Banshee
I'll have one in yellow please
Now we're talking! Personally I'm really looking forward to the future when Bungie has achieved its commendable plan of world domination, and everybody has been issued their own personal Banshee to whoosh around in. Great fun.
Ground targets
When taking out ground targets, you have a couple of options. For maximum safety you can hover a long way off and send in bolts from the fuel rod cannon (perhaps switching to the plasma cannon whilst recharging, if close enough). You may need to move occasionally if a Wraith shot looks threatening. Also beware of Grunts with fuel rod guns; I've underestimated those little devils more often than I care to admit! If you want to feel closer to the action yet still be relatively safe, you can swoop around in tight loops, sending in a bolt each time around. But on Legendary in particular, you really don't want to be low enough to come under fire from ground troops, notably Elites with plasma rifles. Those things hurt!
When using the hovering approach, I generally use thrust-firing to improve my targeting, particularly when a long way off. Just make a brief forwards motion each time you fire, to make the shot straighter and faster. Of course, when using the low tight loop approach, you're automatically using thrust-firing. If a Jackal's plasma ball is heading for you as you hover, you can simply let yourself freefall slightly so the shot goes over the top. The same goes for Hunter blasts and Wraith shots, if you care to hold your nerve.
In tackling a collection of enemy, preferably take out any Shades first as they have the range to damage you. To minimize the amount of fire you take, fly around them until you're ready to send in a shot from the fuel rod cannon. Their fire will usually lag well behind you. Briefly dive in to release the shot, then veer away.
Descent and freefalling
If you want to lose a lot of altitude quickly, freefalling (i.e. no thrust used) is much faster than doing a power dive. Also, the Banshee's pitch makes a difference. The fastest freefalling is in a nose-down or nose-up pitch. Freefalling in level pitch seems to be around 20% slower, while power diving is around 2.6 times slower (based on my testing on PAL Xbox). Freefalling is not quite vertical; there's always a bit of forward movement included.
When freefalling, once you get low enough you can hit the power and pull out of the fall. Or if you wanted to reach the ground, just wait for the impact; it doesn't hurt you or damage the Banshee.
When you're using thrust, the 'A' button causes you to descend almost vertically (there's still some forward movement, as with freefalling). You can potentially use that for landing, but personally I just swoop in, and I have to say that the 'A' button seems redundant.
Anti-Banshee tactics
On foot, it's easy to take out a Banshee with a pistol. On Legendary it takes 23 rounds, on Heroic 20, on Normal 17 and on Easy just 10. Maybe use the zoomed view when it's far off, and maybe use automatic fire when it's not veering about too much. When it dives in on an attacking run, preferably take cover before your shield starts bleeping, then pop back out and resume firing when it angles way. It'll veer off as soon as you become sufficiently obscured.
I quite enjoy taking them down with an assault rifle too. If you want to be efficient with your ammo, wait for it to dive towards you, then fire rapid bursts as it comes in and swoops off. You can bring it down on its first run if you get it right. If you don't mind being more wasteful with ammo, you can also pepper it as it flies about further away. Plenty of bullets will miss, but the few that hit will all add to the damage.
The plasma rifle and plasma pistol can also be used. Actually, it's a nice challenge to see how quickly you can do the job with these weapons in combination. You can do the most damage when it's heading straight for you. Rapid shots from the plasma pistol would do nicely there; pile them into the nose until forced to duck back under cover. When it veers off, you could switch to the plasma rifle and try to continue getting hits, which is where your skill in leading the target and anticipating course changes can make a big difference. Or you could send a 'chaser shot' after it; a plasma ball that chases after the Banshee and homes in, though the pilot may veer away before it catches up. It's great fun delivering the final blow to a smoking Banshee that way. The pilot thinks he's getting away, then the chaser finally catches up and BOOM! Comical stuff, and very satisfying. A chaser shot is best fired when the Banshee is still quite close to you and preferably flying almost directly away. I often make a brief run to line myself up behind it as best I can, then send the shot off using thrust-firing. With it's tremendous range, a plasma pistol is also good for taking down a Banshee on an attack run while it's still distant.
To use the rocket launcher, you'd best let the Banshee come in on an attack run. Once it's heading straight for you, let fly, possibly using the zoomed-in view so you can get it further away. But don't move away too soon else the Banshee may veer off before getting hit. You may take a bit of fire, but hopefully not enough to matter. Rocketing a Banshee when travelling across your line of sight is rather hard even at short range, but you may like to try it just for the challenge. It should be pretty satisfying if you manage to connect.
If you've got a Warthog handy, the chain-gun is likely to make pretty short work of a Banshee of course. If you use it yourself though, you run the risk of getting blasted with a Banshee bolt if you let it come in on a diving run. It would be safer to let a Marine man the gun while you drive around evasively.
Tagging Banshees with plasma grenades is a lot of fun. Takes practice, but it's pretty satisfying when you manage it. You can see a whole lot of this in my Banshee battling movies. A relatively hard type of tag is when the Banshee is curving around and you're having to throw way ahead of it, in an extreme case of leading the target. I call this a curve tag, and there are two examples in BCM26 (clips 12 and 17) plus one in BCM56 at 3:02. Curve tagging is a bit speculative, but as you get a feel for Banshee flight paths and learn how far ahead you need to throw, you can expect your success rate to go up.
Can you shoot the pilot out?
Some parts of the pilot can be seen, notably his feet, so you might be wondering whether you can shoot him out of his machine. But the answer seems to be no. I've made careful attempts at this (e.g. zeroing in with a sniper rifle as the Banshee flies away), and I've had plenty of situations where a Banshee got stuck, enabling me to take my time aiming at all visible parts of him. No success, so I think it's impossible. However, in regard to the two early Banshees in level 2, you could easily be misled into thinking you shot a pilot out, because of something odd which can occur. See my article Departure death anomaly and the associated movie BCM204 (specifically at about 4:37).
Tagged pilots
Sometimes when you're on target with a plasma grenade, the pilot screams, which I long suspected was due to the grenade somehow actually tagging him rather than the Banshee. In BCM65 that theory seemed to be confirmed, as it includes a clip where an angry pilot gets ejected and you can see that he's been tagged. See clip 11 at 2:52. In that example it looks like the grenade sneaks through a slight gap between the fuselage and the back of the canopy. There's another such case in BCM157 at 3:24, where the pilot ends up tagged on the back of a leg.
However, a grenade can also reach the pilot by simply passing straight through the Banshee's exterior! Usually the nose. You'd have to count 'pass-through' as a technical shortcoming in the game; a failure of collision detection. I've seen it many times while battling Banshees in level 2, but it came into especially sharp focus in level 10, where pass-through enables you to snatch the Maw Banshee without overloading. Based on my testing in that situation, it seems like there could actually be something like a 50% chance of pass-through, for throws which target the nose in a fairly ideal way. Surprisingly high!
Ejected pilots
When a Banshee scuffs the ground or other surface and tips over too far (maybe it has to go past vertical, becoming inverted?), the pilot gets ejected (falls out) and then the canopy swings open. Typically this would be due to swirling around after the Banshee or pilot got tagged (tagging the tail or underside or pilot seem to be the best bets for getting a swirl). You can see clips of many such cases in my level 2 Banshee battling movies, but for example there are three in the clifftop location of BCM65 at 2:52, 3:55 and 5:16, and two in the tunnel location of BCM157 at 1:39 and 3:24, where the Banshees were especially prone to knocking against the walls. However, ejection can also simply happen due to clumsy flying, such as seen in BCM60 at 0:44 (flying into a cliff), BCM157 at 4:47 (scraping a tunnel wall), and BCM26 at 3:25 (hitting a rock). In some circumstances you can even cause ejection by making the enemy scrape a wall in pursuit of your own Banshee, as seen in BCM171. Or you can lure it into trouble on foot - which is how you can grab a Banshee at the first bridge of AOTCR!
In cases of ejection where the Banshee hasn't been tagged, it ends up intact. Sadly though, in level 2 you still can't board, as there's no prompt. A real shame, as I'd love to be able to fly around that level. Incidentally, if the pilot got ejected by clumsy flying and survives, he won't try to reboard - or not that I've seen anyway.
I'm not certain that a scuff or jolt is actually needed for pilot ejection. Maybe it can occur merely due to the Banshee being sufficiently far over? Except, I'm not sure it can get to that point, without a knock of some sort. In the 3:55 clip in BCM65, is the pilot out before the Banshee touches the ground? It's not clear (but I think contact has been made by the time of the next frame at least). All I can say for sure is that I've never seen an ejection occur when the Banshee was well away from any surface.
Snuffing or shedding plasma grenades
There were a few freaky occasions in the past when I saw a tagged Banshee fly into the scenery, causing the apparent loss of the plasma grenade, resulting in no explosion. Sometimes the collision even seemed deliberate! For example see BCM56 around 1:58. Later I witnessed situations with a Banshee at ground level where, if I tagged it on the nose, the pilot appeared to deliberately snuff it out by angling the nose into the ground and wiggling the Banshee a bit - which is quite bizarre and comical. You get that with Banshees which have wandered out of their normal territory and acquired 'mad Banshee' behaviour. For example see BCM164 around 0:25 and BCM170 around 4:25. Basically then, it seems that if the grenade is pushed through the scenery, it can get nullified - removed by the game I think.
I've come to call this 'snuffing' because of how it looks, but you could call it shedding if you prefer, because it's not as if the grenade is genuinely being extinguished. Much later on, I realized you can do snuffing in your own Banshee too, which was demonstrated in BCM171 starting around 4:54. Intriguingly though, even when a grenade got snuffed, I still got a greenish flash across the whole screen - presumably for the explosion, though no damage occurred. The flash duration varied, sometimes lasting only a single frame.