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Gatwick Drone Theories

Discussion in 'Serious' started by Bungletron, 20 Dec 2018.

  1. Mister_Tad

    Mister_Tad Super Moderator Super Moderator

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    I think that was my point... what was yours? :p
     
  2. Gareth Halfacree

    Gareth Halfacree WIIGII! Staff Administrator Super Moderator Moderator

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    My point was that they did do the thing they can't do, and it proved to be the wrong thing to do, which is why they can't do it. Again.
     
  3. Bungletron

    Bungletron Well-Known Member

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    Following the drone with another drone is a brilliant and simple solution! Pursue from behind, since you keep a relative speed when you fly the sacrificial drone into a rotor when it is safe so this can be done with highly accuracy. Otherwise just follow the drone to the landing zone and film the culprits. Its better than shooting at it with all the jet fuel and buildings around.

    It does not surprise me at all that there is no contingency for this, the disruption strategy is unprecedented and this is Britain after all. I think at this stage the credible incompetence of the response is the main indicator that supports idiots. Well motivated and technically adept idiots, but still idiots.
     
  4. stuartpb

    stuartpb Well-Known Member

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    I'm a qualified and CAA approved commercial drone operator, I'm worried about incidents like this affecting my livelihood. We are bound by the laws concerning commercial drone operation (Air Navigation Order - 2016). It's odds on that a high profile incident like this is going to result in politicians demanding changes to the existing laws, which then means increased restrictions and regulation for commercial drone operators like myself. We already have a lot of hoops to jump through before we even consider launching a drone.

    In terms of which drone was used, I'd guess at a DJI Inspire or even possibly a custom made drone. The Phantom does look toy like whereas the Inspire does look more industrial. Other industrial drones come at a massive cost, with some hitting tens of thousands of pounds.

    If it was a DJI drone, the operator has been clever and bypassed the firmware set no fly zone safety feature (DJI Geo Zone). DJI included this in firmware updates a while ago, where their drones will not operate in controlled airspace. An operator would have to contact DJI for an authorisation code to be able to operate the drone in these situations.

    I have authorisations from DJI and from my local Air Traffic Control Unit to be able to operate in controlled airspace around my local airport, but I had to meet with the ATCU and demonstrate the fact I can operate safely, both in pre, in and post flight phases. I also have to follow a strict set of procedures and ensure I have a dedicated contact method open to ATCU. So it is possible to lawfully operate drones within an airports controlled airspace.

    The whole thing boils my blood. Commercial drone operations is still a relatively young industry and idiots using drones like this just serves to make it that much harder and also expensive for people who are making a living from it.
     
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  5. The_Crapman

    The_Crapman Don't phone it's just for fun.

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  6. fix-the-spade

    fix-the-spade Well-Known Member

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  7. Nexxo

    Nexxo Queue Jumper

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  8. RedFlames

    RedFlames ...is not a Belgian football team

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    Maybe there is no spoon drone
     
  9. adidan

    adidan Avatar now in stock for xmas 2019

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  10. fix-the-spade

    fix-the-spade Well-Known Member

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  11. Byron C

    Byron C *psst!* This guy is a loser!

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    This was completely deliberate, whoever did this would have known exactly what they were doing. It would have either been quite a few people flying a handful of different drones over the airspace, or a small number flying one or two back and forth.

    High-end "industrial-looking" drones like the DJI Inspire will get you around 20 minutes of flight time; a Phantom 4 around 25-30 minutes, and a Mavic up to about 30. And that assumes optimal conditions: not pushing the motors hard, low wind conditions, fully-charged batteries in good health. Of course as @stuartpb has already pointed out, DJI geo-fences their firmware specifically to stop this - so again if it was a DJI model then whoever is responsible would have had to deliberately hack the firmware to overcome this.

    Of course it could be custom built, I built a 6-rotor hexacopter that you could easily describe as "industrial". Although it's relatively simple to do - the electronics involved really isn't rocket science these days - there is a knowledge barrier in terms of understanding the flight mechanics and being able to properly configure and calibrate the flight controller. Even some standalone flight controllers - particularly ones that are easy to set up like the Naza range - also still have geofencing. If you're intent on disrupting an airport the disadvantage of building your own is that it takes a lot of effort to optimise the battery life - every part you add, even down to which motors & props you choose, will affect your battery life in one way or another. Of course you can double-up on batteries by building custom setups, but that adds weight... which affects your flight time - doubling-up on batteries is a case of diminishing returns. All of this means that if the drones disrupting airports were custom-built then it implies deliberate intent on behalf of those responsible.

    And what was that about further regulation? Oh yes, here we go: https://www.theregister.co.uk/2019/..._kids_flying_toy_helicopters_3_miles_aiports/

    Relevant excerpt - emphasis is mine:

    Let me tell you what a 250g drone will do to a commercial aircraft: scratch the paintwork. That is, of course, assuming that you're not right next door to the airport and such a small model has the battery life - and radio range - to be able to fly to an airport in the first place.
     
  12. VipersGratitude

    VipersGratitude Well-Known Member

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    Not quite. It all depends on how fast the plane is moving. Doing a quick calculation with a stationary 250g drone, assumed plane airspeed of 66 m/s (takeoff speed), and an impact time of .004s (which assumes the drone has a width of 0.25m) you're looking at 8,000+ Newtons of force.
     
  13. Byron C

    Byron C *psst!* This guy is a loser!

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    ...However. You're assuming that the mass is concentrated in one place rather than being distributed - most of the weight would be in the motors and the battery. You're very unlikely to find more than 4 rotors at 250g, so you also need to account for the fact that as soon as one of the propeller blades is damaged - or an arm is snapped - it's going to plummet like a stone. Also bear in mind that such a small drone is going to be made out of plastic, or carbon fibre, so as soon as the frame starts breaking, all that mass is going to start getting distributed over a wider area - chances are that turbulence alone will deflect the debris out of the way.

    And finally, you miss the most important point:

    Little Johnny flying toys in the back garden is not going to cause a risk to a major airport - his cheap little toy drone is going to go out of range of the radio transmitter before long and it'll drop out of the sky. Some drones that size could have the control range to make it out to a runway, but they likely wouldn't have the battery runtime.
     
  14. VipersGratitude

    VipersGratitude Well-Known Member

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    All I'm saying is that it's going to do more than scratch the paintwork. If we're going to play around with scenarios, which I'd rather not but as an example, having even a small amount of carbon fibre and metal sucked in to an engine won't do it much good. I agree on the 2nd point that toys wouldn't reach that those heights, but not all 250g drones are toys.

    I'm pissed about more restrictive drone legislation too, but I'm playing devil's advocate. In H&S they always plan for the worst case scenario.
     
  15. stuartpb

    stuartpb Well-Known Member

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    I'm all for drone legislation, it helps protect my industry. It separates the cowboys from the legitimate operators and gives us a solid base from which we work in terms of standards and safety. So for me it's important that there are rules and safety standards. Where I have the problem is knee jerk reactions to legislation that result in bona fide operators losing out, either in operational functionality, time or money.

    Another sticky wicket for me is the fact that the government agencies are half hearted when it comes to actually enforcing current legislation. I personally know of UAV operators who flout the regulations and get away with it. There are many more doing it who I don't know too. The police are reluctant to enforce, the CAA pass the buck back to the police and we see a total lack of commitment in enforcement.

    I adhere to the regulations because I believe safety is paramount in any operation I conduct. We have to go through a rigorous set of procedures before we've even lifted the drone. We have to conduct pre-deployment surveys, which is very similar to flight planning for aircraft pilots. We also have to obtain permissions (landowner etc.), make necessary notifications (NOTAM's, police, councils, sensitive areas, other air users etc.), carry out an initial risk assessment, on-site survey, on-site and dynamic risk assessments, mark out a take-off/ landing zone, brief landowner, client and flight crew and also manage footfall through the operational area. All that for each and every flight, even training taskings. Then to top that all off, I pay for specialist commercial UAV insurance and a renewal fee to the CAA every year for my PfCO.

    So when I see chancers earning money and doing none of the above, or idiots like the airport flyers getting away with it or getting slapped wrists when public outcry forces the agencies to act, that rankles a lot!!
     
  16. liratheal

    liratheal Sharing is Caring

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    It has got me wondering whether engine builders, who test for birdstrike on their engines, now also test for dronestrike.
     
  17. lilgoth89

    lilgoth89 Captin Calliope

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    Not yet, or at least im not aware of any test from Roll's Royce, Trent or General Electric, but i imagine with these incidents, and indeed rising number of Drone intrusions into secured airspace, it will only be a matter of time before we see a Drone intentionally flown into one, but i imagine nobody really wants to pay for such a test, likely requiring two engines, a large drone, and a tiny quadcopter style ingestion test
    i mean if you used a Trent 1000 from RR ( a typical large engine that powers the popular 787 Dream-liner ) thats 41.7m per unit, and i cant imagine many of the bits are salvageable after a test such as this so that would almost be a total write off ( not to mention use of all the testing equipment )

    The closest i can find, is

    This is obviously ALOT of damange, but the aircraft SHOULD be fine to carry on on one engine as Engine cowlings are designed to contain blade failures, but i would think if a blade caught one of the electric motors and launched it at the cowling it might be defeated, also Lipo batteries could get sucked into the core of the engine and cause ALOT of problems as inside the core, the air is highly compressed, Hot and with alot of wind, none of those things are conducive to damaged Lipo cells behaving themselves



    This is Drone vs wing, as it says it does a large amount of internal damage to the wing, and on a faster jet could of done much more damage to the leading edge of the wing and yes you would have to get pretty unlucky to get a direct hit like this, but as a worst case scenario its scary, especially once you factor in alot of aircraft have fuel tanks inside the wings, which in proximity to a smashed lipo, could be VERY bad if an aircraft is hit during takeoff. also i would put money on a drone that size passing right through a cockpit window, as armoured as they are they are ment to deflect squishy birds rather than solid drones ( and if you watched the Mythbusters chicken gun re-visit, you know that squishyness is important in such impacts )

    one idea that gets floated around alot is netting over the intake of jet engines, which sounds like a good idea on paper, but putting something that is strong enough to stop a bird, and be strong enough NOT to break apart and get ingested itself, means its going to be pretty big, and reduce engine efficiency, and even if the failure rate is 0.001%, Net ingestion would still be FAR more likely than the bridstrikes they intend to prevent
     
    Last edited: 6 Feb 2019
  18. lilgoth89

    lilgoth89 Captin Calliope

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    also to give people an idea of what a snapped blade looks like in a modern engine


    in this test a small explosive charge was used to separate a single blade from the front fan in the drone simulation 4 blades were removed from the same side of the engine, causing even more unbalance
     
  19. stuartpb

    stuartpb Well-Known Member

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    The thing that would worry me as well as damage to the engine and blades, surely there would be potential for wing and fuselage damage due to shrapnel like pieces of the FO and any damaged engine parts/ blades being spat out at high velocity. This would cause an engine failure scenario to get a whole lot more serious wouldn't it? I'm not an aircraft engineer, so I may be entirely wrong.
     
  20. liratheal

    liratheal Sharing is Caring

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    I believe, but I am no expert either, the chassis of aircraft engines are designed to contain the 'oops' scenario.
     

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