Drone Sighting Halts Departures at Heathrow Airport • Hacker News Board

Re: Drone Sighting Halts Departures at Heathrow Airport

#121

Post by CydeWeys » Tue, Jan 08, 2019, 11:36 PM UTC

cronix wrote: post #118

AWildC182 wrote: post #72

Earlier quoted context omitted.

I think the important difference is in the case of a drone, you're dealing with the possibility that it's going to get sucked into a jet engine (which by multi-engine standards should still be "safe"). Therefore the solution can't be worse than the problem and firing off missiles (which may fail and not self destruct correctly) or guns is a bit of an over-reaction. In the case of a military SAM engagement, you go int…

> the possibility that it's going to get sucked into a jet engine I've often wondered why the turbine intakes don't have some sort of "filter" in front to prevent larger objects from entering? Birds have been a problem forever. Why isn't there a simple solution? Even a grid in front like a common 4"x4" chainlink fence would provide. Is there some reason why they're all just wide open?

Jet engines have unbelievably powerful suction on their intake side. A fence wouldn't stop anything; a bird or drone would just get broken up into smaller pieces as it's sucked through the filter.

Similarly there's no fence that could keep this crab out: https://youtu.be/AMHwri8TtNE

Re: Drone Sighting Halts Departures at Heathrow Airport

#122

Post by CydeWeys » Tue, Jan 08, 2019, 11:41 PM UTC

eponeponepon wrote: post #22

I kind of struggle to understand how there isn't enough equipment and electrical engineering expertise on site at a modern airport to pinpoint these drones really quickly - especially at Heathrow. Even a small drone surely makes a ton of radio noise just from its motors, no?

This approach might work at short distances out in the desert, but in an airport or city? Good luck. The noise floor is already incredibly high.

Re: Drone Sighting Halts Departures at Heathrow Airport

#123

Post by brokenmachine » Tue, Jan 08, 2019, 11:42 PM UTC

cronix wrote: post #118

AWildC182 wrote: post #72

Earlier quoted context omitted.

I think the important difference is in the case of a drone, you're dealing with the possibility that it's going to get sucked into a jet engine (which by multi-engine standards should still be "safe"). Therefore the solution can't be worse than the problem and firing off missiles (which may fail and not self destruct correctly) or guns is a bit of an over-reaction. In the case of a military SAM engagement, you go int…

> the possibility that it's going to get sucked into a jet engine I've often wondered why the turbine intakes don't have some sort of "filter" in front to prevent larger objects from entering? Birds have been a problem forever. Why isn't there a simple solution? Even a grid in front like a common 4"x4" chainlink fence would provide. Is there some reason why they're all just wide open?

Have a look at videos of jets blowing vans off the runway and you get an idea of how powerful the sucking is. A bird would get sucked through a chainlink fence in front of the engine.

Also you'd be reducing the efficiency of the engine all the time, which would add up over hundreds of trips.

Re: Drone Sighting Halts Departures at Heathrow Airport

#124

Post by toomanybeersies » Tue, Jan 08, 2019, 11:45 PM UTC

cronix wrote: post #118

AWildC182 wrote: post #72

Earlier quoted context omitted.

I think the important difference is in the case of a drone, you're dealing with the possibility that it's going to get sucked into a jet engine (which by multi-engine standards should still be "safe"). Therefore the solution can't be worse than the problem and firing off missiles (which may fail and not self destruct correctly) or guns is a bit of an over-reaction. In the case of a military SAM engagement, you go int…

> the possibility that it's going to get sucked into a jet engine I've often wondered why the turbine intakes don't have some sort of "filter" in front to prevent larger objects from entering? Birds have been a problem forever. Why isn't there a simple solution? Even a grid in front like a common 4"x4" chainlink fence would provide. Is there some reason why they're all just wide open?

That wouldn't really prevent larger objects from entering, it would just slice them up on entry.

Re: Drone Sighting Halts Departures at Heathrow Airport

#125

Post by CydeWeys » Tue, Jan 08, 2019, 11:47 PM UTC

glenneroo wrote: post #92

darkpuma wrote: post #61

Earlier quoted context omitted.

Pistols and rifles, not birdshot? RPGs? What a complete joke. If you put these morons in charge of hunting birds they'd probably conclude that shooting birds doesn't work either. Try hunting birds with pistols and rifles and you'll have the same result. Meanwhile in Kentucky: https://arstechnica.com/tech-policy/2017/03/judge-rules-in-f... Meanwhile in Virginia: https://arstechnica.com/tech-policy/2016/08/65-year-old-…

I think you might be underestimating the problem. Airports are generally spread across huge areas (square miles/km i.e. one or more football fields) and birdshot from shotguns has an effective maximum range of about 250 meters (according to various websites and charts), therefore you'd need a ton (hundreds?) of these micro-CIWS devices scattered around the perimeter to have any fighting chance. Also you want to make…

Drones could easily fly in above the effective ceiling for birdshot anyway. A drone at 500m will easily interfere with flight paths and is well above the range of shotguns.

Re: Drone Sighting Halts Departures at Heathrow Airport

#126

Post by wokwokwok » Tue, Jan 08, 2019, 11:48 PM UTC

dpark wrote: post #104

tim333 wrote: post #96

Earlier quoted context omitted.

I have a first hand report from someone who works at gatwick that there was a drone hovering near the control tower for a while but I'll admit there seems a shortage of photos.

The question posed is not whether anyone reported seeing drones, but whether the reports are accurate. The fact that you got a first-hand report personally doesn't mean it's any more reliable than the first-hand reports the police received. The claim that they saw it hovering "for a while" actually makes this particular claim less believable. They witnessed it hovering by the control tower for an extended period of t…

This is what I find astonishing.

If a car is on fire in a normal street, half the people just stop to take photos or start live streaming it (this happened in Melbourne recently).

How did no one pull out their phone and take any pictures?

People takes photos of airports and planes all the time because it’s so different from day-to-day stuff.

It seems implausibly unlikely that both no one took photos and no one shared them online.

Re: Drone Sighting Halts Departures at Heathrow Airport

#127

Post by AWildC182 » Tue, Jan 08, 2019, 11:57 PM UTC

cronix wrote: post #118

AWildC182 wrote: post #72

Earlier quoted context omitted.

I think the important difference is in the case of a drone, you're dealing with the possibility that it's going to get sucked into a jet engine (which by multi-engine standards should still be "safe"). Therefore the solution can't be worse than the problem and firing off missiles (which may fail and not self destruct correctly) or guns is a bit of an over-reaction. In the case of a military SAM engagement, you go int…

> the possibility that it's going to get sucked into a jet engine I've often wondered why the turbine intakes don't have some sort of "filter" in front to prevent larger objects from entering? Birds have been a problem forever. Why isn't there a simple solution? Even a grid in front like a common 4"x4" chainlink fence would provide. Is there some reason why they're all just wide open?

The actual answer is aerodynamics. Having a structure in front of the turbine blades disrupts airflow, creating turbulent flow over the blades which causes the blades to lose efficiency. It's much easier to design the engine to be able to run for a little while after ingesting soft FOD than it is to create a good debris cover that doesn't destroy efficiency.

Re: Drone Sighting Halts Departures at Heathrow Airport

#128

Post by AWildC182 » Wed, Jan 09, 2019, 12:08 AM UTC

trhway wrote: post #111

AWildC182 wrote: post #64

To those wondering why we can't just take down the drones, it's not as simple as a jammer or a shotgun. Jamming drones is a non starter for the most part. You can make a drone operate on just about any frequency you want and with modern equipment becoming more frequency agile, this will only get worse. A simple thought experiment would be a drone using GSM for video and control. Can you just jam all phones? Obviously…

Russian airbase in Syria is regularly [according to them] attacked by drones https://www.rt.com/news/415454-drone-attack-syria-turkey/ https://www.cnn.com/videos/world/2018/08/16/drone-attacks-ru... Russian military jamming equipment is pretty powerful though, and these systems are also supposedly deployed there https://en.wikipedia.org/wiki/Pantsir_missile_system (the key in this case is the 30mm radar guided autoca…

I think this is an interesting case. The force response here is a bit different than in non-war-zones but it's still a useful anecdote.

Lasers will probably be part of the solution at some point but it's worth noting some of the drawbacks. You need the target to be above the horizon for safety obviously, so that means you need to be fairly close to it in a semi-urban environment which negates some of the nice range advantages. The other big one is any shiny flat parts of the drone could potentially reflect energy back to the ground briefly, resulting in possible eye damage to anyone within line of sight. The laser would likely be infrared so any aluminum, even unpolished, could become an effective reflector. This could be particularly problematic as people tend to instinctively look at things that burst into bright balls of flame...

Re: Drone Sighting Halts Departures at Heathrow Airport

#129

Post by toufiqbarhamov » Wed, Jan 09, 2019, 1:17 AM UTC

AWildC182 wrote: post #64

To those wondering why we can't just take down the drones, it's not as simple as a jammer or a shotgun. Jamming drones is a non starter for the most part. You can make a drone operate on just about any frequency you want and with modern equipment becoming more frequency agile, this will only get worse. A simple thought experiment would be a drone using GSM for video and control. Can you just jam all phones? Obviously…

Highly directional EMP or something similar seems like it could work, if it existed and didn’t represent an insane proliferation and terrorism threat... which it would. Nor does it solve the problem of the drone falling out of the sky. Truth be told, nothing is going to reliably mitigate the drone or its wreckage crashing, so any interception should ignore the contribution of the drone itself to the safety environment. If a countermeasure is deployed, it’s going to present a risk to the public.

That being the case, a SAM with a net warhead, some kind of rapidly setting foam, or a load of tangling wires seems like it would be most reliable without having to worry about UXO. You could even try to mitigate falling risk by ensuring the interceptor remains attached to the target, and then deploys a series of parachutes.

Re: Drone Sighting Halts Departures at Heathrow Airport

#130

Post by darkpuma » Wed, Jan 09, 2019, 1:38 AM UTC

glenneroo wrote: post #92

darkpuma wrote: post #61

Earlier quoted context omitted.

Pistols and rifles, not birdshot? RPGs? What a complete joke. If you put these morons in charge of hunting birds they'd probably conclude that shooting birds doesn't work either. Try hunting birds with pistols and rifles and you'll have the same result. Meanwhile in Kentucky: https://arstechnica.com/tech-policy/2017/03/judge-rules-in-f... Meanwhile in Virginia: https://arstechnica.com/tech-policy/2016/08/65-year-old-…

I think you might be underestimating the problem. Airports are generally spread across huge areas (square miles/km i.e. one or more football fields) and birdshot from shotguns has an effective maximum range of about 250 meters (according to various websites and charts), therefore you'd need a ton (hundreds?) of these micro-CIWS devices scattered around the perimeter to have any fighting chance. Also you want to make…

I had in mind birdshot CIWS mounted on top of a truck that could tear ass around the airport. Even if you could only place one or two in a fixed location, putting them next to tempting targets for invading drones looking to taunt the airport, such as the control tower, would probably work pretty well. Consider that the invading drone will only succeed in shutting down the airport if somebody notices it; somebody trying to commit economic sabotage will be making the presence of their drone known. If the invading drone goes unnoticed, then it will fail to accomplish it's mission.

As for drones flying too high, that is a problem but one that could be addressed (not solved) by using interceptor drones to spook or bait the invading drone into flying lower. On a non-ballistic sidenote, you could also have race quads configured to rapidly triangulate the origin control signal and collect video evidence of the signal origin. Not fool-proof by any means, but I wager that would be enough to catch all but the most clever/dedicated attackers.

This all seems a bit silly, but if you throw enough money at it I think you can make it work. The question is how much economic harm can a drone do by shutting down an international airport and how much money are you willing to spend to prevent this. My main point here is that the situation isn't nearly as hopeless as a bunch of soldiers taking potshots at the drones with their rifles (that's pretty much guaranteed to be not work and is exceptionally dangerous.)