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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-

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 into the scenario with the assumption that the aircraft you're shooting down is going to do far more damage than it could if it crashes in an uncontrolled manner so it's ok if a SAM misfires and blows up an apartment or the target crashes into a school building because that's a better outcome than a nuclear weapon being released, a strategic target being struck or another 9/11 happening. Now, that's not to say that the equation wouldn't change if there was a realistic threat that someone would mount explosives on a drone and deliberately try to bring an airliner down but for once we can be thankful for the nature of reactionary policy; we can get away with being reactionary here. Edit: to go on a bit of a tangent, I think the best path forward at this point is to have a system that can detect and locate fast moving radio emitters within the perimeter of an airport that don't correspond with an ADS-B target. Such a system might allow you to track the target and attempt to figure out where it came from.

sailfast 8y ago
Agreed and monitoring is definitely the first step. Without knowledge you're not really going to be able to use any sort of weaponry anyway. I'm hoping that this ends up getting handled similarly to birds and we don't have to react at the "enemy aircraft" scale of ballistics.
cronix 8y ago
> 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?
- CydeWeys 8y ago
  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 https://youtu.be/AMHwri8TtNE
- brokenmachine 8y ago
  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.
- toomanybeersies 8y ago
  That wouldn't really prevent larger objects from entering, it would just slice them up on entry.
- AWildC182 8y ago
  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.

sailfast 8y ago

Agreed and monitoring is definitely the first step. Without knowledge you're not really going to be able to use any sort of weaponry anyway. I'm hoping that this ends up getting handled similarly to birds and we don't have to react at the "enemy aircraft" scale of ballistics.

cronix 8y ago

> 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?

CydeWeys 8y ago
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 https://youtu.be/AMHwri8TtNE
brokenmachine 8y ago
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.
toomanybeersies 8y ago
That wouldn't really prevent larger objects from entering, it would just slice them up on entry.
AWildC182 8y ago
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.