De acordo com o SeatGuru , é 110VAC :
In seats equipped with AC Power, all you'll need is the standard wall power brick that came with your laptop or other electrical device. The power on the plane is typically 110V AC and features a semi-universal receptacle that accepts the following types of plugs: US non-polarized 2-blade plug (both blades are the same size) US polarized 2-blade plug (one blade is bigger than the other) US non-polarized 2-blade plug with Ground (aka three-prong) European standard 2-cylindrical prong plug (two round prongs)
Também foi encontrada uma discussão sobre o assunto em flyertalk.com .