Do the oddly angled “stealth” airframe design features that make these batwinged “flying wing” type planes hard to detect inflict a large penalty in manuverability or speed vs more conventional designs with the same weight and available engine power… or not?
Their design makes them difficult (if not impossible) to control without a computer working behind the scenes to keep the “wobbly goblins” steady. I can’t vouch for fuel efficiency when running the same distance as say, an F18 at the same speed, but being invisible certainly improves the odds that the fuel you DO use will not be wasted. There. I completely didn’t answer your post.
Are you sure its the stealth features that make it impossible to control manually? I always thought it was the design that made it fuel efficient at high speeds which made it inherantly unstable.
I’ve heard that the early “flying wing” planes didn’t work well enough because the control surfaces were such a small percentage of the whole flight surface that you had to be an amazing pilot to account for everything.
One of the stealth features is a lack of a vertical tail, which makes it unstable, yet removes the largest source of radar reflections.
Stealth aircraft are less fuel efficient, because the air intake and exhaust ports for the engines must be recessed, so as to reduce their infrared and radar signatures. Also, their sharp angled design is less aerodynamic, creating more drag.
I know that the stealth fighter was specifically designed to be as stealthy as possible, and that they traded off stealth for aerodynamics. They don’t call it the wobbily goblin for nothing. By the time the stealth bomber came along they had figured out how to do the equations with curves instead of straight lines, and the impact on its aerodynamics wasn’t so bad. The B2 is just a big flying wing. Flying wings can be difficult to control, which I think is the main reason the old northrop flying wing got scrapped. But they are fairly efficient flyers, from what I’ve read.
The F-117 can’t go supersonic. It’s an inherently unstable design, which happens to make it fairly manueverable. However, its performance compared to a real fighter is fairly lousy. Despite its designation as a fighter, the F-117 is really more of a light ground attack bomber. I’d hate to be the guy inside it if it ever did get into a dogfight.
The B-2 and the F-117 definately are less capable aircraft because of their stealth design. But the F-22 and the prototype F-23 were not. By the time they were designed, the technology had improved that they were able to make the planes very stealthy and still make them improvements on the F-14, F-15, F-16 and F-18. The F-22 is more radar-observable than the B-2, but it is much much less radar-obserable than our current fighters.
The F-117 doesn’t go supersonic for the same reason that silencers on firearms don’t work with supersonic ammo – relative silence (stealth) and sonic booms don’t go together very well.
It is my understanding that the stealth planes AND the F-14 and F-15 are inherently unstable. The stealth planes gained stealthiness and the front-line fighters gained maneuverability, in both cases by sacrificing stability. All are “fly by wire,” that is they are flown by onboard computers, without which they would all crash promptly. No human pilot could make the hundreds or even thousands of control corrections these planes require every second to remain airborne.
No kidding…I don’t think the F-117 possesses any air combat ability whatsoever. If a proper fighter caught one in the daylight visually the F-117 is toast.
I just saw a thing on Modern Marvels regarding stealth aircraft. They said the B-2 lays claim to the most complex flying machine ever built (edging out the Space Shuttle). It has (IIRC) over 100 computers to keep it flying. Without the computers I don’t think the pilots could control it and would likely crash. The F-117 likewise requires computer input to fly properly although I don’t know if a pilot, with difficulty, could maintain control if the computers failed.
That said I think the B-2 is a fairly efficient design. Cerrtainly it is about as low drag as you can get for an aircraft and that’s gotta be worth something. Also consider that the entire body is the lifting surface which would allow for weaker engines to drive it aloft or (more likely) greater payloads.
Most, if not all modern fighters are inherently unstable.
Unofficially, it has been reported that the F117A has the capability to carry a Sidewinder, but I sure as heck wouldn’t want to be the poor sap flying it and relying on a short range heatseeker with an SU-27 on my 6.
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- I think some terms are being confused here.
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- The only aircraft so far that can’t be flown without computer-assisted controls is the X-29–the wings would twist apart without it. Every other aircraft could be flown without computer assistance, were it not for the fact that the controls are digital fly-by-wire. So if all the computers stopped working, it’s game over–but if there were hydraudlic controls, it would still be useable in some regard. That’s the whole point of the wing-in-front/tail-behind design, and you may have noticed that even though it is now known that flying wings are more efficient, the US military (and indeed, aircraft manufacturers the world over) has been darn slow to abandon this basic aircraft design. The Germans were dabbling in flying wings some 50 years ago, with not a computer in sight.
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DougC, I presume you’re talking about the Horten bombers? The B-2 designers literally copied the old German design, making just a few changes to it. Sadly, I can’t find a decent picture (or even much information about them on-line).
Very true. There is a difference between unstable and unflyable.
Horton IX / Gotha 229 http://www.hotel.wineasy.se/ipms/stuff_eng_detail_hoix.htm
Has actual pics. Bottom of the page has artistic renditions of it. Gives you a better idea of what the gorgeous design really looked like.
I don’t think any of the Horten designs in Tucker’s link were completed or flew. Their HO IX (also known as the GO 229) did, but the war ended before the actual production aircraft were completed.
I don’t know that they really copied the German planes when were designing the B-2. If anything it was based on the B-35 / B-49 that Northrop themselves built in the late '40s.
According to the program I saw on Discovery Wings, the engineers went to the National Air & Space Museum, and crawled all over the Horten plane. It was, after all, the first stealth aircraft. (And if Hitler had been slightly less crazy, the thing would have dropped nukes on NYC.)
The GO 229 flying wing at the Smithsonian is a fighter-bomber comparable to the US P-38 Lightning. It didn’t have anywhere near the range needed to bomb the US or the carrying capacity to get off the ground with a WW II era nuke.
The Horten’s were working on a design for the XVIII Amerika Bomber intended to be able to bomb the US, but it didn’t get out of the design stage before the war ended.
Regarding the F-117, the concept design that eventually lead to the stealth fighter was nicknamed the “Hopeless Diamond” because of its shape and inherent instability.
:smack: You’re right, of course, but the GO 229 was designed to evade radar, and the folks at Northrop did go and study it. It’s also not the only military weapon the US uses that can trace it’s roots back to German work during WW II, pretty much everything in the modern US arsenal is based on work the Germans did.