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Post by Northern lights on Feb 10, 2017 23:54:11 GMT -5
I know a few things about tires. They gotta be round, Tires that are not round work like s-t. They gotta be black, I mean who has ever seen a good working tire that was not black? Actually what's up with that? Why not invent coloured tires? That would sell great in the "hood", then after all that, little white suburban kids will want them.
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Post by BearClause on Feb 11, 2017 1:32:53 GMT -5
I know a few things about tires. They gotta be round, Tires that are not round work like s-t. They gotta be black, I mean who has ever seen a good working tire that was not black? Actually what's up with that? Why not invent coloured tires? That would sell great in the "hood", then after all that, little white suburban kids will want them. Tires don't actually need to be black. Most have carbon black as a filler, but there are other fillers that aren't black. I remember BMX bike tires that came in all different shades. I had some Michelin bike tires that had a green tread. And strangely enough the tires weren't round. They were called "folding tires" because an unused tire could be folded up. I saw some riders stash spares under the seat. They weren't quite like these, but similar: I heard Kumho sold tires that were designed to leave colored smoke when burning rubber. They also left that color on the pavement. Cops hated them because they thought that maybe they'd be used during illegal "sideshows" on public streets. Kumho claimed that it was only for legal, off-road use at things like competitions. I guess the most interesting tire I've seen is one used on the Space Shuttle. They have one that visitors can touch at the California Science Center in LA, as part of the Space Shuttle Endeavour exhibit. It was odd too as it was a bias-ply with minimal tread to save weight, so it's only good for a single landing.
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Post by BearClause on Feb 11, 2017 2:33:48 GMT -5
I think GE kind of missed the boat on high efficiency lighting. They're kind of like Kodak that way, as in "Why mess with something that's making us tons of money?" Someone at GE actually developed the first visible light LED, but they might not have thought of it as doing much beyond indicator lights. In the end I think they're now mostly trading on the name by purchasing from a supplier and slapping on their name on CFLs, LEDs, and other high-efficiency lighting. I got curious about it and apparently someone at GE came up with the first compact fluorescent. It may not have been the same as Kodak and their fear that digital imaging would kill their film business. It was more that the manufacturing was more labor intensive than fluorescent tubes, which can be made with more automation. www.cleveland.com/obituaries/index.ssf/2012/07/edward_e_hammer_of_nela_park_i.htmlThe Smithsonian has the first prototype. I remember circular fluorescents in the 80s, but those basically only worked for table lamps. I was at a store today and saw those "high efficiency" incandescents. Made in Hungary, so even those are likely developed by someone else and relabelled.
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Post by BearClause on Feb 13, 2017 14:50:17 GMT -5
I guess going back to the subject on hand, what has the increased use of carbon fiber meant for inspections and maintenance?
I know it's lightweight and very strong/stiff in certain ways. However, from my experience with bicycles, it has certain issues with weaknesses in specific directions. When carbon fiber fails, it tends to do so in spectacular fashion.
I go back to my materials science class. The prof specialized in material fatigue cracking. I remember he said that one rule of thumb was military aircraft could tolerate cracks up to 1 foot, but cilivilan aircraft might tolerate 3 feet cracks. I'm guessing he was talking about aluminum alloys, but is there a new rule of thumb for newer materials?
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Post by mikegarrison on Feb 13, 2017 15:15:27 GMT -5
I guess going back to the subject on hand, what has the increased use of carbon fiber meant for inspections and maintenance? I know it's lightweight and very strong/stiff in certain ways. However, from my experience with bicycles, it has certain issues with weaknesses in specific directions. When carbon fiber fails, it tends to do so in spectacular fashion. I go back to my materials science class. The prof specialized in material fatigue cracking. I remember he said that one rule of thumb was military aircraft could tolerate cracks up to 1 foot, but cilivilan aircraft might tolerate 3 feet cracks. I'm guessing he was talking about aluminum alloys, but is there a new rule of thumb for newer materials? There are a whole set of new inspection and repair techniques for carbon fiber. Sometimes damage to composite structures (like delamination) is not visible to the naked eye, but it can still be detected with instruments.
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Post by BearClause on Feb 13, 2017 16:03:03 GMT -5
Maybe tangentially related, but is Boeing thinking of getting back into ground transportation? I do remember how the foray into light-rail vehicles went.
Also - how come there's never been a large commercial passenger helicopter?
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Post by mikegarrison on Feb 13, 2017 16:32:41 GMT -5
Maybe tangentially related, but is Boeing thinking of getting back into ground transportation? I do remember how the foray into light-rail vehicles went. Also - how come there's never been a large commercial passenger helicopter? What do you mean? Transport helicopters are already a thing. But an expensive thing.
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Post by BearClause on Feb 13, 2017 16:47:18 GMT -5
Maybe tangentially related, but is Boeing thinking of getting back into ground transportation? I do remember how the foray into light-rail vehicles went. Also - how come there's never been a large commercial passenger helicopter? What do you mean? Transport helicopters are already a thing. But an expensive thing. I mean something like a 200-300 seat passenger helicopter that could do something like shuttle passengers between downtown helipads. I realize the infrastructure (like security) would need to be in place. I know there are heavy lift helicopters, and the Soviets had some pretty massive military helicopters. But why not something for the civilian market? Maybe something different like a civil version of the Osprey.
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Post by mikegarrison on Feb 13, 2017 18:52:19 GMT -5
What do you mean? Transport helicopters are already a thing. But an expensive thing. I mean something like a 200-300 seat passenger helicopter that could do something like shuttle passengers between downtown helipads. I realize the infrastructure (like security) would need to be in place. I know there are heavy lift helicopters, and the Soviets had some pretty massive military helicopters. But why not something for the civilian market? Maybe something different like a civil version of the Osprey. We have something for that already. It's called a "train". Helicopters work OK for air taxi service, and they are used when nothing else will quite work. For instance, helicopters are often used to transport crews to and from offshore oil rigs. But they have scaling problems when they get too big. The very biggest helicopters will hold about 50 people. Civil tiltrotors have been talked about for a long time. They make more sense than helicopters (faster, longer range). But they still aren't as cheap and fast and scalable as fixed wing airplanes. Or trains. You make a lot of tradeoffs in order to get that vertical takeoff and landing.
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Post by Wolfgang on Feb 13, 2017 19:17:28 GMT -5
Is this scene in the TV show "Lost" realistic? I mean, if a guy is standing in front of the air intake area of an engine, will he really be sucked into the shaft and blow up the engine?
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Post by mikegarrison on Feb 13, 2017 19:43:53 GMT -5
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Post by BearClause on Feb 13, 2017 21:37:38 GMT -5
I mean something like a 200-300 seat passenger helicopter that could do something like shuttle passengers between downtown helipads. I realize the infrastructure (like security) would need to be in place. I know there are heavy lift helicopters, and the Soviets had some pretty massive military helicopters. But why not something for the civilian market? Maybe something different like a civil version of the Osprey. We have something for that already. It's called a "train". Helicopters work OK for air taxi service, and they are used when nothing else will quite work. For instance, helicopters are often used to transport crews to and from offshore oil rigs. But they have scaling problems when they get too big. The very biggest helicopters will hold about 50 people. Civil tiltrotors have been talked about for a long time. They make more sense than helicopters (faster, longer range). But they still aren't as cheap and fast and scalable as fixed wing airplanes. Or trains. You make a lot of tradeoffs in order to get that vertical takeoff and landing. We're trying with high-speed rail in California. I guess part of the problem is the cost and politics of building the infrastructure. Even then it's going to be limited to fixed routes.
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Post by BearClause on Feb 14, 2017 21:47:10 GMT -5
Why don't more planes have the ability to dump fuel?
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Post by mikegarrison on Feb 14, 2017 22:03:00 GMT -5
Why don't more planes have the ability to dump fuel? Bad for the environment and generally not necessary. Most planes can land heavy if they need to, but afterward they have to be very carefully inspected, so it's expensive. And if there is no urgent reason to land, just flying around for a while will burn off the extra fuel. That's a lot better for the environment than dumping the fuel would be. Planes have a set of design weights. Maximum taxi weight. Maximum takeoff weight. Maximum landing weight. Maximum zero fuel weight. Each of these is used for structural design and also flight performance design. Maximum taxi weight is a little more than maximum takeoff weight, so the plane has the ability to taxi out to the runway and still take off at MTOW. MLW is what the plane it rated to land at. Upon landing, the plane will typically still have a lot of fuel on board. This extra fuel is "reserve" fuel, and it's there so that if for some reason the airplane can't land at the destination, it can fly to another nearby airport and land there. It will always be less than MTOW. MZFW is the maximum weight allowed for everything except fuel (empty weight plus payload), so it will always be less than MLW. Generally, airplanes can physically takeoff at higher weights than MTOW or land at higher weights than MLW, but they aren't allowed to except under special circumstances. Doing so will mean longer runways are needed. In the case of exceeding MLW, there will have to be inspections done. In the case of exceeding MTOW, that would need special permission and engineering analysis.
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Post by BearClause on Feb 14, 2017 22:31:04 GMT -5
I guess in a similar line of thought, I remember when United used to have a scheduled SFO-OAK-DEN route - from what I heard either on a 727 or 737. The SFO-OAK portion of the flight was supposedly the shortest scheduled jet aircraft flight anywhere at about 13 miles. I heard that some people would just book that if they needed a segment or the minimum 400 miles for United's frequent flier plan. There might be a few charters that do that for repositioning. A lot of big league sports teams fly charters into SFO because the team hotel is in San Francisco, but then take off from OAK because they arrive straight from the stadium/arena.
However, what kind of considerations would be needed for fuel and loading for such a flight? Would it make more sense to load all the fuel needed to get to Denver in San Francisco, or take off with minimal weight and then fuel up again in Oakland?
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