That is the point. The 3P is going to mess up the No Flap/3ENG/2ENG, they are ONLY exposed to the 3ENG in the FRS, on limited # of hops. The No Flap, 2 ENG and 3 ENG Ditch are all new to them in a fleet squadron. They will make mistakes, and dangerous ones. Specifically, IPs are trained, and the squadron invests the extra time and resources in them, to ensure that they know the safe limits of the aircraft and know what is and more importantly ISN'T recoverable in our aircraft. The P3 is a great aircraft and very forgiving, but there are certain regimes of flight, especially slow approaching stall in our aircraft that very bad things can happen. Reference the SIR from Whidbey a couple years ago when they departed controlled flight and over g'd the aircraft and tore open the wing/broke wing struts, etc.
PPCs have the training to go out, execute EVERY mission in the book, land the plane in every emergency setting, but they do not have the qualification yet to teach the emergencies in the aircraft to the upgrading 3p/2p. We as a community let them gain experience as a PPC, running a crew, exposure to the crazy stuff junior pilots do, and then based upon their performance in the aircraft (good stick?, qual early, would he/she make a good IP), then the squadron invests the time/energy into making them an IP. On the backside they become a much better pilot and asset to the squadron. Senior PPCs can elect to let a junior pilot land an emergency, let's say a chips light, etc. But ultimately, the PPC signed for the aircraft and it is his responsibility to bring the aircraft home safely.
You also have to understand that our community has had a decade of hours reductions, and this is the point we are at. We used to routinely let 2Ps sign for the aircraft and go on DFWs. Now we barely have enough hours and aircraft available to meet the mins for our PPCs. During my first tour we had PPCs leaving with 1800 hours, now they are lucky to leave with 1100.
John