The TIE/Ae was originally envisioned by Imperial Engineers as a solution to the poor performance of their basic TIE/In starfighter in atmospheres. They produced and used the ship occasionally, but it was dumped when the Empire began retreating and the cost was not deemed necessary.
Eventually Astragon got a hold of it, and it was one of the few craft they did not modify in any way. Like the original TIE/In, the cockpit was spherical, with two chin-mounted laser cannons. The wing struts and solar arrays were bent like the wings of a TIE Vanguard, only to a greater extent. The ion engines were slightly modified to work better in airspace than in space, so their improved planetary performance did come at some cost. Unlike the normal TIE, it also had shields.
Unlike the original TIE, which relied on cieling racks, the TIE/Ae could land on conventional landing pads due to reinforced wing struts. Despite the lesser ability of its ion engines in space, it could still fly from an orbiting ship to its target planet easily.