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drgitlin posted:Flying Delta One tomorrow for the first time. Normally fly BA transatlantic, either Club World or First. I need someone to hold me and tell me it'll be OK. It's very similar to club world. It's not like you'll be stuck in US domestic first class or something.
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Aug 30, 2016 00:28
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^^  first world problems drgitlin posted:Flying Delta One tomorrow for the first time. Normally fly BA transatlantic, either Club World or First. I need someone to hold me and tell me it'll be OK. I'm sure you will be fine. I, on the other hand, am flying Delta First on a Domestic configured 767-332 from HNL-SLC in a couple weeks which from what I stand is only marginally better than bad coach for the 6 hour flight. At least the outbound 757 is recently redone and supposedly decent. No pods or layflats though which I would kill for .
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Aug 30, 2016 00:38
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Delta flies a domestic configuration 757 from MSP to Rekyjavik. Since that's technically transatlantic it's marketed as business class, it carefully doesn't say delta one anywhere online but it does at the airport. My mom and dad were one of my he few people in that class. When my dad complained the purser had a very long list of the logistical fuckups caused by using a domestic aircraft on that route. He encouraged complaining to delta because the crew's complaints certainly weren't going anywhere.
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Aug 30, 2016 00:56
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um excuse me posted:Everyone here at Pratt is talking about the 737 engine failure. A sigh of relief that it wasn't one of our engines. We're also pretty glad none of the issues were working on are this public. I can guarantee you none of the guys over at GE slept this weekend. I took a look at it, saw that all the parts we make for it are on the exhaust end and said "whatever"
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Aug 30, 2016 01:23
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hobbesmaster posted:Delta flies a domestic configuration 757 from MSP to Rekyjavik. Since that's technically transatlantic it's marketed as business class, it carefully doesn't say delta one anywhere online but it does at the airport. My mom and dad were one of my he few people in that class. When my dad complained the purser had a very long list of the logistical fuckups caused by using a domestic aircraft on that route. He encouraged complaining to delta because the crew's complaints certainly weren't going anywhere. Wait, is special ETOPS qualification not necessary for that route?
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Aug 30, 2016 01:56
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hobbesmaster posted:When my dad complained the purser had a very long list of the logistical fuckups caused by using a domestic aircraft on that route. He encouraged complaining to delta because the crew's complaints certainly weren't going anywhere. Speaking of, American Airlines has a message for you: Maybe YOU should be trying harder if you want a nice flight?!
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Aug 30, 2016 01:57
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Platystemon posted:Wait, is special ETOPS qualification not necessary for that route? Its probably the planes that do MSP-HNL in the winter time. The MSP-KEF route is roughly the same length, but everyone in economy doesn't get a free dinner, booze and a ton of free checked bags. Flying out the cargo hold ran out of room. They started running out of a lot of types of drinks at the start of the 2nd service. The galleys were not large enough to hold the proper international load out or something, idk as I said it was my dad that had a long talk with the purser after complaining about buying a B ticket and wasting some crazy number of miles (it was priced like a delta one flight).
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Aug 30, 2016 02:02
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Phy posted:The clock I wish we could 5 individual posts.
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Aug 30, 2016 02:55
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EvilJoven posted:Hahaha remember when I posted about how as soon as you take all this lovely emergent notacopter technology and fine tune it so it's actually safe and efficient you get a helicopter. I would say that they have it pretty well tuned. How many conventional helicopters are flown hands off on the first manned flight. The only thing holding this technology right now is battery capacity. The small gas turbine generator will take care of that.
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Aug 30, 2016 03:17
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helno posted:I would say that they have it pretty well tuned. How many conventional helicopters are flown hands off on the first manned flight. Yeah, the tradeoff for controlability is safety. Airplanes and traditional helicopters can safely land from altitude even with a total powerplant failure; what happens if the battery fails while this thing's flying? Oops, you drop like a stone because you have no wings and can't autorotate like a copter can.
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Aug 30, 2016 03:24
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helno posted:The only thing holding this technology right now is battery capacity. The small gas turbine generator will take care of that. Is... is that really feasible? Would be pretty awesome to have long range vehicles (flying or not) by using a small traditional engine to generate energy. But I assume that it isn't very efficient
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Aug 30, 2016 03:55
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Phy posted:The clock You can't touch this! helno posted:I would say that they have it pretty well tuned. How many conventional helicopters are flown hands off on the first manned flight. Maybe you could just connect the turbine engine to the propulsion system? Save the weight of the battery system.
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Aug 30, 2016 04:00
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Godholio posted:Maybe you could just connect the turbine engine to the propulsion system? Save the weight of the battery system. But then don't get an electrical engine's responsiveness 
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Aug 30, 2016 04:53
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Pffft just go diesel works for locomotives
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Aug 30, 2016 05:22
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Inacio posted:Is... is that really feasible? Would be pretty awesome to have long range vehicles (flying or not) by using a small traditional engine to generate energy. But I assume that it isn't very efficient Trouble with small gas turbines is that they have to run at a stupidly high RPM. Platystemon posted:Wait, is special ETOPS qualification not necessary for that route? I think there are actually a fair number of diversion airports on the route, between Greenland, Newfoundland, etc.
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Aug 30, 2016 06:05
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Phy posted:The clock That took me longer than it should, but the reward was great. Well done. Enourmo posted:what happens if the battery fails while this thing's flying? Oops, you drop like a stone because you have no wings and can't autorotate like a copter can. You pop the BRS and the whole thing descends safely under parachute. What happens when a single gear in the massively complex gearbox of a twin engine helicopter fails? The rotor falls off and everyone dies. https://en.wikipedia.org/wiki/CHC_Helikopter_Service_Flight_241 Oh and the manufacturer tries to influence the investigation in the media.
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Aug 30, 2016 06:19
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Ola posted:That took me longer than it should, but the reward was great. Well done. you might say he went right up to the factory and picked it up, it's cheaper that way
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Aug 30, 2016 06:20
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Ola posted:That took me longer than it should, but the reward was great. Well done. A 13 man version of this couldn't use a BRS. Also I suspect this thing is going to spend too much of its time below the typical 1000ish ft minimum altitude for BRS deployment.
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Aug 30, 2016 06:39
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hobbesmaster posted:A 13 man version of this couldn't use a BRS. 
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Aug 30, 2016 06:45
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hobbesmaster posted:A 13 man version of this couldn't use a BRS. Oh I'm sure, just a random shot back as it was in the news again a few days ago. I doubt we'll see Volocopters ferrying crew to North Sea platforms. But not even a single seat helicopter can use a BRS. hobbesmaster posted:Also I suspect this thing is going to spend too much of its time below the typical 1000ish ft minimum altitude for BRS deployment. quote:Q. How low can the parachute work? http://www.brsaerospace.com/faq.aspx Envelope corners apply to helicopter autorotation and fixed wing engine out landing as well. e: there's a video of a hangglider trike which accidentally deploys the BRS on takeoff. It inflates immediately, to ill effect.
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Aug 30, 2016 07:10
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Inacio posted:Is... is that really feasible? Would be pretty awesome to have long range vehicles (flying or not) by using a small traditional engine to generate energy. But I assume that it isn't very efficient Using a gas or diesel engine to power an electric motor is very efficient (energy wise) and works really well. Pretty much every large ship or train uses this scheme (more recently hybrid cars). But while it's energy efficient it's not size or weight efficient. Size + Weight usually is trumps in aerospace.
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Aug 30, 2016 13:34
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Well, that weirdocopter can lift a 450kg payload. Is that enough for a small generator? I imagine that even with the greatly increased weight the range would be much improvedslidebite posted:Pffft just go diesel works for locomotives Let's make a locomotive-sized hoverbike!
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Aug 30, 2016 14:34
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rscott posted:I took a look at it, saw that all the parts we make for it are on the exhaust end and said "whatever"  Edit: their stock didn't even budge haha. um excuse me fucked around with this message at 15:10 on Aug 30, 2016 |
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Aug 30, 2016 15:06
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I was at the hospital today to get some blood work done, and I brought along an old magazine called "Air Classics" from around 1985. It featured two aircraft I'd never heard of: The Miles M39B Libellula (Dragonfly) George Miles was a designer of private aircraft in the 1930s, and owned his own firm. In the early part of World War 2, he learned that the two main British fighters, the Hurricane and the Spitfire, were not terribly good at being adapted to carriers - visibility over the nose is kinda important. So, he set to work in secret, [that is to say, secret from the British Government, which was supposed to approve of all design efforts] and designed a wooden fighter with tricycle landing gear, and nestled the pilot right in the nose of the airplane. He also got an eyeful of the Westland Delanne:  a Westland Lysander turned surrealist and loved the idea of turning the tail of a airplane into a second set of wings. Excited to try out his new ideas, he made a small scale mockup, using spares from his successful line of trainer aircraft. As it was a mockup, he also built the thing out of wood. It was completed by May 1942. The results were...not great, at least initially. The first flight, the test pilot was reluctant to fly it, leading Miles to take the pilot's seat himself. The M39 proved really reluctant to unstick itself from the ground, until Miles discovered he could get a lot of lift by throttling down his engine to zero during the takeoff maneuver. He then discovered, once airborne, that the center of gravity had been improperly calculated, and it was only through Miles's natural piloting skill that the plane managed to land.  When the Air Ministry first saw the M39 design, monocles popped and there might have been actual rudeness. The Ministry said it would never fly, and Miles retorted that it already had flown. This made the Ministry angry that a plane had been built without its say-so, and issued Miles a formal reprimand. With the center of gravity fixed, the M39 proved a stable, competent flyer that Miles used to test out and confirm his ideas on the whole "double wing" concept, though the Air Ministry now hated it and the Admiralty was just not interested. Now that Miles knew the idea worked, submitted a design to the latest RAF bomber competition in July 1942. Despite the Air Ministry now looking at its shoes and saying maybe a new high altitude bomber was not really needed (it must have finally sunk in how fantastic the DH Mosquito was in this role) Miles also started a new wooden mockup of his new heavy bomber, a 5/8s scale copy of what Miles was thinking of. The mockup was powered by two DH Gypsy Major engines, a inline motor making about 140 hp. The real thing would have used supercharged Merlins (the Merlin 60) making about 1300 hp. The M39B:    Miles once again suprised the Air Ministry with the flying prototype, but since the prototype was flying well from the get-go and was showing real promise, they restrained their grumbling. They were kinda dickish about taking control of the weird aircraft so they could properly test it, and managed to have two accidents with it right away: first when the pilot forgot to lower the landing gear, and then when Miles had repaired that and sent it back, it was blown over when somebody was doing some engine testing. The design was extensively tested and shared with the Americans, who found it interesting, but was never put into production. Next: Goodyear's Ducks and Drakes: Personal Amphibians
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Aug 30, 2016 17:02
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hobbesmaster posted:A 13 man version of this couldn't use a BRS. What is the real limit for BRS? What are the heaviest loads that are airdropped? Murgos posted:Using a gas or diesel engine to power an electric motor is very efficient (energy wise) and works really well. Pretty much every large ship or train uses this scheme (more recently hybrid cars). But while it's energy efficient it's not size or weight efficient. I'm wondering how much weight could be saved if the turbine didn't need to be able to lift the copter, just keep it in level flight. Takeoff would be done battery-assisted. Admittedly planes and copters normally operate much closer to their max power, so there wouldn't be nearly us much benefit as with cars.
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Aug 30, 2016 17:34
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EvilJoven posted:Hahaha remember when I posted about how as soon as you take all this lovely emergent notacopter technology and fine tune it so it's actually safe and efficient you get a helicopter? Murgos posted:Using a gas or diesel engine to power an electric motor is very efficient (energy wise) and works really well. Pretty much every large ship or train uses this scheme (more recently hybrid cars). But while it's energy efficient it's not size or weight efficient. Cut that in half for efficiency reasons and I'll need a 300hp engine to fly my 1500lbs sky car, maybe I could get away with less. A high performance lightweight engine like a turbocharged motorcycle engine might be light enough and produce the required power. This is also an application where a Wankel would be appreciated. So now I have a gas-electric generator powering my flight motors, but I would also add a battery pack. The battery pack would not be used unless in the case of an engine failure. The battery pack would have enough juice to make an emergency landing from cruise altitude but not much more. Vitamin J fucked around with this message at 17:47 on Aug 30, 2016 |
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Aug 30, 2016 17:44
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Vitamin J posted:I have a concept in my brain I've been kicking around for a couple years. Right now the efficiency of a gas-electric hybrid drone is about 50%, you put a 4hp gas engine on an AC generator and you get 2hp out basically. If you scale that up to a train or ship it's a lot better but at smaller scale it's less efficient. Based on extremely rough calculations I made using a 25" hobby propeller, I would need roughly 100hp per 1000lbs for flight which includes enough overhead for maneuvers. It always comes down to this though. Why lower your efficiency and add complication by creating a system where the liquid fuel combustion engine turns an electric motor which turns the propulsion mechanism, when you could just directly power the propulsion mechanism from the combustion engine and do away with the middle man? You could still run a secondary independent emergency battery or ram air combination electrical drive as backup in case the combustion engine fails. In fact independent would be the better way of doing it from a safety perspective.
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Aug 30, 2016 18:07
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Linedance posted:It always comes down to this though. Why lower your efficiency and add complication by creating a system where the liquid fuel combustion engine turns an electric motor which turns the propulsion mechanism, when you could just directly power the propulsion mechanism from the combustion engine and do away with the middle man? You could still run a secondary independent emergency battery or ram air combination electrical drive as backup in case the combustion engine fails. In fact independent would be the better way of doing it from a safety perspective. However, having the ICE engine run just a generator tends to decreade failure rates due to less need to change RPMs on the motor repeatedly.
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Aug 30, 2016 18:10
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Let's not forget that the reduced mechanical components may lighten the craft enough to completely justify a two step energy conversion with efficiency losses. No shafts, supports, lubrication systems, dampers, collective components etc.
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Aug 30, 2016 18:16
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I don't think those electric multirotors will replace anything but leisure craft just yet, but that could be the dawning of something new. I'd imagine snowboarders for instance would be happy to cut their budget and increase their green image by being multirotor'ed up to the mountain top instead of going by carbon spewing AS350.Saukkis posted:What is the real limit for BRS? What are the heaviest loads that are airdropped? BRS themselves say 3400 lbs, obviously bigger things have been supported by parachutes but then we have to start considering acceptable deployment times and packaging weight and volume. Perhaps 4 BRSes, one every 90 deg of the ring? That could in theory carry 10200 lbs with one to spare for redundancy.
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Aug 30, 2016 18:54
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Ola posted:I don't think those electric multirotors will replace anything but leisure craft just yet, but that could be the dawning of something new. I'd imagine snowboarders for instance would be happy to cut their budget and increase their green image by being multirotor'ed up to the mountain top instead of going by carbon spewing AS350. that's actually brilliant. Make it wearable, and in case of avalanche, up up and away!
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Aug 30, 2016 18:58
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Linedance posted:that's actually brilliant. Make it wearable, and in case of avalanche, up up and away! We can make it voice activated! 
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Aug 30, 2016 19:08
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Linedance posted:It always comes down to this though. Why lower your efficiency and add complication by creating a system where the liquid fuel combustion engine turns an electric motor which turns the propulsion mechanism, when you could just directly power the propulsion mechanism from the combustion engine and do away with the middle man? You could still run a secondary independent emergency battery or ram air combination electrical drive as backup in case the combustion engine fails. In fact independent would be the better way of doing it from a safety perspective. Also this: https://www.youtube.com/watch?v=_7jENWKgMPY
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Aug 30, 2016 19:09
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Guys, what if instead of throttling the engines, we controlled the pitch of the rotors. And what if instead of several rotors, we just had one? We could control attitude by varying the pitch of the blades throughout each rotation.
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Aug 30, 2016 19:23
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Nebakenezzer posted:I was at the hospital today to get some blood work done, and I brought along an old magazine called "Air Classics" from around 1985. It featured two aircraft I'd never heard of: Never stop posting Nebakenezzer. I hope you are well, I need you to live so I can keep reading your awesome posts.
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Aug 30, 2016 19:24
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Platystemon posted:Guys, what if instead of throttling the engines, we controlled the pitch of the rotors. And what if instead of several rotors, we just had one? We could control attitude by varying the pitch of the blades throughout each rotation. Sounds complicated. That'll never work.
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Aug 30, 2016 19:30
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Vitamin J posted:Because electric motors are capable of changing their speed 400+ times per second which is required for a multirotor to fly. There is no way to design a mechanical system that does it as well or as simply. A gas-electric generator powering electric motors is mechanically simpler than any direct drive system you can imagine. Ah, didn't realize that was the case with how multi rotors worked. Carry on then! So you're talking about a centrally located engine/generator, then running power feeders and control wiring to each rotor which is being run by its own electric motor right? Makes sense. How about this for emergency recovery though... Rather than run all the motors off battery if there's an engine failure, switch a couple of them to be generator and let the rotors spin off ram air, providing some amount of electricity to the remaining rotors to control the rate of descent? Would need less battery that way, if it actually worked.
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Aug 30, 2016 19:34
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I can't help but think they would get some sort of airbag/parachute combo looking thing. I don't think you could make blades that small store enough energy to auto rotate effectively. I'd love to hear the guy who is a helicopter expert chime in on a subject matter like that.
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Aug 30, 2016 19:57
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um excuse me posted:I can't help but think they would get some sort of airbag/parachute combo looking thing. I don't think you could make blades that small store enough energy to auto rotate effectively. I'd love to hear the guy who is a helicopter expert chime in on a subject matter like that. I'm not a heli expert, but I do know sophomore-level physics. Rotational energy scales directly with moment of inertia, which for a rotor (essentially a rod rotating about the midpoint) scales directly with mass, and with the square of length. So even reducing length by half, you'd need four times the mass, so either you've got massive draggy airfoils or you're making your blades out of, like, tungsten to get the same energy storage. And then you've got half the blade length, meaning (probably) less torque from the airflow to spin the rotor up on the way down. And multicopters are way smaller than half of a typical rotor.
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Aug 30, 2016 20:10
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Platystemon posted:Guys, what if instead of throttling the engines, we controlled the pitch of the rotors. And what if instead of several rotors, we just had one? We could control attitude by varying the pitch of the blades throughout each rotation.
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Aug 30, 2016 20:14
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