5 ms·

If it was burning a fuel wouldn't you also expect it to be easily visible through their thermal camera?

jacurtis 5y ago
This is my mental debate. On one hand it seems like the endurance of the aircraft would suggest it had to be combustion based. But that would make it appear on thermals, so the fact that it is invisible to thermal would suggest it has to be electric. An interesting mystery.
greedo 5y ago
Modern military drones/UAV have some IR shielding/diffusion.
- postalrat 5y ago
  How about some examples? This thing was apparently pretty small. I'd like to see how they managed to pack in all these abilities in something just a couple feet across.
  - shadilay 5y ago
    Basic IR shielding is not actually that complicated, you just need an opening to mix cold air with the exhaust as seen on the new H-60 derivatives.
    - postalrat 5y ago
      Exhaust will always mix with ambient air. You make it sound trivial to develop a turbine engine that won't show up on a thermal camera. If have figured out how to make doing so simple I'm sure many militarys are willing to pay billions for your ideas.
      - shadilay 5y ago
        The goal is to make it show up less. You can see the open duct here: https://upload.wikimedia.org/wikipedia/commons/d/dc/UH-60_2nd_Squadron%2C_2nd_Cavalry_Regiment_%28cropped%29.jpg https://upload.wikimedia.org/wikipedia/commons/d/dc/UH-60_2n... Here's the updated design: https://www.youtube.com/watch?v=WPc578CV-78 https://www.youtube.com/watch?v=WPc578CV-78
jcrawfordor 5y ago
Yeah if it had like a turbine engine it should have been pretty obvious on the thermal camera unless it had some kind of countermeasure. The pilots seemed to think it had very low thermal emissions, but I do wonder if they were also just having a really hard time getting it within the sight of their thermal camera. I would personally tend to guess operator error (unable to keep the camera pointed at it due to its fast motion) over it having very low thermal emissions, because hiding the exhaust from something like a small jet engine is not at all easy.

This is my mental debate. On one hand it seems like the endurance of the aircraft would suggest it had to be combustion based. But that would make it appear on thermals, so the fact that it is invisible to thermal would suggest it has to be electric. An interesting mystery.

greedo 5y ago

Modern military drones/UAV have some IR shielding/diffusion.

postalrat 5y ago
How about some examples? This thing was apparently pretty small. I'd like to see how they managed to pack in all these abilities in something just a couple feet across.
- shadilay 5y ago
  Basic IR shielding is not actually that complicated, you just need an opening to mix cold air with the exhaust as seen on the new H-60 derivatives.
  - postalrat 5y ago
    Exhaust will always mix with ambient air. You make it sound trivial to develop a turbine engine that won't show up on a thermal camera. If have figured out how to make doing so simple I'm sure many militarys are willing to pay billions for your ideas.
    - shadilay 5y ago
      The goal is to make it show up less. You can see the open duct here: https://upload.wikimedia.org/wikipedia/commons/d/dc/UH-60_2nd_Squadron%2C_2nd_Cavalry_Regiment_%28cropped%29.jpg https://upload.wikimedia.org/wikipedia/commons/d/dc/UH-60_2n... Here's the updated design: https://www.youtube.com/watch?v=WPc578CV-78 https://www.youtube.com/watch?v=WPc578CV-78

jcrawfordor 5y ago

Yeah if it had like a turbine engine it should have been pretty obvious on the thermal camera unless it had some kind of countermeasure. The pilots seemed to think it had very low thermal emissions, but I do wonder if they were also just having a really hard time getting it within the sight of their thermal camera. I would personally tend to guess operator error (unable to keep the camera pointed at it due to its fast motion) over it having very low thermal emissions, because hiding the exhaust from something like a small jet engine is not at all easy.