Though Ryanair could well be heading down this route [1]

[1] http://www.independent.ie/irish-news/three-ryanair-mayday-ca...

The only exception that airlines will sometimes do is to juggle around destination and alternate airports so that they can save some fuel on that (you have to have enough fuel to reach an alternate airport, and then 45 minutes in addition to that).

I also spend significant time on aviation/pilot forums, and I've literally never heard of "lots of paperwork" for any emergency that resulted in a safe, no injuries landing. The topic comes up regularly in the "should I have declared an emergency or not?" discussions, the common argument against is "I don't want the paperwork" (a strange trade off against a life-safety question in any case), and the most I've heard as routine followup is a phone call from an inspector.

My experience is exclusively US, so perhaps it's different in other areas of the world.

The only issue I've ever caused was triggering a TCAS warning for a landing airplane because I was slow on starting a turn. Even though there were VFR conditions and we were at a safe dinstance, the other pilots said they had to report it as a matter of company policy, and my instructor had to make a few phone calls afterwards.

> At least two memorandums were sent to Ryanair pilots detailing the company's concern about what was described as "excess fuel explanations" -- a description of the reasons flight commanders have to give if they take on extra fuel over the recommended minimum fuel load.

Is "because it's only the minimum!" not a valid answer?

It was a "mayday" because they didn't have enough fuel to return to the original airport they were going to land at and/or to continue waiting in a holding pattern for another hour.

But think of a a hypothetical situation where low fuel situations somehow were common, unforeseeable and unavoidable. And if dropping a passenger could indeed make a difference between full crash or safe landing. It's a shitty situation, but it makes sense to give somebody a chute and kick them out, instead of letting all die.

But critically low memory situations aren't unavoidable. Not overallocating is one very easy solution.

Sometimes is pretty much all of the time. My SO works as cabin crew for one of the large airlines you will have heard of, and they typically always overcommit. It isn't just because they are greedy and want lots of money though (well I guess it kind of is). As you said, they know some people won't turn up, but also they may decide to change the class of the airline (economy and business -> economy, business and first) depending on how people book or what aircraft are available on the day.

United is infamous for this, prompting a sound piece of advice: if for some reason you're in first class on a flight scheduled for an A320, don't take a seat in row 3, since odds are high it'll be swapped to an A319 (which only has two rows in F) day of the flight. In theory there's a pecking order for who gets downgraded in that case (first, anyone who moved up to F on a status upgrade, then the paid F fares starting with whoever was latest to check in), but in practice the gate agent just bumps row 3 and calls it a day.

I think the parent poster was in part referring to operational upgrades (very common at British Airways — they will dramatically oversell the Y cabin and op-up people into J/F as needed), which don't necessarily require an equipment swap.

Another option uniquely available to European carriers that you might not have seen in the U.S. is to adjust the number of J/Y seats in an aircraft: on most intra-Europe flights, the "business-class cabin" is the same seats as the coach cabin, but with a blocked middle seat and a movable divider so you know where Y starts.

(Come to think of it, I guess BA will sometimes swap equipment to a flight with fewer classes of service — for example, the LHR-DME route can lose its lie-flat Club World seats overnight sometimes after unplanned equipment swaps — but I don't think BA does this for yield management, because it's costly to them to have to pay refunds to people they've inconvenienced.)

Certainly not in the current airline environment. Even with a perfectly loaded plane, they only make a little money, and you can't plan for a perfectly loaded plane with any kind of confidence without double-booking.

I phrased what I said poorly. They always allow overcommit, but they try to work it out so that on average they efficiently make use of their seats without constantly having to give people giveaways and bad customer experiences.

http://business.time.com/2013/04/08/air-travel-by-the-pound-...

The problem with translating that approach to OSes is that you can easily deadlock the entire system.

So... a lot like killing a process.