The joys of unintended consequences...
I asked someone who knows how low fuel MAYDAYS on calculated less than 30 minutes FFR work in first world aviation nations. That person’s response:
Yes this is the case. So this creates the very real situation that when you arrive at Destination with let’s say 45min in the tank and you are told that you are required to take up the hold for 20min you, as required by the law, declare a MAYDAY and advise ATC that you will be landing with less than 30min in the tanks. ATC then acknowledge your MAYDAY and reorder the stack so that you are No 1 to land. Having now been vectored straight for the approach the Flight Management Computer tells you you are going to land with 44min of fuel so you advise ATC that you are no longer critical fuel and are retracting the MAYDAY.
Now obviously any ‘free thinking’ culture could deal with this, but certain other ‘remain within the box’ thinking cultures, having retracted the MAYDAY, you are no longer entitled to priority and so ATC, to vastly reduce their workload, will slot you back into the ‘flow’ they had spent their entire shift setting up and your MAYDAY was about to ruin. So back to the holding pattern you are sent… Repeat. [Lead Balloon comment: Note that this highlights the silliness of deeming something to be an emergency when it’s not.]
So for these ‘situations’ we were instructed that once a MAYDAY was declared it was not to be retracted. Seems simple enough, except for the fact that when a MAYDAY is declared all sorts of services (fire, ambulance, hospital…) are mobilised which are definitely not needed [Lead Balloon comment: Note that this highlights the silliness of deeming something to be an emergency when it’s not.]; which is why once the aircraft is vectored direct that the MAYDAY be retracted so the free thinking nations can justify why the[y] didn’t mobilise these services in the first place; because you declared a ‘Fuel MAYDAY’ and provided them enough information that they realised that once they vector you direct, the situation would be solved - although plenty of paperwork would need to follow. But, where [Kamarian] isn’t the primary language, and where [Kamarian] isn’t the style of thinking, there is no such thing as a Fuel MAYDAY, there is just a MAYDAY.
In the case of [specified country], it was known that certain operators declared MAYDAY to regain lost time. [Lead Balloon comment: Unintended consequences always flow from ‘good idea’ rules.] For this reason, if you declared a MAYDAY and the reason was you were going to land with less than Critical Fuel, then an official was going to come on board and double check that you really did land with less than or very close to 30 min of fuel. This then meant you were basically forced to enter the hold and wait until you are down to 35ish min of fuel before declaring the MAYDAY. And people wonder why planes crash more frequently in [specified country].