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Post by Cybermortis on Apr 12, 2017 10:34:03 GMT
A Huey at full load is one tenth the weight of the smallest and lightest Airbus in service, so can decelerate a hell of a lot faster.
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Post by the light works on Apr 12, 2017 14:19:23 GMT
I vaguely remember that the capsule's terminal velocity was 175 mph, and that the helicopter's terminal velocity was the same. So, matching speed was theoretically possible, with proper timing. so how would they "Match" speeds if the helicopter is not able to exceed that terminal velocity to "Catch up", or speed up once the capsule approached... and 175mph for me is the speed of a capsule AFTER initial deployment of a chute, it would be going many times that speed to break through our atmosphere. 175mph is about stall speed of a light aircraft taking off... Cessna speeds...not a free-fall as a capsule that just came from spaceOn calculating speed of reactions inclusive here, starting at 19,000 ft ceiling of huey you suggest, and having it at terminal velocity as the capsule approaches, manover into some kind of parallel path, match exact velocity, extend "robot arm", then "catch" the capsule, restart the engine, change from nose down dive to usual attitude, or how else did they get past the rotors without clobbering them, And now "Brake" the capsule and the aircraft, bring under control, and start "flying" All whilst doing this by "Remote control", and having lag between communications, and I didnt even go anywhere near effective range of the remote control's radio range here, You may have noted the exact time I suggest they ran out of air space there?.. 19,000ft is a long long way, unless you are trying to throw the air-brakes on from free-fall at the time. At 500mph, commercial airliners start slowing down over London to land at Manchester Airport, and thats 3 hrs by road, but only 30 mins by air, to landing. Thats "Gentle" de-acceleration, its not like the pilot wants to slam the brakes so hard he ends up with all the passengers in his lap?.. I also suggest that the "standard" rotors on that aircraft would snap off under the strain of trying to brake just the aircraft in that situation. Let lone a "Capsule" as well. If that is anything like the capsule that the Apollo landings used as well, it takes a HUGE heavy lift aircraft to lift one of them off the ocean after landings?.. did anyone have a weight of the capsule?.. this may be the deal breaker. If its one that needs say a flying banana Chinook, or sikorsky sky-crane to lift, "Busted"?.. The weight of the capsule, even if its a half ton soaking wet, would be many many many tons under de-acceleration of whats needed to not go splut?.. g-forces off the scale type braking there. haven't seen it, yet, but I would suspect the capsule is more along "pull it inside the helicopter" dimensions.
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Post by the light works on Apr 12, 2017 14:24:01 GMT
A Huey at full load is one tenth the weight of the smallest and lightest Airbus in service, so can decelerate a hell of a lot faster. more to the point, commercial passengers tend to whine about spilling their champagne, so the helicopter can decelerate faster.
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Post by Lokifan on Apr 12, 2017 15:36:26 GMT
I vaguely remember that the capsule's terminal velocity was 175 mph, and that the helicopter's terminal velocity was the same. So, matching speed was theoretically possible, with proper timing. so how would they "Match" speeds if the helicopter is not able to exceed that terminal velocity to "Catch up", or speed up once the capsule approached... and 175mph for me is the speed of a capsule AFTER initial deployment of a chute, it would be going many times that speed to break through our atmosphere. 175mph is about stall speed of a light aircraft taking off... Cessna speeds...not a free-fall as a capsule that just came from space The matching speed was explained as follows: 1. According to the show, the capsule was falling out of orbit at high speed. But, it's terminal velocity was 175 mph even without a parachute, which it would reach at some point inside the flight envelope of the helicopter. The speed is determined by the air resistance and the mass of the capsule. 2. So, you take the helicopter up as high as it would go (ceiling was not mentioned as I recall), then kill the engine and let it fall and reach it's own terminal velocity, which Just Happened to be the same 175 mph. Again, air resistance and mass determine terminal velocity of the helicopter. 3. In essence, gravity was accelerating the helicopter downward to 175 mph, while air resistance was decelerating the capsule down to 175 mph at the same time. So, at some time they'd both be falling at the same speed, a constant 175 mph. It was now a matter of timing to make sure they reach the same altitude while at that speed. Cut the engine too late and the helicopter can't catch up to the capsule; too early and the capsule never catches up to the helicopter. The timing had to be perfect, and of course our heroes could do it...at least, the script said they could! Recovering a falling space capsule has been done in the past (although with functional parachutes) with aircraft. Here is video of the "Skyhook": Having said that, it's obvious this is a different setup, but the principles are a bit similar. The helicopter maintained a flat, belly down attitude throughout the operation. The capsule dropped down in front of the stalled rotors, hanging neatly in front of the cockpit. The arm shot out from beneath the cockpit to capture the capsule, and pulled it close to the cockpit. The engine restarted the rotors, and flew happily over to the military base. The helicopter was unmanned, so being gentle wasn't a big concern. Yeah, I mentioned the stresses involved earlier sounding fishy, right? But, remember, this is a special Hechian Super Robocopter, not a Huey! Therefore, the blades won't snap because they're hand made unobtanium coated invincibilium, the engine starts instantly, and the lifting/deceleration spec is (cough cough) lbs... In the show, the capsule was maybe two meters tall and a bit more than a meter in diameter. It was tapered, but not severely. I'd say that it's physical proportions resembled the SpaceX Dragon, like in this image: Note: It was much smaller than the Dragon. Yeah. Like I said: fishy.
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Post by the light works on Apr 12, 2017 16:12:01 GMT
so how would they "Match" speeds if the helicopter is not able to exceed that terminal velocity to "Catch up", or speed up once the capsule approached... and 175mph for me is the speed of a capsule AFTER initial deployment of a chute, it would be going many times that speed to break through our atmosphere. 175mph is about stall speed of a light aircraft taking off... Cessna speeds...not a free-fall as a capsule that just came from space The matching speed was explained as follows: 1. According to the show, the capsule was falling out of orbit at high speed. But, it's terminal velocity was 175 mph even without a parachute, which it would reach at some point inside the flight envelope of the helicopter. The speed is determined by the air resistance and the mass of the capsule. 2. So, you take the helicopter up as high as it would go (ceiling was not mentioned as I recall), then kill the engine and let it fall and reach it's own terminal velocity, which Just Happened to be the same 175 mph. Again, air resistance and mass determine terminal velocity of the helicopter. 3. In essence, gravity was accelerating the helicopter downward to 175 mph, while air resistance was decelerating the capsule down to 175 mph at the same time. So, at some time they'd both be falling at the same speed, a constant 175 mph. It was now a matter of timing to make sure they reach the same altitude while at that speed. Cut the engine too late and the helicopter can't catch up to the capsule; too early and the capsule never catches up to the helicopter. The timing had to be perfect, and of course our heroes could do it...at least, the script said they could! Recovering a falling space capsule has been done in the past (although with functional parachutes) with aircraft. Here is video of the "Skyhook": Having said that, it's obvious this is a different setup, but the principles are a bit similar. The helicopter maintained a flat, belly down attitude throughout the operation. The capsule dropped down in front of the stalled rotors, hanging neatly in front of the cockpit. The arm shot out from beneath the cockpit to capture the capsule, and pulled it close to the cockpit. The engine restarted the rotors, and flew happily over to the military base. The helicopter was unmanned, so being gentle wasn't a big concern. Yeah, I mentioned the stresses involved earlier sounding fishy, right? But, remember, this is a special Hechian Super Robocopter, not a Huey! Therefore, the blades won't snap because they're hand made unobtanium coated invincibilium, the engine starts instantly, and the lifting/deceleration spec is (cough cough) lbs... In the show, the capsule was maybe two meters tall and a bit more than a meter in diameter. It was tapered, but not severely. I'd say that it's physical proportions resembled the SpaceX Dragon, like in this image: Note: It was much smaller than the Dragon. Yeah. Like I said: fishy. "fishy" being above average for the scorpion writers. I presume with a special built robocopter, it would be possible to disengage the rotors from the engines and brake them to a stop. both preventing autorotation from being an issue, as well as eliminating the spool-up time of the turbines. it would have been smarter to drive the helo down under power, if you were reaching out from under the rotor disc to snatch the capsule, anyway. that would give you a broader "matching speed" window, as well as eliminating the restart lag. but I guess a team of geniuses wouldn't have thought of that
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Post by WhutScreenName on Apr 12, 2017 20:58:10 GMT
I'm surprised you didn't mention Happy using the nail files to claw her way back in a wind tunnel that was blowing strong enough to hold another, heavier character 5 feet off the ground... first of all, could the nail files actually be stuck into the ground as easily as a stake into soil? 2nd, would they be strong enough to hold her weight, 3rd, would she have any chance of holding onto them and make her way forward?
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Post by Lokifan on Apr 12, 2017 21:33:09 GMT
I'm surprised you didn't mention Happy using the nail files to claw her way back in a wind tunnel that was blowing strong enough to hold another, heavier character 5 feet off the ground... first of all, could the nail files actually be stuck into the ground as easily as a stake into soil? 2nd, would they be strong enough to hold her weight, 3rd, would she have any chance of holding onto them and make her way forward? Yeah, I kind of missed some of that. Wasn't she driving it through the sheet metal floor of the room? Would that make a difference? And another thing--the room was a wind tunnel chamber. One thing that irritated me about that scene is that there were "baffles" at both ends of the room, and they closed one end (the exhaust). Wouldn't that overpressurize the chamber and blow out the walls? And no one noticed the sound of all this happening a few inches away in the conference room?
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Post by the light works on Apr 13, 2017 4:01:01 GMT
I'm surprised you didn't mention Happy using the nail files to claw her way back in a wind tunnel that was blowing strong enough to hold another, heavier character 5 feet off the ground... first of all, could the nail files actually be stuck into the ground as easily as a stake into soil? 2nd, would they be strong enough to hold her weight, 3rd, would she have any chance of holding onto them and make her way forward? Yeah, I kind of missed some of that. Wasn't she driving it through the sheet metal floor of the room? Would that make a difference? And another thing--the room was a wind tunnel chamber. One thing that irritated me about that scene is that there were "baffles" at both ends of the room, and they closed one end (the exhaust). Wouldn't that overpressurize the chamber and blow out the walls? And no one noticed the sound of all this happening a few inches away in the conference room? yeah, holding stainless steel nail files in her bare hands and driving them into the metal floor. then we have the ancillary myths: you can use a stainless steel nail file to smooth rivet heads - yep, busted. takes the cutting edges right off. of course, there's the myth that a stainless steel nail file is a high end file. as for the sound - the president had a band playing, and the general making a speech in an attempt to cover the noise. also: with the business end of the torch sealed into the capsule through the test port, the wind tunnel shouldn't have affected the flame - but the lack of air inside the capsule should have, unless the fuel carried its own oxidizer. the capsule should have thrown the helicopter (which was a huey with standard rotor) off balance. palladium melts at 2831 degrees ((F) since that's what they presumably used in the show) palladium IS used in catalytic converters, and it forms a surface layer of palladium oxide at 800 degrees C. en.wikipedia.org/wiki/Palladiumglobal production is currently 222 tonnes per year. and the top price n record is $1100.00 per troy ounce. so I guess we can add space mining of palladium being a worthwhile investment to the myth list
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Post by the light works on Apr 13, 2017 4:28:18 GMT
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Post by Lokifan on Apr 13, 2017 5:46:18 GMT
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Post by Lokifan on Apr 13, 2017 5:56:25 GMT
Hey, like I said, it was a running joke in the show. On a related topic, I found it funny that this show made me remember a mnemonic a friend of mine back in 7th grade made up for the difference between a meteoroid, a meteor, and an meteorite. Meteor OIDS are Out In Deep Space. A meteor ITE is In The Earth. A meteor is between the two.
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Post by silverdragon on Apr 13, 2017 9:29:54 GMT
A Huey at full load is one tenth the weight of the smallest and lightest Airbus in service, so can decelerate a hell of a lot faster. Not so fast Padwan... the rotors are designed to take "Maximum load" so much that modern rotors have a load limit warning in them to help the pilots know when they are reaching the limits. And that bell sound quite more often than I would like?.. turns out tipping a flying banana to 27degree is close to its maximum limit when they do the displays, and can put micro-fractures in the rotors, even on a completely empty airframe that has minimum fuel to aid in its agility, which kind of throws a spanner at flying a head-down approach to full flare to miss the ground in any rotary wing at maximum speed descent into how wide the turn needs to be before you rip the rotors off?.. Unlike a jet, you cant throw it in full backwards thrutch and "trust" the airframe to do the rest, you have to graduate any change in control to ease in sudden change in direction. "A body in motion"?.. If you go watch any display team at work, and note the difference between a fast jet tumbling about the skies pulling close to 8g, and a helicopters slow almost graceful display even at full tilt... There is no such thing as a high numbers anti-G-suit for helicopter pilots.?.. That should be enough to sort of indicate you cant change direction "that fast", any direction, and "Flaring" the blades to slow down suddenly can only be done "At a certain rate". Yes slowing down from full speed takes a heck of a lot less than slowing down an airbus to stall speed from full thrutch... But the huey is doing just under 200, the airbus is 500 at usual cruising speed, thats the difference between a Nascar and a Ford Escort when you stomp the brakes, the escort will maybe stop faster, but it wasnt doing that fast anyway?.. So if you take a helicopter that is close to its maximum weight, ANY manoeuvre, however minor it may be, including reacting to a sudden gust of wind, has to be done gently, its not how much you can get off the ground, its how much you can fly with, which is why helicopter pilots are constantly in a state of Schroedinger cat doing calculations on fuel, load, height, distance and a whole lot more at every step of the flight. And probably why there are not many autopilots in helicopters.... This is why I am questioning the weight of that "Capsule", and how that may affect the balance of the chopper. Its an important ask. The weight of that capsule may widen the operational box that the chopper may fly in from a hundred yards to half a mile to make a turn if its heavy enough. Sure as eggs is eggs its also going to change the ability to flare to slow down. So can we get an estimate in weight of that capsule?.. and can we compare that to the max payload of that chopper, and then asses how its attached, if the robotic arm is the only think "Hanging on", then what is the sheer strength of that arm, and think also of the Simpsons episode wrecking ball here, that helps to look at the angles you can use to swing a heavy weight before it topples the machine swinging it, this is sort of how you have to look at how you can swing a payload under a rotary wing aircraft. I hope I am managing to ask the right sort of questions on this one, as I say, I was never that much "Up" on rotary wing, they had their own crews, who knew all this maths stuff that is unique to rotary wing aircraft, I just stood and watched as that noisy flappy bird lifted impossible loads and just "Hung" in the air from sky-hooks?.. they fascinated me enough to ask a few questions, which is what I am basing what I know on, as I got sensible answers. Now I have a sensible question to ask, why the hell didnt they just get a fast jet to go chase this capsule?.. it would have made the numbers a hell of a lot easier to work with. And perhaps a lot easier to explain, "why cant we use the chopper", because it wouldnt work is all?..
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Post by silverdragon on Apr 13, 2017 9:33:06 GMT
Aw shooks, you just spoiled a whole interesting discussion by going all sci-fi-fi-fi on me?..
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Post by silverdragon on Apr 13, 2017 9:35:39 GMT
General rule of thumb, an asteroid is an asteroid until it hits the ground, or "Something", then its a metiorite. But only if it survives. If it doesnt, its "Debris"..... which is a posh word for dust that clogs your air intake?.. Asteroid comes from the Greek words for "Star-like", or star-shine, as observed flying through the sky on any given night. It aint a star if it hits yer foot, so then its meteor, the suffix "Ite" is a size definition, meteor is large, add ite for a small one?..
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Post by Cybermortis on Apr 13, 2017 11:34:09 GMT
If an Airbus and a Huey are travelling at the same speed, the Huey will be able to decelerate faster than the Airbus due to having less momentum due to its lower mass. (MUCH lower, the weight of the smallest Airbus doesn't include passengers and cargo).
It's the same reason an old mini can stop in a shorter distance than a fully loaded 18 wheeler truck.
The comparisons between a passenger jet and a helicopter do have problems of course. But it's not really fair or helpful to argue that something that is so significantly heavier can be used to show or indicate how quickly or slowly a smaller object could slow down.
I'd also note that this is probably a situation, based on the scenario presented, where damaging the aircraft to the point it requires major repairs or may never fly again, might not be considered important.
The wilki entry indicates the carry capacity of a Huey is some 3,880 lbs, so the capsule would have to weight no more than around 4,000lbs; Assuming that they were able to strip out at least 200 lbs of weight when installing the remote control system. (This might not be unreasonable as 200lbs would be more than covered simply by not having a pilot and copilot)
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Post by the light works on Apr 13, 2017 13:35:15 GMT
the happy fun guy helicopter they used in the planning stages had 4 blades.
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Post by the light works on Apr 13, 2017 13:36:29 GMT
General rule of thumb, an asteroid is an asteroid until it hits the ground, or "Something", then its a metiorite. But only if it survives. If it doesnt, its "Debris"..... which is a posh word for dust that clogs your air intake?.. Asteroid comes from the Greek words for "Star-like", or star-shine, as observed flying through the sky on any given night. It aint a star if it hits yer foot, so then its meteor, the suffix "Ite" is a size definition, meteor is large, add ite for a small one?.. an asteroid is a big rock in space. a meteor is a small rock in space. either of them that makes it to the ground is a meteorite.
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Post by silverdragon on Apr 14, 2017 6:13:10 GMT
If an Airbus and a Huey are travelling at the same speed, the Huey will be able to decelerate faster than the Airbus due to having less momentum due to its lower mass. (MUCH lower, the weight of the smallest Airbus doesn't include passengers and cargo). It's the same reason an old mini can stop in a shorter distance than a fully loaded 18 wheeler truck. The comparisons between a passenger jet and a helicopter do have problems of course. But it's not really fair or helpful to argue that something that is so significantly heavier can be used to show or indicate how quickly or slowly a smaller object could slow down. I'd also note that this is probably a situation, based on the scenario presented, where damaging the aircraft to the point it requires major repairs or may never fly again, might not be considered important. The wilki entry indicates the carry capacity of a Huey is some 3,880 lbs, so the capsule would have to weight no more than around 4,000lbs; Assuming that they were able to strip out at least 200 lbs of weight when installing the remote control system. (This might not be unreasonable as 200lbs would be more than covered simply by not having a pilot and copilot) "A Body in motion stays in motion until a force acts upon it...." And the forces are the engines.. small ones for light planes, bigger for bigger?.. May I introduce the "Force" A Few words from Wikapedia now on the Rolls Royce Trent engines, which are as accurate as damn it to be pedantic over... And there are two to four of them dependant on size of airframe. Sorry to say your argument is not quite as simple as that?. The braking force of "Just" the airbrake on a Bugatti Veyron at above 100mph is the same total braking force of a small family hatchback. Needless to say, it isnt much use at 30 mph, but at three four five times that speed?.. So chuck a few brakes by putting the engines in reverse thrust and extending a few flaps on a Airbus, and what braking force have you got on one of them?. On to your braking distances of a fully loaded 18wheeler, and I can tell you I have MUCH better brakes than the old first generation Mini... To make it fair, have your mini tow a trailer, because the art of keeping it behind counts here. That mini was built on all round drum brakes, I have dual vented disks twice the size of the wheels of a mini, and a hell of a lot more rubber creating rolling resistance than a mini, the braking distance of an old mini are pretty much what it says should be allowed by the highway code, and I am on air. Much more, "empty", because of all that rubber, I may have greater problems stopping without the trailer overtaking, I can brake better in a straight line loaded than empty, because the trailer wheels of an empty just lock up and leave twin black lines on the road most of the time. which doesnt aid braking distances at all. On a good clear straight road, with a combined weight of say 30 tons, with a trailer with working load sensors and its own form of ABS, on my modern Volvo artic, I would put my Hat on the modern 18wheeler being able to stop maybe even faster than the original mini at say 45mph?.. The art of stopping fast is being able to keep the back from overtaking the front. If you are to detach the trailer, I can assure you I CAN stop in less distance from 30mph than a mini, I know this, because experience, sudden sheep of a pedestrian on a bloody phone, how I didnt hit him I still dunno.... So on to what can stop faster. The Helicopter that runs out of speed before an A-380 can get airborn, or the plane from total full thrust to standstill as a percentage of speed when given the beans on the brakes "In an emergency", because a flying airbus can drop 200 mph extremely quickly and still fly. But you are comparing chalk and cheese... helicopters fly slower anyway, they can come to a stop faster because they dont have to land, which requires a certain speed to make that landing, if however you left the engines in full reverse to "drop" out of the sky at say 20,000 ft, at well below stall speed, even if the fly by wire would let you go that slow, to give it time to start flying again to land, I have no idea at what rate of loss the speed would change to make that stop, because I dunno anyone damn fool enough like me that would want to try it. And then I dunno anyone who owns one who would let a fool like us try that anyway?. However, from 200mph to standstill relative to airspeed, at full thrust reverse with all the airbrakes on, I suspect the change in speed would impress you?. However, again, as no one does that much, I aint sure you even can do that, aeroplanes of the fixed wing variety aint designed to do that. Unless its the Hercules that was designed for operation "Credible Sport", that could slow and land inside a sports stadium. Or a Harrier.... Now there is an idea. Put a Huey against a Harrier and see who stops faster when the harrier pilot pulls the handbrake.... that is a competition your about to loose, because them I know, and they can stop on a bloody hatpin?..[given the right pilot..] they just raise the nose slightly and let that Rolls Royce Pegaus "chew a bit of air", .....
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Post by Cybermortis on Apr 14, 2017 12:49:51 GMT
You can't put the engines of comercial passenger jets in reverse during flight.
Back in 1991 there was a crash caused when the engines on an aircraft went into reverse during takeoff. Since then it has been mandatory for multiple safeguards to be in place to prevent the engines going into reverse unless its on the ground.
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Post by the light works on Apr 14, 2017 14:12:20 GMT
and I still say you are comparing apples and boat anchors.
the airbus cannot decelerate rapidly, because they don't want to jostle the passengers. but beyond that you are looking at completely different acceleration profiles. the airbus is reducing speed in normal flight, while the helicopter is recovering from freefall. even a harrier performing a "handbrake" is a different sort of critter.
the only real comparisons one could do is of a helicopter and a harrier doing a maximum vertical takeoff, because you're not going to talk anybody into letting you stand their airbus on its tail and try to do a vertical takeoff.
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