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MrChips posted:Switzerland also feels the need to maintain a strong defensive stance in support of their neutrality. Instead of dispersing to roads, they've dug their air force into the mountains:
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Mar 8, 2010 08:01
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orange lime posted:They drop off on takeoff. Landing is accomplished by having a high-powered chase car (Buick Wildcats back in the 60s and 70s) follow the plane along the runway and maneuver under one wing. The pilot drops the wing and it latches onto the roof of the car until the pogos can be reinstalled. The chase cars do not catch the wing. The wing tips have skids, and are designed to drag the short distance the plane travels between when it looses aileron authority and stopped. Once stopped, they then reinstall the wing gear. The chase cars are there because the pilot has no real view of the ground, so the people in the chase cars talk them down.
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Apr 2, 2010 19:28
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All I gotta say really is one word. Compound. http://en.wikipedia.org/wiki/Wright_R-3350 Something tells me power recovery methods are going to become fairly commonplace as we try to squeeze more power from our engines.
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Jun 23, 2010 19:37
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The Ferret King posted:Even with his explanation, I don't think I quite understand why normal spin recovery techniques didn't work at first. He mentions the ailerons being the only loaded control surfaces (albeit slightly) during the spin, when normally it's the rudder that kicks you out of the unwanted rotation. For the elevators, again hand out the window of your car, this time pointed into the wind. When you twist your wrist you get no effect. That's all the leading elevator could do. The trailing elevator was in the wind shadow of the rudder. the rudder is mostly an extention of a very tall fuselage. And in the spin you're just cutting a wide wake in the air, not pushing it along the body. Therefore you're getting little (or as his control feel indicated) no airflow across the rudder. This also meant the rudder was ineffective. Now in the spin, the wintips were sticking out in to clean-ish air. So they still did have some useful airflow across them. That's why his ailerons had some stick feel. And why they were useful in recovering the plane.
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Jun 25, 2010 15:11
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grover posted:He had the presence of mind to realize they were not acting as roll control anymore, but that the drag from using them was useful in yaw control and slowing the spin. I can't believe how calm the guy was, I think I'd be freaking out! Sitting here, calmly thinking about it. It's a logical solution. You've got one wing going forward, the other going backwards. Instead of making differential lift, you'd get all lift, or all downforce from the way ailerons are setup. At least in a spin. I'm mighty impressed.
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Jun 25, 2010 15:23
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I wouldn't say scramjets are "unsolved" just.. "seriously early in development" Heck the wright brothers engine used flame tubes for ignition!
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Jun 29, 2010 05:00
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Something that hasn't been mentioned yet. The oxidizer weighs something like four times as much as your fuel does. So ditching the oxidizer doesn't just save you "half the weight" it saves you 4/5 of the weight! That has massive effects on structure.
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Jun 30, 2010 02:58
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Those are aerodynamic balances. They help offset the forces on control surfaces as air speeds increase.
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Aug 3, 2010 21:30
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two_beer_bishes posted:Think of them as power steering for the roll axis. Those would be boost tabs ;-) THOSE are killer. they allow a mere mortal to steer a b29.
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Aug 3, 2010 22:23
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I'm accustomed to seeing mass balances inside the wings themselves, and aerodynamic balances at the wingtips. You'll see them quite commonly on elevators and rudders. I"m saying that spade isn't there for CG reasons. The spade is there for CF reasons. I'd imagine the use of a spade makes more sense due to the length and high aspect ratio of the control surface. Using an aerodynamic ballance in the middle of an alerion is going to have less flutter and torque issues than you'd find in a nice stocky control surface like a rudder, where using the tip for aerodynamic balance is very common.
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Aug 4, 2010 08:49
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the physics changes in strange ways as you get to smaller aircraft. most of the planes had so many guy wires that their glide ratio would be non-existant. :-( People have made flying models of most of the historic "silly" planes. With some mild care with cg choice, and sufficient power, almost anything will fly.
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Sep 7, 2010 05:38
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the lawnmowers are amusing. Sadly they can't actually cut grass...
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Sep 7, 2010 19:25
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Saga posted:If that's not the remains of a fake USAF/USAAF paintjob, it would surely make her a C47, not a DC3. Other than sperg value, what's the real difference between the two?
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Sep 8, 2010 14:24
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Yup, that airliner had people inside, and the pilot outside.
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Sep 10, 2010 16:20
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In ground effect aircraft are weird. Those iranian aircraft will only fly "well" within 1/4 of their wingspan of the ground. Cheaper, and certainly more effective than a hydrofoil. http://en.wikipedia.org/wiki/Ground_effect_in_aircraft
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Sep 29, 2010 14:29
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as engine failures go, that's not so bad. Looks a like "just" a simple engine fire.
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Nov 4, 2010 13:07
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They're very much going the wrong way with military aircraft these days. Simple is good. These flying supercomputers are putting way to many eggs in a basket.
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Nov 23, 2010 15:55
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Tremblay posted:Simple isn't really going to get the job done the way we want to get it done. Sensors to the shooter is the trend that kind of took it a step too far. Its very easy to oversubscribe your pilots/shooters. Now there is some more thought going into *what* gets to the operators. Atleast from what I've seen. I think they're making lots of mistakes. Stealth is passive tech. Jets need only minimal electronics to keep users from doing stupid poo poo and making them flame out. It takes less horsepower than is available in a micro controller to keep an inherently unstable aircraft pointed forward. And yet, somehow, we're running around with the equivalent of a cray supercomputer in these things? IIRC, there's two of them, for redundancy. We're to the point where the price for aircraft and maintenance means we need to maintain very, very small stocks of them. That single F22 going down took out what, 0.8% of the entire inventory? I can think of half a dozen ways of defeating such a small force of aircraft. What immediately comes to mind is very large bags of gravel... Or any opposing force with numbers 4x greater than the attacking sortie. Unless we're talking naval vessels, taking out a single anything shouldn't make that sort of change to the inventory. The design groups, and number of roles we want a single aircraft to fulfill is downright stupid at this point. Multi-role never beats specialist. I am not "all for" drones. I think if there's a place where they can have clear room to defend against anything, I think they've got a place. (I'm thinking fleet defense, and foreign airspace patrols in particular) Taking great care as to what information reaches your pilot matters. I think not nearly enough thought has been put into this. I think this is something that would easily be solved by a very small group of people, instead of the very large committee style planning that goes on now.
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Nov 23, 2010 19:09
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azflyboy posted:The B-47 suffered from the same slow throttle response (which makes an aborted landing interesting), so the aircraft were occasionally fitted with a parachute that was deployed on approach to allow the engines to be kept at a higher RPM without accelerating the airplane. This is a tendency of most jet engines. Fast throttle response from a jet requires some really advanced tuning. "just a jet that works" is pretty easy. Most engines of that era were "just engines that work, and engines that work without melting down under normal operation. Modern jet engines are metallurgical miracles. Oh, and thank god for fadac!
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Nov 30, 2010 16:56
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InitialDave posted:Short answer: Glass fibre has lost of short, random threads all mish-mashed at different angles, whereas carbon fibres are in woven sheets like a cloth. To take advantage of CF construction, you pay attention to the direction the fibres are running in, as well as the thickness/number of layers. You can also "tune" a structure to behave in a certain way under different loading directions by having more fibres running in one direction than in others. No. Every bit of structural fiberglass I have seen on an aircraft was done with cloth made exactly the same way as carbon. You don't see chopped strand matt in any structural role excepting as a filler material spacing out actual structural layers. You're correct on the fiber direction thing, that's in common with all composite materials. (wood, spectra, kevlar, nylon, carbon) And you will find those materials where their abilities are best used. Spectra and kevlar have very good abrasion resistance, and are used on "wear points" for many nylon and carbon structures. Forged composites sounds just like the normal fiber filled injection molded carbon and nylon parts that have been around for a long time. Just.. a lot more fiber. And I really doubt you'll come anywhere near the resin/fiber ratio you can get with a good layup. However, it looks to be monumentally cheaper.
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Dec 8, 2010 08:13
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Toyota's! :-) And it's not unique. http://www.youtube.com/watch?v=zOhj7X1-x10&feature=related2ndclasscitizen posted:Is that good or bad? Because Lambo made an entire car out of stuff. Nerobro fucked around with this message at 16:28 on Dec 8, 2010 |
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Dec 8, 2010 16:25
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Excuse me... what's that in front of the F14's?
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Jan 12, 2011 19:20
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Slo-Tek posted:A Monogram model of the conjectural F-19 stealth fighter. It was way cooler than the Testors version. Exactly. Now... that is life size. WTF.
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Jan 12, 2011 20:42
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eggyolk posted:I'd assume that China developing a functional fighter of their own is a pretty big deal.
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Jan 14, 2011 22:10
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OptimusMatrix posted:Does anyone remember the old Microsoft Flight Simulator where you could adjust the shape and surface area of the wings on the planes? I wish they'd bring that back. FS4. I still have it.
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Jan 24, 2011 15:36
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Did anyone think that it's using gps. It's RECEIVING ONLY. :-) I'd be a lot more worried on approach. But on takeoff, the plane is going to get off the ground, where it gets up, doesn't really matter.
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Mar 3, 2011 16:25
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Cellphones, of all devices, are fairly well shielded. By necessity; as they are trying to receive some stupidly weak signals, and when transmitting, their a very noisy place to be. They are also very low power. The tv screens on the back of seats are going to generate more electrical noise. Especially from the inverters to drive the CCFL backlights. Most cellphones are using led backlights now. Now if you are talking having the cell radio on, it's a completely different story. And again, for the given example, we're talking takeoff. It's not like you can miss the SKY. If you want to talk trouble, insulin pumps still use EL backlights. EL backlights are frighteningly noisy electrically. You're not required to turn them off, and they are blatantly non shielded. (most current models are sold in clear cases..)
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Mar 3, 2011 17:10
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brains posted:seven or eight years ago when everyone had those cheap nokia phones, every day i went flying i would hear some interference over the local CTAF every time someone flying in the area was about to get a phone call. it got to the point where people would just call out, "turn off your phone" over the radio. That's great. But unrelated. GSM makes some signals that make even just bare speakers twitch. That's intentionally pumping out as much as 500mw through a tuned antenna. But we're not talking an intentional transmitter. We're talking about a pocket computer with no intentional transmitters transmitting. With a design that is designed to be electrically quiet!
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Mar 3, 2011 20:39
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That's probably all your can expect. voicemail notification and texts are single packet things. Cellphones stop making sense when they're talking to more than five or six cell sites. Just being on the observation deck of the john hancock building is enough to make the phone want to throw a fit.
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Mar 8, 2011 15:59
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 This is the block assembly from a R4360. http://en.wikipedia.org/wiki/R4360 1.1lb/hp. 3500hp. This is not quite my favorite radial, but it's close.
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Mar 9, 2011 16:27
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That may well be the best flying video I've seen. What's it with the french and getting amazing shots of their aircraft.
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May 22, 2011 07:33
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wow, my buddy lives only a few miles from there. He's been informed, maybe we'll get pictures. Sad though that anything classic like that should crash.
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Jun 13, 2011 18:18
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BonzoESC posted:It's because there's nothing to them. In the Space Shuttle Maim Engines, two small turboshaft engines drive the fuel and oxidizer pumps, and there's a combustion chamber that most of the fuel and oxidizer are pumped to. Just the two rotating shafts for the pumps, no reciprocating parts like a car engine, and no big fan to decrease the jet velocity like an airplane engine. The downside is you need to carry both inputs to the reaction, and they're terribly inefficient in atmosphere. Simple as they sound, they're wildly complex. Once your cross from pressurized tanks to turbopumps things for from "tough" to "insanely hard" to get right. The pumps are high energy. You're pumping O2 with a rocket motor that's turning the pump to move it. Turbopump equipped motors have a tendency to eat themselves.
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Jul 5, 2011 15:30
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Argentic posted:I visited Wings Over the Rockies recently and took some pictures I thought this thread might want to see. The whole gallery is here, I'll try to post the best of each plane. the [timg] tag just makes it scale the picture, it doesn't actually reduce the size. They look small, but that's still 11 megs of images. What I'm saying, is you're crushing peoples browsers and their internet connections. Nice pictures. Post the small versions.
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Jul 11, 2011 22:39
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Thanks :-) Those are some great shots.
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Jul 12, 2011 03:40
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Does this bring new meaning to "Get to the choppah!"
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Aug 4, 2011 14:09
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BonzoESC posted:So here's how I understand it: turbine engines are used in planes because they are a good tradeoff between mass and reliability, and take an efficiency hit due to a lower compression ratio than a reciprocating piston engine. Since trainz don't have to climb to 30,000 feet, and don't crash into the ocean under an engine failure, they use big heavy reciprocating engines that are reliable due to being overbuilt relative to an aero engine. No. Because that's not how it works. Turbines are used in jets becasue they're run at high throttle settings for long periods. They get compression ratios upwards of 100:1. They have huge bypass ratios, and get really good BSFC. When throttled back, jets can get down to 2:1 or lower compression ratios, leading to really really lovely fuel usage. Piston engines are used in trains becasue they have decent BSFC at part throttle as well as full throttle. Near idle diesels have very good BSFC because they run very, very lean. Just like a jet. The reasons diesels have good fuel economy, are also why diesels need turbocharging to reach the same power levels that spark ignition motors get naturally aspirated. using jet thrust to power a train is just stupid. I'd need to look up the physics on it again, but small jets are not very good at transferring their energy to the surrounding environment, large slow streams of air do a much better job. Or in the case of a train, PTO and a gearbox.
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Aug 18, 2011 22:50
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slidebite posted:I agree, although I don't think a turbine powering a generator for a train instead of a big recip diesel would necessarily be a ridiculous idea. The UP turbines were limited both by the mechanical technology of the day, and the control electronics. They were lots of relays, and I'm not even sure if they had tubes! A modern turbine would do the job a lot better. IIRC they had 20 notch throttles. However, we have an entrenched technology, that would be virtually imposable to get around.
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Aug 19, 2011 06:55
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Something tells me that turboprops need more maintenance than actual jets need. You've got a rather serious gearbox, and pitch control mechanisms. And I can't imagine that one of the massive bypass turbofans that are common now are all that far behind on fuel economy.
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Sep 12, 2011 03:27
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Cygni posted:Turboprops need like 1/10th the maintenance of turbofans. That doesn't make any sense to me at all. Care to explain?
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Sep 12, 2011 04:23
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