Ubuntu recover bitlockered drive
I had a look at disklocker, but using bdemount seems a lot simpler. You don't need to decrypt anything just unlock and mount as NTFS.
Mount partition with recovery key
Assuming bitlocker partition is 1 on primiry drive, aka sda1, with your recovery key xxxxx-xxxxx etc.
mkdir /tmp/a /tmp/b sudo bdemount -r xxxxxx-xxxxxx-xxxxxx-xxxxxx-xxxxxx-xxxxxx-xxxxxx-xxxxxx /dev/sda1 /tmp/a
This should expose a single raw file bde1 of the full size of partition, /tmp/a/bde1
Mount unlocked contents
Loop mount this raw file read only, giving /tmp/b as the partition contents, (contents of the ntfs filesystem)
sudo mount -o loop,ro /tmp/a/bde1 /tmp/b
Thus you should now have /tmp/b/Windows etc.