NcFTPd general.cf file configuration
Don't forget to restart NcFTPd after modifying the general.cf file.
The FTP protocol mandates that the transfer type default to ASCII until the client specifies otherwise. Every FTP client program should automatically specify binary on behalf of the end-user, but this option is available if you absolutely must set the default to binary. The only reason to do this is if your server interacts with a broken FTP client program, which the client user will not change or fix.
Note that by changing the default from ASCII, you may break FTP compliant client programs trying to download in ASCII mode, which are right to assume that the default is already ASCII.