As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: GROUND AIR ACCESS PANEL OPEN DURING TAKEOFF. ANOTHER AIRCRAFT NOTICED AN OPEN/MISSING PANEL ON TAKEOFF, TOWER RELAYED THAT INFORMATION AND DECESION WAS MADE TO RETUN TO CLT. AS A PRECAUTION EMERGENCY DECLARED AND AIRCRAFT LANDED OVERWIGHT WITHOUT INCIDENT. MAINTENANCE FOUND 52-40B HP DR LATCH/HINGE - GROUND AIR ACCESS PANEL OPEN DURING TAKEOFF AND SECURED PANEL.