An aircraft "stall" is a loss of lift "Stalls in fixed-wing flight are often experienced as a sudden reduction in lift"
in other words the wings are not working, even though the engines are. there may be warning horns or sounds in the cockpit
not quite a twin engine, but two minutes of searching 'royalty free sfx engine ' found me http://soundbible.com/3-Lawn-Mower-Cutoff-Sound-.html
loop the first part a couple of times before the cutoff and it could work.