back to article EU aren't kidding: Sky watchdog breathes life into mad air taxi ideas

The European Aviation Safety Agency (EASA) has issued a public consultation on how to regulate futuristic air taxis that take off and land vertically. In a proposed “special condition for small-category VTOL aircraft” published on its website on Monday, the agency said it has “received a number of requests for the type …

  1. Christian Berger Silver badge

    In Germany there actually is a strong push for those ideas in the ruling party

    And yes, they get ridiculed for that a lot, but those people simply aren't smart enough to understand why "air taxies" are a mad idea.

    1. jpo234

      Re: In Germany there actually is a strong push for those ideas in the ruling party

      A lot of things we take for granted today was considered a mad idea when people came up with it. We will see what comes from it. A lot of very smart people think there is some merit...

      1. Tigra 07 Silver badge
        Mushroom

        Re: In Germany there actually is a strong push for those ideas in the ruling party

        Taxis crashing into other vehicles and your garden wall - bad.

        Taxis crashing into skyscrapers and multi-storey buildings - really really bad.

        How will we stop bad eggs/suicidal/depressed people/terrorists from getting jobs as flying taxi drivers and suiciding themselves into high profile targets? We need plans in place.

        1. Alan Brown Silver badge

          Re: In Germany there actually is a strong push for those ideas in the ruling party

          "How will we stop bad eggs/suicidal/depressed people/terrorists from getting jobs as flying taxi drivers"

          $Hint: robot air taxi drivers have fewer things to avoid than robot ground taxi drivers. This is an area where monkeys won't be allowed to take the controls.

          In any case this is mostly a bad idea. "Flying cars" comes from the "personal freedom" brigade, but we don't have the energy resources to sustain existing demands for everyone on the planet, which means that it results in more societal stratification and more terrorism (poverty, inequity and deprivation breeds such things)

          Solving the energy problem without poisoning the biosphere (hint: "renewables", wind and solar are all rearranging the deckchairs on the Titanic) is a more pressing problem. Flying cars can come later.

          1. imanidiot Silver badge

            Re: In Germany there actually is a strong push for those ideas in the ruling party

            "$Hint: robot air taxi drivers have fewer things to avoid than robot ground taxi drivers. This is an area where monkeys won't be allowed to take the controls."

            You'd think that, it's not actually the case. On top of that robot air taxi drivers suddenly have to deal with moving objects in 3 dimensions and with unpredictable movement patterns. Unlike robot ground taxi drivers where everything happens in pretty much a 2d plane with much more predictable movement. Dealing with 2 or 3 aircraft in close proximity in a landing pattern is a handful, dealing with 5 is stressful, dealing with 30 is impossible without outside guidance and ATC.

          2. Robert Helpmann?? Silver badge
            Childcatcher

            Re: In Germany there actually is a strong push for those ideas in the ruling party

            Flying cars can come later.

            Not necessarily. Working things out in parallel speeds up overall progress. I very much agree with the statement that humans shouldn't be allowed to drive, so robot chauffeurs are mandatory for this to work but saying we shouldn't work on A because B is more pressing is a false dichotomy.

            As to this increasing societal stratification, that's a temporary effect. So many things that we take for granted were once the purview of royalty, the nobility and the very wealthy. Spices and imported foods, transportation other than shank's mare (hell, how about the ability to move more than a few miles from home?), access to all sorts of arts, the ability to communicate with remote sites via text or voice or video... all of these things and many other started out as something the average person couldn't afford and then worked their way down to cheap ubiquity.

    2. Anonymous Coward
      Anonymous Coward

      Re: In Germany there actually is a strong push for those ideas in the ruling party

      I'd not say air taxis are a bad idea, local aircraft flight are basically this already.

      Air taxis done bad are a bad idea.

      Sorry for the downvote, but making the specific logical response is better than just painting everything with a bad brush. You'll lose everyone if you say everything is bad, if you point out the one part that is wrong, you might gain some.

      Sadly, I think they will just ignore the one fault, and carry on regardless (we have had to learn the hard way with cars and other tech :( ).

  2. malle-herbert Silver badge
    Joke

    How to regulate futuristic air taxis...

    Multipass ?

    1. I ain't Spartacus Gold badge
      Happy

      Re: How to regulate futuristic air taxis...

      I believe regulation in that case was to fit all the police air taxis with large calibre machineguns.

      How well this worked in practise was outside the scope of the documentary in question...

  3. Steve K Silver badge

    Autorotate to where?

    In fixed-wing or rotary-wing aircraft, a controlled glide or autorotation needs to be initiated by the pilot, and a suitable landing site quickly identified.

    One only has to look at the tragic Clutha incident to see what happens if this goes wrong over an urban environment.

    The software challenges to deal with this situation in the case of automated air taxis will make the flight control systems seem easy. It will also lead to air lanes between fixed landing sites being enforced since then potential emergency sites can be kept on those routes.

    There is no way that these will be permitted in densely-populated areas due to these risks. Helicopters are restricted in where they can fly over population centres, and twin-engines are mandated in most such cases (Clutha was a fuel management issue according to AAIB even though the machine had 2 engines).

    I don’t see how the proponents of these devices can expect different treatment to existing aircraft as the risks are largely the same.

    1. Anonymous Coward
      Anonymous Coward

      Re: Autorotate to where?

      I agree. These things need multiple engines (which some have), or possibly emergency parachutes. But even then, they would need flight lanes with clear/empty ground underneath. At which point, they just become as difficult to space allocate as cars.

      Oh, and we all know how easy it is to seperate a car, bicycle and pedestrian, but how well it goes convincing people to allocate the land for the speratation!

      1. steelpillow Silver badge

        Re: Autorotate to where?

        Probably a corner of some car park, re-designated an aerial taxi dropoff point. Can only follow routes with a continuous supply of such.

        It should be easy enough to specify a deployable paraglider or similar controlled-descent device, with independent control system and say 10 mins power supply, for use when the main flight power fails.

        It might be a touch less easy to implement such a system and get it certified.

        1. AndyS

          Re: Autorotate to where?

          >It should be easy enough to specify a deployable paraglider or similar controlled-descent device, with independent control system and say 10 mins power supply, for use when the main flight power fails.

          A full-craft paraglider, with separate power supply to keep it flying for 10 minutes?

          Yeah, I suppose it would be easy to specify that. I can specify all sorts of things - like a spaceship with capacity to take 100 people to mars, and return them, with a transit time of of less than 6 months. Oh, and if something goes wrong, it will automatically return safely to Earth.

          Doesn't mean there is any link to physical reality, sadly.

          1. John Brown (no body) Silver badge

            Re: Autorotate to where?

            "Doesn't mean there is any link to physical reality, sadly."

            Yep. Like the existing prototypes have pretty strict weight limits and fairly short flight times. Electric ones will need a full charge after pretty much every journey so new battery ad charging tech required since current systems won't do a "fast" charge to anywhere close to 100%. So your taxi either spends significant time not earning money while charging or carries enough extra batteries to counter the fast charge limits (don't forget the weight limits!)

    2. ThatOne Silver badge
      Devil

      Re: Autorotate to where?

      > I don’t see how the proponents of these devices can expect different treatment to existing aircraft as the risks are largely the same.

      Better lobbying?

    3. Def Silver badge
      Joke

      Re: Autorotate to where?

      Clearly futuristic air taxis just need an auto-vaporise-on-failure feature. This will solve the potentially costly hospital bills of any passengers, and remove the possibility of someone on the ground being crushed by a falling vehicle.

  4. jpo234

    > But where the aircraft doesn’t have conventional wings or a main rotor, this poses problems.

    Chutes?

    1. Anonymous Coward
      Anonymous Coward

      Ejector seats?

      1. Peter2 Silver badge

        Ah, your thinking of the safety of the people in the vehicle?

        Aircraft regulation is done the other way around. It looks at the safety of the people that a ton of weight is going to land upon, having fallen a few thousand feet from the operational height.

        Parachutes, even attached to the vehicle is insufficient for use in a residential area by aircraft rules because if the vehicle lands on a building (even slowly) then it can still cause fatalities because most roofs are designed to keep the rain out, not to support the unexpected impact of a ton worth of weight moving at a speed of ~50mph (with parachutes) to the terminal velocity of the vehicle which will be several hundred mph.

        Hence why the manufacturers want to throw out the aviation safety book. The people who may be beneath these things when they fall out of the sky may have different thoughts on the subject, however.

        1. jmch Silver badge

          "Parachutes, even attached to the vehicle is insufficient for use in a residential area..."

          You would need to mandate a minimum height - If it's too low the chute won't have time to deploy. The critical bit would then be takeoff / landing, which could be mandated to be exactly vertical only over the designated landing area.

          For transit between landing areas you follow existing roads. Of course there still exists the risk of one of these falling out of the sky onto other traffic, but better than falling on pedestrians.

          1. Kernel

            "The critical bit would then be takeoff / landing, which could be mandated to be exactly vertical only over the designated landing area."

            That'll be a definite success - there's good reason why helicopters normally aim to get as much forward speed as they can as soon as their feet are off the ground and it's not because the pilot wants to show how clever they are.

            There's a thing called, I believe, the 'deadman's curve' in regard to helicopters which plots the relationship between height and the required forward speed to successfully initiate auto-rotation at that height - protracted vertical ascents/descents with zero forward speed mean you spend far too long on the less desirable side of this graph.

            1. werdsmith Silver badge

              "All parachutes need plenty of height to deploy: very few people have survived a bail-out under 2000 ft."

              ----

              Height, or forward speed can also deploy them. 1000 feet is more than enough height as any base jumper will tell you.

              The parachute recovery system on the Cirrus SR22 aircraft (which descends the entire plane and occupants) is officially set at 400 feet. But can be done lower, BRS parachutes 260 feet and some have been used successfully as low as 100 feet.

              1. Robert Helpmann?? Silver badge
                Childcatcher

                "All parachutes need plenty of height to deploy: very few people have survived a bail-out under 2000 ft."

                ----

                Height, or forward speed can also deploy them. 1000 feet is more than enough height as any base jumper will tell you.

                Alternatively, they could take a page from the various Mars landers and deploy a giant airbag to provide drag and perhaps some padding on impact.

        2. Keef

          I agree Peter2:

          'most roofs are designed to keep the rain out, not to support the unexpected impact of a ton worth of weight moving at a speed of ~50mph'

          However, I'll just leave this here...

          https://www.bbc.co.uk/radio4/hometruths/dakotaonroof.shtml

          1. Peter2 Silver badge

            However, I'll just leave this here...

            https://www.bbc.co.uk/radio4/hometruths/dakotaonroof.shtml

            In the case of a Dakota DC3 hitting a terrace row of houses then you'll note that the nose section has gone through both sides of the roof, plus whatever supports were in the way holding the roof up. The 29 meter long wing & engines hitting the roof did stop the aircraft with very considerable damage to both the roof and aircraft.

            However, that's not really directly comparable to a flying car. If a flying car hits a roof then firstly it's not likely to be horizontally as this was, it's more likely to becoming in vertically as a result of a fall. It's also not going to have a ~30 meter wing to distribute the weight. It's going to have all of the velocity concentrated upon a meter area like a wrecking ball.

            1. annodomini2

              @Peter2,

              It's also not going to have a ~30 meter wing to distribute the weight. It's going to have all of the velocity concentrated upon a meter area like a wrecking ball.

              Yes the CSA is smaller, but the mass is much lower ~500-1000kg vs 7000-12000kg for the DC3

              Someone would have to do the maths obviously.

              1. Peter2 Silver badge

                Why bother? A "rule of thumb" works quite well a lot of the time.

                The flying car has a 30th of the impact area with a 12th of the weight. The impact area was what stopped that Dakota, as you can see by the way the nose was sticking out of the far side.

                A flying car is going to be of similar size to a car, probably with higher weight if it's being battery powered. We know that cars at or a bit under 30MPH go through walls because it's happened numerous times.

                https://www.mirror.co.uk/news/uk-news/four-hospital-after-car-crashes-11103940

                https://www.expressandstar.com/news/local-hubs/staffordshire/stafford/2017/07/31/crash-leaves-gaping-hole-in-wall---but-no-injuries/

      2. Tigra 07 Silver badge
        Black Helicopters

        RE: AC

        Ejector seats have to be specifically tuned for the passenger and can seriously injure your neck and spine. They are not to be used sparingly, or at all if can be avoided. They could never be used in this industry.

        1. F111F
          Boffin

          Re: RE: AC

          Ejection seats are not "tuned" to a passenger. They are designed to save a person fitting a range of height/weight values. That said, a 0/0 system (0 height/ 0 forward velocity) is one hell of a ride and can/has done damage to vertebrae, spinal cords, improperly placed arms/legs, etc., sometimes forcing fighter pilots to switch to trash-haulers after an ejection. It is seen as slightly better than dying.

    2. jmch Silver badge

      "Chutes?"

      The linked article says the whole plane has it's own chute

    3. Martin Gregorie Silver badge

      Chutes?

      All parachutes need plenty of height to deploy: very few people have survived a bail-out under 2000 ft. That said, a whole-vehicle recovery system should work from a lower height because it is designed to lower the aircraft with the people still inside, so there's no bail-out needed and the only predeployment activities are to realise there's a serious problem and to pull the red knob.

      However, even the rocket-extracted Ballistic Recovery System isn't guaranteed to give a safe recovery from less than 400 ft in straight and level flight or from less than 1000ft if the aircraft is spinning. Almost any other imaginable circumstance is likely to have a safe recovery height within that height range, though there doesn't seem to be much, if any, data on how well a BRS system would deploy after engine failure in a hovering aircraft which would still be falling relatively slowly.

      But, IIRC all the above minimum survival height estimates assume deployment is over flat ground, so no allowance is made for the incident occurring over trees, tall buildings etc. or the possibility of the aircraft colliding with something while the chute is deploying and the plane still has significant forward speed.

  5. Christoph Silver badge

    Time to update an old song?

    "Taxis keep falling on my head"

  6. Tigra 07 Silver badge
    Black Helicopters

    Uber of the sky...

    "The aircraft must be equipped with a [cockpit voice] recorder"

    I know they're probably hoping for intellectual radio talk from an experienced pilot, but if this becomes the Uber of the sky the recordings will be very very common...

    "Can we make a stop at the kebab shop on the way home?"

    "I prefer the direct route"

    "Can I have a go flying this?"

    "I think i'm gonna be sick!"

    1. Christoph Silver badge

      Re: Uber of the sky...

      "Of course I'll still respect you in the morning"

      "Are we there yet?"

  7. NanoMeter

    Antigravity

    Is what's needed. Just kiddin, but large wings, propellers, jet streams will be a problem. Hidden propellers like on drones might work. Many small ones around the airtaxi, instead of four big ones.

    1. Alan Brown Silver badge

      Re: Antigravity

      "Many small ones around the airtaxi, instead of four big ones."

      With that you arguably don't need a vertical stabiliser, but the practicality of the whole thing is still questionable, just like the ideas of generator-connected turbines driving multiple ducted fans on a wing.

  8. DropBear Silver badge

    O RLY?

    "In conventional fixed-wing aircraft, loss of an engine means you start gliding back to terra firma under the pilot’s control. In a helicopter, autorotation happens: the main rotor keeps turning thanks to wind pressure, providing enough lift to make a controlled descent to a safe landing."

    ...and in basically all modern "air taxi" prototypes which tend to be many-rotor aircraft, you won't even notice the loss of one of them if you have a bit of luck. At worst, you'll find it advisable to land as soon as possible, but plummeting is not on the table, as long as those devising the flight software were something other than monkeys with typewriters.

    Multiple redundant power supplies would be expected and with four rotors you don't need them all to land in a reasonable manner. With six, you can even pretend nothing happened. And there are actual flying designs with eleventy billion smaller rotors - those would be basically indestructible short of dropping a bridge on them or flying them into a mountain.

    ALL OF WHICH are inherently safer than either fixed-wing or rotary-wing aircraft having to snowflake down to the ground unpowered, trying to stay in the air very much like a brick doesn't, placing its hopes and prayers on the ability of the pilot to crash at least somewhat gracefully.

    PS: ...also? Parachutes ARE a thing on these, and they deploy basically instantly. Look up "ballistic parachute" some day.

    1. I ain't Spartacus Gold badge

      Re: O RLY?

      Hmmm. I feel you're being rather optimistic.

      Also, these aren't being built by the aircraft industry (who've at least heard of safety), but by Silicon Valley playboys - who don't appear to give much of a fuck about anything. And certainly not any inconvenient standards they can try to lobby their way out of. So I've not got much faith in the software or the hardware.

    2. imanidiot Silver badge

      Re: O RLY?

      If it's designed like a quadcopter you need all 4 to stay in the air. In a hexacopter you can lose one and keep control or 2 in limited cases but lose yaw control. Not exactly confidence inspiring. On top of that it's very often not the motor giving up but the control electronics. And how likely is it for a problem with the control electronics to be limited to just the one motor controller? More motors doesn't have to mean more reliability. It just means moving the common point of failure further up the chain. If the battery or battery controllers fail you suddenly have no engines at all for instance.

      Even ballistic parachutes require an amount of altitude to work, and usually more altitude than you'd be willing to fall.

  9. Rich 11 Silver badge

    figure out how the human cargo will not be dropped like a stone to certain death

    Simples. The AI assigns a value to each item of human cargo, based upon their mass and their level of raucous behaviour during the flight, then decides which piece (or pieces) of ballast are best propelled forcefully down through the euphemistically-named 'escape hatch' beneath each seat. Newton's Third Law ensures that the lives of the remaining cargo units are extended for a little longer, and the removal of mass also increases the chances that whatever remains of the multiply-redundant power/lift system may be sufficient to land the taxi either a) safely, or b) less fatally (no Category C will be defined or accepted).

  10. Anonymous Coward
    Anonymous Coward

    In safe hands

    Is this the same all-knowing and well-run EU that just demonstrated their ability to shoot down planes that hadn't even taken off yet? Glad those F16's didn't cost you any taxes.

    1. I ain't Spartacus Gold badge

      Re: In safe hands

      That was the Belgians.

      And surely it doesn't count as shooting down, when the plane was already on the ground. Surely this calls for the phrase "shooting up".

  11. Alan Brown Silver badge

    > And surely it doesn't count as shooting down, when the plane was already on the ground. Surely this calls for the phrase "shooting up".

    It's not the first time something like this has happened. The last incident I saw reported (there are doubtless others) resulted in the massacre of an adjacent cornfield when a tech accidentally inserted a safety clip the wrong way up in the wing of an Aermacchi MB326 at Ohakea in the 1990s. That one supposedly barely missed another aircraft on the ground.

  12. Nick Sticks

    Helicopter emergency landing....

    Hmm, I don't actually remember ever reading/hearing about a helicopter using autorotation to land safely.

    Does it ever happen or is it a case of just reducing the impact speed to get a better chance of survival?

    1. Steve K Silver badge

      Re: Helicopter emergency landing....

      Autorotation is trained for by helicopter pilots - whether autorotate to ground or autorotate with power recovery.

      In essence you trade rotor speed/inertia for lift just as you approach the ground and flare out. You have to have sufficient rotor speed for this, and in order to maintain this before reaching the ground you need to flatted out the rotor pitch using the collective pitch lever so that it effectively freewheels. Depending on the type you will either have a freewheel clutch or with most 2-stage turbines you don't need one as the rotor system is driven by the gas flow from the turbine itself rather than directly.

      It is easier in some types with higher rotor inertia and in types with low intertia (primarily the Robinson R22/R44 and potentially R66) you have seconds to lower the collective before you have insufficient rotor speed any you plunge to fiery doom.

      The Clutha crash was caused (after the induced fuel starvation) by there being insufficient inertia in the rotor system (due to rotor RPM decay) to maintain flight and cushion the landing.

      Autorotations (out of necessity or training) are not an infrequent frequent occurrence in the helicopter world because the alternative is an uncontrolled descent - as a passenger - to flaming death.

      1. SkippyBing Silver badge

        Re: Helicopter emergency landing....

        'In essence you trade rotor speed/inertia for lift just as you approach the ground and flare out. You have to have sufficient rotor speed for this, and in order to maintain this before reaching the ground you need to flatted out the rotor pitch using the collective pitch lever so that it effectively freewheels.'

        Minor correction, the rotor isn't freewheeling. The rotor blades are twisted along their length, partly to reduce the lift generated by the outer sections as due to their much higher velocity the bending forces on the blades would be too great. This also means with the collective fully down the outer portion is in negative pitch so that the lift vector is now forwards of vertical, which provides an autorotative force which drives the blades. The inner portion is still providing lift which keeps the rate of descent to a sensible figure (normally less than 1500'/minute). Once near the ground you trade speed for lift to reduce the descent rate to something you'd be comfortable landing at.

        As in the Clutha accident if the rotor speed decays below a certain level it's not possible to recover it, above that level you can normally increase or decrease the rotor speed to alter the glide ratio and various alarms should let you know if you're getting close to the limits.

      2. Rich 11 Silver badge

        Re: Helicopter emergency landing....

        you plunge to fiery doom

        No fiery doom if the reason for the crash was a failure to keep an eye on the fuel gauge. Still a closed-coffin funeral, though.

    2. SkippyBing Silver badge

      Re: Helicopter emergency landing....

      'Hmm, I don't actually remember ever reading/hearing about a helicopter using autorotation to land safely.'

      US Army Chinook

      https://www.fayobserver.com/9397fb59-5c26-529c-b3c7-0abd743ef162.html

      Danish AF Merlin after an apparent triple engine failure (UK exchange pilot flying)

      https://www.pprune.org/rotorheads/576333-eh101-emergency-landing.html

      There was also a successful auto rotation by a UK Apache in Afghanistan after they lost drive to the tail rotor.

      https://www.pprune.org/military-aviation/579736-ah-64-tail-rotor-loss-article.html

      Ultimately the usability of the aircraft afterwards is determined more by the terrain the auto rotation is carried out to, as unlike most airfields it's unlikely to be perfectly smooth. One of my instructors managed to get a Lynx on to a beach after an engine failure which was good flying going by the alternate landing sites, jungle or sea.

  13. johnfisher

    These ideas are worth when people are modest and can handle the change, this is an exciting news though.

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