Vifam7 Posted October 8, 2014 Posted October 8, 2014 Just out of curiosity, why is this? Is it because of thrust vectoring engines or that the idea of variable geometry wings are too cumbersome and heavy to make it worthwhile? Mainly, it's because advances in wing design, fly-by-wire, and high thrust engines made the need for VG wings unnecessary. Quote
Chronocidal Posted October 8, 2014 Posted October 8, 2014 The VG wings were also one of the significant nails in the F-14 service life's coffin, from what I recall. Besides all the stresses of carrier operations in general, the entire wing was mounted on a giant bearing, and all the parts within the wing support structure had to absorb stresses and flexing from varying directions. The entire problem of designing a variable geometry wing is kind of an aeroelastic nightmare. VG wings still can and do give some great advantages to certain aircraft, but you pay a very high cost in maintenance and general wear and tear for those benefits, especially on a carrier-based aircraft. Quote
Nekko Basara Posted October 8, 2014 Posted October 8, 2014 (edited) Just out of curiosity, why is this? Is it because of thrust vectoring engines or that the idea of variable geometry wings are too cumbersome and heavy to make it worthwhile?I think that the general consensus is that advanced static wing shapes can match enough of the aerodynamic versatility of variable geometry wings without the massive penalties in weight, volume, and mechanical complexity.Also - relevant to the F-14/F-23 hybrid concept - variable geometry is basically incompatible with stealth, because stealth shaping relies in part on limiting radar reflectivity to specific aspects. This is why on stealth aircraft you typically see that any shapes which aren't curved and blended have edges that align with (that is, are parallel to) a few specific angles. The leading edges of the wings match the leading edges of the tail, the edges of the intakes, the edges of the sawtooth cuts on any panels, etc. Having wings that change angle would mess this up in a big way. Edited October 8, 2014 by Nekko Basara Quote
SchizophrenicMC Posted October 8, 2014 Posted October 8, 2014 I'm not convinced passive stealth is effective enough for all of the aerodynamic compromises it entails. Not for a fighter/attacker. VG wings are decidedly unnecessary because it's possible to use computers to give control surface dynamics that allow more swept-back profiles to have lower stall speeds and better manners at a wide range of speeds. That wasn't the case in 1972, so the F-14 made sense. There are still unique advantages to the VG wing, but they're often outweighed by the disadvantage of mass and maintenance. Like Chronocidal said, the wings rest on a massive bearing that has to withstand most of the lift load of the aircraft, as well as withstand the load of the wings' weight during landing, and all of the g-loading during flight. It can do that, for awhile, but it needs frequent maintenance. Non-carrier VG aircraft can sometimes get away with this- look at the Tornado and F-111. But the F-14 was a large carrier aircraft with them. With that said, the ASF-14 would have been a significant redesign of the airframe, similar to the F/A-18E over the CF-18C/D. It would have involved changes to the wing profile and variable geometry design, as well as the replacement of traditional controls with fly-by-wire systems. While these wouldn't have negated the disadvantages of the VG wing, they would have helped. Mostly I'm just sad they scrapped all of the tomcats. Shoulda left a few for aerial demonstrators. Quote
Devil 505 Posted October 8, 2014 Posted October 8, 2014 Mostly I'm just sad they scrapped all of the tomcats. Shoulda left a few for aerial demonstrators. You can blame Iran for that one. The U.S. didn't want any spare parts to fall into their hands. Quote
F-ZeroOne Posted October 8, 2014 Posted October 8, 2014 I seem to recall, though, that having encountered problems with the F-111 Grumman deliberately designed the F-14s wing-box (i.e. the point around which the wing swiveled) to be extremely durable; I recall reading that it was basically entirely machined out of titanium. Quote
David Hingtgen Posted October 8, 2014 Author Posted October 8, 2014 Weight. Weight weight weight. Always an issue, but even more so nowadays---weight affects range, weight affects payload. Both civil and military planes are going for more range and more payload with a high priority. Even flap and aileron designs are being simplified in the name of weight. Sure, triple-slotted fowler-flaps inherently give more drag and lift for landing---but they're heavier than single or double-slotted ones. Triples replaced with doubles, doubles replaced with singles... Pneumatic vs electric vs hydraulics systems, wires vs fiber optics---none are being chosen in the name of raw performance, but purely by "what weighs less for this section of the plane". A swing-wing mechanism is heavy, regardless of any aerodynamic gains it offers. And almost everything nowadays is "yeah, it may be better---but it's heavier!". "Almost as good but lighter" is the big trend lately. Even 2D vs 3D vectoring---guess which is superior, but which one is almost as good but lighter? Quote
Devil 505 Posted October 8, 2014 Posted October 8, 2014 Doesn't go far enough. Look at this: I could probably go even further than that. Quote
F-ZeroOne Posted October 9, 2014 Posted October 9, 2014 Sorry to go off-topic (sort of), but whats the blue Valkyrie that looks like an upgraded VF-1? Quote
miles316 Posted October 9, 2014 Posted October 9, 2014 Sorry to go off-topic (sort of), but whats the blue Valkyrie that looks like an upgraded VF-1? BlueValk=Max (red Baron of Macross)!!!!!!!!! Quote
Devil 505 Posted October 9, 2014 Posted October 9, 2014 Sorry to go off-topic (sort of), but whats the blue Valkyrie that looks like an upgraded VF-1?It's the VF-3000 Crusader. It was featured in the game Macross M3 which starred Max, Milia, and their adopted daughter, Moaramia. Quote
F-ZeroOne Posted October 9, 2014 Posted October 9, 2014 Ah, thank you - I'd heard of it before. miles316, I have a reasonable idea what blue signifies in Macross - basically, AWESOMENESS is about to happen. Quote
SchizophrenicMC Posted October 9, 2014 Posted October 9, 2014 You can blame Iran for that one. The U.S. didn't want any spare parts to fall into their hands. It's politics. Even if Iran somehow managed to get spare parts from USAF demonstrator squadron or USANG patrol squadrons, they wouldn't be able to wage any kind of meaningful combat against anyone with those planes. Otherwise, they might have actually tried at some point in the 42 years they've owned the planes. Quote
Devil 505 Posted October 9, 2014 Posted October 9, 2014 It's politics. Even if Iran somehow managed to get spare parts from USAF demonstrator squadron or USANG patrol squadrons, they wouldn't be able to wage any kind of meaningful combat against anyone with those planes. Otherwise, they might have actually tried at some point in the 42 years they've owned the planes. Actually, I believe they did manage to acquire some spare parts back in the '80s, as part of the Iran-Contra scandal. Also, it is known that Iran looked to the Soviets at one point for technical assistance, with at least one Tomcat ending up in Russian hands. Quote
electric indigo Posted October 9, 2014 Posted October 9, 2014 Even if Iran somehow managed to get spare parts from USAF demonstrator squadron or USANG patrol squadrons, they wouldn't be able to wage any kind of meaningful combat against anyone with those planes. Otherwise, they might have actually tried at some point in the 42 years they've owned the planes. They did, actually. http://en.wikipedia.org/wiki/Jalil_Zandi http://en.wikipedia.org/wiki/Islamic_Republic_of_Iran_Air_Force Quote
Devil 505 Posted October 9, 2014 Posted October 9, 2014 Meanwhile, in South Korea: I'm surprised the KF-X is still ongoing after the RoKAF selected the F-35. Quote
electric indigo Posted October 9, 2014 Posted October 9, 2014 Looks like they insist on canards and two engines... Quote
Shadow Posted October 9, 2014 Posted October 9, 2014 (edited) Actually, I believe they did manage to acquire some spare parts back in the '80s, as part of the Iran-Contra scandal. Also, it is known that Iran looked to the Soviets at one point for technical assistance, with at least one Tomcat ending up in Russian hands. Ofcourse in exchange, the Soviets got their hands on the AIM-54A which probably played a huge role in the development of the R-33 Amos used on the MiG-31. I would have preferred to have seen all of the F-14A and B models retired in 06 and kept the remaining Ds in service until 2018 or so. Atleast until the messiah that is the F-35 enters Naval service. Edited October 9, 2014 by Shadow Quote
Scyla Posted October 9, 2014 Posted October 9, 2014 *snip* I'm surprised the KF-X is still ongoing after the RoKAF selected the F-35. So they crossbreed an Raptor with the Typhoon and a Super Hornet? Quote
Gakken85 Posted October 10, 2014 Posted October 10, 2014 I love the gripen. Would be cool to see a fan racer coverted to one haha Quote
Fatalist Posted October 10, 2014 Posted October 10, 2014 Give or take on the music, but there's some amazing shots in this video Quote
SchizophrenicMC Posted October 10, 2014 Posted October 10, 2014 I maintain that US Navy fighter pilot is the coolest job ever. Quote
Coota0 Posted October 11, 2014 Posted October 11, 2014 It's politics. Even if Iran somehow managed to get spare parts from USN demonstrator squadron or USNR squadrons, they wouldn't be able to wage any kind of meaningful combat against anyone with those planes. Otherwise, they might have actually tried at some point in the 42 years they've owned the planes. Just a quick fix. Quote
SchizophrenicMC Posted October 12, 2014 Posted October 12, 2014 Too bad about that space treaty. Quote
David Hingtgen Posted October 13, 2014 Author Posted October 13, 2014 Hello from the future past. http://24.media.tumblr.com/tumblr_m5mih7pMlg1qf71bqo1_1280.jpg http://www.yojoe.com/vehicles/88/phantom/ Quote
Nekko Basara Posted October 13, 2014 Posted October 13, 2014 Now I have the theme to Microprose's "F-19 Stealth Fighter" stuck in my head. I played the hell out of that, way back when. Quote
reddsun1 Posted October 13, 2014 Posted October 13, 2014 Now I have the theme to Microprose's "F-19 Stealth Fighter" stuck in my head. I played the hell out of that, way back when. OMG, I remember that one. Oh Lord--the crap that a google search'll turn up... Quote
Shadow Posted October 13, 2014 Posted October 13, 2014 I never played F-19. I played it's pseudo successor, F-117A. I recall reading on the F-19 game wiki page that the Soviets bought up quite a few copies of the game. Quote
wmkjr Posted October 13, 2014 Posted October 13, 2014 Man, I remember those Testor and Monogram F-19 kits . Quote
modelglue Posted October 13, 2014 Posted October 13, 2014 I would like to thank the previous seven posters for slamming those dusty memoires out from the back of my cluttered mind, and making a boring day totally awesome. In return, I offer this: https://www.google.ca/search?hl=en-GB&site=imghp&tbm=isch&source=hp&biw=980&bih=1185&q=cobra+raven+jet&oq=cobra+raven+jet&gs_l=img.12...3894.17244.0.20526.25.19.4.2.2.0.689.5683.2j7j3j1j0j6.19.0....0...1c.1.55.img..10.15.1841.eZPLgdtIhZE Quote
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