Common errors in English: Usage of As usual.

 As Usual

Incorrect: As usually, he arrived late. 

Correct : As usual, he arrived late.

Note: The phrase "as usual" means "as is usual/common or has happened before” “As usually' is not a phrase at all. We can, however, use only "usually” to mean "in most cases” or "generally”. 

For example:

I usually go to bed at 11 o'clock.