FTB has a lot of random crashes (for example, sprinkler on top of a certain pipe - I forget which). Often the solution is to just delete the block. I'm able to do this with MCEdit however because the world file is 2.7GB zipped, the server I host often goes down for the entire day while I download, edit, re-zip, then upload and unzip. Is there a way to remove/set a specific block to air via the console?
You can't actually change the block via the command line, but you don't need to download the whole map in order to edit the block in MCEdit.
Each set of chunks are stored in a separate file, so using a Region Finder you can determine while file you need to download. You can then edit it and re-upload the file to the server.