As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON CLIMB FROM KTOL TO KNGU, NR 1 OIL PRESSURE LIGHT CAME ON WITH NORMAL PRESSURE INDICATION. CREW PERFORMED ABNORMAL CHECKLIST. AIRCRAFT LANDED AT KNGU WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED OIL PRESSURE SWITCH IN ACCORDANCE WITH THE DOUGLAS AIRCRAFT MAINTENANCE MANUEL. OIL FILTER INSPECTED OK. RAN NR 1 ENGINE PER ATI ENGINE RUN HANDBOOK. OPERATIONAL AND LEAK CHECKS GOOD. AIRCRAFT WAS RETURNED TO SERVICE.