Generally, the main character, who is often an Ace Pilot, will be stuck in the fight of his life, being peppered with gunfire from all sides, have a "bogey" (or more) on his tail, and/or something similar, which are all keeping him from his almighty goal of Saving the World/Nation/Galaxy/People by blowing up the enemy mothership/main headquarters. Then, it happens. The tune of the battle changes, and hopelessness becomes hope. Out of the smoke and into the fray comes some dependable ally (who often wasn't even supposed to be there in the first place) who will clear a path a like a big damn hero, deliver a snappy one liner or some inspirational words, then assure the main character that they've got him covered. Cue the climactic finish.
Sometimes their buddy has Changed His Mind, Kid to give the moment more weight.
This trope can also occur outside of vehicles, but those situations generally double as You Shall Not Pass! moments.
A case of Truth in Television. USAF doctrine is that on an attack run, one pilot will be assigned as a "shooter" and his wingman as "cover", the wingman's job being to get hostile aircraft off of the shooter as he makes his run. The Army does something similar, pairing up squad members into "buddy teams" that move in combat using a system called bounding overwatch, where each member alternates between moving from one covered position to another and covering their buddy's movement by shooting at the enemy so they keep their heads down.
- In Macross Frontier, Alto gets tailed on his way to take out Grace and is just about to get hit by a few stray lasers. Brera then appears, after having gone missing for most of the battle, and saves him. This is especially awesome because Brera spends most of the series as an antagonist, or at least an enormous jerk, and was previously the one who had shot down Alto. Brera then tells the hero that he'd cover him, and the two clear a path straight to the Big Bad.
- Done with epic proportions in Mobile Fighter G Gundam. Just when Domon and the rest of the Shuffle Alliance are staring down the Devil Gundam with its impossibly huge face, all of the Gundams in the world unite and join their assault, allowing for the main heroes to go in and try to take it out from the inside.
- Happens at the Second Battle of Jachin Due in Mobile Suit Gundam SEED—the secondary cast of the Three Ships Alliance takes on and holds off waves of both ZAFT and Earth Alliance mobile suits as well as their battle fleets so that Kira and Athrun can move in to take out Rau Le Creuset and stop the GENESIS superweapon, respectively.
- In Mahou Sensei Negima! Asuna and Setsuna arrive with Misora and Kotarou to save Negi as he is riding off to face Chao. He was nearly overwhelmed untill they arrived just in time to save him.
- Kotarou also bought time for Negi during the fight with Rakan while the latter set up his Duplex Complexio and Thunder God's Lance: Titanslayer spells.
- Recently, Fate saved Negi's life from Secundum's attack.
- While not a literal enactment of this trope, in One Piece Sanji always has the crew covered, as he occasionally ducks out of the action (without anyone noticing) for an inordinate amount of time only to reappear just when hope seems lost to enact a plan he's spent the last umpteen chapters concocting unbeknownst to his crew and the readers - resulting in a narrow escape. For example Alabasta, Water Seven, Enies Lobby.
- Parodied with Usopp, who often claims this, but usually uses it as an excuse to avoid direct combat.
- Happens in the TV series adaptation of Record of Lodoss War. While trying to get to Castle Conquera on the Dark Island of Marmo before the Evil Wizard Wagnard can sacrifice their friend to revive the Goddess of Destruction, they're faced with fighting the ancient and powerful evil Black Dragon, Narse. Just as the heroes are losing time and seemingly going to lose the battle, an old friend from the previous season, Shiris, comes back leading a team of wyvern-riders, who tells them "We'll take care of it!" Happens again to Shiris when her corps are about to lose to Narse, when along comes the ancient and powerful (and more importantly, good) Gold Dragon-Queen, Mycen, who then duels with Narse in a Dragon-on-Dragon deathmatch.
- To a lesser extent, also happened in the first episode of the original OVA adaptation of Record of Lodoss War. When Parn and Deedlit get separated from the group and are about to get burnt by a dragon's breath, they find a barrier blocking the fire: the other heroes have arrived and Slayn, the sorcerer of the group, cast an abjuration spell to save them.
- Elite soldiers cover Eren's attempt to seal the gate of Trost in Attack on Titan.
- The X-Wing Series, being about fighter pilots who generally have wingmates, uses this phrase and permutations of it a lot. Sometimes it's as dramatic as this, but usually it's the response to being told that Six is making an attack run. Often literally Six; Wraith Six, "Runt" Ekwesh, is something of a Berserker in his early appearances, making it a matter of "cover Runt or else".
- Han Solo from Star Wars. The ever pessimistic smuggler had initially abandoned the Rebel Alliance before the Battle of Yavin, reasoning that it'd be a Suicide Mission. Then, when Luke is being tailed by three TIE Fighters, one of them piloted by Lord Vader himself, and most certainly doomed to be shot down, Han Solo and his Millennium Falcon come out of the sun and rain down hell on them, taking one out, causes the other to panic and ram Darth Vader's ship, sending it careening into space. This gives Luke all the freedom he needs to take down the Death Star with a few proton torpedoes.
- Done in a slightly different way in Independence Day. Instead of the ones doing the covering appearing out of nowhere to save the day, it's the one to be covered who flies in from the smoke to bail everyone else out. During the battle, all the other fighter pilots had used up their missiles, leaving them without any effective means to take out the alien mothership once it exposes its main weapon. Just when all hope is lost, Russell flies in with the last missile in tow. The badass president and his wingmen then keep the other alien fighters off his tail as he makes his Heroic Sacrifice.
- In Star Trek, when they invade the Narada, Kirk stuns one of the Romulans so Spock could do a Mind Meld and find out where Spock Prime's ship is. While Spock is doing that, Kirk shoots another Romulan who was approaching from behind.
- In Stargate: The Ark of Truth, Teal'c is shot by Ori forces and left for dead while Daniel and Vala are taken captive. After he comes to, the audience watches Teal'c march his way across mountains and plains to the Ori city, to the room where Daniel Vala and Adria are confined, in time to distract Adria and then knock the now-active ark open right into the face of the Doci.
- In the opening commando raid of The Desert Fox, a commando shouts, "Cover me!" while he throws a grenade. Then he runs off allowing the man who was covering him to get shot dead. Several other commandoes are gunned down as they retreat because they're not using the fire-and-movement tactics they'd be using in real life.
- Spoofed in Police Squad!, where Frank Drebin's "Cover me!" gets a blanket tossed on top of him. He spends the rest of the gunfight stumbling around helplessly.
- Stargate SG-1:
- Teal'c appearing out of nowhere in "Upgrades," when the team had ditched him to go off on a mission, just in time to save Daniel's ass. He does it again in season 8, when Sam and Daniel were trapped on Osiris' ship, about to be killed by The Trust.
- In the Series Fauxnale "Lost City", SG-1 is aboard a Goa'uld transport in the Antarctic trying to tunnel down to an Ancient weapons platform when a large force of Death Gliders and Alkesh are detected heading straight for them. All seems lost when suddenly the USAF battlecruiser Prometheus and her squadron F-302 fighters show up and engage the Goa'uld attack force to buy time for SG-1. The Prometheus herself parks directly over their transport and uses her point defense guns to ward off any Death Gliders that come close.
- The Equalizer. McCall wounds a bad guy, then kicks his pistol over to the Victim of the Week and says to keep him covered. As the man's a Non-Action Guy, he only gets a blank look until McCall gets more specific. "You point the gun at him, put your finger on the trigger, and cover him."
- Blake's 7. Confronted by a Professional Killer, Avon shouts to Tarrant, "Don't worry, I'll cover you!" Tarrant engages in Good Old Fisticuffs with his larger opponent, then we Gilligan Cut to Avon calmly sitting in a chair holding his sidearm. With some difficulty Tarrant knocks the killer on his back, whereupon Avon strolls over and sticks the gun in his face, forcing his surrender.
- Final Fantasy IX had one in a much bigger way. As the party approaches the final dungeon on the Invincible airship, a legion of dragons comes to meet them to stop them from landing. Unfortunately, the ornate piece of junk actually has no useful weapons. But wait! Straight from out of the clouds comes every airship in existence armed to the teeth, who clear a path so that the heroes can put an end to the Big Bad once and for all.
- A slightly more specific event comes right when the Invincible is about to get plowed down by a stream of dragons. Beatrix, in Queen Brahne's flagship, flies in from the blue and literally covers the Invincible so it can pass the final stretch.
- Another Final Fantasy example, this one from IV: After returning from the Moon, Cecil and friends are horrified to see that they're too late to stop the awakening of the Giant of Bab-Il, a kilometers-tall monstrosity that starts devastating the countryside. As they gape in horror, they see a huge burst of artillery on the Giant's flank... and the entire armed forces of the world arrive to buy Cecil's party some time to enter the Giant, all with the Theme of the Red Wings rising in the background.
- Star Fox:
- In Star Fox: Assault, during the final mission Star Wolf ropes in all the bogeys so that Star Fox can make it to the Aparoid Queen.
- Also occurs in Star Fox Adventures, during the final boss fight. When Fox gets lodged in between the villain's teeth, Falco, who had yet to appear in the entire game and was barely mentioned in passing, flies in from outer space to lend a helping hand. With bombs.
- Star Fox 64: "Great Fox will cover you!" *pew pew! BOOM!*
- Ace Combat:
- Appears in Ace Combat 6: Fires of Liberation during mission twelve, when Shamrock and Talisman are being chased by Estovakia's entire airforce after having destroyed a Weapon of Mass Destruction, the situation looks hopeless until all the pilots you've been helping during other mission's show up to lend a helping hand. Cue ass kicking.
- Also occurs in the second-to-last mission of Ace Combat 5: The Unsung War. Razgriz's home base, the carrier Kestrel has just been sunk, and it seems that they will be only four planes fighting past two armies to take down the real bad guys before the Kill Sat gets deployed. Then, as they approach the mission site, squadrons from both armies join them, not only providing cover but also bringing resources that Razgriz didn't have when they started out, resources that prove instrumental in winning.
- Danny Phantom episode "Reign Storm" where Danny, despite donning a super powered suit, is still outnumbered by the current Big Bad's gigantic army. Initially unwilling to fight at first, Danny's Rogues Gallery comes out to battle, clearing a path for Danny so that he can take down the villain and save the world.
- Happens all the time in Justice League and Justice League Unlimited. Earliest being in "In Blackest Night" where Green Lantern plays shield for Flash (twice) in the middle of a battle against the Manhunters, and says this quote almost word for word.
- Spoofed again in Transformers Animated, Sari asks Cloud Cuckoo Lander Wreck-Gar to "Cover Me!". So he throws a blanket on her.