B757 flight crew has a cockpit window pressure leak.

Attributes
ACN	716781
Time
Date	200611
Local Time Of Day	0001 To 0600
Place
Locale Reference	navaid : iiu.vortac
State Reference	KY
Altitude	msl single value : 36000
Aircraft 1
Controlling Facilities	artcc : zid.artcc tower : ord.tower
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 180 flight time total : 19000 flight time type : 300
ASRS Report	716781
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	other flight crewa other flight crewb
Consequence	Other
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Aircraft

Narrative:

We were level in cruise flight about 1 hour south of ord. An extremely loud squeal started from the area of window 3R. We checked pressurization and nothing had changed which would cause the noise. We asked for lower and descended to FL320; still no change. We continued descent to FL240; still no change. The noise was so loud that the ATC controllers asked us to try a different radio because we were barely readable above the squeal. We tried the opposite automatic controller of the pressurization; no help. The cabin was no longer at maximum differential pressure; but we could barely communicate with each other and thought of a possible divert to ind or iiu. The first officer asked if he could try to raise the cabin in the manual mode. I agreed and asked him to make sure he didn't drop the masks. He raised the cabin to 4500 ft; with the differential pressure at 6.8 psi the squeal stopped and we continued to ord. I have never heard such a loud; ear piercing squeal from a window in flight. It was very distracting and as we were coming up on our 13TH hour of duty time on the 4TH day of a 4 day trip; we were fortunate to be able to quiet the sound and continue to ord. I commend the first officer on a job well done.

Original NASA ASRS Text

Title: B757 FLT CREW HAS A COCKPIT WINDOW PRESSURE LEAK.

Narrative: WE WERE LEVEL IN CRUISE FLT ABOUT 1 HR S OF ORD. AN EXTREMELY LOUD SQUEAL STARTED FROM THE AREA OF WINDOW 3R. WE CHKED PRESSURIZATION AND NOTHING HAD CHANGED WHICH WOULD CAUSE THE NOISE. WE ASKED FOR LOWER AND DSNDED TO FL320; STILL NO CHANGE. WE CONTINUED DSCNT TO FL240; STILL NO CHANGE. THE NOISE WAS SO LOUD THAT THE ATC CTLRS ASKED US TO TRY A DIFFERENT RADIO BECAUSE WE WERE BARELY READABLE ABOVE THE SQUEAL. WE TRIED THE OPPOSITE AUTO CTLR OF THE PRESSURIZATION; NO HELP. THE CABIN WAS NO LONGER AT MAX DIFFERENTIAL PRESSURE; BUT WE COULD BARELY COMMUNICATE WITH EACH OTHER AND THOUGHT OF A POSSIBLE DIVERT TO IND OR IIU. THE FO ASKED IF HE COULD TRY TO RAISE THE CABIN IN THE MANUAL MODE. I AGREED AND ASKED HIM TO MAKE SURE HE DIDN'T DROP THE MASKS. HE RAISED THE CABIN TO 4500 FT; WITH THE DIFFERENTIAL PRESSURE AT 6.8 PSI THE SQUEAL STOPPED AND WE CONTINUED TO ORD. I HAVE NEVER HEARD SUCH A LOUD; EAR PIERCING SQUEAL FROM A WINDOW IN FLT. IT WAS VERY DISTRACTING AND AS WE WERE COMING UP ON OUR 13TH HR OF DUTY TIME ON THE 4TH DAY OF A 4 DAY TRIP; WE WERE FORTUNATE TO BE ABLE TO QUIET THE SOUND AND CONTINUE TO ORD. I COMMEND THE FO ON A JOB WELL DONE.

Data retrieved from NASA's ASRS site as of January 2009 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.