Gatwick drones -what utter stupidity and selfishness

[TheLurker]

No I didn't miss it, the drone "lost",

Ermm, I think you may have missed the fact that in the Chilean incident the passenger in the helicopter was hurt when the drone smashed through the canopy.  As it weighed 0.75kg I assume the passenger was quite badly hurt.

[jiberjaber]

Meanwhile in Germany...

https://twitter.com/i/status/1363806958843748358

[Davef]

No I didn't miss it, the drone "lost",

Ermm, I think you may have missed the fact that in the Chilean incident the passenger in the helicopter was hurt when the drone smashed through the canopy.  As it weighed 0.75kg I assume the passenger was quite badly hurt.

Unlucky to be bopped on the end of the nose.

[Cudzoziemiec]

The "human capable" drone in the Goodwood incident – would the human in the drone have been a passive passenger, at the mercies of the controller on the ground? That sounds scary. Or would they have been in control of the machine? In which case it surely ceases to be an unmanned aerial vehicle and they would presumably require a private pilot's licence.

[Diver300]

The "human capable" drone in the Goodwood incident – would the human in the drone have been a passive passenger, at the mercies of the controller on the ground? That sounds scary. Or would they have been in control of the machine? In which case it surely ceases to be an unmanned aerial vehicle and they would presumably require a private pilot's licence.

It was a scale model of the human capable machine. It was over half size, but smaller and lighter than one that could carry a person.

The designers hadn't properly looked at the failure modes of the model. I hope the crash made them stop or at least take time to work out what could go wrong with a bit more care.

[Cudzoziemiec]

It reminds me that in Bristol we're getting "flying taxis" in 2023 (yes oh yes that date is absolutely entirely guaranteed cast-iron definite, I read it in the Brizzle Post), which it seems are basically large drones. Presumably with a pilot. (The idea is they will take well-heeled passengers from the city to the airport – about ten miles – and vice versa, rather than general taxi services, so it does make a bit of sense.)

[TimC]

While the projected in-service date seems wildly optimistic, there's a lot to be said for the quad-rotor concept as a replacement for single-rotor helicopters. Ground footprint is one of the disadvantages, but if the mechanics of control after the loss of a motor or rotor can be resolved, I see a place for it as transportation.

[Mr Larrington]

While the projected in-service date seems wildly optimistic, there's a lot to be said for the quad-rotor concept as a replacement for single-rotor helicopters. Ground footprint is one of the disadvantages, but if the mechanics of control after the loss of a motor or rotor can be resolved, I see a place for it as transportation.

Yes, they can be a bit on the large side:



 

[Diver300]

While the projected in-service date seems wildly optimistic, there's a lot to be said for the quad-rotor concept as a replacement for single-rotor helicopters. Ground footprint is one of the disadvantages, but if the mechanics of control after the loss of a motor or rotor can be resolved, I see a place for it as transportation.

I don't think that a quad rotor craft can be controlled with one rotor inoperative. Control of roll, pitch, yaw and power are all needed.  With three rotors, there are only three control inputs so it can't work.

A helicopter has cyclic (fore-aft and left-right, so two controls) plus collective and tail rotor power. A fixed wing has ailerons, rudder, elevators and power, but they are usually stable in flight so you can get away with fewer. Multi-rotor craft are unstable in all directions so all four are needed.

A 6 rotor machine may be able to control will the loss of one rotor.

[TimC]

Yes, I know how a helicopter works. I can, at a push, even describe retreating-blade stall and vortex ring (RAF A2 fixed-wing QFI, so my description might be a bit superficial!).

I believe a quad-rotor can be controlled with the loss of a rotor if each rotor is gimballed, which would allow each rotor to give an element of sideways thrust. The loss of a motor is probably more easily resolved with back-ups. The point is that if it looks economically viable, it will be done. If it looks likely that it won't be cheaper than a single-rotor helo, it won't happen.

[Beardy]

Yes, I know how a helicopter works. I can, at a push, even describe retreating-blade stall and vortex ring (RAF A2 fixed-wing QFI, so my description might be a bit superficial!).

I believe a quad-rotor can be controlled with the loss of a rotor if each rotor is gimballed, which would allow each rotor to give an element of sideways thrust. The loss of a motor is probably more easily resolved with back-ups. The point is that if it looks economically viable, it will be done. If it looks likely that it won't be cheaper than a single-rotor helo, it won't happen.

From a purely redundancy pooling of view, helicopters are just about the daftest idea for getting aloft that there is, a position that they haven’t exactly shown to be erroneous over the years. That said, I don’t actually know what their failure rate is in comparison to fixed wing, though their operational capabilities have largely negated any increased risk.
Multi rotor with demonstrable redundancy capabilities may improve the safety shortcoming, real or perceived, and is something that will be required if they are to fly over dense population centres. 

[TimC]

Indeed. I hate them with a passion. But that's not an entirely rational response!

[Beardy]

As a glider pilot I can’t really get any further away from helicopters while remaining in a structured aircraft  I like the idea that there are two ways to fly, with finesse or with an engine, although tour CFI* once opined  that anyone could fly, it was doing it at speed that took the skill.

* Tom Eagles, also a jet pilot instructor in the RAF. How cool is that, a flying instructor called Eagles. Perhaps one for the nominative determination thread 

[TimC]

I had a student called eagles. Her dad was a Royal Navy test pilot of some renown. She is now a B777 Captain with BA. Sadly, I don't know Tom - it would be funny if he were Anna's son!

[Beardy]

I had a student called eagles. Her dad was a Royal Navy test pilot of some renown. She is now a B777 Captain with BA. Sadly, I don't know Tom - it would be funny if he were Anna's son!

I think him being her son is unlikely given that I learnt to fly in the 80s and he was club CFI and a senior RAF flight instructor at the time. 

[Davef]

While the projected in-service date seems wildly optimistic, there's a lot to be said for the quad-rotor concept as a replacement for single-rotor helicopters. Ground footprint is one of the disadvantages, but if the mechanics of control after the loss of a motor or rotor can be resolved, I see a place for it as transportation.

I don't think that a quad rotor craft can be controlled with one rotor inoperative. Control of roll, pitch, yaw and power are all needed.  With three rotors, there are only three control inputs so it can't work.

A helicopter has cyclic (fore-aft and left-right, so two controls) plus collective and tail rotor power. A fixed wing has ailerons, rudder, elevators and power, but they are usually stable in flight so you can get away with fewer. Multi-rotor craft are unstable in all directions so all four are needed.

A 6 rotor machine may be able to control will the loss of one rotor.

https://youtu.be/bsHryqnvyYA

[TimC]

I had a student called eagles. Her dad was a Royal Navy test pilot of some renown. She is now a B777 Captain with BA. Sadly, I don't know Tom - it would be funny if he were Anna's son!

I think him being her son is unlikely given that I learnt to fly in the 80s and he was club CFI and a senior RAF flight instructor at the time. 

Ah, which puts him a good bit older than Anna, who was around 20 in 1987, when I took her on. Oh well.

[Ginger Cat]

While the projected in-service date seems wildly optimistic, there's a lot to be said for the quad-rotor concept as a replacement for single-rotor helicopters. Ground footprint is one of the disadvantages, but if the mechanics of control after the loss of a motor or rotor can be resolved, I see a place for it as transportation.

I don't think that a quad rotor craft can be controlled with one rotor inoperative. Control of roll, pitch, yaw and power are all needed.  With three rotors, there are only three control inputs so it can't work.

A helicopter has cyclic (fore-aft and left-right, so two controls) plus collective and tail rotor power. A fixed wing has ailerons, rudder, elevators and power, but they are usually stable in flight so you can get away with fewer. Multi-rotor craft are unstable in all directions so all four are needed.

A 6 rotor machine may be able to control will the loss of one rotor.

Generally true. However the new DJI Matrice 300 (a quadcopter) can land on 3 rotors. It will rotate but retains some ability to control direction as it does emergency landing. It also has better redundancy than most and is IP45 rated. That is where cutting edge commercial inspection type UAVs are.

Geofencing, anticollision sensors, aircraft proximity alert, return-to-home if signal lost are usual capabilities on many drones.

Hexacopters can retain control having lost a rotor.

You get pitch, roll and yaw by speeding up some rotors compared with others. Faster 2 on same side gives pitch/roll, diagonal opposite gives yaw. (Half the rotors spin clockwise, half spin counterclockwise). Usual controller layout puts pitch and roll on right stick and yaw/throttle on left stick. But other modes are available on better controllers. Need a main controller board on drone to manage rotor speeds as human reflexes could never make the constant micro changes to rotor speeds needed for control.

The Goodworth incident has attracted much discussion (and condemnation) in the responsible drone community.

Other info: my company has a Permission for Commercial Operations (for drone use) from CAA and i have completed  the new GVC. I do fly drones commercially on occasion.........)

GC

[Diver300]

The video of quadcopter landing on 3 rotors showed it spinning a lot, which aligns with what Ginger Cat says.

If diagonally opposite rotors turn in opposite directions, you're starting with a Chinook arrangement, and it's probably stable in roll around a line joining the diagonally opposite rotors.

Control of pitch will lead to spinning. Using the rotor opposite the missing one may correct that spin at the cost of roll, but that might not matter if it's stableish in roll, so I agree that it's possible to land with some control, if spin can be tolerated.

What that does seem to need is the two diagonally opposite rotors to be turning in the opposite directions. If not, I would have thought that the spin would be very fast. My tiny quadcopter has diagonally opposite rotors turning in the same direction, and I thought that was the norm.

So is landing with one rotor missing so difficult that most designs don't bother? Is there some disadvantage of having the clockwise rotors near each other?

[TimC]

In little photography drones, the asset itself isn't worth enough to put lots of expensive mechanical technology into survivability. To make the leap into human transportation, that will have to come.

Chinooks fly mainly through magick and the Earth rejecting them (as in all hicopleters), but the counter-rotating rotors are essential if no tail rotor is used - and they of course must be fully articulated so that the two rotors can counteract the yaw induced by each rotor's motion. The loss of a rotor on a Chinook is terminal - it cannot fly on one rotor. It can lose a powerplant, as both engines drive the rotor system.

As I mentioned above, if a quad-rotor has gimballed electric motors so that each rotor can apply a degree of sideways force, there's no need for the complicated and expensive articulated rotor heads that helicopters use, and if the gimballing is sufficient then the loss of a motor/rotor could be accommodated. Effectively, the asymmetric rotor becomes a tail-rotor, though with a degree of vertical thrust also. The main advantage of a quad-rotor is its simplicity, and that needs to be maintained if it's to have any advantage over other aerial vehicles.

[TheLurker]

Oh FFS!

https://www.theguardian.com/us-news/2021/jun/04/tern-bird-eggs-abandoned-drone

Just when you think people cannot be any *more* stupid, thoughtless or selfish...

[Jakob]

While the projected in-service date seems wildly optimistic, there's a lot to be said for the quad-rotor concept as a replacement for single-rotor helicopters. Ground footprint is one of the disadvantages, but if the mechanics of control after the loss of a motor or rotor can be resolved, I see a place for it as transportation.

Single rotors are safer and more efficient than quad rotors. Loss of a motor/rotor in quad rotor is instant loss of control. 6 rotors you start to have a chance of not crashing. 8+ is better. More rotors = less efficient.
Helicopters are statistically safer than fixed wing. They crash a little more (And a lot of that can be directly contributed to the environment they fly in, ie wire environment), but survivability in a crash is higher.

[Kim]

Helicopters are statistically safer than fixed wing. They crash a little more (And a lot of that can be directly contributed to the environment they fly in, ie wire environment), but survivability in a crash is higher.

Spoken like a true darksider.

[TimC]

‘They crash a little more’…!

I think you need to be a little more specific with your stats. Let’s start with public-transport helicopters versus public-transport fixed-wing aircraft. I’m not interested in private aviation; that’s amateur hobbyists playing at it, with all the variability of talent, knowledge and skill that that implies. I’m not saying public transport helicopters are unsafe, but they are far short of public transport fixed wing in any sensible safety analysis.

[pcolbeck]

My cousin was until he retired a few years ago a Colonel in the Army Aircorp. He had a vast experience of flying helicopters including in action in Iraq and Afghanistan, as a trainer and a couple of spells flying black ones for those gents at Hereford. He loved flying choppers. He also has a PPA.
He will not take anyone up for a joy ride in a helicopter. He will take them up in a light aircraft.

That's a professionals opinion of the relative safety of helicopters versus fixed wing.