Delete Repeating Groups of Rows

This one should be easy!

I have a large spreadsheet which is a composite of 100 text files. Each file has a few lines of information followed by a lot of data. I need to delete those few lines of info so that all of the data is back to back. Last time I was here, it was recommended that I use arrays for such a large file. I'm not really sure how to do this, so I'm asking for help!

I've attached a file containing about the first 1000 lines of my file. The real file is 27,400 lines long. In the attached file, I need to get rid of lines 1 through 17 (it's ok to keep the current, bias, and position headers), then repeat the next time it starts over.

Thanks in advance!