B737-400 lands safely following a loss of B system hydraulic system.

Attributes
ACN	727525
Time
Date	200702
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 6000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : zzz.tracon
Operator	common carrier : air carrier
Make Model Name	B737-400
Operating Under FAR Part	Part 121
Navigation In Use	other vortac
Flight Phase	descent : approach
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 250 flight time total : 19000 flight time type : 6000
ASRS Report	727525
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : declared emergency flight crew : landed in emergency condition
Consequence	other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

On vector to land at ZZZ; we lost system B hydraulic fluid and thus had to declare an emergency and land at ZZZ with fire equipment standing by in case system a was lost. I was the PF; and the captain did an excellent job of running the lengthy checklists required. The landing was uneventful; with limited loss of required system; due to system a maintaining normal pressure. System B loss was due to a ruptured line.

Original NASA ASRS Text

Title: B737-400 LANDS SAFELY FOLLOWING A LOSS OF B SYSTEM HYDRAULIC SYSTEM.

Narrative: ON VECTOR TO LAND AT ZZZ; WE LOST SYS B HYD FLUID AND THUS HAD TO DECLARE AN EMER AND LAND AT ZZZ WITH FIRE EQUIP STANDING BY IN CASE SYS A WAS LOST. I WAS THE PF; AND THE CAPT DID AN EXCELLENT JOB OF RUNNING THE LENGTHY CHKLISTS REQUIRED. THE LNDG WAS UNEVENTFUL; WITH LIMITED LOSS OF REQUIRED SYS; DUE TO SYS A MAINTAINING NORMAL PRESSURE. SYS B LOSS WAS DUE TO A RUPTURED LINE.

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.