After 15 minutes in the hover with that main tank fuel now unusable LOW FUEL 1 light comes on, followed by LOW FUEL 2 four minutes later. If those captions were missed then a further 8 minutes later Engine 1 quits, followed by engine 2 after a further four minutes.
The "GONG" every 3 seconds might get your attention hopefully.
P.S. I wrote your first quoted post in 2004.