For sure, I think in an English speaking country you would probably get your point across. They would most likely come back with asking for confirmation that you are declaring 'mayday', but you would probably cause varying degrees of confusion in many other countries.

I suppose the aim is to make it absolutely clear as quickly as possible that you want ATC to press the big red button labeled 'crash' which sets off the alarms in the airport fire station and causes other controllers to start diverting flights away and telling planes on approach to go around.

These two podcast episodes about the last major crash at Heathrow are pretty interesting if you want to know what happens in ATC during something like this. The fire appliances were already en route before the plane hit the ground. http://airlinepilotguy.com/adam-spink-and-speedbird-38-part-... http://airlinepilotguy.com/adam-spink-and-speedbird-38-part-...