As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
COCKPIT AIR NOISE IS VERY LOUD. CHECKED FLIGHT DECK NOISE LEVEL PER SERVICE TIP 21- 22-00 PAGE 902 STEP 7. NOISE LEVEL INDICATED A GREATER THAN 3DB CHANGE WHEN RT RECIRCULATION FAN WAS SELECTED. FOUND THE RIGHT PACK STUCK IN HIGH FLOW. REPLACED CONTROL VALVE CARD M864, NO HELP. REPLACED RELAY K416, CHECKED OKAY.