"CAA" type environment explains it. Post-war French airlines pioneered the "commander manages flight and first-officer flies" concept successfully - the Brits never caught on. RHS & LHS is a fossilized notion. Doesn't matter where the "commander" sits or whether he is the handling pilot or not. Last time I checked, every multi-engine IFR helicopter has duplicate controls and instrumentation for this very purpose. The AB139 is the first and only aircraft I''ve seen with a Right Seat Only landing and takeoff restriction in the Flight Manual. Hopefully even that is only temporary.
malabo