8 replies to this topic

[GreenMachine]

This subject was touched upon elsewhere, but maybe there are issues that could be discussed here.

 

I have seen reports of people developing these, looking like overgrown consumer drones - four (or more) outriggers providing lift/propulsion, central module housing occupants.

 

I will preface my 'question' by saying I recently had the experience of flying a drone for the first, and so far only, time.  I was impressed with the ease at which it flew under my clumsy control, and the precision of its responses, especially the return-to-base function.

 

Putting aside the economics of such a device, what are the issues that are going to prevent, or at least be solved, for at least a limited commercial market?

 

Range

They must not only travel horizontally, they require energy to simply 'stand still', a prerequisite seems to be a 'quick charge' facility at destination and a high power density in the battery.

 

Navigation

I include collision avoidance in this, as even relatively small numbers over a CBD/tourism hotspot would create a high collision risk, let alone interaction with RPT aircraft.  It seems to me the actual navigation to a particular point is child's play by comparison, and I note that commercial aviation has ground and traffic collision avoidance sytsems in operation already.

 

Motor/battery power densities

Density in terms of mass, volume not so much.  The mass of these vehicles will be a critical factor in driving (sorry) their feasibility, followed closely by their range.  Battery technology will be the key determinant of their future feasibility?

 

Infrastructure

I include regulatory infrastructure, as well as things like destination storage ('parking') and charging.  Regulation will be a major hurdle, particularly if autonomous cars are any guide.  We already have ATC with a high degree of automatic oversight, I don't see this aspect being a deal breaker but no doubt it will require work.  The first adopters (at private level) will be wealthy people, so I can see destinations rubbing their hands, and 'air taxi' operators will probably operate to/from nodes, rather than door-to-door.

 

I'd be interested on others' thoughts.

[404KF2]

I don't see the interest other than on the technical side, as a hobby.

 

Star Wars-like air traffic is never going to happen. An engine or motor failure in a car is sad, but in any hovering type aircraft it's likely tragic. 

[Greg Locock]

They will still need dedicated heliports to land at.

 

Safety - They can't just land in a park, the wind velocities near a hovering rotorcraft are 100 mph or so.

Noise - cars are limited to 70-74 dBA at full throttle at 50 kph (roughly). This is expensive to achieve and compromises safety, but is supposedly necessary to improve quality of life in cities. A full size rotorcraft will be noisier than 1000 cars.

[BRG]

This is my fault, as I triggered this by mentioning flying cars as a joke for getting people into COTA.

 

The concept of flying cars is (a) entirely feasible in technological terms, but (b) entirely impractical in real world terms.  Current aviation rules call for vertical separation of at least 1000 feet and horizontal separation on 3 to 5 nautical miles.  With the skies around our major airports already pretty busy, there is little scope for adding more flying machines of any type without compromising safety.  Recent events in New York show the dangers of mixing civil and military aviation, let alone allowing a bunch of unqualified bozos loose in the air.

 

Current private pilot licencing requires many hours of study, a number of rigorous examinations (including medical) and hours of flight training under instructors.  That all costs a lot.

 

Etc etc etc.....look, this whole idea is a pipedream that is trotted out every year or so and is not going to happen.  Yes, there has been some technical progress that makes it possible to build something that COULD be used as a flying car, but the practicalities rule it out.  No government is going to want to risk the carnage that might ensue, not on their watch anyway!   The most we can expect is that these new craft will be added to general and microlight aviation under the exisitng regulations.

[Afterburner]

I think it's way more likely that, if it becomes commonplace, personal flight looks like this.

[GreenMachine]

This is my fault, as I triggered this by mentioning flying cars as a joke for getting people into COTA.

 

The concept of flying cars is (a) entirely feasible in technological terms, but (b) entirely impractical in real world terms.  Current aviation rules call for vertical separation of at least 1000 feet and horizontal separation on 3 to 5 nautical miles.  With the skies around our major airports already pretty busy, there is little scope for adding more flying machines of any type without compromising safety.  Recent events in New York show the dangers of mixing civil and military aviation, let alone allowing a bunch of unqualified bozos loose in the air.

 

Current private pilot licencing requires many hours of study, a number of rigorous examinations (including medical) and hours of flight training under instructors.  That all costs a lot.

 

Etc etc etc.....look, this whole idea is a pipedream that is trotted out every year or so and is not going to happen.  Yes, there has been some technical progress that makes it possible to build something that COULD be used as a flying car, but the practicalities rule it out.  No government is going to want to risk the carnage that might ensue, not on their watch anyway!   The most we can expect is that these new craft will be added to general and microlight aviation under the exisitng regulations.

 

This is difficult to argue with, you have done a great job of predicting the future by looking at the status quo/past.

 

Thing is, the current regulatory environment is a product of the time when flying safely was totally dependent on the knowledge and skill of the driver, and extremely rigid regulation of flight and flight vehicles.  In fact, that has already broken down by hugely relaxed requirements for the 'ultralight/recreation' class, both in the aircraft and their piloting.

 

Technology relevant to their operation seems to be approaching the point where ultralight/recreational regulation could be finessed to accommodate like rotorcraft, probably the main adjustment might be the weight limit, to accommodate a craft with multiple electric motors and a battery pack.

 

Rotor-dependent flight has inherent 'challenges' - a challenge that helicopters face, and seem to have met with some distinction given their operation over cities and in the other highly publicised uses they are deployed.  While some of these lessons (and technologies) are transferable, there will be other areas wher the lessons and solutions will have to be developed.

 

In short, we need to be careful about predicting the future as a continuation of the ruling paradigm.  I am reminded of the other discussion here, over electric cars/Tesla/Musk, I should go back and try and get a better sense of that discussion and how it related/predicted what we have seen on those subjects, but I that is not going to happen any time soon.

[BRG]

Aviation regulation is inherently conservative, sticking with the tried and tested rather than leaping into the unknown.  That is why for example until very recently, aircraft piston engines still used magnetos, even though electronic engine management had become the norm in the auto industry and was proven ultra reliable. It took many years before twin engined jets were permitted to operate across the Atlantic Ocean (ETOPS).   You  mention rotor aircraft operating over cities, but the rules in the UK demand twin-engine helicopters for such use.  Over London and its environs, they must follow the course of the River Thames to provide a safe® ditching place.

 

To imagine that regulators would suddenly ditch their cautious approach and allow free aerial traffic flows,  particularly over urban areas, is unlikely to say the least.  You mention ultralights etc, but these comparatively few in number and mostly fly over rural areas where their risk factor is less.  I am not sure if free ultralight flight over London (or Sydney, say) would be well received by the powers that be?

 

The whole concept of flying cars is that they would not be a rare toy for the ultra-rich, but would be in common use.  The idea of dozens of these criss-crossing the sky over urban areas fills me with dread!

[Bloggsworth]

Well, It'll be one way of depopulating major cities...

[gruntguru]

"Never" is a much-overused word.

 

Forever is a very long time.