As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE FLIGHT, THE MAIN ROTOR TRANSMISSION LOW OIL PRESSURE LIGHT ILLUMINATED. AN UNSCHEDULED PRECAUTIONARY LANDING WAS MADE IN AN OPEN FIELD WITHOUT INCIDENT. FOLLOWED HELICOPTER MM TROUBLESHOOTING PROCEDURES AND FOUND THE MAIN ROTOR TRANSMISSION OIL PUMP FAULTY. REPLACED THE MAIN ROTOR TRANSMISSION PUMP WITH A SERVICEABLE UNIT. RETURNED ACFT TO SERVICE.