The question of how long the MGB in any helicopter will last without oil is a problem we've all discussed over the years. I once had an ST start puking transmission oil sitting on the deck of a drill ship about 180 miles south of the Louisiana coast. Apparently one of the hydraulic servos became loose and pivoted into the transmission oil cooler line. If you've ever watched the transmission in an ST at idle bounce around because of the elastrometric bearings you know it only takes a few seconds to gouge a nice hole. We lost about 3 gallons of oil in 2-3 minutes.
After shutting down and watching the HLO crew clean up the mess, I was asked what would have happened had we been airborne when this happened. Looking at all the oil on the deck I told them we would have probably had to ditch as the nearest rig was 80 miles to the north. Wouldn't you know it, that comment went up the major oil company chain of command and back down to me. I told them, I was asked and I was straight with the people I fly. Figured it was probably a good thing to have an oil company vp actually have to confront reality, if for only a short while.
Now that I'm in the 92, the same considerations apply. 5psi and above and low and slow with options - fairly quick options. One of the little exercises I think about is how far in front and how far off to the side of that freighter or tanker (one good thing about our area of the Gulf is there are major shipping lanes) do I shoot for in just that situation. I also have a number of platforms that are rated at 17500lbs that are in the FMS just in case.
Afterall its not just the MGB. Tail rotor gear boxes, drive shafts, fires - all kinds of things mean get your ass on the ground.