As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TAKEOFF AFTER GEAR RETRACTED, LEFT MAIN LANDING GEAR RED UNSAFE LIGHT ILLUMINATED. RECYCLED GEAR AND RAN ABNORMAL CHECK LIST TO NO AVAIL. RETURNED TO ILN. COMPLETED ADJ/TEST OF LEFT GEAR UPLATCH MECHANISM AND PROX SENSOR. PERFORMED GEAR SWING. SYSTEM OPS CHECKED GOOD IAW DC9 MM 32-31-4.