Which of the following is a common indication of low oil pressure in a helicopter?

A red warning light on the instrument panel is a crucial indication of low oil pressure in a helicopter. This warning light is part of the aircraft's system designed to alert the pilot to potentially hazardous conditions. When the oil pressure falls below the normal operating range, a warning light activates to draw the pilot's attention, signifying that immediate action may be required to address the issue.

Low oil pressure can lead to inadequate lubrication, which may cause engine damage or failure if not addressed promptly. Therefore, recognizing this warning light is vital for the safety of the flight and the well-being of the aircraft.

While increased engine noise, fluctuating RPM, and a low fuel warning light may indicate issues requiring attention, they are not specific indicators of low oil pressure. Increased engine noise might suggest other mechanical problems, fluctuating RPM can relate to various operating conditions, and the low fuel warning light addresses fuel levels rather than oil pressure. Thus, monitoring the red warning light is specifically critical for oil pressure awareness.