There's really no good handheld melee weapon for AIRs. The good ones are built into other parts. If you're getting killed by an Amateus that's not under the influence of Hyper Shot, make some distance and shoot at it. If it hops, ignore it, kill the rest of the stuff, tell your local suicide-Fencer about the hopping ART that's all lonely now that you made swiss cheese of the group. This is assuming you're using a rifle-range weapon. If you're using D/BMGs, Plasma Guns, or other close-mid range weapons, just fly away and wait for an opening. You shouldn't be aiming to engage an Amateus unless it's near-dead anyways. It's on the list of "shit to avoid for AIR units". TBG, DG, Destructor (at a range, less so when you're overhead and it can't get a Sub Weapon lock), Maxis I, Amateus, Albatreos, agressive Lily Rain, anything that moves faster than you while flying...
In ART heavy rooms on small/straightforwards maps, you shouldn't have attacking on the top of your mind. Focus instead on killing and protecting. Fly around your ART lines tearing up LND units that come in. I'd rather encounter a VF on my Lazflamme's gun raids than an AIR unit with a good gun on ANY map. Use your mobility to survey the area; You can take much shorter paths than other bots, so use that extra time checking for raiders and oddly placed heal pits. You should never attack an established ART line unless you know they'll all be neutralized in some fashion before they can respond (not responding at all is best, don't let them even know who just shot that Sturbanger in the ass for half its HP). Only advance when you can go as an ESCORT.
There's no point in risking your neck on an AIR unit. You're not a sturdy bot. As an AIR, you sacrificed your armor for wings. Make the most of them! You can easily survive a whole game if you put your mind to it. You move fast, ignore terrain, mess with cameras, and have a ton of annoying weapons. There's no reason for the average AIR to even be on the same launching level as the enemies. Pick your targets, you can afford to with that huge boost guage.