What was found
STRONG BURNING RUBBER ODOR WITH APU BLEED AND RECIRC FAN ON. PLACED RECIRCULATION FAN ON MEL 21-20-2 DMI 535705. RETURNED TO SERVICE.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
STRONG BURNING RUBBER ODOR WITH APU BLEED AND RECIRC FAN ON. PLACED RECIRCULATION FAN ON MEL 21-20-2 DMI 535705. RETURNED TO SERVICE.