First of all, just so as the 'enthusiasts' don't keep clouding the thread, could we use the correct definitions here. Every two crew flight has to have a designated COMMANDER (CMDR). Usually that is the highest ranking pilot, the CAPTAIN (CPT). The FIRST OFFICER or SENIOR FIRST OFFICER (FO or SFO) is usually second in command (although some cabin crew seniors would love to dispute this
) The CAPTAIN usually sits in the left hand seat (LHS) but doesn't have to. If it's a TRAINING CAPTAIN (not a captain under training) they may sit in the right hand seat (RHS) with an FO who may be upgrading to CPT for example.
In theory, you don't need a CPT on a flight. You could have two FO's as long as one was designated COMMANDER but not likely. So to clarify for the 'enthusiasts', you need two pilots, usually a CPT and an FO with the CPT being in COMMAND. What often confuses some people who are not in the business is that you also have other designations for the roles the pilots have. EITHER pilot will usually take turns it handling the aircraft and is designated 'pilot flying' or 'handling pilot' (PF or HP). The other pilot will assume the 'pilot not flying' or non-handling pilot' (PNF or NHP) role which covers other things like the radio, paperwork etc.
So, the COMMANDER (the or a) CAPTAIN usually sits in the LHS and could be PF or PNF. The SECOND IN COMMAND (an FO or another CAPTAIN) usually sits in the RHS and will either be PF or PNF. In the UK for example, the COMMANDER logs all flight time whether PF or PNF as P1. The SECOND IN COMMAND logs PF time as P1u/s (under supervision) and PNF time as P2. Clear as mud eh?
In the scenarios quoted above, some or all LINE CAPTAINS are checked out in the simulator every six months to operate from the right hand seat (RHS). They have to demonstrate that they can fly a circuit with an engine failure at take-off (EFATO), an approach, go-around and another approach to a landing... successfully. To suggest that these CPT's that occasionally fly in the RHS are dangerous is probably an exaggeration but they certainly aren't proficient. Throw in any number of complications and the situation could turn nastier than most would like. It is just lining up a few more slices of the swiss cheese.
It is of course a sign of poor management if a company is paying SECOND IN COMMANDS a CAPTAINS salary. It is much more profitable if the company employed enough FIRST OFFICERS, usually at around two thirds to a half the salary of CAPTAINS. Most companies employ FIRST OFFICERS with the idea that they are future captains in training. Of course, if they forget to remind themselves of this and keep employing direct entry captains then the first officers tend to get fed up and look for employment elsewhere.
Having two CAPTAINS on the flight deck for normal, non-training, line flying is not ideal and can be the cause of CRM issues. Also, the CAPTAINS acting as SECOND IN COMMAND have to log their PNF time as P2 (assuming it really bothers them at this stage) and any PF time as P1u/s, assuming that the company allows CAPTAINS in the RHS to actually be PF!
So, in conclusion, it's not illegal to have two LINE CAPTAINS as crew. It's not even unsafe unless things start to go wrong. It just means that less slices of the swiss cheese need to be lined up for an accident to happen. If it only happens occasionally then it's no big deal but if it starts to happen regularly then it is a sign of bad management, poor beancounting and the airlines Flight Ops Inspector should be keeping a close eye on things.
Maybe a sign of the times that there really is a shortage of qualified and experienced pilots and the worm can turn on the beancounters.
