John, I may be able to find someone who can dig that up. Depends on who retired recently.
The lore in the SH-2F (passed down to us newbies in the early 80's) was that one crew lost the oil in the combining gear box and headed back to their little frigate, at the NATOPS recommended power setting. About 30 minutes later they landed and shut down, so there was one data point that it might work for 30 minutes based on an event. But NATOPS was still all about "get it out of the sky" as the rule.