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2:09 PM
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A: Why are there still fighter pilots in cockpits?

ChrisThat's a great way to make a fighter jet even more fantastically expensive while being less effective. One obvious problem is latency. 1000 miles is about a 10 millisecond round-trip delay alone even before you add the time it takes to capture and trasmit the wide-angle high-definition images req...

 
Why would 10 ms be a problem?
"time it takes to capture and trasmit the wide-angle high-definition images required to replicate what a pilot could see from the cockpit." I thought the cockpit was already full of images that the pilot was looking at. Don't fighter pilots fly IFR frequently?
"if they can disrupt communications they can crash your jets." If there is no visibility from the cockpit and everything is jammed, a fighter pilot will fly with inertial navigation until they are out of range of the jamming. A computer could do the same thing; there's no way a "remote controlled" jet would not fall back to inertial navigation. If the adversary can disrupt your communications at all possible landing sites, then the remote controlled aircraft might crash. It would take a massive amount of power for the adversary to jam signals close to the plane's base.
 
@AnonymousPhysicist 10 ms alone is unlikely to be noticeable. But it gets added on top of all other delays. IFR flight is not done with instruments, not high-definition images of the surrounding area. And even if the cockpit were fully of images, transmitting them wirelessly takes time. Sure, a jet could fall back to inertial navigation and automatically fly back to its home base. But that's still a mission kill that wouldn't be possible with a pilot in the cockpit. And if an adversary can make your fighter jets beeline for their home base that makes it pretty easy for them to shoot it down!
 
Consider, "average" human reaction time is around 200 ms. A pilot would likely have faster reactions than average, perhaps 150 ms. By comparison 10 ms is not that much but could also be the difference between success and a lot of paperwork.
 
The latency issue is more one of variance resulting from the wireless link that would inherently be required than one of a high average latency. Humans can (and do) learn to compensate for even a fifth of a second of latency without much issue, but that only works if the latency is consistent. If the latency varies by more than about 10%, it becomes almost impossible to reliably compensate for it, especially if it’s changing very rapidly (which is the norm for long range wireless links).
 
@AnonymousPhysicist: in a dogfight, yes it seems plausible to me that 10 ms extra transmit latency on top of the sensors / local display / input latency could make the difference between a guns kill or not (on offense or defense), or maybe avoiding a missile or not. Video-game enthusiasts care about that amount of latency in a monitor, for example: rtings.com/monitor/tests/inputs/input-lag says 20 to 30 ms of total input lag can become noticeable. Video games, especially FPS, make latency more important that is would be most of the time for flying a plane worth > 100M $, but...
 
2:09 PM
@PeterCordes Dogfights do not exist any more. The guns on "fighter" jets are for ground attack.
 
@AnonymousPhysicist: Latency could still matter for reacting to threats in general, like a missile launch or AA fire from the ground. If latency was the only problem, it might not be a showstopper, but it's at least worth mentioning. Jamming, hackability, and possibility of damage to comms equipment, are other direct problems with a remote control system. A human onboard might be better able to save a damaged plane by using all their senses. OTOH, it might be much cheaper to make planes more "disposable" with no human life at stake.
 
@AnonymousPhysicist, back during World War II, they discovered that a fighter pilot could spot and correctly identify an aircraft seen for as little as 5 milliseconds.
 
@Mark That is not a plausible claim.
 
Perhaps "fighter jet" is a uniquely bad mission for drones, but what exactly is that mission? Largely shooting down other manned aircraft, right? So if we get to a point where the only other manned aircraft are other fighter jets, what's the point again?
 
@AnonymousPhysicist, Renshaw S. "The visual perception and reproduction of forms by tachistoscopic methods." J Psychol 1945;20:217-32.
 
2:09 PM
@Mark Note that this is not related directly to latency or reaction speed. If you can react to something that is only in your field of view for 5 milliseconds, that doesn't mean you can react to it in milliseconds. It still takes ~200 milliseconds plus the latency before a human can react to something.
 
@Chris: Right - which would turn the ~200ms window into a ~205-~215ms window in a remote controlled capacity, as I understand.
 
@Mark I checked the reference. It does not give details of the tachistoscope, but it is clear that the tachistoscope is not comparable to the view out of an airplane. I have seen and identified very bright images that were visible for only 1 nanosecond before; it's quite easy, but of no use for piloting.
 
A 10ms round trip would probably be extended by relaying over indirect links, each of which buffers and resends packets, adding not just time but variability. The increased time alone would still be manageable. But control systems with feedback will often take more than one round-trip to do anything interesting
@AnonymousPhysicist we can all see ns and even ps laser flashes, locate them, and get an impression of their shape and, given sufficient context, size. Of course that's much brighter than an aircraft (but 6-9 orders of magnitude?), and the eye doesn't exactly integrate , but with sufficient contrast, especially against an uncluttered sky, locating and identifying is very plausible. Don't forget that a well-drilled pilot would be trained to tell aircraft types as easily as you or I might tell a hexagon from a circle
 

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