This has been kicking around in my drafts folder for a while and an entry on a new-to-me blog gives me reason to finish it. If there is more than one pilot assigned to a flight, one of them is designated pilot-in-command. As pilot-in-command you are given latitude to make decisions. That's what it's about. There is air law to follow, plus you are given a number of manuals and data to help you make those decisions, but most of them, even the laws, give considerable latitude for a pilot to do what is safe in a particular case.
It's not so much that you are required to follow every manual. It's that you are required to not screw up. You can find justification for almost any action in the manual, but so can the company find condemnation. I can honestly never think of an occasion where a colleague got in trouble for violating a rule when no harm (i.e. regulatory action, aircraft damage, complaint, or harm to public image) was done. Right up until it isn't done well, pilots get praised for their ability to land in stiff crosswinds. That's getting the job done.
That's why the captain is paid significantly more than the FO. The captain is the one who approves or vetoes such a decision, whether she is the one at the controls or not. As PIC you know that if you go off the end of the runway, chew up the props, run out of fuel, damage something with jet blast, blow a tire, ding a wingtip, incur a noise complaint, arrive late, divert, or annoy a customer, questions will be asked. If there's an accident, the relevant authorities will go over everything you did with reference to the laws, the SOPs, the AFM, the FDR, the CVR, the instructions given by ATC, the weather, the NOTAMs, the charts and every other recording and piece of paper they can find. And if they find a recommendation or a policy or a memo that you were not following to the letter, you are screwed.
If something beyond your control goes spectacularly wrong, like the gear lever has been moved to the down position, but one of the wheels won't lock down, you're not blamed specifically for that, although you might be accused of not spotting some damage on the preflight inspection.
I can't remember where I grabbed this exchange from. A movie? A TV show?
"You think you have all the answers."
"I'm the captain. That's my job."
Often I think the first officer's job is even harder, and this story (told on someone else's blog) illustrates that well. Of course Sulako beat me to the punch, but I still wanted to link to it. The story was originally on her personal blog and the traffic from here was more than she wanted, so I've taken out the link. See her medevac stories here. Ensuring a safe flight is the responsibility of both pilots, but the no-go decision is harder for the FO. If the FO wants to go, but the captain says "we're not continuing, the ice is too bad," the FO can say, "oh, I didn't think it was that bad," or even "you're a chicken," (with a smile) but has no reason to argue. The FO might be a bit embarrassed and vow to be more diligent at checking the weather next time. But no one really loses face.
Now let it be the captain who wants to go when the FO says the conditions are not suitable. The FO may have to fight for her life to alter that decision. Had there been passengers and injury or death involved in this flight, as there have been in so many before and after it, Dagny would probably have been exonerated. She repeatedly and strenuously objected to the captain's decisions, and finally did override them. But many first officers who have been placed in that position have no descendants. I hope Dagny gets to tell this story to her kids, to teach them to stand up for what they believe in.
Oh and a straw poll: I say "Pee Eye See" but I've heard people refer to "pick-time" in their logbooks. If you are a pilot, please tell me how you pronounce PIC.