Answer:
It can be repaired with disk utility / recovery algorithms
In UNIX it can be done by scanning
In FAT file scan the FAT looking for free entries
Step-by-step explanation:
When the crash happens, it is not a problem for UNIX and FAT file system
It can be repaired with disk utility/recovery algorithms.
The recovery algorithm is a list of all blocks in all files and takes a compliment as new free file.
In UNIX scanning can be done at all I-nodes.
In FAT file problem cannot occur because there is no free list .If there was any problem than it would have to be done to recover it to scan the FAT looking for free entries.