[HN Gopher] Weightless: Parabolic flight on an A310
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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.
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