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Cat Mattress posted:Think of them as normal turbofans with a really, really high bypass ratio. Their main advantage is greatly decreased fuel consumption. On the downside, they're much noisier and yes, they seem more likely to eject their blades in a random direction than a ducted fan design. You didn't say anything new here. All examples of prop fans are compared to turbofans with a smaller disc area. Yes, the bypass ratio of that flying example on the DC-9 is higher, because the prop fan disc itself is larger than the engine on the other side. My question was, is a prop fan inherently more efficient than a ducted fan? That means a comparison of the two with equal disc diameters and bypass ratios. It seems that the only application propfans are being tested for are tail-mounted engines on narrow-body aircraft, where I guess the actual advantage is being able to obtain a larger disc area without an inordinately large increase in weight on a sensitive structural area that would be required to keep the fan ducted like in a normal turbofan.
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Jan 2, 2017 22:10
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CarForumPoster posted:Is 120 of these not interesting or funny (except the reaper one) idea for names enough? Maybe 6-7 more pages are needed This is Something Awful, poo poo ain't done 'till it emerges at the antipode.
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Jan 7, 2017 20:43
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holocaust bloopers posted:Yea it's a great read. Absolutely mind boggling that the F-22 came about in 1988. A bunch of run-of-the-mill flying wing UAV's and a fusion reactor that, like all fusion reactors, is "10 to 15 years out." Allegedly an unmanned hypersonic SR-72 and an optionally-manned U-2 replacement. I suspect that because Ben Rich didn't have the same hold over Lockheed leadership that Kelly Johnson had, he probably didn't get to hand-pick his replacement and now Skunk Works is just a milquetoast blue-sky development program within Lockheed with the invasive amount of corporate oversight that Johnson constantly fought to avoid. Occasionally when Lockheed is worried about bad press on something they've done, they'll trot out some concept that a Skunk Works engineer doodled because it's what he WISHES he was working on instead of the Desert Hawk RC plane so they can say they're working on something cool.
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Jan 15, 2017 15:47
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God drat I was just making a joke about Skunk Works getting neutered. Here's a B-36 with tank treads that was probably already posted in this thread because it was uploaded 6 years ago: https://www.youtube.com/watch?v=eDCgMlomhvM
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Jan 16, 2017 01:55
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FrozenVent posted:My naval architecture teacher used to joke that ships are designed from the propeller out; I assume it's the same for airplanes. Propeller science is ridiculously complex. Getting it precisely right is complex but basics like number of blades, diameter, and even twist are a relatively simple matter of Blade Element Momentum Theory. You're going to have a maximum diameter from the beginning due to either clearance or keeping tip speeds down. Mathematically you can make a propeller of any diameter with any number of blades absorb the power you need it to, but if you're designing a two-blade prop and the model says you need an 18-inch chord at some point, then you know it's time to add more blades or adjust gearing if you've got the overhead for more prop speed. Then you run the model through CFD, find out everything is wrong and just pull things out of your rear end until it works.
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Jan 28, 2017 17:00
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Finger Prince posted:They're fully painted default white before they ever see daylight. The parts arrive at the factory pre painted. No, they're not. However, the carbon is not on the outer surface of carbon aircraft skins. There's a layer of copper mesh or foil for lightning strike protection, and a layer of fiberglass for corrosion protection and a suitable painting surface that makes up the final outer layer. The inside surface is also mostly covered in fiberglass in order to avoid having to use fay sealing for metal brackets. There's plenty of pictures on the internet of unpainted A350's and 787's being towed between hangars (usually on their way to the paint hangar), and they're all that same weird brown you get from the reddish-brown of the copper being just slightly visible through the off-white fiberglass ply. There ARE carbon parts that don't have copper or glass plies, but they're all in locations that are never exposed to sunlight once installed, and most remain unpainted. The frames and the clips holding them to the skin, for example, which are completely covered by the outside skin and the interior paneling. Source: I literally wrote the plans for manufacturing skins for one of them, AND I handled the deliveries to the OEM, notably unpainted when we shipped it.
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Feb 10, 2017 07:12
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Finger Prince posted:Counterpoint, I've seen them being put together, and clambered around inside and outside them at various states of being put together, and have been to the production line on multiple occasions. But don't just take my word for it; http://bfy.tw/A0Uo You also said they arrive at the factory painted. Seeing as I delivered them to you unpainted, I know that wasn't true. Googling more recent deliveries has revealed to me that Boeing has offloaded painting to my previous employer since I left, however. Willing to bet that had less to do with UV protection and more to do with Boeing wanting to do less work. If you go more than 2 rows down that google image search, you start seeing tons of unpainted 787's in the late stages of final assembly. You can even spot line units where painting was offloaded to suppliers one-by-one. Also, as you can see, Airbus has no problems taking unpainted A350s outside in the daylight, because there's no exposed carbon once you're done making a carbon fiber skin panel.
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Feb 10, 2017 17:31
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Ola posted:Once you mute the psychotically relentless action movie score, there is still quite a bit of insanity left, of the aeronautical kind. Someone on Reddit pointed out that Colin Furze already accomplished this AND was actually safer about it (because his had shrouds around the rotors).
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Feb 23, 2017 01:54
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Ola posted:I would much prefer the rotors to be above, so the center of gravity is dangling beneath the center if lift and it's harder to accidentally chop a body part off. Multirotors (or rather, throttle-controlled multirotors and not cyclic-controlled like a CH-47) are already inherently unstable, so having the CG above the CL makes basically no difference since you already need a computer to control it. And having them above your head basically means decapitating yourself if you try to get off while parked. Deptfordx posted:That looked terrifyingly impractical just drifting around in a hangar. The thought of flying around at speed, in the open, on that thing is making me wince just thinking about. It looks like the set-up of your origin story "How I became a Quadraplegic." That's pretty much the case for anything you could called a "bike," hover or otherwise.
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Feb 23, 2017 17:07
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Nostalgia4Infinity posted:Yeah but they're like way away in the distance and its a trick of perspective. Yeah, it's perspective. The aircraft is 23' 3-5/8" tall, the propeller is 22 feet in diameter. ApathyGifted fucked around with this message at 18:31 on Mar 17, 2017 |
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Mar 17, 2017 18:24
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pthighs posted:Call me crazy, but I actually prefer the version with canted wings. It looks cooler. Canted wings+ sharktooth leading edge. Also that prototype doesn't have the dihedral on the tail, which I always thought was really cool.
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Apr 7, 2017 15:45
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Inacio posted:This really hosed me up at first glance. Yeah, my thought process as I figured that photo out was: "drat, look at those clouds!" "Wait that's a mountain." "I wonder if anyone's ever flown into a mountain because it looked like clouds to them." "I'll post this exact thought process because if someone has, a goon will definitely know about it."
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Apr 9, 2017 16:06
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Neither this, CFIT, or the Venezuelan flight mentioned are even close to the situation I was talking about. Air New Zealand is the closest, but even that was a matter of being a whiteout.
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Apr 9, 2017 19:44
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Inacio posted:The Osprey has the biggest prop to plane* ratio, right? The AW609 might have it beat, but only because it's basically the same aircraft with a small bizjet fuselage.
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Sep 10, 2017 18:33
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Fayez Butts posted:There's a civilian version of the Osprey? Is that safe? It's been in development for years, and they crashed one of the prototypes two years ago, so probably not? Edit: First flight was in 2003, and they still haven't entered production.
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Sep 10, 2017 19:20
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PT6A posted:So that's three fatal crashes out of seven built? It’s an amphibious LSA. So you get to combine the idiosyncrasies of amphibious operations with that sweet spot of just enough experience to feel confident and not nearly enough to back it up. Plus he has a tweet from just days after he acquired he plane about how flying low level over water feels like flying a fighter jet.
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Nov 8, 2017 02:06
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Comrade Gorbash posted:I'd still take the Musk fanboys over the Jobs fanboys. At least Musk doesn't cast being a toxic unrelenting rear end in a top hat as a business strategy. He's been sued twice for not paying out overtime, and there's an anecdote that gets passed around where if you ask for a raise, he'll do your job for a month. If he's better than you at your job after a month, he fires you. And the base pay at SpaceX is the typical "why the hell is pay in one of the most expensive areas of the country lower than everywhere else?" thing that LA aerospace has going on.
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Feb 10, 2018 22:16
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The funny thing about me bringing up the Musk assistant anecdote if that I wasn't even thinking about the unfairness or the bullshittedness of it, it's the drat stupidity of the idea. You don't hire someone to do their job better than you can (especially if you're a savant as Musk apparently is). You hire them so you don't have to do that poo poo and can spend your time doing something else. I'm sure I can clean toilets better than most people if I put my mind to it, but I ain't firing the janitor and taking over his job if I someday become CEO of a company. Likewise, if you really wanna show you're the best, you'd swap jobs. CEO works as the assistant, assistant works as the CEO. If the assistant does a better job running the company, you either GTFO or accept you're the bottom bitch now.
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Feb 12, 2018 03:02
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There’s a meme on the aviation subreddit that every time someone posts anything about the SR-71, someone has to post a ridiculous meme-ified version of Aspen 20 because if it doesn’t happen, someone will come in and post it like they’re the only person in the world who’s read it and they have a mandate from God to share it. At one point there was even a bot to handle the task.
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Jun 29, 2018 16:47
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Mortabis posted:North Dakota is the only place I've ever seen anyone drive 100mph. One time driving up I-65 in Indiana I ended up in drat near bumper-to-bumper traffic that was doing 105. We got passed by a cop on the right, and he didn't even glance over at us. I don't know how the hell that all happened, all I can surmise is that no one wants to be in loving Indiana.
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Oct 28, 2018 01:15
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BIG HEADLINE posted:Speaking of E-2s, there was one circling Manhattan today at low level. Definitely got my attention. Great, now we get a bunch of news stories about people freaking out thinking it was 9/11 2: 9/12 like after the Air Force 1 photo op.
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Dec 20, 2018 01:21
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mlmp08 posted:They should copy the US method of naming knee-jerk laws stupidly. Gotta be an acronym for GATWICK though.
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Dec 22, 2018 15:50
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e.pilot posted:The legendary tail number N420DR is wasted on a DJI quadcopter. There's a ton of Honda Jets that are N420XX just because the model number is HA-420 and they kinda default to that if the customer doesn't specify a tail number they want.
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Mar 4, 2019 03:26
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Elviscat posted:He was clearly trying to ditch the pursuing fighter with the maneuver at 1:15 in this video. https://youtu.be/Jv1ZN8c4_Gs Ha, literally the same day I get an e-mail from a recruiter trying to fill a Design Engineer position in Tehachapi. I'm unemployed right now, and I wouldn't touch that with someone else's 30 foot pole. Incidentally, if anyone has an engineering job in Greensboro they want to hire for that isn't at Honda, hit me up.
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Jun 25, 2019 20:47
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KYOON GRIFFEY JR posted:you down with trucks because Volvo Mack is right there I already applied there and haven't heard anything back. Only one of my contacts there works in my field and he's been living up to his reputation of never checking his messages. I've got a more reliable contact at BE in Winston-Salem but their applications require you to put in an amount for salary request and I refuse to low-ball myself. I might have better luck this go around because I went through the Collins (yay mergers) job portal this time, and they don't require that. And if I haven't gotten anything within the next 6 months I'll go back to Honda, because all the managers who would have been there to remember laying me off will have been turned over.
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Jun 26, 2019 05:07
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Charles posted:Some teenager made it to Hawaii a few years ago, I thought The CNN article about him said (at the time in 2014) there had been 105 known attempts, and 25 survivors.
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Jul 2, 2019 23:01
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Potato Salad posted:Armored F15 Isn't that just an F-15E?
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Jul 9, 2019 22:10
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Godholio posted:The F-15E is not an up-armored F-15. It's a structurally sturdier (for payload) two-seater redesigned primarily for air-to-ground missions, while the A-D models' motto was "Not a pound for air to ground." And this is the requirement he gave that answer for: quote:Design a close support aircraft using only technology available in 1985. Minimum top speed 400mph. Must capable of carrying at least 5000kg of munitions and carry internal gun. Must be low-cost, highly resistant to ground-fire and have minimal ground support requirements. STOL or rough-field capability a plus. An F-15E is closer to that than throwing armor on a A-D. Although my answer would just be an A-10.
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Jul 10, 2019 20:14
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EightBit posted:Man, I would have figured that flight safety critical switches that could remotely be subject to liquid spills were designed to be resistant to that failure mode. I guess that bean counters are the bane of all human existence. In passenger stuff we put drip shields underneath every gap around a panel that someone could even remotely put a drink on. But when I worked on cockpit installs, there was no such thing because in that plane there was no flat surface to put a drink. My last project was one of those super-first-class suites. We built a full mockup for PDR and purposely handed out lots of coffee and water to the customer reps to log where they were absent-mindedly setting them down when inspecting the mockup. One of them put it on top of the door. Another on top of the IFE monitor. A third on top of the charger/usb ports.
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Feb 6, 2020 16:21
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Arson Daily posted:you wouldn't believe how many life jackets get stolen from our airplanes. people will take anything not bolted down at any time. So much so that it's a preflight check for the flight attendants. Shocker: it's a huge pain in the rear end when one goes missing! Used to make those super-nice first class suites that cost 40k per ticket. The middle eastern airlines ALWAYS want a bunch of gold trim on everything. They're our most replaced parts because people who can afford 40k tickets for a loving airline flight while pry that poo poo off with the dinnerware and steal it.
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Apr 29, 2021 18:05
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Cojawfee posted:Is it actual gold? Would be hilarious if they were stealing gold spray painted plastic or something. We tried anodizing with a gold color but it didn't look gold enough, so it ended up being gold-leaf plated aluminum with some sort of clear protective coating, which apparently looked gold enough for people who literally own piles of gold bars.
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Apr 29, 2021 20:21
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