Charge MBP without A/C Socket

[SwaGGeReR]

In a few days I will board an 8-hour flight which has no A/C sockets. However, my seat will be equipped with a USB socket that can charge my iPhone. Is there any way to charge my MBP in this situation?

 

[simsaladimbamba]

Not via USB.
But then there is this, maybe your seat can work with that.