What was found
AFTER TAKE OFF, PASSING 4000 FT, MAIN CARGO DOOR WARNING LIGHT ILLUMINATED. VERIFIED THE CARGO DOOR WAS CLOSED AND LOCKED IAW AMM.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
AFTER TAKE OFF, PASSING 4000 FT, MAIN CARGO DOOR WARNING LIGHT ILLUMINATED. VERIFIED THE CARGO DOOR WAS CLOSED AND LOCKED IAW AMM.