Up, Up, and Away

The classic flying pose: stretched out, with one or both arms above the head. In both cases, this creates the illusion of 'obvious' aerodynamicness, as the resulting shape looks vaguely bullet or gooselike, since the human body tends to look very silly in flight otherwise.

From Superman's catch phrase, originated on radio to indicate to the audience when he was taking off, in his earlier cartoons and comics.

Anime and Manga

 * The Dragon Ball series have flying poses of all kinds: hands extended (curled into fists or kept straight), hands back, one hand stretched, etc.
 * Astro Boy: It's an iconic pose of The Mighty Atom.
 * Tsuna from Katekyo Hitman Reborn uses his flames as a propellant, like the Iron Man example below, as such depending on where he needs his thrust he will point his hands in that direction.

Comic Books

 * Superman himself, of course.
 * Referenced directly in The Iron Giant, where the rocket-powered giant really doesn't have to do this, but Hogarth insists for style purposes.
 * In Alan Moore's run on Supreme, there's a funny twist on the phrase. Originally (like, back when he was still in newspapers) Superman couldn't fly, just jump really, really high. ("Faster than a speeding bullet! More powerful than a locomotive! Able to leap tall buildings In a Single Bound!" Sound familiar?) At one point, we see the earliest version of Supreme, who's a Superman pastiche, and he can't fly, either. His catchphrase? "Up! Up! And over!"
 * Golden and early Silver Age Superman artist Wayne Boring's flight style for Superman was quite unique: he would draw flight scenes with Superman standing completely upright and in a running/jogging pose.
 * Christopher Reeve flew gliders as a hobby and used that experience to make Superman's flying feel more believable in his films.

Fan Works

 * Subverted two times in With Strings Attached. John wouldn't dare pose like this in flight; he'd probably drop right out of the sky. He usually hooks his thumbs in the waistband or belt loops of whatever pants he's wearing. And Paul, just after receiving Super Strength and thinking he's been turned into Superman, leaps into the air yelling the phrase—only to discover, several thousand feet up, that he can't actually fly. Good thing he's Nigh Invulnerable.

Film

 * Averted in Iron Man, who keeps his hands back to use his palm-mounted repulsors as flight stabilizers.
 * Before that The Rocketeer flew the same way, for roughly the same reason (although he lacked the hand-mounted stabalizers).
 * In 1984's Supergirl, director Jeannot Szwarc deliberately tried to avoid making the flight scenes similar to those in the Christopher Reeve Superman movies, opting instead for a more "feminine" ballet-inspired take.
 * Metroman usually uses this pose when flying in Megamind. When is given Metroman's powers, he initially flies like he's driving a car, until  admonishes him to "be more like Metroman." Given his inexperience, though, he spends a good bit of his airtime spinning and flailing around.

Literature

 * Peter Pan doesn't say it straight, but it is strongly implied that you can't fly with one hand bound behind your back.
 * That, and it's hard to have happy thoughts while being fed to a crocodile.
 * Disney's Peter Pan doesn't give a second thought to aerodynamics, though, and is able to fly backwards, upside down, or while pretending to run on clouds.
 * Similarly, Peter from the Fox cartoon series would frequently fly forwards, backwards, in a sitting position, sideways, upside-down....as characters go, Peter just loves to show off, in any incarnation!

Live-Action TV

 * The first time in The Greatest American Hero that Ralph Hinkley tries to use his alien-powered supersuit to fly, a young bystander helpfully explains to him that he has to adapt this pose to get airborne. It works, sort of.
 * In a parody sketch on Saturday Night Live, a superhero was chastised by her Super Team for, among other things, failure to assume the "proper" flying position; she flew while standing upright.
 * Averted in Nightman, who uses an anti-gravity belt to fly. He flies in a mostly vertical pose (sometimes at a 45-degree angle).
 * The Ninja Megafalconzord from Mighty Morphin Power Rangers.
 * Kamen Rider Skyrider

Video Games

 * Super Mario Galaxy. The flight power from the Red Stars seems to be centered in Mario's hands, and he needs to hold them outward to fly or hover.
 * Of course, arms-out is his standard flight pose in games with flight power-ups.
 * One theory is that this is because one-arm-up is already taken for his jumping pose, and his arms are too stubby to look aerodynamic or cool if he holds them both over his head.
 * When City of Heroes added flight poses, one was the classical one knee bent one first forward Up, Up, and Away pose, and another was the both hands forward "high dive" one.

Web Comics

 * This page in Cheshire Crossing, with flying monkeys. And two pages later, with the same monkeys and Wendy.
 * In Schlock Mercenary, Sergeant Schlock goes so far as to grow a third arm to look cool in this strip.
 * In El Goonish Shive, while Nanase never felt the need to assume this pose while flying, Elliot certainly did. It may have had something to do with the Superhero spell.
 * Axe Cop has a variation on this: in order to fly, he has to clench one hand and leave the other open. According to Word of God, this is because some superheroes fly with closed hands and some fly with open ones, so Axe Cop does both at once.

Web Original

 * Parody superhero blog 'Sliced Bread 2' devotes some thought to flying poses here. Among the types he identifies are 'classic superman', 'I'm an airplane' and 'braced on barstools'.
 * In "Ayla and the Tests" of the Whateley Universe, Phase (after a couple months of having powers) is ''still' learning how to fly without having serious steering and angular momentum problems. He gets major grief from some other students because he's seen flying in the 'supergirl' posture.
 * In keeping with the series' love for metahumor, at one point Generator tries out several different flying poses, including the two-fisted "Superman" style and the one-arm-forward "Supergirl" posture.

Western Animation

 * Optimus Primal did this a lot in the first season of Beast Wars, before he got proper flight modes.
 * Season three had his flight mode stuck in the "both arms forward" position, replacing his head with G1 Prime's spark cockpit.
 * Western Animation/Freakazoid subverts this. He attempts this pose, but gets told "Freakazoid, you can't fly!" This is followed by Freakazoid running around (often completely aimlessly) with both arms stretched over his head and making "whoosh" sounds to simulate flying anyway.
 * The Powerpuff Girls
 * Danny from Danny Phantom who does it often. The same rule applies to his Opposite Sex Clone and the Big Bad. Not a lot of ghost baddies do this though, must be more of a hero thing.
 * Or a half-human thing.
 * Word Girl uses this constantly.
 * In Ren and Stimpy, Powdered Toast Man inverts the trope by flying backwards in the pose. At least once, he did it while upright.
 * The title character of Captain Planet and the Planeteers does this, as shown in the image provided.
 * Even though they're miniature winged horses rather than humanoids, pegasus ponies (usually Rainbow Dash) in My Little Pony Friendship Is Magic often do this when flying fast.
 * In the first Legion of Super Heroes animated episode, the novice Clark Kent is brought to the future. As he has been keeping everything under wraps, he hasn't flown yet -- but the Legion needs him at full capacity. He spends most of the episode careening about and crashing -- until Brainiac 5 tells him to adopt the traditional pose -- for aerodynamic reasons. It takes him a while to get the hang of it, though. And his own flight ring.

Real Life

 * This pose (more or less) is briefly assumed at the end of the recovery phase of swimming the butterfly stroke, which is coincidentally sometimes called "fly" for short.
 * In the sixties, some ski jumpers used to use a pose rather like this in the air.