CFII instructor as passenger (FAA)

There is nothing in the FAR's that says an instructional flight or flight
instruction must begin and or end on the ground.

If you are legal to operate as PIC and current to carry passengers, your
CFII can obviously just be a passenger. At some time he can also pull out
the foggles and say "here, put these on and we'll do a little IFR "training"
on the way." Then you can pull them off and say "that's enough". Or he may
say, "just leave them on and I'll be your safety pilot, no more grilling and
harping on you." Or any number of scenarios.... "fly me to the practice area
and we'll work on maneuvers"... Just because an instructor is in an
airplane doesn't mean he is acting as an instructor, he may be acting as a
passenger, or as a safety pilot, switching roles as needed. I do believe
that as a professional CFII, he should be alert and ever conscious of the
progress and safety of the flight, willing and able to assist the "student"
if needed.

Jim