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Sagebrush posted:A few years ago when Canada was starting to debate a new fighter purchase, I saw Lockheed Martin ads on the sides of buses in Ottawa. They even put them on the o-train, which is basically a dedicated university service line. Beats me. "Look at the money we are pumping into your economy, Canada! Imagine the money we will pump building planes!" Could be worse, they could have bought DeHaviland Canada until the deal fell through, then dump it for almost nothing.
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Feb 7, 2016 00:31
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https://www.youtube.com/watch?v=jqtCiQXse9U
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Feb 7, 2016 09:07
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https://www.youtube.com/watch?v=G7LErwBNobU
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Feb 7, 2016 20:16
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Hey look a good youtube comment is first for once! quote:I flew that airplane. It eventually became N15DF, in service with Express One International as a cargo aircraft. It is notable for the "hump" on the back; Due to the stress of the RATO bottles, the upper fuselage developed micro-cracks and had to be laminated with several layers of extra aluminum sheet. The result was a visible hump. edit: is that a tail strike at 33s?
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Feb 7, 2016 20:19
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Did that helicopter pilot almost die or does he just own a bunch?
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Feb 7, 2016 20:19
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buttcoinbrony posted:Did that helicopter pilot almost die or does he just own a bunch? yes
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Feb 7, 2016 21:21
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hobbesmaster posted:Hey look a good youtube comment is first for once! Sure looked like it. I'm sure that didn't help the airframe stress.
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Feb 7, 2016 22:16
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hobbesmaster posted:edit: is that a tail strike at 33s? It is, but the 727 had a built-in tail bumper, so it isn't as bad as it could be otherwise. 
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Feb 7, 2016 22:51
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Caconym posted:The shoe bomber was TATP iirc. Shoe bomber was TATP and PETN. If he'd had pure TATP, he probably would have gone boom well before ever making it to the aircraft. poo poo is sensitive as hell.
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Feb 7, 2016 23:11
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Like a BOSS.
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Feb 7, 2016 23:40
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MrChips posted:It is, but the 727 had a built-in tail bumper, so it isn't as bad as it could be otherwise. That's actually a tail strike indicator, used to alert the crew and maintenance that inspections may be required.
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Feb 8, 2016 00:28
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buttcoinbrony posted:Did that helicopter pilot almost die or does he just own a bunch? Well, both, and probably didn't plan his weight and performance sufficiently. I actually just learned about this last week from an unrelated story: when a helo is overloaded, the rotors pitch to a higher angle of attack to try and generate more lift (the rotor speed is designed to remain constant). This increases the drag the rotors are creating, and thus the torque that has to be canceled out by the tail rotor. At a very high AOA, the tail rotor isn't powerful enough to offset the torque and the entire helo starts to spin like that. What I bet happened is that the helo was fine while cruising to the target area since it was getting translational lift, allowing for a lower rotor AOA. As soon as it slows down to hover, the rotors have to pitch higher, causing more drag and the entire thing starts spinning. As soon as it dumps its water, the weight is lowered and the rotors can pitch back down to a manageable AOA. Basically everything about helicopters is ridiculously unintuitive. Their flight characteristics are completely alien compared to fixed-wing aircraft and they are primarily held aloft by wishful thinking and voodoo.
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Feb 8, 2016 00:43
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Helicopters are going to be the first thing to go away when we figure out antigravity poo poo.
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Feb 8, 2016 00:54
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Wingnut Ninja posted:Well, both, and probably didn't plan his weight and performance sufficiently. I actually just learned about this last week from an unrelated story: when a helo is overloaded, the rotors pitch to a higher angle of attack to try and generate more lift (the rotor speed is designed to remain constant). This increases the drag the rotors are creating, and thus the torque that has to be canceled out by the tail rotor. At a very high AOA, the tail rotor isn't powerful enough to offset the torque and the entire helo starts to spin like that. To be fair, that is a really difficult environment to be flying in. Look at how windy it is too.
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Feb 8, 2016 01:19
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Wingnut Ninja posted:Basically everything about helicopters is ridiculously unintuitive. Their flight characteristics are completely alien compared to fixed-wing aircraft and they are primarily held aloft by wishful thinking and voodoo.
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Feb 8, 2016 01:21
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Relevant: https://www.youtube.com/watch?v=eXR1olg_I0w He more or less nails the stereotypical understanding of flight characteristics everyone has from video games.
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Feb 8, 2016 02:26
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Nerobro posted:Now consider quadcopters. The fact that quadcopters only became a thing after we developed superintelligent, superlightweight computers is an excellent illustration of how bizarre helicopter aerodynamics are.
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Feb 8, 2016 05:00
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Wingnut Ninja posted:The fact that quadcopters only became a thing after we developed superintelligent, superlightweight computers is an excellent illustration of how bizarre helicopter aerodynamics are. It wasn't just the computers, it was also vibrating-structure gyroscopes and MEMS accelerometers. A major part of the navigational problem for the space race was developing gyros that didn't suck.
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Feb 8, 2016 05:51
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Helicopters don't seem that bizarre, just that you can't alter one control without having to adjust some other control or have a computer do that for you. Counter-rotating rotors do away with some of the weirder problems, like having to push the cyclic to one side as you gain forward airspeed because a single rotor has unbalanced lift.
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Feb 8, 2016 06:02
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Wingnut Ninja posted:The fact that quadcopters only became a thing after we developed superintelligent, superlightweight computers is an excellent illustration of how bizarre helicopter aerodynamics are. They "kinda sorta" were done in the early 90's. Some people built VTOL's using conventional helicopter gyroscopes. If you have a duct, ducts are somewhat self stabilizing. Which makes for some really annoying control problems. "being aware of orientation" is such a harder problem to solve. I have trouble getting into that toilet bowl swirl on my helicopters. I should figure out what i'm doing wrong there..
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Feb 8, 2016 06:26
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um excuse me posted:Relevant: My understanding from DCS: Huey is "gently caress helicopters"
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Feb 8, 2016 06:35
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Nerobro posted:They "kinda sorta" were done in the early 90's. Some people built VTOL's using conventional helicopter gyroscopes. If you have a duct, ducts are somewhat self stabilizing. Which makes for some really annoying control problems. Controls were definitely a factor to the fruition of multirotor remote controlled aircraft, but another factor was the power to weight ratio that was available. LiPos and brushless motors weren't commonplace in RC stuff 10 years ago. Not to mention the FETs capable of handling the power. My first R/C car used a servo to actuate a 3 speed control that literally used gigantic resistors to provide a voltage divider to the 20 turn brushed motor. RC tech has come a really, really, long way for multirotors to exist in the last decade.
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Feb 8, 2016 06:58
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Relevant to helicopter chat... https://www.youtube.com/watch?v=_Qj63KoB7k4
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Feb 8, 2016 07:17
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Helicopters really are the ugliest things.
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Feb 8, 2016 07:25
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hobbesmaster posted:My understanding from DCS: Huey is "gently caress helicopters" The number of times I've been doing a happy landing and all of a sudden I lose lift and crash -_-
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Feb 8, 2016 08:13
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The Locator posted:Relevant to helicopter chat... I think I'm going to puke
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Feb 8, 2016 10:16
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Hey nebuchadnezzar, The Great War channel (following WW1 week by week 100 years later) just posted a special episode on zeppelins during the war: https://youtu.be/nlQgprSGpNI Not as detailed as your writeups obviously but an interesting overview anyway. A good channel in general too.
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Feb 8, 2016 18:33
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While I knew and understood conceptually what was happening above my head, for some reason I'm now much more reluctant to get in to a helicopter again. The difference between playing with newbie level RC sailplanes or a Cub type trainer and the toy quadcopter I got for christmas was absolutely incredible. Zero margin for error on the quad, while the sailplanes in particular were so forgiving they occasionally became difficult to land. Definitely calls to mind the quote someone had about "Planes want to keep flying, helicopters desperately want to fall out of the air unless everything is going absolutely right." Also another thanks for that zeppelin video and that channel, haven't watched it yet but very interested. Edit: Judging by loss rates I think all those early and not so early jets were at least 1/3-1/2 helicopter by mass. drzrma fucked around with this message at 19:17 on Feb 8, 2016 |
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Feb 8, 2016 18:40
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drzrma posted:"Planes want to keep flying, helicopters desperately want to fall out of the air unless everything is going absolutely right." I just finished Red Eagles and it seems the MiG-23 must have had a little helicopter in him.
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Feb 8, 2016 18:59
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Sagebrush posted:Helicopters really are the ugliest things. You shut your whore mouth. <  >
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Feb 8, 2016 20:24
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Beauty is in the eye of the beholder and there's a lot of visually impaired people around  A-10 AH-64 are a pair of major beauties but then again my taste in women is the kind who looks like they can and regularly do flip cars over
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Feb 8, 2016 21:29
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MrLonghair posted:Beauty is in the eye of the beholder and there's a lot of visually impaired people around Do you also prefer later fat F-16s with warts and lumps instead of early sleek ones? You monster.
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Feb 9, 2016 00:42
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I'm sure many of you have seen this but..... Good job Boeing. I guess the pilot did ok too. http://youtu.be/Q9WNnJprwzU
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Feb 9, 2016 01:26
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Holy poo poo. Good job, captain.
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Feb 9, 2016 01:48
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Yea the Constellation is loving ugly.
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Feb 9, 2016 01:58
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Jealous Cow posted:I'm sure many of you have seen this but..... Good job Boeing. I guess the pilot did ok too. From the related videos section: https://www.youtube.com/watch?v=JoWS_SHe4gU Not sure if I ever seen someone bounce a 747 that hard before.  (eh I probably have just forgetting)
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Feb 9, 2016 02:13
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Sagebrush posted:Helicopters really are the ugliest things. 
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Feb 9, 2016 02:24
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http://i.imgur.com/r1LswcI.gifv http://i.imgur.com/NBwY59U.gifv
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Feb 9, 2016 05:57
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Feb 9, 2016 06:12
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The Locator posted:Relevant to helicopter chat... so watch this clip at 0.25 speed and it's a great demonstration of a fully-articulated rotor system in action. you can see the pitch decrease as the blade is advancing (higher relative wind to the blade means less angle of attack required) and increase on the retreating side (low relative wind, high AoA), which allows for higher airspeeds without retreating blade stall. you can also see the blade tip move up with higher pitch and down with lower pitch (otherwise known as flapping) due to the advancing side generating more lift than the retreating side. it's tough to see but there is also horizontal movement of the blade in relation to the main rotor hub (known as leading and lagging) which helps dampen the inertia of the blade as it spins. all of these translate into less stress and vibration conducted into the airframe from the rotor system, which for helicopters is a big plus!
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Feb 9, 2016 06:21
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