JAR Ops Requirements
Just for your interest this is what JAR Ops says about operating from either seat.
Appendix 1 to JAR–OPS 1.968
Pilot qualification to operate in either pilot’s
seat
(a) Commanders whose duties also require
them to operate in the right-hand seat and carry out
the duties of co-pilot, or commanders required to
conduct training or examining duties from the righthand
seat, shall complete additional training and
checking as specified in the Operations Manual,
concurrent with the operator proficiency checks
prescribed in JAR–OPS 1.965(b). This additional
training must include at least the following:
(1) An engine failure during take-off;
(2) A one engine inoperative approach
and go-around; and
(3) A one engine inoperative landing.
(b) When engine-out manoeuvres are carried
out in an aeroplane, the engine failure must be
simulated.
(c) When operating in the right-hand seat, the
checks required by JAR–OPS for operating in the
left-hand seat must, in addition, be valid and current.
(d) A pilot relieving the commander shall have
demonstrated, concurrent with the operator
proficiency checks prescribed in JAR-OPS 1.965(b),
practice of drills and procedures which would not,
normally, be the relieving pilot’s responsibility.
Where the differences between left and right seats
are not significant (for example because of use of
autopilot) then practice may be conducted in either
seat.
(e) A pilot other than the commander
occupying the left-hand seat shall demonstrate
practice of drills and procedures, concurrent with the
operator proficiency checks prescribed in JAR–OPS
1.965(b), which would otherwise have been the
commander’s responsibility acting as pilot nonflying.
Where the differences between left and right
seats are not significant (for example because of use
of autopilot) then practice may be conducted in
either seat.
[Ch. 1, 01.03.98]
Normal practice is that only Training Captains would fly in both seats as the Licence Skill Test (LST) and Licence Proficiency Check (LPC) is carried out in the simulator in the LHS or RHS. To operate from both seats requires a further check in the RHS if the bulk of the LPC was completed in the LHS.
That said there is nothing to prohibit any Captain or F/O being qualified to operate from both seats providing the JAR and approved training is completed. Normally up to the company with the agreement of the Authority.
As to logging flight hours, time spent as P1 where the individual is 'The sole manipulator of the flight controls' may be recorded as P1C even though the pilot was not the aircraft commander as recorded in the documentation.
Also, if the type rating qualification is in Part 1 of the licence i.e. recorded as P1 as opposed to P2, all flying could be claimed as P1 from either seat.
All a bit wooly.