Wow - EVERYONE needs to slow down on this one.
First and foremost, for the legal side of things there can only be one Pilot-in-Command during a flight. Period. Got it?
Pilot-in-Command under supervision (PICUS) is a
Training Event during which time the
First Officer may log Pilot-in-Command time so long as they meet certain minimum requirements as outlined in the regulations and the Company Operations Manual.
PICUS does not denote who is
legally in charge of the aircraft. Although the First Officer must
operationally make all the decisions, they do not hold the licence and are therefore
not legally the pilot in command of a Transport Category aircraft. They are, however able to log the time as Pilot-in-Command as it is considered
training. The actual Pilot-in-Command is also able to log, Pilot-in-Command time.
Here are the requirements as it applies to a specific airline in Canada:
1. PICUS may be aquired from the co-pilots seat provided all the PIC functions described below can be performed from that seat, otherwise a minimum of 10 hours under PICUS must be conducted from the Pilot-in-Command seat:
a) With the exception of taxiing, at least all the flight functions of a PIC including flight planning, take-off, enroute flying, approach and landing; and
b) A minimum of one take-off and one landing for each ten hours of flight time; and
c) no passengers may be on board during thep portion of flight time aquired in the Pilot-in-Command seat.
2. The conditions for PICUS applicants are as follows:
a) the applicant holds a CPL with multi-engine rating and a Group 1 Instrument Rating;
b) Has already accumulated 150 hours PIC;
c) Has accumulated a minimum of 100 hours dual flight time in aeroplanes;
d) Has accumulated a minimum of 2,100 hours in aeroplanes;
e) Has passed all ATPL examinations.
3. The applicant who meets those conditions are credited with:
a) Not more than 50% of the flight time to a maximum of 100 hours acquired under PICUS;
b) all flight time must be acquired within 12 months preceeding the date of application for the ATPL.
There are some additional references to who the training pilot can be, some paperwork stuff and other "non-essential to the discussion" information, but I'll leave that all out.
Suffice it to say that you just don't go ahead and log PICUS - you have to be approved in your COM, the Training Pilot has to be approved by the operator and the Pilot has to complete paperwork much the same as your initial Line Indoc, you can only log so much, and the aircraft has to be able to perform almost all the tasks from the right seat as from the left and if you're doing it from the left, you cant have people in the back.
You do have to make a notation in the "REMARKS" Section of your personal log too that shows it as PICUS, e.g YYZ-YOW-YUL-YYZ (PICUS). That way they know that when you have written in 3.0, they are only counting 1.5 (and if you write in 1.5 they are going to doc that down by 1/2 so always put in the full amount UNLESS STATED OTHERWISE IN THE COM).
I hope this all helps.