Now if people are asking about "best practice" then perhaps I shall concede that visual manouvring a heavy jet isn't easy and requires a great deal of care and attention. If you are going to then ensure you and your colleague know what you a are doing - set bottom lines, gates, and communicate.
When I am flying into airfields into the states I personnally decline clearance that ask me to visually "follow" the aircraft ahead. Judging sufficient separation between "heavies" is tough (can you accurately judge 2 or 4nm range to another aircraft?).
But I am not saying that it should become a rule that we don't do it. I am saying that it is outside MY comfort envelope and should a colleague ask to do it I would express my concerns but evaluate each case on its indidual merits (ie carry out a risk analysis).
