[HN Gopher] Weightless: Parabolic flight on an A310 ___________________________________________________________________ Weightless: Parabolic flight on an A310 Author : Napsty Score : 84 points Date : 2022-09-13 11:26 UTC (11 hours ago) (HTM) web link (www.flightradar24.com) (TXT) w3m dump (www.flightradar24.com) | ultrahax wrote: | I did one of these with https://www.gozerog.com/ a few years | back. Not cheap, but memories that'll last a life-time. Started | with lunar and mars gravity, before going full zero g. Like the | article says, just make sure you have your ass pointed at the | ground before they bottom out! | 2OEH8eoCRo0 wrote: | Semi off topic- I'm seeing a Global Hawk and Rivet Joint doing | God's work over the Black Sea. Outstanding! | raverbashing wrote: | Yes, it seems it's been non-stop since the beginning | mellavora wrote: | yes, see i.e. | | https://mil.in.ua/en/news/three-british-and-american- | surveil... | | 23 feb 2022 | | the surprise would be if this was NOT happening. | phreeza wrote: | How is this related at all? | 2OEH8eoCRo0 wrote: | Related to flightradar24. Not related to parabolic flight. | bjkchoy wrote: | One of my preferred video clip ever was filmed entirely during a | parabolic flight: | | OK Go, Upside Down & Inside Out https://youtu.be/LWGJA9i18Co | SwiftyBug wrote: | This is unbelievably cool. I can't even imagine how they | prepared and rehearsed for that! | toss1 wrote: | What an insane lot of fun that must have been -- so much fun | just to watch them having fun! | qwertox wrote: | Wow, that was wild. | CharlesW wrote: | "How We Did It" video: | https://www.youtube.com/watch?v=pnTqZ68fI7Q | | _" In the course of 21 flights, we had about 58 unscheduled | regurgitations."_ | divbzero wrote: | The weightless chain reminds me of the latter half of | _Seveneves_. | segfaultbuserr wrote: | I didn't know it's possible using an unmodified airplane. My | first thought was: wouldn't this maneuver simultaneously set off | all the alarms bells in the cockpit, as if the plane is crashing | to the ground? After a quick search on YouTube, it indeed does, | but not really a big deal... | | > _2:43 - This parabolic manoeuvre isn 't the normal kind of | thing that you do in an Airbus, and the software in this plane | hasn't been modified because to do so would be a huge effort to | re-qualify it. With the normal software, you have the normal | alarm saying, "This doesn't seem like a very good idea, guys," | and one of the pilots that isn't too busy on the other two axes | is turning off the alarms that we don't need to worry about and | keeping track of the ones we might need to worry about._ | | https://www.youtube.com/watch?v=FO_Ox_dH0M8 | smackay wrote: | The Portuguese Space Agency (yes, there is one, Go Portugal) | recently ran a competition for teens to fly with Air Zero G. | Thirty kids, including my son (majority were girls), shipped out | today for the Air Force base at Beja. They fly on Friday. | qwertox wrote: | Congratulations for him and his peers for having the | opportunity to experience this. I can imagine that this will | have a long lasting effect on their minds. It would be great to | know what it did with him and the others in 10 years. | futile-systems wrote: | "Mom, can I visit the ISS?" | | "We have the ISS at home." | | The ISS at home: | rootbear wrote: | My pilot friend did this maneuver in a light plane (Cesena 172?) | with me once or twice. It was cool to see my camera floating in | front of my face for a few moments. | rbanffy wrote: | I wonder if there isn't an easy way to automate the parabolic | flight - the autopilot should be clever enough to do it by itself | without needing human intervention. | ilogik wrote: | it's a lot more complicated than it sounds: | | https://youtu.be/M67YP-f-LyI?t=592 | mromanuk wrote: | It baffles me that they need five pilots to accomplish this. | rbanffy wrote: | I imagine it's for an abundance of caution, as they are | flying these planes way outside what their normal operations | manual recommends. I assume a 320 NEO or a 737 MAX would slap | the hand of the pilot if they attempted to go for a +50 | degree climb and scream expletives in the voice alert system. | 6stringmerc wrote: | Okay you just gave me a mental image of an Airbus autopilot | system so angry at you it starts swearing in French. | Totally agree with safety and 'normal use case this is not' | situation. | a4isms wrote: | Bombardiers will issue a stream of Quebec sacres: | | https://en.wikipedia.org/wiki/Quebec_French_profanity | HPsquared wrote: | It kind of does already: | https://youtu.be/vmbzKsqKQoI#t=30s | UI_at_80x24 wrote: | Defaulting back to it's `native` language (of the | programmers). That would be hilarious and should be on | the next AirPlane spoof. | | Mel Brooks, where are you! | rbanffy wrote: | I thought about a cartoon robot articulated arm with a | white glove trying to wrestle the control column from the | pilot. | a4isms wrote: | Or the autopilot computer ejects by itself with a small | parachute. Very Looney Tunes! | Sohcahtoa82 wrote: | Well...in MS Flight Simulator, I know the voice alerts will | yell at you to warn you about terrain, of if your AoA is | too great ("Sink rate!"). | | But they don't care about high climb angles until you | eventually stall. | severine wrote: | "I'm sorry, Dave. I'm afraid I can't do that." | nvusuvu wrote: | FTA "To fly a parabola takes 3 pilots working in concert. Two | pilots sit in front of the control columns and a third sits | in the center jump seat to manage the engines. When flying a | parabola, one pilot is responsible for the pitch of the | aircraft and the other for the roll. The pilot responsible | for the roll of the aircraft actually has a modified control | column in order to put as little pressure on the yoke as | possible, allowing the pitch pilot to focus on the correct | parabola timing." I think precise timing requires many | pilots. Lots to keep track of in the name of science. | bombcar wrote: | Yeah doing a parabola is relatively easy. Doing a nearly | perfect one to maximize weightlessness without | overstressing something is harder, so having one pilot for | each aspect makes sense. | | Another for radio and another for "general everything | watching; the captain" makes sense. | 6stringmerc wrote: | My aviation family has a long history all the way back to | training pilots for WWII (already highly experienced - too | much so for combat) so my hunch is accuracy and redundancy. | | Under normal conditions, sure it's a one time maneuver, | within limits, etc. This is much more of a risk-laden | undertaking with the repeated stress on the airframe, the | human body, and so having individual attention on important | individual tasks - with experience and brain computing speed | machines still can't match for a brilliant stick and yoke | pilot in unexpected conditions - this is for safety. | | Also considering my background with French culture, I imagine | the discussion went something like "we could do it with fewer | personnel, but why? This works." | lm28469 wrote: | Yeah let's put Musk's autopilot in it and lose 20 people | every few years when the plane get scared by the shadow of a | cloud. That'll save money | [deleted] | mellavora wrote: | "Wow, this is hard. Therefore, AI must be the cheaper | solution!" | segfaultbuserr wrote: | It's plain old Control Theory, no AI needed. | rbanffy wrote: | This doesn't need AI. The physics are very well understood. | All that's needed is a better autopilot with better awareness | of surrounding conditions and more precise control of the | aircraft. | laverya wrote: | The real question is "does it cost more to certify the | autopilot to do this than it does to pay for an extra two | pilots", and with my understanding of aerospace costs that | answer would be "very, very much yes". | chasd00 wrote: | a pixhawk, ardupilot, some Lua, and a handful of servos and | you're there. ;) | rbanffy wrote: | > "does it cost more to certify the autopilot to do this than | it does to pay for an extra two pilots" | | I bet it does. Parabolic flights aren't really a huge market. | londons_explore wrote: | I could imagine the autopilot could do a much better job. | | In the ideal 'zero-g' flight, you can release a ball at the | start, and it should stay stationary (relative to the cabin) | for the whole flight. | | That means the plane body must be to within a few inches of | the exact perfect location in the sky 30 seconds later. | | I haven't flown planes, but I imagine that making sure they | follow precisely a path with an accuracy of an inch in all | three dimensions while travelling at 600 mph is no easy feat. | But an autopilot with a fast control loop might be able to do | it. | throwaway744678 wrote: | I guess even a supercomputer would not be able to | compensate for wind gust, turbulence, etc. | HPsquared wrote: | There isn't much turbulence, wind gusts etc. at altitude | - these are more of an effect of the bumpy and uneven, | alternative hot and cold surface at ground level - the | bumps are usually all smoothed out by the time you are | high up in the air. | | (besides large storms, of course) | | EDIT: Turns out there is sometimes some turbulence at | altitude, caused by large mountains, storms and the jet | stream - but these are all predictable and avoidable. | groby_b wrote: | All the autopilots in the world aren't keeping a plane to | within an inch in all three dimensions. It'd be nice, but | turbulence is a thing :) | | More importantly, actual position isn't that important - | you care about relative acceleration being as close to 0g | as you can. | | And with the 3-pilot setup the A310 zero g flights have, | they maintain +/- 0.02g. Now you add to that the fact that | developing an autopilot you can trust in that situation | costs a good chunk of money, the fact that it's a specially | modified plane (so it's more or less a one-off effort), and | the fact that pilot costs are negligible compared to the | rest of the flight cost. | | At this point, you can get a minimal increase in precision | for a large expenditure up front. You'll still have the | 3-pilot setup (you want to be able to recover on | malfunction), so operational costs aren't reduced. | | At that point, the question becomes "why would you" | rbanffy wrote: | The "easy" way to do it is to mandate autopilots to have | the capability for precise ballistic trajectories. This | would need better positioning, accelerometers, and | meteorological radars and would also enable fully | autonomous landings (if the plane can be aware of air | densities and speeds around it, it can nail the landing | even with wind gusts). | groby_b wrote: | Wait what? If your landings are a ballistic trajectory, | kindly step away from that stick ;) | | And that's kind of the point - nobody except the few | planes that fly parabolic trajectories needs this. So | good luck mandating something affecting all of aviation | with no practical use except for a handful of flights. | | Autoland already exists. And can handle crosswinds up to | 25kts. It's just that using them is an incredibly intense | task - your reaction time to fix mistakes is a bit short. | | That's why most landings are still manual, unless | visibility is so bad that you have no choice. | | (Also, the idea that meteorological radar could give you | enough info about air density to preemptively handle air | gusts is... a bold future) | rbanffy wrote: | I didn't say parabolic landings. I said the same | capabilities required to fully automate parabolic flights | would allow safer landings because precise trajectory | control even when there is turbulence around the plane is | a very desirable feature. | | On second thought, it could pay for itself in preventing | aborted landings. | jaywalk wrote: | Most passenger airliners flying today can land | automatically, but are only allowed to do so when | visibility is so bad that it's the only option. It's | called CAT III Autoland. | gilded-lilly wrote: | The "vomit comet" (American equivalent of this) has autopilot | for yaw and roll only. | [deleted] | helsinkiandrew wrote: | There's some scary videos from the cockpit in an A300 and (I | think an) A310 doing parabolas: | | https://www.youtube.com/watch?v=Ty5B-7CinB8 | https://www.youtube.com/watch?v=f-pMLZP6HL8 | ape4 wrote: | Maybe the pilots should wear helmets. | wil421 wrote: | Wow that last one was pretty crazy to see. I guess they had | some camera rig that would keep the camera level with the | horizon. | scrumper wrote: | Amazing video. | | I'd guess not mechanical? Look at the dashboard top, lower | left over the first minute or so: There's a screw head that | keeps popping in and out of existence which suggests some | kind of heavy software correction to me. | iamjackg wrote: | Yeah that looks like the kind of artifacting you might get | from a 360deg camera that's trying to hide itself from the | footage. ___________________________________________________________________ (page generated 2022-09-13 23:02 UTC)