AFAIK, the ground power at the airport gate is 208 wye 400 Hz.
See ISO 6858.

For example, the 787 has three 90KVA connections.
http://www.boeing.com/commercial/aeromagazine/articles/qtr_3_08/pdfs/AERO_Q308_article2.pdf
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433