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cvbbdd
Post subject: Re: Planebucket Discussion ThreadPosted: March 14th, 2014, 2:09 pm
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Newb wrote:
I will go ahead and make a request, can anyone make Fictional Designs? I'd really be interested to see what people can come up with.
i got tons but they are topdown only

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  • USS Kearsarge crane ship No. 1(on hold) need pics
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klagldsf
Post subject: Re: Planebucket Discussion ThreadPosted: March 14th, 2014, 4:41 pm
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BoxOfRoundRocks wrote:
[ img ]
AV-122 Dragon is a heavy bomber built mostly from scraps of MiG 25 fleet in 70's to counter threat by fascistic Rameniak. Built largely from steel and wood as aluminum was difficult to get through naval blockade. Steel skeleton gave aircraft ability to absorb damage that could destroy any other bomber with penalty on performance. It has low speed, low ceiling and flies and can take hits like ton of bricks.
Ok.

Aerodynamically, there is nothing wrong with the design. It's very much inline with 1st generation or even 2nd generation jet bomber designs (though a bit outdated with the 3rd generation design that the MiG-25 represents, but I'm assuming that's what you're going for).

The backstory on the construction used for this plane...a different matter entirely.

I don't know how wood or steel are supposed to be incorporated exactly...both are far, far from ideal for a plane of this size and complexity. The DH Mosquito really represents the max performance you're going to get out of an all-wood construction. What worked for it isn't going to work with a large jet bomber design. The "steel skeleton" - I'm having a lot of trouble trying to conceptualize that. Having an internal "skeleton" isn't really how planes work save for the type of "bug smashers" I fly (like Piper Cubs and what not). Most planes have what's called a "monocoque" (yes, pronounced like something that really can't be said on these boards) construction where the outer skin and the "skeleton" holding the aircraft together are one in the same (like the exoskeleton on a typical bug that gets smashed on the windshields of the types of planes I typically fly) or, actually more typically, a "semi-monocoque" construction where the skeleton and outer skin are fused together (when you look at an airplane being constructed, this comes off in the form of ribs, stringers, and whatever that are riveted or welded to the aircraft skin - you can't really separate one from the other and have a distinct structure left, just a pile of stringers and aluminum sheets).

Yes steel (and titanium) construction worked for the MiG-25 but I can't see it working for something this large without having exceptionally powerful and thirsty engines. If a naval blockade is going to prevent you from building large aluminum aircraft, you're most likely going to have to import the best you can from whatever state you signed yourselves up as clients/satellites to. If the same blockage prevents aircraft delivery, then you're SOL (artillery and missiles are probably going to displace what would be more conventional tactical aircraft developments, i.e. South Africa).


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BoxOfRoundRocks
Post subject: Re: Planebucket Discussion ThreadPosted: March 15th, 2014, 3:04 pm
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klagldsf wrote:
I don't know how wood or steel are supposed to be incorporated exactly...both are far, far from ideal for a plane of this size and complexity. The DH Mosquito really represents the max performance you're going to get out of an all-wood construction. What worked for it isn't going to work with a large jet bomber design. The "steel skeleton" - I'm having a lot of trouble trying to conceptualize that. Having an internal "skeleton" isn't really how planes work save for the type of "bug smashers" I fly (like Piper Cubs and what not). Most planes have what's called a "monocoque" (yes, pronounced like something that really can't be said on these boards) construction where the outer skin and the "skeleton" holding the aircraft together are one in the same (like the exoskeleton on a typical bug that gets smashed on the windshields of the types of planes I typically fly) or, actually more typically, a "semi-monocoque" construction where the skeleton and outer skin are fused together (when you look at an airplane being constructed, this comes off in the form of ribs, stringers, and whatever that are riveted or welded to the aircraft skin - you can't really separate one from the other and have a distinct structure left, just a pile of stringers and aluminum sheets).

Yes steel (and titanium) construction worked for the MiG-25 but I can't see it working for something this large without having exceptionally powerful and thirsty engines. If a naval blockade is going to prevent you from building large aluminum aircraft, you're most likely going to have to import the best you can from whatever state you signed yourselves up as clients/satellites to. If the same blockage prevents aircraft delivery, then you're SOL (artillery and missiles are probably going to displace what would be more conventional tactical aircraft developments, i.e. South Africa).
[/quote]
It's built in somewhat desperate situation where bonds to U.S.S.R. have cooled down a bit as a punishment for rejecting communism and going with different political ideals. MiG-25 spare parts such as Tumansky R-15 engines, known to wreck themselves in combat were stockpiled for war time use when they might break faster than rebuilding was possible, leaving mighty warplanes grounded.

"Steel-skeleton" was a best phrase i could come up with to describe wood construction and steel trusses that hold everything together. It's got a "keel" or a backbone that runs through almost all of the airframe and to that steel truss are attached ribs, wings and other parts. Most of aluminum used are in landing gear, control surfaces, nose, leading edges and high temperature areas such as engine nacelles where plywood would not work as well. Wing spars are made of three steel trusses similar to that of back bone and wood ribs are attached to them. Wings are covered with thin plywood sheet skin made of sheets that are only 1,2 by 2,4 meters, an industrial standard size. As a result plenty replacement skin material is easy to get everywhere in Navajanir and damage to skin can be repaired very quickly even by woodworkers who have never touched an aircraft in their life.

It is a weapon of desperate times like He-163 was. Still it did well in war with Rameniak and conducted numerous fire bomb raids on enemy territory and shot down few enemy aircraft with R-40 missiles. After war Navajanir's relations with Soviet Union took turn to better and Dragon was replaced in first line service by supersonic bomber.

Edit. I fail at life to some extent. Quotes also.

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klagldsf
Post subject: Re: Planebucket Discussion ThreadPosted: March 15th, 2014, 4:04 pm
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BoxOfRoundRocks wrote:
It's built in somewhat desperate situation where bonds to U.S.S.R. have cooled down a bit as a punishment for rejecting communism and going with different political ideals. MiG-25 spare parts such as Tumansky R-15 engines, known to wreck themselves in combat were stockpiled for war time use when they might break faster than rebuilding was possible, leaving mighty warplanes grounded.
Ok, but the R-15 is designed for a very specific flight envelope. Any nation will stockpile large amounts of whatever engines all its planes use.
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"Steel-skeleton" was a best phrase i could come up with to describe wood construction and steel trusses that hold everything together.
I don't know if that will work.
Quote:
It's got a "keel" or a backbone that runs through almost all of the airframe and to that steel truss are attached ribs, wings and other parts.
That is exactly how not to design an aircraft's internal structure. At best you've introduced large internal members that are going to get in the way of the plane's ability to hold things, principally bombs. You can look at a whale skeleton to see what kind of construction that means (i.e., a very big backbone/keel that is going to dictate what the rest of the airplane looks like). Most real, large aluminum airplanes are built like a whale skeleton - but minus the backbone. Now that the skeleton is composed entirely of just the ribs, you have a lot more flexibility in take-off weight and how to actually design the aircraft. Since the ribs are bonded to a very strong exoskeleton, you don't need to worry about the lack of a backbone.

Planes do have a keel of sorts called the main spar but it runs perpendicular to what you're thinking - it's the "backbone" of the wing and it's what the ribs and stringers for the wing attach to. The shape of the wing (it helps that the fuselage gets much of its structural strength in being tubular) and the relatively lightweight and internal volume of the wing (it's not holding any heavy systems other than engine, hydraulics and fuel and all three of those don't care about what kind of internal volume the wing spar takes up) means it can not only get away with this, it must.
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Wing spars are made of three steel trusses similar to that of back bone and wood ribs are attached to them.
Oh, so you do know what wing spars are, my bad.
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Wings are covered with thin plywood sheet skin made of sheets that are only 1,2 by 2,4 meters, an industrial standard size. As a result plenty replacement skin material is easy to get everywhere in Navajanir and damage to skin can be repaired very quickly even by woodworkers who have never touched an aircraft in their life.
Well, I don't know if that's going to work. Yes it's ostensibly the same as the Mosquito but the Mosquito 1.) was operating at a different level of technology 2.) at a different operating environment (different speeds and most importantly at a different scale) and 3.) perhaps most important of all, the Mosquito had a very short shelf-life (if the plane could only last a few sorties, they were making so many it was good enough and they can and did salvage the engines and other parts from the shell for re-use on others if they ended up outlasting the plane). Many if not most Mosquitos simply and literally rotted out due to poor care and storage conditions.

And now that I've mentioned that you're no doubt planning on preventing that with proper care and storage conditions. I can store a wooden, say, Waco biplane in a limited climate-controlled hangar all by myself no problem. Long-term maintenance, however, is very labor intensive. And this is for a small single-engine aircraft that's still in production. For something like this you're pretty much going to do what the USAF does for B-2s now.

And if you think "that's ok, I'll just make more to make up for the attrition", that's going to be a very expensive proposition too.


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BoxOfRoundRocks
Post subject: Re: Planebucket Discussion ThreadPosted: March 15th, 2014, 8:00 pm
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klagldsf wrote:
Ok, but the R-15 is designed for a very specific flight envelope. Any nation will stockpile large amounts of whatever engines all its planes use.
That is a good point. I need to come up with an excuse to have them or alter backstory. Probably both.
klagldsf wrote:
That is exactly how not to design an aircraft's internal structure. At best you've introduced large internal members that are going to get in the way of the plane's ability to hold things, principally bombs. You can look at a whale skeleton to see what kind of construction that means (i.e., a very big backbone/keel that is going to dictate what the rest of the airplane looks like). Most real, large aluminum airplanes are built like a whale skeleton - but minus the backbone. Now that the skeleton is composed entirely of just the ribs, you have a lot more flexibility in take-off weight and how to actually design the aircraft. Since the ribs are bonded to a very strong exoskeleton, you don't need to worry about the lack of a backbone.
Plywood skin brings some limitations in durability and there's definitely space for spar inside hull this large. With wing area in this aircraft i believe it's easier to mass out than bulk out bomb bay. Kind of Starlifter problem inverted. Payload limits on full fuel load would make it reasonable to load up lighter napalm canisters or mixed load of small irons and incendiaries.
klagldsf wrote:
Planes do have a keel of sorts called the main spar but it runs perpendicular to what you're thinking - it's the "backbone" of the wing and it's what the ribs and stringers for the wing attach to. The shape of the wing (it helps that the fuselage gets much of its structural strength in being tubular) and the relatively lightweight and internal volume of the wing (it's not holding any heavy systems other than engine, hydraulics and fuel and all three of those don't care about what kind of internal volume the wing spar takes up) means it can not only get away with this, it must.
Building something of this size out of only wood would be too difficult as you have said before and aluminum in pre-war naval blockade is needed for other purposes. Steel is available so even as it's not ideal material it would be used. Truss would be triangular and fairly slim and high in ratio of something like one to two as it would need to hold just against . Could fit loong fuel tank inside backbone and here and there in hull. Fuel tanks might also fit inside wings between spars.
klagldsf wrote:
Well, I don't know if that's going to work. Yes it's ostensibly the same as the Mosquito but the Mosquito 1.) was operating at a different level of technology 2.) at a different operating environment (different speeds and most importantly at a different scale) and 3.) perhaps most important of all, the Mosquito had a very short shelf-life (if the plane could only last a few sorties, they were making so many it was good enough and they can and did salvage the engines and other parts from the shell for re-use on others if they ended up outlasting the plane). Many if not most Mosquitos simply and literally rotted out due to poor care and storage conditions.
Then skin must be replaced on every now and then.
klagldsf wrote:
And now that I've mentioned that you're no doubt planning on preventing that with proper care and storage conditions. I can store a wooden, say, Waco biplane in a limited climate-controlled hangar all by myself no problem. Long-term maintenance, however, is very labor intensive. And this is for a small single-engine aircraft that's still in production. For something like this you're pretty much going to do what the USAF does for B-2s now.
Meh. It's a wartime contraption made in desperate times to (mainly fire)bomb soft targets. I'll take those that are not lost in combat and push in airbase's darkest corners where they do not impede operations and let them slowly rot away forgotten and alone. Then i scavenge their decomposing hulls to keep MiG-25's and other aircraft airworthy. After couple years one corpse gets picked up, it's wings are clipped off and it's towed away for restoration. In few years it finds it's final resting place in nice aerospace museum where westerners can take pictures of it and buy merchandise.
klagldsf wrote:
And if you think "that's ok, I'll just make more to make up for the attrition", that's going to be a very expensive proposition too.
I'm not that NS yet. Or am I?

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klagldsf
Post subject: Re: Planebucket Discussion ThreadPosted: March 15th, 2014, 8:27 pm
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I don't think you're really appreciating what building an aircraft around a fuselage "backbone" would be like, especially if you want it pressurized (another thing wood isn't really great for). Really, you're asking for the aircraft to have no choice but to look like this:

[ img ]


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BoxOfRoundRocks
Post subject: Re: Planebucket Discussion ThreadPosted: March 15th, 2014, 11:54 pm
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Why pressure? We're not building comfortable airliner here.

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klagldsf
Post subject: Re: Planebucket Discussion ThreadPosted: March 16th, 2014, 7:50 am
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Pressurization isn't for the crew to feel comfortable, it's to prevent them from dying. Especially sensitive humans start to black out as little as 15,000 feet above sea level, and most people start to feel the onset of blackout at 18,000 feet, which is why it's illegal for aircraft to operate higher than that without either pressurization or oxygen masks.

Now I know what you're thinking now, your crew will just operate with oxygen masks then. It's really a temporary fix and even then, a rather ugly fix. Oxygen masks tend to limit crew movement and be imperfect (particularly in sealing), which is why the B-29 was such a big deal in that it had pressurization. The B-17 could fly almost as high as the B-29 operationally but it really sucked to be on one in the meantime.

Then you're probably thinking that this thing is going to be on the low-level mission only. Which I suppose is fine.

Also, it doesn't change the fact that a structural "backbone" like what you're describing is going to very rigidly dictate the shape of the aircraft. Kiss compound curves of any sort goodbye, for starters.


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BoxOfRoundRocks
Post subject: Re: Planebucket Discussion ThreadPosted: March 16th, 2014, 4:55 pm
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klagldsf wrote:
Now I know what you're thinking now, your crew will just operate with oxygen masks then. It's really a temporary fix and even then, a rather ugly fix. Oxygen masks tend to limit crew movement and be imperfect (particularly in sealing), which is why the B-29 was such a big deal in that it had pressurization. The B-17 could fly almost as high as the B-29 operationally but it really sucked to be on one in the meantime.

Then you're probably thinking that this thing is going to be on the low-level mission only. Which I suppose is fine.
Low altitude would probably be safer as in Vietnam soviet SAMs were a real threat to US aircraft. Dragon is facing western systems a decade later. Oxygen masks could bring an option to fly over some systems with lower ceiling.
klagldsf wrote:
Also, it doesn't change the fact that a structural "backbone" like what you're describing is going to very rigidly dictate the shape of the aircraft. Kiss compound curves of any sort goodbye, for starters.
Well.. Then I have to scrap that idea. Let's say that aircraft is built with aluminum monoque fuselage with some structures like cabin floors, parts of fuselage skin, bomb bay and wings made of pine wood and plywood to save valuable aluminum.

This has been fun and educating. Thx.

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klagldsf
Post subject: Re: Planebucket Discussion ThreadPosted: March 17th, 2014, 1:47 am
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BoxOfRoundRocks wrote:
Low altitude would probably be safer as in Vietnam soviet SAMs were a real threat to US aircraft.
Fun fact: the vast majority of U.S. aircraft losses were a result of low-level anti-aircraft fire of the old-fashioned WWII kind (indeed, many from artillery pieces quite literally left over from WWII) including the KS-19 and M1939. And again, in Desert Storm many collation aircraft losses were from anti-aircraft fire while at low or medium altitude. The only way to survive a modern anti-aircraft defense network is to either disable the network itself or equip your aircraft with the technology that will allow it to be undetected by said network (which anymore means broadband stealth).
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Well.. Then I have to scrap that idea. Let's say that aircraft is built with aluminum monoque fuselage with some structures like cabin floors, parts of fuselage skin, bomb bay and wings made of pine wood and plywood to save valuable aluminum.

That will work, I suppose. Just remember that if you're going to design something with a keel or backbone - look at a whale and you'll see that it's basically a cone-shaped animal. On the human torso, what's not supported by the shoulders or hips is for the most part supported and/or protected by the rib cage - which indeed is tubular-shaped. This is true of just about any animal with an internal skeleton. Bugs and other creatures with exoskeletons on the other hand actually get away with pretty complex structures. What works when going up the animal kingdom might actually be going backwards when dealing with structural engineering.
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This has been fun and educating. Thx.
You're welcome.


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