grammar explanation please

[Roskyposky]

What is the difference between these two expressions:

It needs no pilot.

It doesn't need a pilot

I would like to know a grammatical explanation, when do you use the first and when the second one. I understand there i s no difference in meaning, but I would like to know why one or the other.
Thank you very much.

[Tdol]

The first could be used to add greater emphasis on the fact- in speech, you could stress 'no' to do this.