invasion help. . . again

You could place a teleporter that will only except flying vehicles.
That way they would just teleport back to the covenant base ( or wherever you chose)

 

It is important that the game experience support the cohesion of your story line, so you can come across issues like this. I have a similar problem on the map I am working on. Falcons are used to transport to a beach head staging area for a second phase assault. But what to do with the falcons at the end of phase 1? I tried the gate and agree it is cheesy to see people fall out of the sky to their deaths when they were "successful" at securing the beach head. My solution (thus far) is to allow the spartans to have 4 falcons at the start of the round, and none of them respawn. If they cannot secure the beach head with those, then they are out of luck. And if they can maintain them through out the game, then good for them. In this case, the story line slightly bends for the tools at hand.

When you think about it, it is more natural of a story line to start with X equipment and that is all you get for the rest of the game. To avoid them flying into the elite base, I keep the door narrow. Given the right aesthetics, this works fine for me. And I suspect by the third phase the falcons will be history anyway (or the elites deserve to lose!).

 

Give the Spartan defenders a pair of rockets or better yet a rocket hog. That banshee will go down in no time.
Gauss hogs and lasers work too but don't lock on and can be too overpowering.

 

This could work, you already have a lot of banshies on your map, though falling out of the sky would let you control where elites start in Phase 2 effectively. If you added some neutral banshies between the ones you have now a few people who died could come back too. Just keep the splazor on a really long respawn time. I hope I have been helpful throughout your design process, and don't forget to private message that feedback to me later!

 

I could have sworn I told you about the teleporter thing whilst we were playing and you raised concerns... (btw, to keep it "normal looking" then you can just put it above the hangar, and have a huge bottom on it, I do like big bottoms, I cannot lie...)

If you didn't like that though, then you can also have a class where elites have plasma pistols/there is some on the map. That way, you don't have a hugely powerful weapon on the map (unless you wanted one) yet the banshees are slightly worthless as they can be brought down quickly/stolen.

In testing, I was the one who drove the banshee into the hangar however I found it was not very affective, I would ask why the worry, is it that big of a deal? It was a quirk or me, I didn't mind it at all (even once I became jacked).