A B757 crew reported excessive noise in flight making communications with ATC and between themselves...

Attributes
ACN	883840
Time
Date	201004
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Pressurization System
Person 1
Function	Pilot Not Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy

Narrative:

The aircraft had been written up on previous flight with excessive cockpit noise. While climbing out it was very difficult to communicate to other pilot. Decided to stay at FL270 and turn off left pack for noise considerations. After about 5 minutes at cruise got cabin warning horn and master cautions. Cabin indicated above 10;000 ft. Followed QRH procedures; declared emergency to get lower altitude. Was able to get cabin below 10;000 ft at lower altitude. With concurrence from dispatch continued to our destination. O2 masks did not deploy and no passenger problems. Aircraft has history of very loud cockpit noise with both packs and recirculation fans on. Very difficult to communicate without having to talk very loud. Although maintenance says 80-100 decibels is acceptable some planes have been continuously written up for high noise levels. A review across the board should be done of all 757s to ensure any modifications have been done correctly and all duct work is clean and working properly.

Original NASA ASRS Text

Title: A B757 crew reported excessive noise in flight making communications with ATC and between themselves difficult. The left recirculation was turned off to reduce noise but the cabin altitude climbed above 10;000 FT on a single pack. An emergency was declared and the crew descended.

Narrative: The aircraft had been written up on previous flight with excessive cockpit noise. While climbing out it was very difficult to communicate to other pilot. Decided to stay at FL270 and turn off left pack for noise considerations. After about 5 minutes at cruise got cabin warning horn and master cautions. Cabin indicated above 10;000 FT. Followed QRH procedures; declared emergency to get lower altitude. Was able to get cabin below 10;000 FT at lower altitude. With concurrence from Dispatch continued to our destination. O2 masks did not deploy and no passenger problems. Aircraft has history of very loud cockpit noise with both packs and recirculation fans on. Very difficult to communicate without having to talk very loud. Although maintenance says 80-100 decibels is acceptable some planes have been continuously written up for high noise levels. A review across the board should be done of all 757s to ensure any modifications have been done correctly and all duct work is clean and working properly.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

A B757 crew reported excessive noise in flight making communications with ATC and between themselves difficult. The left recirculation was turned off to reduce noise but the cabin altitude climbed above 10;000 ft on a single pack. An emergency was declared and the crew descended.