To add on to this answer (which is correct):
Your “of” can also just be a regular file if that’s easier to work with vs needing to create a new partition for the copy.
I’ll also say you might want to use the block size parameter “bs=” on “dd” to speed things up, especially if you are using fast storage. Using “dd” with “bs=1G” will speed things up tremendously if you have at least >1GB of RAM.
IIRC Alaska Airlines knew the plane had issues and decided to keep flying it anyway.
So yes, it’s Boeing’s fault the plane’s door blew off, but Alaska Airlines also deserves blame for continuing to fly a plane that was reporting issues with the door hatch.