S-92 MRGB "run-dry" time....
maxwelg2,
The MRGB in the S-92, like all other FAA certified rotorcraft MRGB's, is qualified for operating in a 30 minute loss of lube condition while maintaining power levels sufficient for level flight. Thus the pilot has a 30 minute period after the HUMS gives an indication of loss of lube circuit pressure, in which to continue at level flight and/or perform an emergency landing. So that should not be a concern to you.
Regards,
riff_raff