I've been reading the RFM extract originally posted by HC in April 2005
http://www.pprune.org/rotorheads/365...ml#post6036981
MAIN GEAR BOX OIL SYSTEM FAILURE
Symptom:
MGB OIL PRES or MGB OIL HOT or MGB CHIP or ACC 1 CHIP or ACC 2 CHIP
CAUTION
The main AC generators are cooled by main gearbox oil. Loss of cooling oil may result in mechanical failure of the generators and loss of main electrical power.
Confirming:
Main gearbox oil pressure is less than 35 psi, or
Main gearbox oil temperature is greater than 130 degrees.
Action:
1. Descend to minimum safe altitude.
2. APU - ON
3. APU GEN - ON
4. Land as soon as possible.
If the MGB OIL PRESS warning indicator also illuminates:
1. MGB OIL BYPASS switch - BYPASS
WARNING
BYPASS must be selected within 5 seconds after the warning indicator has illuminated to ensure an adequate quantity of oil remains in the gearbox. DO NOT activate BYPASS if the warning indicator is not illuminated.
2. Land as soon as possible.
If MGB oil pressure continues to decrease or there are loud/unusual noises, unusual vibrations or progressively increasing power required to maintain flight:
3. Land immediately.
It does look a bit more complex then anything similar for the EC & AW products I'm most familiar with. Why the comment about the APU?
It also makes no mention of pressures below 35psi other than continued pressure drops should lead to landing immediately. Was this changed after ther April 2005 near-ditching in Norway?