As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT INTAKE LIGHT ILLUMINATED INTERMITTENTLY ABOUT EVERY 20 SECONDS IN FLIGHT. NO OTHER ABNORMAL INDICATIONS. AIR RETURN TO DTW. MAINTENANCE FOUND LOWER DUCT BURNED. REMOVED AND REPLACED LOWER DUCT LT SIDE, OPS CHECK GOOD IAW SAAB MM 30 SN/OFFL180888, SN/ON L290548.