Max airspeed limit with a single engine inoperative.

Max airspeed limit with a single engine inoperative.

• A. 145 knots
• B. 120 knots
• C. 130 knots
• D. 100 knots

Answer: (C)

When one engine is inoperative, the helicopter has far less available power and a tighter safety margin for rotor RPM and control authority. To ensure you can maintain rotor speed with the remaining engine and still have enough tail rotor effectiveness to control yaw, a maximum airspeed is set in the flight envelope. For the UH-60, that OEI limit is 130 knots. Pushing beyond this speed reduces the margin for maintaining rotor RPM and control, increasing the risk of loss of control or inability to recover from an engine-out situation. The other speeds are either below the published limit or exceed what the aircraft is certified to safely handle OEI, which is why 130 knots is the correct maximum.

When one engine is inoperative, the helicopter has far less available power and a tighter safety margin for rotor RPM and control authority. To ensure you can maintain rotor speed with the remaining engine and still have enough tail rotor effectiveness to control yaw, a maximum airspeed is set in the flight envelope. For the UH-60, that OEI limit is 130 knots. Pushing beyond this speed reduces the margin for maintaining rotor RPM and control, increasing the risk of loss of control or inability to recover from an engine-out situation. The other speeds are either below the published limit or exceed what the aircraft is certified to safely handle OEI, which is why 130 knots is the correct maximum.