20 degrees nose down!!!???
I feel a little uncomfortable arguing the toss about a situation that would probably take you somewhat by surprise. The 'seriously nose-down' advocates may find that the level of rotor decay and height loss frustrates the 'fly-away' and the prospect of 'tent-pegging' into the oggin is not a happy one. Arm-chair theorists need to exercise a little caution as the intervention time may be more than you think.
The key as far as I can tell in the sim, (and no I cannot vouch for its fidelity in this respect and we can only look at weights up to 6400kg), is windspeed. If you have 20 knots through the disc you can just about get away with anything by just flying away and keeping the Nr above 92%.
Obviously the more shp you have the better position you are in and the latest generation of twins certainly aim to deliver in that department. It seems however that increasing the shp to make the OEI situation any better will keep pushing the cruise Ng/ITT into the lower/less efficient part of a turbine's operating range and increasing the fuel consumption as a result. Can we make turbines any more efficient in the mid-range? After years of focussing on the top end it may be time to look at this aspect of turbine design.
If a helicopter's primary task is in the HOGE environment then we owe it to the crews to address the issues an OEI situation raises. Exposure can be acceptable for take-off and landing but not - I suggest - during a rescue, during a low-speed search, during anti-submarine operations and any other task we dream up that leaves us languishing in the most hazardous part of the flight envelope.
G.