As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: STRONG ODOR IN CABIN AFTER TAKE OFF. NEVER DISSIPATED TILL ENGINE SHUTDOWN. AIR INTERRUPTED BACK TO DFW. ODOR IN FLIGHT DECK CABIN. EMERGENCY DECLARED. FLIGHT WAS OVERWEIGHT FOR LANDING. REMOVED AND REPLACED AUXILIARY POWER UNIT PER JOB CARD 26L31049003.** (CLOSED)