If we’re talking about aircraft, the combination of modern radar mitigation and modern sensor packages would allow a time traveling plane or drone to be effectively invisible in 1925.
Sure they’re not going to bend light around themselves, but they can fly outside of visual range and 1925 radar technology won’t stand a chance of detecting them.
Maybe this is a stupid question, but aren't they still going to be loud as fuck, and quite visible? How high do you need to be before you're not audible or visible? I guess go at night, sure, but...isn't all that crap more about being hard to precisely target than it is about being literally undetected?
Not a stupid question at all. I’m not sure about piloted aircraft, but drones currently operate at altitudes where they can’t be seen or heard from the ground.
Sure they’re not going to bend light around themselves, but they can fly outside of visual range and 1925 radar technology won’t stand a chance of detecting them.