Bell 407 xmsn oil pressure fluctuation
Am experiencing an xmsn oil pressure fluctuation which I have not previously observed. Begins about 5 minutes into the flight and varies between about 40 psi and 60 psi (always in the green) , and cycles this way about once per second. Until recently oil pressure has been steady at about 55 psi at all times in flight. This fluctuation continues on the ground after a flight while at 100% RPM, but is not visible at ground idle. Wondering of anyone has guidance on the cause and significance of this?
I have been told by more than one experienced individual that the transmission on this helicopter will run for an entire tank of fuel after a loss of all oil before seizing. Cant seem to get any "official" confirmation of this. May be true, may be urban myth. Any thoughts?