Case is not sensitive with that. AFAIK, kismet uses an upper ioctl to place the card into RFMON and creates a new VAP interface. If you have the entire aircrack-ng suite, you could just use airmon-ng to do this for you - which will issue via iw* with "intelligent" driver tracing.
ERROR: Neither the sysfs interface links nor the iw command is available. Please download and install iw from http://wireless.kernel.org/download/iw/iw-0.9.17.tar.bz2