battery power recycling. > Holy shit! Even more extraordinary that they found someone willing to takeoff after that...

Those are 27 power cycles spread across all the different flights described in that section of the document, not 27 power cycles for one single flight.

Re: Status of F-35 – Senate Armed Services Committee Statement [pdf]

#65

Post by ecnal »

mrweasel wrote: post #25

>The combination of re-hosted immature software and new processors resulted in avionics stability problems that were significantly worse than Block 2B So, the upgrade actually made thing worse. I'm sure I'm colored by many of the negative articles about the F-35, but other than "we already spend a lot of money on this thing" and "there's no plan b", why aren't the F-35 scrapped? For the US, it would maybe make sense…

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).

Re: Status of F-35 – Senate Armed Services Committee Statement [pdf]

#66

Post by beamatronic »

wrong_variable wrote: post #23
nabla9 wrote: post #20

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…

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.

Re: Status of F-35 – Senate Armed Services Committee Statement [pdf]

#67

Post by braythwayt »

icegreentea wrote: post #52
gaius wrote: post #41

Earlier quoted context omitted.

You could start a brand new Harrier programme right now, same basic design but new build airframes, avionics and engines using modern materials, and you would still beat the F35 not only into-service, but in a stand-up fight if it ever came to that.

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…

"Hunh, ComplicatedX is expensive and 20% of the project is causing 80% of the overruns. We should just do SimpleY, we get 80% of the value for 20% of the price!"

...Ten years later...

"SimpleY is no longer Simple, it turns out that although we got 80% of what we wanted for 20% of the price, the last 20% of what we wanted were responsible for 80% of the overruns!"

Re: Status of F-35 – Senate Armed Services Committee Statement [pdf]

#68

Post by Impl0x »

This might be off topic, but there are a few comments on here (mostly) joking about why we even should bother designing planes like the F-35 to be operated locally by humans. I'm curious, does anyone have any info on the state of drone fighter planes, either remotely piloted or completely autonomous? Does such a project even merit consideration when we could innovate missile systems instead?

Re: Status of F-35 – Senate Armed Services Committee Statement [pdf]

#69

Post by maxerickson »

Gravityloss wrote: post #19
vonmoltke wrote: post #9

Earlier quoted context omitted.

The unit production cost (the cost of building an aircraft, not including amortized R&D) for the F-22A is about 50% higher than for the F-35A. You could certainly argue that two F-22As is better than three F-35As, but that is an issue that needs to be considered. Furthermore, the F-22A was already running into parts obsolescence issues when I was working on it (2002 - 2006). Those would have continued to get worse ha…

The solution should be relatively straightforward. Purpose built different airframes, with relatively conservative technology. Share components where it makes sense. Manufacture lots of airframes and spares. Update components later. The next US fighter / attack program is going to be like that. It aims a lot lower and should be more predictable. I've lost track if it's called F-X or F/A-XX or what now, and what are t…

Yes, my naive reaction to reading about these planes and the maintenance requirements is that they are pushing for capabilities that are unreasonable given the available technology.

Re: Status of F-35 – Senate Armed Services Committee Statement [pdf]

#70

Post by robotresearcher »

matt-attack wrote: post #53
tomjen3 wrote: post #26

Earlier quoted context omitted.

Honestly why do we still spec these with pilots? Why not make a generation of hyper-advanced missiles? It has got to be cheaper and easier (you don't need to visualize anything, because it is a computer) and you wouldn't even need active lifesupport.

...but you'd need a ton more software, which based on the F-35's history, is already the key hurdle in its design.

Or maybe less software since there is a lot of pilot-support stuff you don't need any more.
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