As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RT RECIRC FAN NOISY. COMMUNICATION & BRIEFING EXTREMELY DIFFICULT. CHRONIC HISTORY OF NOISE. POSSIBILITY DUCT BLOCKAGE AND RECORD CFM AND NOISE FINDINGS. WILL NEED UP TO 6SH SLOT TO ACP. REPLACED 2 EA RECIR FILTERS, FLOW AND DECIBEL CHECK WITHIN LIMITS BUT VELOCITY STILL NOT WITHIN, NEED TO REPLACED LT PACK FLOW CONTROL VALVE UNDER OSTF H1415. DUCT LEAK CHECKED OK. REPLACED LT FLOW CONTROL VALVE. LEAK & OP CHECKED. OPS TEST GOOD REF SERVICE TIP21-22-00 FLOW OF 371FPM & 72 DB NOISE.