ultrasonic cleaning for disk heads

I thoroughly enjoyed Marc's video of the head cleaning. Some dumb questions from a guy who has not yet experienced his first head crash on a removable-pack hard drive: When it happens, am I correct in assuming that the pack is toast, and should never be loaded again? My removable-pack drives are DEC RL02 drives and a Data General drive with one removable and one fixed platter, using cartridges of the same style as the RL02. The DG drive has a glass encoder, so I presume that it requires realignment after removing the heads for cleaning. I might have acquired an alignment pack for it already. But since the RL02 drives use servo bursts on the media, do they require realignment after removing and replacing the heads? -- Mark J. Blair, NF6X <nf6x at nf6x.net> http://www.nf6x.net/