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Well, from my experience, the low-hanging fruit with improving existing configurations has mostly been done. The Navy has taken the Hornet to its logical full d

Well, from my experience, the low-hanging fruit with improving existing configurations has mostly been done. The Navy has taken the Hornet to its logical full development potential by orchestrating the creation of the Super Hornet, which is more than a simple 15% scale up, it's a whole new airplane. The Super should serve for the next 25 years or so. Although the Navy is beginning to do the initial studies for its replacement... One thing that constrains a lot of the older aircraft is electrical power. They don't have the big generators and high voltage DC power systems that the newer jets have. Those newer systems provide a lot more power budget for running all the advanced sensors. Now, I suppose you could add this capacity to older aircraft, but that's expensive because all this is really tied into the engine and would require some extensive mods. That means time out of service, and tying up depot maintenance. Maybe this is worth it in some cost/benefit comparisons -- I haven't really done the math. Just trying to point out a big gotcha in upgrading that most people don't often think about.

nickpsecurity 11y ago
See, now you're getting to the kind of stuff I'm talking about. They need more power budget. Other things about them are pretty good or easy to update. So, do a clean slate design following the other plane's strengths as much as possible while adding the new stuff. The result is not the same plane. Yet, it should deliver more value than a basic upgrade of old plane while having way less risk than a program requiring tons of R&D (eg F-35). Now, my proposal doesn't negate the possibility of investing in next-gen tech. The F-22 program didn't bother me because we have to push ourselves as far as possible in any specific area. The results usually trickle down into other, affordable tech. F-35, far as I can tell, benefited a bit from that program. The U-2, SR-71, B-2, and F-117 all offered unique capabilities. Just prefer that the majority of our fleet is cost-effective and value-driven. Leads to build on what's proven. U-2 is probably one of better investments given it's apparently still paying off (see below). Could probably use that F-35 sensor system & some control assistance for pilots. However, it could all just be an excuse for local Majors to jump in GTO's and tear up the tarmac. ;) http://www.popularmechanics.com/military/a7818/chasing-the-u-2-spy-plane-in-a-pontiac-gto-11000804/ http://www.popularmechanics.com/military/a7818/chasing-the-u...
- engi_nerd 11y ago
  Addressing your first paragraph, I have the feeling that the F-18 E/F Super Hornet is a real-world example of what you're talking about. A good airframe (the legacy F-18) was taken as the baseline for a new aircraft that featured greatly improved systems in all areas (including electrical power generation!). Does a Super Hornet deliver more value than a legacy F-18? Absolutely, I don't think anyone familiar with the type would argue otherwise. Anecdotally, all my friends with experience on both ranges of F-18 love the Supers. I've never touched them on any kind of engineering project though. But the Super Hornet was not risk-free (not that you implied such a program would be, I feel that you gave the concept a fair shake). It encountered some problems that almost killed the program. Here: http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA387614 http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=ht... Click on the link next to "PDF url" to obtain the report. This is a study of what almost wiped out the program...Trans-sonic wing roll-off, aka "wing drop". Much more readable article here: http://www.nasa.gov/centers/langley/news/factsheets/F-18.html http://www.nasa.gov/centers/langley/news/factsheets/F-18.htm... The cause was a difference in the wing-fold in the larger Super Hornet as compared to the original Hornet. You never know where risk can come from. You can, as you are no doubt well aware, try to schedule some risk out of the system, and design risk out of it, but it's always there. This is not an argument against your point -- after all, the F-18 E/F is a real world example, as I said, and a successful one -- but pointing out some of the caveats of it. Even things that seem like they should be simple can turn out to be complex. A lot like software...
  - nickpsecurity 11y ago
    Actually, I agree the Super Hornet is an example, maybe the best, of what I propose. The results show it delivered on my promise as well. It's no surprise that they ran into problems. Matter of fact, the problem is a common one in system evolution: assumptions built into use of components in version 1 no longer apply in version 2 but it wasn't taken into account. IIRC, this was the same reason for the failed conversion that destroyed the Ariane 5 rocket. The receiving component assumed and was coded for a smaller number, resulting in an overflow. This is why I'm a fan of keeping unambiguous, mathematical specifications (eg Z) side-by-side with readable, English description side-by-side with design. The specs should embed assumptions, maybe more visibly than other things. We've seen this in software with both Eiffel/Ada's Design-by-Contract and static analysis tools with similar pre- and post-conditions. You could say typing also helps. The person using a component should be able to readily tell what its requirements were and do a manual/automatic sanity check. Personally, I'd be surprised if your CAD tools for aerospace don't have requirements or integration checking features built into them. F/18 started around the time that such tools would've both been feasible and had computers that could run them fast. Do they seriously not have ways of catching at least obvious problems with component reuse?

nickpsecurity 11y ago

See, now you're getting to the kind of stuff I'm talking about. They need more power budget. Other things about them are pretty good or easy to update. So, do a clean slate design following the other plane's strengths as much as possible while adding the new stuff. The result is not the same plane. Yet, it should deliver more value than a basic upgrade of old plane while having way less risk than a program requiring tons of R&D (eg F-35). Now, my proposal doesn't negate the possibility of investing in next-gen tech. The F-22 program didn't bother me because we have to push ourselves as far as possible in any specific area. The results usually trickle down into other, affordable tech. F-35, far as I can tell, benefited a bit from that program. The U-2, SR-71, B-2, and F-117 all offered unique capabilities. Just prefer that the majority of our fleet is cost-effective and value-driven. Leads to build on what's proven. U-2 is probably one of better investments given it's apparently still paying off (see below). Could probably use that F-35 sensor system & some control assistance for pilots. However, it could all just be an excuse for local Majors to jump in GTO's and tear up the tarmac. ;) http://www.popularmechanics.com/military/a7818/chasing-the-u-2-spy-plane-in-a-pontiac-gto-11000804/ http://www.popularmechanics.com/military/a7818/chasing-the-u...

engi_nerd 11y ago
Addressing your first paragraph, I have the feeling that the F-18 E/F Super Hornet is a real-world example of what you're talking about. A good airframe (the legacy F-18) was taken as the baseline for a new aircraft that featured greatly improved systems in all areas (including electrical power generation!). Does a Super Hornet deliver more value than a legacy F-18? Absolutely, I don't think anyone familiar with the type would argue otherwise. Anecdotally, all my friends with experience on both ranges of F-18 love the Supers. I've never touched them on any kind of engineering project though. But the Super Hornet was not risk-free (not that you implied such a program would be, I feel that you gave the concept a fair shake). It encountered some problems that almost killed the program. Here: http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA387614 http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=ht... Click on the link next to "PDF url" to obtain the report. This is a study of what almost wiped out the program...Trans-sonic wing roll-off, aka "wing drop". Much more readable article here: http://www.nasa.gov/centers/langley/news/factsheets/F-18.html http://www.nasa.gov/centers/langley/news/factsheets/F-18.htm... The cause was a difference in the wing-fold in the larger Super Hornet as compared to the original Hornet. You never know where risk can come from. You can, as you are no doubt well aware, try to schedule some risk out of the system, and design risk out of it, but it's always there. This is not an argument against your point -- after all, the F-18 E/F is a real world example, as I said, and a successful one -- but pointing out some of the caveats of it. Even things that seem like they should be simple can turn out to be complex. A lot like software...
- nickpsecurity 11y ago
  Actually, I agree the Super Hornet is an example, maybe the best, of what I propose. The results show it delivered on my promise as well. It's no surprise that they ran into problems. Matter of fact, the problem is a common one in system evolution: assumptions built into use of components in version 1 no longer apply in version 2 but it wasn't taken into account. IIRC, this was the same reason for the failed conversion that destroyed the Ariane 5 rocket. The receiving component assumed and was coded for a smaller number, resulting in an overflow. This is why I'm a fan of keeping unambiguous, mathematical specifications (eg Z) side-by-side with readable, English description side-by-side with design. The specs should embed assumptions, maybe more visibly than other things. We've seen this in software with both Eiffel/Ada's Design-by-Contract and static analysis tools with similar pre- and post-conditions. You could say typing also helps. The person using a component should be able to readily tell what its requirements were and do a manual/automatic sanity check. Personally, I'd be surprised if your CAD tools for aerospace don't have requirements or integration checking features built into them. F/18 started around the time that such tools would've both been feasible and had computers that could run them fast. Do they seriously not have ways of catching at least obvious problems with component reuse?