Helicopter pilots: Are you there? Watch out for this and get involved - AIN Alerts

AgustaWestland, EASA Explore Safe Reject Approach

AgustaWestland and EASA are discussing a new approach to the height-velocity (H-V) diagram for multi-engine helicopters, proposing to replace it with “safe reject” indications. They advocate adopting the idea of “fly away” in case of engine failure to make the most of the helicopter’s performance rather than relying on a diagram that shows operators what not to do. With the fly-away maneuver, the pilot determines a flightpath that keeps the aircraft clear of obstacles. Bernardino Paggi, an AgustaWestland expert in flight-test methodologies, identified this common misconception: “If I fly outside the H-V area, I am always safe.” In fact, he said, a rejected takeoff from the takeoff corridor might result in the helicopter hitting an obstacle. Paggi said H-V envelopes are demonstrated on only one type of surface (usually a runway) and cannot be applied to all surfaces from which a helicopter can be operated. To guarantee actual one-engine inoperative (OEI) capability, AgustaWestland proposes that the regulation clearly require a statement of applicability, such as, “This level of performance can be achieved only over this specific surface.” Paggi also suggested that the VTOSS (takeoff safety speed) concept should replace climb-out speed. “Safe vertical rejects and hover-out-of-ground-effect fly-away performance provide a safer and operation-oriented envelope,” compared with the existing “no-fly zone,” he added.