People tend to be incompetent in movies -- that's how our heroes are able to make so many daring escapes. However, there are some movies whose entire plotlines depend on characters inexplicably forgetting hugely important details about their professions and making glaring procedural errors in the jobs they supposedly do every single day.
In Die Hard 2: Die Harder (that subtitle must never be ignored or forgotten), Dulles International Airport gets taken over by a ruthless former colonel who specializes in naked karate.
"Hey, how can we let the audience know this guy's crazy in just a single image?"
Dozens of inbound flights carrying thousands of passengers are forced to circle in an endless holding pattern, and unless his demands are met, Colonel Karateboner will use the hijacked systems at Dulles to either trick the planes into crashing or keep them in the air until they run out of fuel and nosedive into oblivion.
Or until the pilots just fly to another airport. Dulles is hardly the only airport on the East Coast -- it isn't even the only airport in D.C.
Every runway from Virginia to Pennsylvania could be reached by a commercial jet within two hours. What pilot is just going to keep flying around in circles until all the fuel burns up and they drop out of the sky, incinerating himself and 500 passengers? Any responsible flight crew would start contacting other airports for clearance the instant it looked like running out of gas might become an issue.
"Let's not bother any other airports with this."
Also, the flight path of Dulles intersects with those of two other major airfields -- Reagan International Airport and Andrews Air Force Base. Any plane circling Dulles would constantly be passing in and out of the flight paths of the other two.
Doug Francis Realty
We don't actually speak Plane Map, so we're just assuming that these colorful rectangles translate roughly to "Die Hard 2 was stupid."
Even if for some absurd reason the pilots never radioed a single other airport, they would still get hailed by Reagan and Andrews operators every time they crossed those flight paths, because that's what air traffic controllers do to prevent midair collisions. And if the planes still managed to run out of gas before touching down somewhere, there would be no need for Bruce Willis to start a fire to guide them safely down the blacked-out runway at Dulles -- any sane pilot would just glide on over to Reagan or Andrews, where all the lights are still on and there's no explosions or gunfire.
In Terminator 2, Schwarzenegger and friends blow up an office building in a massive shootout with every police officer in Los Angeles, and then crash a stolen SWAT van into an equally stolen SWAT helicopter in the middle of a freeway before jackknifing a tanker truck of liquid nitrogen (also stolen) into a steel mill that is inexplicably operating with a full staff in the middle of the night, and for some reason has its own exit just off the interstate in the middle of the most densely populated city on the West Coast. They then have a climactic showdown with the T-1000, completely undisturbed by anyone.
"Y'know what? I don't think I really care how the rest of tonight plays out."
So what happened to the police? They were actively pursuing Arnold and Sarah Connor -- they think Arnold is the same Terminator from the first film (a known cop killer), and Sarah Connor is a high-profile mental patient who just escaped from an institution (where she was put for blowing up a building). So the LAPD catches up to these two, a massive firefight ensues wherein dozens of officers are injured, Sarah Connor blows up another goddamned building, and then she and Arnold escape into the aforementioned freeway destruction derby ... and the cops don't follow them?
The police couldn't possibly have lost them -- two of the highest priority suspects in the state's history tear ass down the freeway in a police van, being chased by a police helicopter that subsequently crashes and explodes all over the road. Did nobody call this in? Or did every peace officer in the city just decide they'd had enough for the evening?
"The city doesn't pay for overtime. After 5, law and order ain't our problem."
Speaking of cops ...
In The Dark Knight, the police are transporting Harvey Dent in an armored truck when the Joker diverts their convoy into an underpass and traps them in an ambush. He does this by blocking off the main road with a flaming fire truck (because irony is a form of humor and his name is the Joker).
"Get it? Get it? Oh, right. You're all dead."
Then a garbage truck boxes the convoy in, allowing the Joker to pull beside them in his tractor trailer and take his sweet time shooting progressively larger guns at Dent's truck until Batman finally shows up to save the day ...
Hey, why didn't that dude in the back get a mask?
... rescuing a bunch of on-duty cops escorting one of the city's most valuable public officials. This is a detachment of heavily armed SWAT officers, not a high school volleyball team. Moreover, they know full well that they're dragging Harvey Dent across Gotham specifically to bait the Joker. When the convoy inevitably gets attacked, they sit in their cars watching as a man in a bright purple suit cheerfully reloads a bazooka and do absolutely nothing. None of these highly trained officers think to fire their weapon a single time.
"Hold up. Let's see where he's going with this."
One particularly annoying policeman goes so far as to wail "I didn't sign up for this!" when he specifically signed up for this exact task. Did he and the rest of the team seriously accept the assignment and say to each other, "We'll be totally fine, there's no way the Joker is going to show up and do precisely what he said he'd do, which incidentally is the exact purpose of this mission"?
Furthermore, what about not going into the underground tunnel in the first place? The Joker's roadblock didn't exactly close off every thoroughfare in Gotham City.
The cops even make a comment about how stupid going underground is as they're doing it. The fire truck is only blocking the right side of the road -- why not just go around it, or stop and wait for the thing to be moved? They are the police, after all.
The Men in Black (or MiB, if you're celebrating the Willennium) fight dangerous aliens on an inconspicuous level with two-man teams, and only if shit gets truly loud do they send in reinforcements.
The shit here must be deafening.
After all, they have laser guns and memory erasers, so there really shouldn't be much that one or two agents can't handle.
Except in the first film, when Agents J and K have to stop a giant alien cockroach from stealing a spaceship and leaving the planet. If the alien succeeds in escaping, Earth will be destroyed. The entire MiB organization is aware of the stakes ... but they still only send two guys to deal with it. Two people, one of whom has only been doing the job for a few days, against a nigh-invulnerable star beast and his flying saucer. If he kills J and K (which he can easily do) or simply ignores them and fucks right off into space, every living creature in the world will die.
If not, we get Wild Wild West, which is like dying.
Is keeping a low profile really still the primary concern here? It's not like J and K haven't already torn ass through the Midtown Tunnel in a rocket car on their way to shooting down a massive spacecraft with plasma cannons. Plus, the MiB have a device that erases memories, so it doesn't matter how big a spectacle they make (in the second film, we see that they can wipe out memories on an irresponsibly large scale).
Congratulations. Every doctor in New York has now forgotten math.
Earlier, we see that MiB headquarters is filled with agents. What exactly are those agents doing that keeps them from pitching in to stop Star Roach? There can't be 30 other world-ending scenarios going on simultaneously that require their attention. Are they just sitting around watching SNL clips on Hulu and hoping the planet doesn't explode?
"Why do we even have all these other cars?"