What kind of power adaptor on airplanes?

[Longhorn]

I'd like to bring my laptop on an upcoming trip and the battery won't last very long. I understand many planes have power connections for outlets but does it require a special kind of adaptor or can I use my AC adaptor? Thanks!

[Berserker]

1. I just flew Sun Country

and now I know what a sardine feels like. I did not see any adapters but then again if you are 2 feet tall and weigh 60lbs you may be able to wiggle around and find something on the armrest.

[Osamasux]

2. It won't help you on a plane, but the Amtrak Acela

has regular 120v outlets at every window seat. Another reason I prefer it to air travel when it's an option.