FAA AC 33-7:2009
FAA AC 33-7:2009 Guidance For 30-second And 2-minute One-engine-inoperative (oei) Ratings For Rotorcraft Turbine Engines Gives guidance and acceptable means, but not the only means, for demonstrating compliance with the specific requirements applicable to 30-second and 2-minute One-Engine-Inoperative (OEI) rotorcraft tu