Narrative:

On ILS DME runway 1L (iad), just before OM gear down and then proceeded to move flaps from 10 degrees to 20 degrees. Observed that there was no movement on the flap indicator. Looked at the hydraulic pressure gauges which now both showed zero. Declared emergency, completed landing checklist and QRH items and landed safely and stopped the airplane. We were then towed to the gate. Mechanics told us that a hydraulic line in the belly had chafed and that we had lost all the hydraulic fluid. They said that this was a relatively common occurrence and that it had happened before. My suggestion is that the hydraulic lines should be better protected so that this does not occur again. Supplemental information from acn 307912: total loss of hydraulics on approach at iad ILS DME runway 1L. Callback conversation with reporter revealed the following information: reporter stated that he did not receive back any details as to the hydraulic lines chaffing since the director of maintenance does not respond to the pilots request to know 'what happened.' however, he did get the idea from others that there are 2 hydraulic lines in the center section of the bottom of the fuselage that rub together causing a line failure. He heard that another aircraft flight crew experienced the same thing shortly after his incident. He stated that a copy of his report goes through to the FAA for their review. However, he has not heard or observed any communications from the company regarding this problem.

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Original NASA ASRS Text

Title: A HYD FLUID LEAK WAS DETERMINED TO HAVE BEEN CAUSED BY A CHAFED LINE. HYD FAILURE. EMER DECLARED.

Narrative: ON ILS DME RWY 1L (IAD), JUST BEFORE OM GEAR DOWN AND THEN PROCEEDED TO MOVE FLAPS FROM 10 DEGS TO 20 DEGS. OBSERVED THAT THERE WAS NO MOVEMENT ON THE FLAP INDICATOR. LOOKED AT THE HYD PRESSURE GAUGES WHICH NOW BOTH SHOWED ZERO. DECLARED EMER, COMPLETED LNDG CHKLIST AND QRH ITEMS AND LANDED SAFELY AND STOPPED THE AIRPLANE. WE WERE THEN TOWED TO THE GATE. MECHS TOLD US THAT A HYD LINE IN THE BELLY HAD CHAFED AND THAT WE HAD LOST ALL THE HYD FLUID. THEY SAID THAT THIS WAS A RELATIVELY COMMON OCCURRENCE AND THAT IT HAD HAPPENED BEFORE. MY SUGGESTION IS THAT THE HYD LINES SHOULD BE BETTER PROTECTED SO THAT THIS DOES NOT OCCUR AGAIN. SUPPLEMENTAL INFO FROM ACN 307912: TOTAL LOSS OF HYDS ON APCH AT IAD ILS DME RWY 1L. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT HE DID NOT RECEIVE BACK ANY DETAILS AS TO THE HYD LINES CHAFFING SINCE THE DIRECTOR OF MAINT DOES NOT RESPOND TO THE PLTS REQUEST TO KNOW 'WHAT HAPPENED.' HOWEVER, HE DID GET THE IDEA FROM OTHERS THAT THERE ARE 2 HYD LINES IN THE CTR SECTION OF THE BOTTOM OF THE FUSELAGE THAT RUB TOGETHER CAUSING A LINE FAILURE. HE HEARD THAT ANOTHER ACFT FLC EXPERIENCED THE SAME THING SHORTLY AFTER HIS INCIDENT. HE STATED THAT A COPY OF HIS RPT GOES THROUGH TO THE FAA FOR THEIR REVIEW. HOWEVER, HE HAS NOT HEARD OR OBSERVED ANY COMS FROM THE COMPANY REGARDING THIS PROB.

Data retrieved from NASA's ASRS site as of July 2007 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.