DFC,
You don't need an instructor on board when doing your 3 landings in 90 days, and you don't need one one when doing your 6 approaches in 6 months.
Unless the pilot considers it necessary.
One can tell from these threads the people who are the product of a nanny state, and those who aren't.
Keef, read the FAQ kindly posted by bookworm, what do you think?