I've heard of a small low coast operator doing this somewhere in E-europe.I guess the reason it's a shortage of F/O in that particular area,and the availability of retired captains,age 55 or bellow.
Regarding CRM and safety,my opinion,I wouldn't allow this type of operation on a normal operation.
Although it may seem safer to have two experienced captains on the flight deck,actually it can be only one PIC.
Even CRM says that all decisions must be taken after analyzing all infos and opinions from people involved,but the captain has the final decision call.What if there are two captains?....
And I guess it' not viable economically.The captain salary it's higher than a F/O's,and having 2 capt on the flight deck doesn't mean you'll have less pilots on the fleet.You'll have the same required number of pilots,only more capt to pay.
