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kmcormick9 posted:The best sound Especially when it's constantly in your ears several years later.
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Feb 24, 2015 03:49
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Godholio posted:Especially when it's constantly in your ears several years later. What?
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Feb 24, 2015 04:05
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MrYenko posted:What? WHAT?
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Feb 24, 2015 04:08
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TF-33 whine is cool as gently caress. I love that sound.
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Feb 24, 2015 04:40
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I grew up falling asleep to that sound...lived near Offutt and at the time the different flavors of -135 that operated out of there were still years away from getting re-engined with CFM56s, so whenever they were flying around at night you could hear them even if you couldn't see them. The OC-135 Open Skies aircraft and WC-135 "weather recon" birds are still rolling with TF33s though.
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Feb 24, 2015 05:02
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iyaayas01 posted:I grew up falling asleep to that sound...lived near Offutt and at the time the different flavors of -135 that operated out of there were still years away from getting re-engined with CFM56s, so whenever they were flying around at night you could hear them even if you couldn't see them. I thought the "weather" that the WC-135 sampled was fallout from nuclear explosions? Or am I thinking of another special mission -135?
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Feb 24, 2015 05:47
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That is probably why there are "quotes" around "weather recon"  http://en.wikipedia.org/wiki/WC-135_Constant_Phoenix because yeah, it samples fallout-related weather
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Feb 24, 2015 05:52
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Do the anti-nuke goggles actually work fast enough to protect vision?
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Feb 24, 2015 06:01
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Nebakenezzer posted:Like a Muffler on a car or a silencer on a gun? They're the same thing. Hiram Maxim held the original patent for both. Modern car mufflers have some frippery, but compare, say, a glasspack to a gun suppressor. Jet hush kits are, as has been explained, entirely different.
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Feb 24, 2015 07:09
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Bad Angus! Bad!
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Godholio posted:Do the anti-nuke goggles actually work fast enough to protect vision? according to this, they respond to an increase in brightness after 4µs, and switch from full transparent (which is only 20%) to full opaque in under 100ns from being triggered. For comparison, a modern welding helmet responds in ~50-100µs. I don't know if 4.1µs of flash will cause permanent damage, or a loss of night vision which would probably count as a soft kill in a hostile environment. edit: two minutes of googling found this graph for a 19kt yield, which would suggest that 4µs might be safe. I think the initial rate of rise is a function of atmosphere, not yield, as it's the atmosphere going opaque due to a shock-wave caused by x-ray heating. Yield would influence the height of initial peak and time+shape of the second peak. If my understanding is correct, then much larger blasts should be pretty much the same as this for <300µs. (edit #2: apparently nuclear blasts are pretty much the same in the first few hundred µs, so my understanding is correct and the goggles should prevent injury, but I still don't know if they help night vision) 
Captain Postal fucked around with this message at 08:11 on Feb 24, 2015 |
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Feb 24, 2015 07:38
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Psion posted:More like a car muffler, yeah. Hushkits mix exhaust air with outside air and any bypass air available, and I think the exhaust tubes themselves are shaped to try and dampen the fan noise (as you'd expect, the small, high RPM fans at the front of old engines are basically banshees) OK, it's super late and I'm wiped out, but I will do my best to explain how a hush-kit works, because none of the explanations so far have been all that good. In a jet engine, the single largest source of noise is from the interface between the high-speed jet exhaust and ambient air...the so-called "shear layer". In the shear layer, the exhaust is adding energy to the ambient air from its temperature, velocity and whatever small amount of residual pressure is left as it exits the jet pipe, causing it to expand and contract rapidly, which in turn releases a good portion of that energy as sound. That hissing noise you hear when you use the high-pressure wand at the car wash? That's exactly the same thing, on a very small scale - the stream of water is doing the same to the air surrounding it. Anyways, what a hush-kit does is that it attempts to mix more ambient air in with the exhaust, greatly increasing the surface area of this shear layer, which in turn adds a smaller amount of energy into each unit of ambient air, reducing the expansion and contraction and thereby reducing the amount of noise generated. This is also one of many reasons why turbofans are favoured over turbojet engines in airline operation; the (relatively) slow-moving air coming off the fan, where the majority of the engine's thrust is generated, not only imparts less energy on a comparable volume of ambient air at the shear layer, it also has the effect of shrouding the high-velocity core exhaust as well.
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Feb 24, 2015 09:40
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Hey guys, some idiot from the internet found MH370! Russia didn't have enough hostages to
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Feb 24, 2015 17:19
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bitcoin bastard posted:Hey guys, some idiot from the internet found MH370! Russia didn't have enough hostages to Why are we buying stealth planes?! The Chinese didn't even notice the Russians flying a hijacked 777 across half their country!!!
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Feb 24, 2015 19:59
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Mazz posted:Why are we buying stealth planes?! The Chinese didn't even notice the Russians flying a hijacked 777 across half their country!!! Or did they? 
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Feb 24, 2015 23:13
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https://www.youtube.com/watch?v=6eZm3TWKAlI&feature=youtu.be I wonder why we haven't done this for any of the every single Army helicopter ever named after actual people we forced off their land (I don't actually wonder but it might be nice.)
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Feb 25, 2015 00:32
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Plastic_Gargoyle posted:https://www.youtube.com/watch?v=6eZm3TWKAlI&feature=youtu.be I think Hughes actually did something like that for the Apache way back when it was first introduced, but it wasn't nearly as cool. Also pretty sure some Guard unit also did something similar when they got their first UH-72 a few years back.
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Feb 25, 2015 00:55
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Plastic_Gargoyle posted:https://www.youtube.com/watch?v=6eZm3TWKAlI&feature=youtu.be The USA have done that for many of their copters named after native tribes. Here's an example from 2011: http://www.nativetimes.com/index.ph...livery-ceremony
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Feb 25, 2015 00:59
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Cat Mattress posted:The USA have done that for many of their copters named after native tribes. Here's an example from 2011: http://www.nativetimes.com/index.ph...livery-ceremony quote:The Block III helicopter has 26 new technologies to enhance its capabilities, including an improved drive system; a new composite main rotor blade; an increase in the hover ceiling altitude at greater gross weight; and a more powerful on-board computer system to help pilots remotely fly unmanned aircraft and streamline maintenance. ...the gently caress? Does this mean Apache pilots will now operate UAV's at the same time as the Apache? Or is the Apache going to be capable of unmanned flight? 
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Feb 25, 2015 04:15
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MrChips posted:This is also one of many reasons why turbofans are favoured I just wanted to clarify one point on this: high bypass turbofans - that shrouding effect is more pronounced. Low-bypass, well, can't hear you over the sound of this loving JT8D! Captain Postal posted:...the gently caress? Does this mean Apache pilots will now operate UAV's at the same time as the Apache? Or is the Apache going to be capable of unmanned flight? My first thought was something like the Apache hiding behind convenient cover [x], gunner uses a drone to spot [bad guys], then they pop out and shoot them with a Hellfire or whatever. Helicopters against modern short-range antiair is a losing proposition for the helicopter, so minimizing your risk and maximizing your quality of targeting to pop and shoot seems logical? I'm just making this all up but it sounds cool so I'm going with it. Psion fucked around with this message at 04:32 on Feb 25, 2015 |
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Feb 25, 2015 04:29
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Found this on the subject. http://www.army.mil/article/125676/ quote:HOW TEAMING WORKS
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Feb 25, 2015 04:52
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Meanwhile the drone pilot in a stinky shack somewhere in the desert of the U.S. replies back to the Apache pilot with "gently caress you [n-word] that's my kill! gotta boost my KDR"  as the circle of xbox-life is finally complete.
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Feb 25, 2015 05:21
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Duke Chin posted:Meanwhile the drone pilot in a stinky shack somewhere in the desert of the U.S. replies back to the Apache pilot with "gently caress you [n-word] that's my kill! gotta boost my KDR" Army doesn't fly their RPAs from CONUS, they fly from in-theater. Everybody/everything rotates in/out with each new Army unit deploying/redeploying. Yes, this includes all the equipment, including both aircraft and ground control stations. Yes, it is inefficient as it sounds. This is why the Army shouldn't have airplanes. Also with the Apache pilot "flying" Grey Eagle, he isn't really flying it in the sense of actively controlling the aircraft with direct control inputs, he's just telling it to follow a series of pre-determined waypoints and then point the ball at something interesting that the pilot wants to look at..as opposed to the enlisted guy on the ground in the trailer who normally accomplishes that task.
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Feb 25, 2015 06:42
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Bit of a laugh: http://aviation.stackexchange.com/questions/8913/what-is-the-minimum-stopping-distance-for-a-747-400 quote:Im looking at purchasing disused 747-400:
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Feb 25, 2015 08:25
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quote:If it were me, I would flood the runway with some kind of heavy mud, like drilling fluid or a non-flammable oil. That would probably do it. I would obviously do some physical calculations to make sure it would work before trying it. 
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Feb 25, 2015 08:32
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quote:Southwest Airlines on Tuesday announced it grounded 128 jets after it failed to inspect backup hydraulic systems designed to serve as a back-up in case of trouble with the aircraft's rudder system. Weren't those backups PCUs put into place because of the crashes in the early 90s?
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Feb 25, 2015 09:00
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iyaayas01 posted:Army doesn't fly their RPAs from CONUS, they fly from in-theater. Everybody/everything rotates in/out with each new Army unit deploying/redeploying. ~Dramatic License~, okaaaaaaaaaaay?  Still, that seems unnecessarily convoluted yet I am completely unsurprised.Party Plane Jones posted:Weren't those backups PCUs put into place because of the crashes in the early 90s? The fact that there's a whole wiki page just for that... http://en.wikipedia.org/wiki/Boeing_737_rudder_issues
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Feb 25, 2015 10:18
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Can the gunner not be trusted with a drone? How are we supposed to get badass Apache/Grey Eagle formation videos if the pilot has to fly both birds? 
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Feb 25, 2015 13:01
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 This Top Gun prequel is looking weird, but I would totally watch it.
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Feb 25, 2015 13:17
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drunkill posted:Bit of a laugh: That leaves zero room for ground roll.
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Feb 25, 2015 14:22
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holocaust bloopers posted:That leaves zero room for ground roll. It's Australia the dirt is probably drier and tougher than Tarmac.
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Feb 25, 2015 14:27
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A Handed Missus posted:
quote:Applications of the Continental J69 Better engine than the real tomcat then.
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Feb 25, 2015 15:24
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Well, this is aeronautical and insane. First pictures I've seen of the Stratolaunch mothership in construction. Will be the largest airplane ever, by a healthy margin, when it is complete. Twin-hulled, twin-boom, 6 engine White-Knight style lifter designed to carry a medium sized 3 stage rocket up to altitude and launch satellites into LEO. http://aviationweek.com/blog/inside-rocs-lair I really thought air breathing first stages were a good idea before SpaceX started Buck Rodgersing with flyback first stages, but at this point in both their developments, feel like flyback stages are a lot more scalable.
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Feb 25, 2015 16:43
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 drat. Worthy of its name for sure. Can't wait to see that thing fly.
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Feb 25, 2015 16:50
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Luneshot posted:
Saw Burt Rutan doing a Q&A on the White Knight II mothership, claiming that it was the largest, and best, aerobatics aircraft the world had ever known. Story goes that without the cargo, the aircraft has a greater than one thrust ratio, and the spanloaded wing is good to 8Gs or something insane like, 8Gs isn't when the wing breaks, that's just when the bolts holding the engines on sheer off. I suspect the Roc will be mathematically similar. So wanna see this project either succeed so wildly that they will have some surplus motherships, or fail so dramatically that it will go up for recievership auction so somebody can buy it and find a very large piece of sky to really wring it out. Seeing a football field doing snap rolls is my poo poo. Slo-Tek fucked around with this message at 17:10 on Feb 25, 2015 |
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Feb 25, 2015 16:59
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Slo-Tek posted:Saw Burt Rutan doing a Q&A on the White Knight II mothership, claiming that it was the largest, and best, aerobatics aircraft the world had ever known. Story goes that without the cargo, the aircraft has a greater than one thrust ratio, and the spanloaded wing is good to 18Gs or something insane like, 18Gs isn't when the wing breaks, that's just when the bolts holding the engines on sheer off. Seeing as the cockpit is off center a football field doing snap rolls might have some issues for the pilot.
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Feb 25, 2015 17:00
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hobbesmaster posted:Seeing as the cockpit is off center a football field doing snap rolls might have some issues for the pilot. Training vehicle for the Millennium Falcon
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Feb 25, 2015 17:29
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At the risk of starting something that can't be stopped: Drones seen at night over Paris
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Feb 25, 2015 17:39
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Slo-Tek posted:Saw Burt Rutan doing a Q&A on the White Knight II mothership, claiming that it was the largest, and best, aerobatics aircraft the world had ever known... Barrel rolls, maybe. Snap, no. You still have to deal with inertia along the thrust axis, and that thing has football fields worth of inertia.
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Feb 26, 2015 03:26
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Cross-posting this from the physics thread in ask/tell: I made an observation yesterday, and I couldn't understand what was going on. My family and I were departing Rochester airport, where weather conditions are best explained by analogy to Hoth as far as my California mind is concerned, and our plane (Embraer 175) had to undergo a deicing procedure before we could flee the frozen Northeast. My daughter and I were seated behind the wing, and we got a great view of the anti-ice fluid streaming off the trailing edge as we took off. But I noticed something really surprising (to me) on the aileron. A pool of green anti-ice fluid persisted on the back half of the top surface of the aileron well after takeoff which as I watched changed from a mostly flat pool of fluid into a standing wave, maybe 3-6 inches tall, almost like a mohawk. It hung around for maybe a minute or two after takeoff. I could not take a picture because my daughter was already very engaged with my phone. Can anyone explain what was going on there? It definitely did not freeze. I'm not sure what exactly the fluid was, the plane was sprayed twice, first with orange fluid, then with green fluid. The green stuff was still all over the wing when we started the take-off roll. It was dancing and rippling and waving. As far as I could tell, it sort of dripped away upward, perpendicular to the top surface of the aileron. I'd point out that the fluid only acted strangely on the aileron, on the wing surface on either side, and the flaps closer to the wing root, the anti-ice fluid just streamed off as I expected, like rain off a car window.
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Feb 26, 2015 07:00
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Hermsgervørden posted:Cross-posting this from the physics thread in ask/tell: I made an observation yesterday, and I couldn't understand what was going on. My family and I were departing Rochester airport, where weather conditions are best explained by analogy to Hoth as far as my California mind is concerned, and our plane (Embraer 175) had to undergo a deicing procedure before we could flee the frozen Northeast. My daughter and I were seated behind the wing, and we got a great view of the anti-ice fluid streaming off the trailing edge as we took off. But I noticed something really surprising (to me) on the aileron. A pool of green anti-ice fluid persisted on the back half of the top surface of the aileron well after takeoff which as I watched changed from a mostly flat pool of fluid into a standing wave, maybe 3-6 inches tall, almost like a mohawk. It hung around for maybe a minute or two after takeoff. I could not take a picture because my daughter was already very engaged with my phone. Can anyone explain what was going on there? It definitely did not freeze. I'm not sure what exactly the fluid was, the plane was sprayed twice, first with orange fluid, then with green fluid. The green stuff was still all over the wing when we started the take-off roll. It was dancing and rippling and waving. As far as I could tell, it sort of dripped away upward, perpendicular to the top surface of the aileron. I'd point out that the fluid only acted strangely on the aileron, on the wing surface on either side, and the flaps closer to the wing root, the anti-ice fluid just streamed off as I expected, like rain off a car window. As an engineer, I would've loved to have seen that. In simplest terms that I can, you witnessed the fluid getting caught in aerodynamic effects. Being on a control surface or lift generating device (I'd like to ask if it was actually an aileron or a flap you were observing), the air coming over is usually transitioning from laminar to turbulent flow, which can have some interesting effects. There is a thin layer of non-moving air called a boundary layer, which exists in the laminar flow regions. When it gets too big, the flow transitions from laminar (smooth) to turbulent behavior. Possibly you saw the water getting trapped in that transitional area, or the water was being atomized and the pooling was just most of the fluid coming together in a common area (which can be caused by how the air flows over the wing).
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Feb 26, 2015 07:36
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