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I was watching the most recent 74 Gear video and there was a graphical demonstration of how pilots are reliant on GPS while taxiing. Sure, I believe that in th

I was watching the most recent 74 Gear video and there was a graphical demonstration of how pilots are reliant on GPS while taxiing. Sure, I believe that in the air, GPS is redundant. But what Kelsey explained is that, before GPS and graphical maps, pilots on the ground would rely on paper charts that were manually updated and placed in huge binders. They would scour these paper charts to understand what taxiways they needed to take across the airport to get from gate to runway and back again. Nowadays, the pilots have a nice screen where an image of the airport is displayed underneath a nice arrow depicting the aircraft in its GPS location and velocity. It's more difficult to get lost now, because you can see at a glance on the screen where you are. Looking outside your windows can often confuse, and fog and darkness and unfamiliarity can confound someone who is already lost. The issue on 74 Gear was that someone got lost and thought they were in an entirely different location, when actually they had intruded on an active runway while just trying to taxi. A very dangerous situation, as you can tell. I believe that, if GPS were jammed and unavailable, pilots would possibly be able to fall back on these paper charts, that is, if they are even being maintained anymore, but it would be error-prone, and any taxiing pilot would need to exercise utmost caution not to get lost like that.

lxgr 3y ago
Many large airports have high-precision ground surveillance radar for that very reason, and the software interpreting it can often issue automatic runway incursion warnings, operate visual “safe to cross” indicator lights etc., all without relying on GPS. There is definitely responsibility on the pilots to not take a wrong turn, and that job gets harder without precision navigation systems, but more than one thing normally has to go wrong for a runway incursion to occur, as far as I understand.
- NoZebra120vClip 3y ago
  The incursion that Kelsey was demonstrating happened at a very small airport, in fact, and indeed, several things had gone wrong.
ExoticPearTree 3y ago
For taxiing they use GPS just as Google Maps for driving, but it is mostly for pilot convenience to look at a screen and taxi than to look outside at the taxiway markings which in some poor visibility conditions are hard to spot and without the GPS they would I guess require a Follow Me car. Regarding the runway incursion scenarios, you need to pay attention to the lights on the taxiways, because runway entries are highly illuminated and visible even in really low visibility conditions. You just don't enter an active runway by mistake. "Paper charts" as you call them, are physical charts of airpots maps akin to a city map. And as a pilot you are required to know how to read and use those maps. Just as with SID/STAR charts. Pilots are expected to know how to fly using only basic instruments (airspeed, altitude, attitude, vertical speed, compass, banking), and even with some of those not operational. Long story short, GPS jamming at an airport is an inconvenience rather than something critical.

lxgr 3y ago

Many large airports have high-precision ground surveillance radar for that very reason, and the software interpreting it can often issue automatic runway incursion warnings, operate visual “safe to cross” indicator lights etc., all without relying on GPS. There is definitely responsibility on the pilots to not take a wrong turn, and that job gets harder without precision navigation systems, but more than one thing normally has to go wrong for a runway incursion to occur, as far as I understand.

NoZebra120vClip 3y ago
The incursion that Kelsey was demonstrating happened at a very small airport, in fact, and indeed, several things had gone wrong.

ExoticPearTree 3y ago

For taxiing they use GPS just as Google Maps for driving, but it is mostly for pilot convenience to look at a screen and taxi than to look outside at the taxiway markings which in some poor visibility conditions are hard to spot and without the GPS they would I guess require a Follow Me car. Regarding the runway incursion scenarios, you need to pay attention to the lights on the taxiways, because runway entries are highly illuminated and visible even in really low visibility conditions. You just don't enter an active runway by mistake. "Paper charts" as you call them, are physical charts of airpots maps akin to a city map. And as a pilot you are required to know how to read and use those maps. Just as with SID/STAR charts. Pilots are expected to know how to fly using only basic instruments (airspeed, altitude, attitude, vertical speed, compass, banking), and even with some of those not operational. Long story short, GPS jamming at an airport is an inconvenience rather than something critical.