Soldier: Wait, does this kid even have a driver's license? Lloyd: No, no he doesn't. Soldier: Then why the hell is he in a goddamn prototype Gundam? Lloyd: Because we are very, very desperate.
A common device whereby a character, usually an Ordinary High School Student, is thrust into piloting a machine that they wouldn't be allowed anywhere near under normal circumstances due to a disaster or enemy attack.
Our hero might have an assload of raw talent, secretly be a Replacement Goldfish, part of the next stage in Human evolution or just play videogames a lot, but whatever the reason, he now has to pilot the thing in the middle of a battle (where he is now a prime target) just to get out of the situation alive. And boy, does he!
Of course, the problem afterwards is how to keep them in the machine after the crisis has passed. It could be that all the normal pilots were wearing Red Shirts that day, or the fact that the machine is kind of an Empathic Weapon, and can only key itself to its first pilot (or just likes him better), but for the time being, he's stuck in the cockpit of an engine of destruction, whether he wants to or not.
Widely used in Mecha Shows. A Sub Trope of Powers in the First Episode.
And Kamille Bidan in Zeta Gundam since he, off screen, reviewed the data on the Gundam Mk.2 by hacking his dad's computer... though Kamile, Teen Genius that he is, does invent his own Mid-Season Upgrade.
Judau Ashta in Gundam ZZ, who is initially horrible at piloting.
And Loran Cehak in ∀ Gundam who unlike other examples did have a driver's licence ... for a few months.
Tobia Arronax of Crossbone Gundam manages to subvert this - when Space Pirates attack, he jumps into a grunt MS, gets defeated but explicitly not killed, and joins up with the Crossbone Vanguard despite two completely separate chances to walk away. And he's still not a terribly competent pilot until halfway through the second volume. Of course, it's subverted another way in that when he takes that first MS, he tells a soldier who protests that he's an engineering student with a license to pilot construction MS, and at the very least he'll be another gun out there.
And Kira Yamato in Gundam SEED, the Series basically being a retooled update of the original makes this a necessity.
Shinn Asuka in Gundam SEED Destiny, who is a Kamille's Expy of sorts, is actually a trained pilot when the series starts. Not to mention the pilots in Gundam Wing and Gundam 00...
Speaking of Gundam 00, this trope played straight with Saji Crossroad when he was asked by Ian to pilot the 0-Raiser and deliver it to Setsuna so they can combine.
In Tomino's own Gundam novels Amuro is a trained, if young, military pilot, and is a lot less whiny than in the series.
Noticing a pattern here? No wonder that Gundamjack became a word among anime fans....
Subverted in Gundam Age along the lines of Zeta Gundam, the first protagonist had a hand in designing the mobile suit and knows how it works.
And completely averted during the second generation. Flit deliberately leaves the Gundam where Asem can find it because he had always intended to give it to him.
This trope may as well have been built around Shinji Ikari from Neon Genesis Evangelion, apart from his falling into the cockpit of EVA-01 was pretty much planned by Gendo and Ritsuko. Initially, he refuses to pilot it owing to his massive inferiority complex, but agrees once he sees that Rei is in no condition to even stand on her own. Over the course of the series, he continues to pilot it for any number of reasons, all of which he'll express over the series before settling for "Because I have nothing else".
Averted with the other pilots. Asuka was selected from age six and trained for years to earn her title. Rei was literally built to pilot the Evangelion...maybe. Kaworu's pretty much perfect for the job. If only he wasn't an Angel. And Mari? She's just nuts.
Of course, this trope, like everything else Eva touches, is deconstructed. With no training, combat experience or even a clue where the power button is, Shinji basically gets his ass kicked in his first Angel fight until his Eva takes over and beats it up.
Akito Tenkawa in Martian Successor Nadesico. He was trying to run for it and the mecha was a handy getaway vehicle; everyone else thought he was volunteering to draw the enemy's attention.
Renton in Eureka Seven ends up almost literally falling into the cockpit of the Nirvash typeZERO while delivering a crucial part to it. He then proceeds to unlock its true potential and earn his place as co-pilot.
Although really, the cockpit falls on Renton (the Nirvash crashes into his house) before he takes the leap that puts him in the driver's seat.
A variant of this trope is used in Full Metal Panic!: Sousuke is already a highly skilled Humongous Mecha pilot when he is forced to pilot the experimental Black Box Arbalest mecha, though he does return to using his normal mech type for a bit eventually he is forced into becoming the Arbalest's designated driver when it turns out the machine's AI calibrated itself to him and can't be reset.
Macross offers a deconstruction, as Hikaru Ichijo (a.k.a. Rick Hunter of Robotech), a stunt-flying prodigy, ends up in the cockpit of a Humongous Mecha just when the day needs saving. He proceeds to stumble around and cause a great deal of property damage as civilian display team flying doesn't really translate to military jets or robot piloting skills. A crash course from a mentor keeps him from falling into buildings, but he only becomes competent after enlisting in the army and spending a reasonable amount of time in training.
Alto, and later with considerably less success to Sheryl, in Macross Frontier. Apparently the fact that Alto (and later, Sheryl) was going to piloting school might have been supposed to justify this, but this is the same as someone who's only partially completed real life flight school Falling into the Cockpit of the military's latest top-secret fighter! Sheryl's attempt has more realistic results.
When Alto tries to get to fly it a second time Ozma punches him in the face for his insolence and has him thrown out. Its only afterwards that Ozma gives him a chance, but he has to go through the proper channels first.
In Code Geass, Suzaku is the only soldier available to pilot the new Lancelot Knightmare Frame because he's at base recovering from a point-blank bullet wound while everyone else is out slaughtering civilians. It later turns out that he's the best match for the mecha.
The dialog implies that Suzaku's aptitude was tested when he first enlisted, but since only native Britannians are allowed to pilot Knightmares his high marks meant bupkis.
For exactly this sort of situation, of course. Nobles can overturn minor rules like that at will, may as well know who has the most aptitude.
Besides, someone may have had the idea to test Honorary Britannians as well as pureblood Britannians to 'prove' that the latter are superior to the former, under the auspices of "equal treatment". Naturally, when that doesn't pan out, the results are quietly suppressed.
An oft-overlooked example are the Japanese rebels; it's overtly stated that, until a certain point in the series, they don't have any Knightmare Frames of their own, only ones that they've stolen from the Britannians. Given how large the things are, what opportunity would they have had to practice with them enough to be good enough to go toe-to-toe with the military? Particularly egregious in Kallen's case, since her group operate in a city; at least the JLF could conceivably have found a quiet patch of countryside. Not only that, but she later manages to master the new KFs sent to the Black Knights by Kyouto and Rakshata with extraordinary speed and ease...
Actually, her group manages to get hold of a single Glasgow - the older military-use KMF type - and apparently they all try it out. Kallen, of course, is the best, and gets to pilot it in their operation.
Lelouch is a close one. He's not amazing or anything, but he handles a Sutherland quite well on his first try, only briefly admitting that it's not as easy as it seems. He's had some minor training, using the test type Ganymede, but that didn't have even half of the features of the modern Sutherland, like the weapon/grappling cable, and the gun, which he uses to great effect in his first deployment. Admittedly, he doesn't even remotely fall in, but he never gets actual training, either.
The main protagonist in Zoids: New Century Zero (the first series broadcast in America) Bit Cloud fits this trope to a T. Not only is he thrust into piloting the Liger Zero in the first episode, with no piloting experience beforehand, but the Liger also refuses to allow anyone else to pilot it.
In Zoids: Chaotic Century, the first series in Japan and the UK, Van comes across a Shield Liger in the desert, but would not have been able to pilot it were it not for his robot companionZeke's help. Unlike many examples of this trope, he keeps piloting it not because others make him, or because only he can, but because the Zoid belongs to him.
Simon of Tengen Toppa Gurren Lagann ends up having to pilot the Lagann almost immediately after he finds it, despite his protests. Fortunately for him, it's an Empathic Weapon of sorts. And HOT BLOOD accomplishes everything in TTGL.
ALLHot Blooded characters end up being able to pilot a Gunman eventually, usually after only a little bit of fumbling. Rossiu manages to learn in the brief time he's in Gurren's cockpit and Kamina's away during the Hot Springs Episode.
Gunmen are explicitly stated to have ridiculously intuitive controls. It's said that one just has to "do what feels natural" and the machine practically pilots itself, which does provide some Justification.
In keeping with its love of mecha tropes, Magical Girl Lyrical Nanoha does this as well—Nanoha comes into possession of Raging/Raising Heart completely by chance. The third season later implies that trained professionals with similar weapons don't even come close to what Nanoha managed to do immediately.
They can't match her POWER, but as Chrono made clear, many likely outmatched her SKILL until she underwent her own brand of Training from Hell. The difference between latent-talent/power and hard-work practice/skill is one of the minor themes of the series.
Ayato from RahXephon has this happen. Sort-of. He thinks he's an Ordinary High School Student, but the mech was actually made for him and he was guided to it mid-battle on purpose.
Hibiki Tokai in Vandread is a partial subversion: He was trying to steal the mecha in the first place.
Also he made his mech at the Factory, and knows which part is what so he knows, in theory, how to pilot it.
Hokuto and Ginga come near the titular mecha of Gear Fighter Dendoh during an enemy attack, while the assigned pilots are still on their way; predictably, they end up inside.
In fact, the mech itself picks them up and deposits them in the cockpit.
Soukou No Strain also features Sara Werec, another trained field mecha pilot, getting into an experimental machine in the middle of a battle. Her superiors have no idea that she's ever piloted a Strain before.
In Orguss 02, Humongous Mecha mechanic Lean is forced to pilot in order to escape an ambush of the cargo plane he was in. This trope is subverted in the following episode; he's brought into the organization that pilots Decimators, but told flat-out that only the best of the best are even considered as pilots. He does fall back in in the last episodes, where he's the best pilot available to stop an Omnicidal Maniac — even though he's blind at the time...
Fafner In The Azure: Dead Aggressor is a perfect example of this. In the first episode Kazuki has to pilot Fafner despite the fact that up to that point he was not even aware that such a mecha existed.
It's later explained that he was made (literally) to pilot the mecha, along with the rest of his generation.
In Dual! Parallel Trouble Adventure, Kazuki Yotsuga only climbed into that mecha cockpit to rescue its injured pilot... then it slammed shut on him, and he had no other choice...
Subverted in Fang of the Sun Dougram - the good guys take the protagonist to their secret base where they keep the titular Humongous Mecha and offer to let him pilot it. Suddenly, enemies attack, and just as our hero gets ready to invoke this trope, the Dougram is snatched away by a cargo helicopter.
Gram River sort of has this happen to him in Mars Daybreak: It actually came out to catch him, and given that they were underwater at the time, it was more of a sinking than falling.
Subverted in Candidate for Goddess. In very first episode main hero of series finds 5 most powerful mechas during a battle and literally falls into the cockpit of one of them. Yet, even when MECH ITSELF was asking him to pilot it and join the battle, he refused because he didn't know anything about piloting.
In Zettai Muteki Raijin Oh. Jin, Asuka, and Kouji(and later Maria, but only through remote control) become mech pilots only because they happened to be there when the Mech's previous owner was dying. Then it's played literally as Once an Episode, during the school's massive Transformation Sequence, the said pilots are literally thrown into the cockpit before launch.
Averted in BreakBlade. He was a gifted student in the military academy who couldn't operate a golem because he is an Unsorcerer; he suddenly has to pilot an ancient Golem he can use.
Hirono Keita from Betterman. Not only fits the trope to a T; he almost literally falls into the cockpit of the mecha, and happens to be a Dual Type, able to pilot it.
Seina Yamada of Tenchi Muyo GXP is actually tossed into the cockpit, mostly because the people who did so realized the god (the machine he was tossed into) had chosen him. And mostly because he accidentally dragged a bunch of pirates in with him and they wanted him to get rid of them.
In Idolmaster Xenoglossia, Haruka Amami falls into an iDOL's open cockpit after being tossed high into the air by the same iDOL. Later we find that Haruka had passed a blind test on her aptitude as a potential iDOL Master, however, even the ones who set up the test were surprised that the iDOL had a seemingly arbitrary attraction to Haruka, when it had not even respond to a trained and experienced Master.
In The Black Island Thompson and Thomson commandeer an airplane mechanic to fly a plane to chase after Tintin. The untrained pilot performs a lot of accidental aerobatics, and ends up winning a prize in an aviation contest.
Fan Works
The Bleach fanfic The Shining Dark does this with Ichigo fittingly. Justified, as Ichigo is already trained and has a strong knack for it.
And it sort of happens to Luke in Star Wars. Both only had extremely limited experience flying civilian craft before ending up flying starfighters at decisive battles in their respective conflicts.
In Luke's case, there's an Expanded UniverseHand Wave / All There in the Manual statement that an X-Wing's controls aren't that different from the Incom T-16 Skyhopper, a very fast, small three-winged civilian airspeeder that's parked in his garage in A New Hope. In the original trilogy novels, he's been grounded from it for reckless flying. He'd damaged the hull, which was why he took the landspeeder when looking for R2. You see him playing with a small model when he's talking to the two droids for the first time. When he talks of "tagging womp rats", he's referring to aerial target practice.
"Sir, Luke's the best bush pilot in the outer-rim territories." Film canon. Perhaps Biggs is exaggerating a bit to help Luke get in the cockpit, but this statement strongly implies that he's flown more than landspeeders.
Incom is also the same corporation that designed the X-Wing, so it makes sense that there would be some similarities.
A different manual, in addition (this being the NPR Radio Drama version of ANH, the same one where Wedge chews him out for that Dissimile) actually has a scene where the Alliance dumps Luke in an X-Wing simulator for a bit of crash course training. Which, I suppose, counts as falling into the simulator cockpit...
Also, in the expanded universe, Maarek Stele (the player character of TIE Fighter) was originality a mechanic who was in a fighter (testing it), and happened to be in a position to save a high ranking officer from attack.
And Anakin Solo gets to use the Empathic Weapon variant, the hyperspace repulsors of Centerpoint Station. Are we sensing a pattern here?
Airplane!! Ted Striker must pilot a multi-engine airliner even though he has only flown single engine fighters. Plus he has his drinking problem. <splash>
Thankfully, he gets some help from air traffic control.
In the 1980 Flash Gordon film, Flash has to take over over the controls of a plane when the pilots are sucked through the windshield (or maybe disintegrated) by Emperor Ming.
Civilian pilots are recruited and given a few hours of lectures before taking to the sky in modern fighter jets without any actual flight simulations and manage to help win a battle against the aliens.
Will Smith's character pilots the crashed UFO to dock with the mothership. Despite not knowing about aliens until two days prior, he defends himself as the best choice because he's "seen these things in action" and therefore knows of their maneuvering capabilities.
Literature
The Temeraire series has Captain Lawrence in a similar situation with a dragon, minus the initial battle. He's simply bonded to one of the rarest dragons in the world. A lot of the conflict is derived from various authority figures trying to get Temeraire to let someone else be his partner.
Live Action TV
The climactic scene of the Chuck episode "Chuck vs. the Helicopter".
This is more or less how Ziggy becomes Ranger Green in Power Rangers RPM.
Really, most of the Power Rangers in general fall into this category. It IS a show that depends on Humongous Mecha to win the day, after all...
Tabletop Games
In the Warhammer 40,000 comic Titan, Princepts cadet Hekate is thrust into commanding the massive Warlord Titan Imperious Dictatio when the previous Princeps he was assigned to observe unexpectedly dies in the middle of a battle.
R. Talsorian Games' Mekton Zeta is a roleplaying game geared to the Humongous Mecha genre, and this trope may (and probably will) be invoked at least once in any given campaign, no matter the setting.
Video Games
In the Super route of Super Robot Wars Alpha, your character gets into the Grungust Type 2 when the plane carrying it crashes into his or her school during a fight between Mazinger Z and the Monster of the Week. On the Real route, your character is a young pilot in the military...who also falls into the cockpit of an experimental mech that happened to be at the base you're assigned to during an enemy attack; this time being the Huckebein Mk II and the Titans. As it turns out, the whole thing was a set-up by Ingram.
In Super Robot Wars Judgement, playing as Touya will have the unit you picked crash into a school building near him, complete with Unwanted Harem while Mazinger Z and its female sidekick defend the school from enemies.
It's also lampshaded by Gai early on, who says that anyone that gets a mech that way is destined for greatness.
Nearly every protagonist in the Zone of the Enders series, with the exception of Radium in IDOLO. It helps that the Orbital Frames typically have some sort of AI to help.
James Links in Dolores, i is a bit of a subversion: The mecha in question was actually being sent to him in the first place.
James Links IS an experienced veteran, while the AI (Dolores) has personality of an innocent child
Dingo Egret is actually an experienced pilot by the time he finds Jehuty
Dingo however was asked if he would like a refresher VR training program since it was several years since he piloted a military grade frame (He was using LE Vs until he found Jehuty)
Played straight in the rare, yet extremely enjoyable 'Mech sections of FEAR 2. A possible Lampshade in that the manual specifies that only a highly trained 'Mech pilot should even think about touching the controls. Michael Beckett is the furthest thing from a pilot. Michael Beckett in a 'Mech is all but unstoppable.
In Xenogears, Amnesiac Hero Fei stumbles into the cockpit of a downed mech when his Doomed Hometown gets caught in the crossfire. Fortunately, he was a skilled pilot before losing his memory. Unfortunately, his forgotten self isn't a very nice guy. And by purest coincidence, the mech he happens to crawl into is a special kind that only he can unlock the true potential of.
The concept is used in the video game Steel Battalion, where your character is told he will have many months of simulator training before being allowed near the cockpit of a VT. True to form, the enemy attack, the character gets in the cockpit with the manual (the game is trying to tell you to do the same) and begins mission number 0. Actually much harder than Amuro makes it look...
In US version, the hero of Blaster Master just finds a machine lying around there.
A variation occurs in Ace Combat 5. Archer is a trained pilot...more or less. He's been through flight school, anyway, he just...hasn't completed his qualifications training yet when his base comes under attack and he climbs into a spare fighter. He ends up being a member of Wardog ( later Razgriz) squadron, the most accomplished aces in the game.
Web Original
Grif in Red vs. Blue has never had any special vehicle training, as far as we know, yet somehow he always manages to end up as the designated driver. While he's great with a jeep, unlike a lot of examples he's not necessarily a good driver of some of the more exotic vehicles he drives... like the Pelican he crashes.
Sarge: You do know how to land this, right?
Grif: Sure. That just means "stop flying", right?
Sarge:Brace for impact!
Western Animation
Played with in Megas XLR: Coop finds the Megas in a junkyard after it's flung into the past and becomes the hero and pilot... but only because the cockpit was beyond repair to the point where Coop rebuilt it out of a Cool Car and several jury-rigged video game systems, which means that Coop is literally the only one who can pilot it.
Played straight by Kiva, who lands in and learns to drive a car in all of about five seconds, rationalizing that such a simple machine should be easy if Coop could pilot Megas.
Cubix: In the first season finale, four of the Doctor K's five personal mechs are revealed to have cockpits and manual overrides (up til then, they just followed his orders). The kid heroes end up piloting them when they sneak into his base to retrieve the damaged Cubix. This comes in very handy when K transforms the entire base into the skyscraper-sized Kulminator.