Read your existing BRMS recovery reports. They will probably tell you how
to do it even if the tape drive is not an alternate IPL device. Remember,
this early part of the recovery is probably not BRMS specific because,
well, in a bare metal recovery you do not have BRMS loaded yet.
It may not be an alternate IPL device, but it probably is an alternate
installation device. There are ways to 'flag' a device as one of them and
you may want to check that out. I forget if you have an HMC or not.