"Mayday" is the internationally agreed code, so that's one reason to use that - but US accident investigators also noticed a pattern that American pilots are often too reluctant to declare emergency status when it's appropriate as it is here, because they feel it's "not that bad" yet. Having them say it's an emergency without saying "Mayday" is good enough and might mean a few more cases that should have been emergencies are declared as such.
I might look for the link later, but there's an incident with a Youtube reconstruction where a private pilot is nearly out of fuel, the weather is poor, and he's approaching a USAF base en route to his last hope landing site. Airbases are military facilities, closed to civilian traffic. He asks the controller if he can land there. She says he can't... unless it's an emergency.
He should say "Yes, this is an emergency, I'm on fumes here and the weather is much worse than I expected". She'd turn on the airfield's powerful landing lights, and maybe he'd spend the evening explaining his screw up and apologising to a base commander or at worst spend the night in a cell. Nobody dies. Instead he pressed on, and his dire situation only became clear to her when it was too late and he was already doomed.
Listening to the audio, the pilot first says, "We've experienced an engine failure, need a turn." ATC does not respond, so he calls again and says "Mayday" in order to unequivocally get their attention.
There are actually two different emergency calls. There is "mayday", and there is "pan-pan", which is a less urgent version of "mayday", but that is hardly ever used.
I landed on a private runway due to bad weather. I saw it was private on the chart but seriously did not care.
It was over a mile long and had landing lights. It was owned by some Texas billionaire brothers who kept their jet there. The people there were actually super nice and loaned us a car to get lunch.
Experienced pilots don't mind calling mayday, but:
1) Often ATC will ask you a lot of distracting questions. It starts with what the problem is and how many souls are on board, but can be lengthy and doesn't solve your problem.
If you listen to the Sully Hudson flight, you can hear how terse Sully is to avoid a conversation with ATC while he's busy flying.
2) You may be asked for a written letter afterwards, or an investigation may start. Your airline would be interested.
3) ATC is not responsible for your plane, and cannot fly it for you. Most ATC don't even have an airplane rating.
Pilots have a "get out of jail free card" by filing a NASA report for non-intentional violations. You can search that database.
I filed one once when I was flying an old rental with sketchy navigation equipment into Class B just in case the gauges were out of tolerance.
I might look for the link later, but there's an incident with a Youtube reconstruction where a private pilot is nearly out of fuel, the weather is poor, and he's approaching a USAF base en route to his last hope landing site. Airbases are military facilities, closed to civilian traffic. He asks the controller if he can land there. She says he can't... unless it's an emergency.
He should say "Yes, this is an emergency, I'm on fumes here and the weather is much worse than I expected". She'd turn on the airfield's powerful landing lights, and maybe he'd spend the evening explaining his screw up and apologising to a base commander or at worst spend the night in a cell. Nobody dies. Instead he pressed on, and his dire situation only became clear to her when it was too late and he was already doomed.