Thrust wants you to know he's coming. (Let's ignore the double-double entendre that comes from that.) The other Decepticons have learned there's no being sneaky when he's around. He's a loud-mouthed braggart who will claim victory before he's even taken the field. He tries to terrify and demoralize the enemy with loud rumbling roars from his engines and boasts from his vocal circuits. The truth is that Thrust is mostly bluster with little to back it up. Any sort of strong resistance can send him flying back the way he came.
His alt-mode is a Modified VTOL F-15 Eagle.