EMB120 hydraulic emergency lands safely at sfo.

Attributes
ACN	569604
Time
Date	200212
Day	Tue
Local Time Of Day	0601 To 1200
Place
State Reference	CA
Altitude	msl single value : 9000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : nct.tracon
Operator	common carrier : air carrier
Make Model Name	Brasilia EMB-120 All Series
Operating Under FAR Part	Part 121
Navigation In Use	other vortac
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : multi engine pilot : instrument pilot : commercial pilot : cfi pilot : atp
Experience	flight time last 90 days : 200 flight time total : 6000 flight time type : 2000
ASRS Report	569604
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : landed in emergency condition flight crew : declared emergency
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

We experienced a hydraulic failure en route to sfo. There are 2 hydraulic system and this one controls the inboard flaps and brakes. We had almost zero hydraulic fluid in the reservoir, but still had normal pressure. The flight attendant confirmed a very small amount of fluid coming from hydraulic compartment out on the engine compartment. We decided to lower landing gear and flaps early, over the VOR outbound, to see if the flaps would work. When flaps were selected, hydraulic pressure fell to zero and no inboard flaps. Although the aircraft is capable of landing with only outboard flaps and we had very long runways at sfo, I decided it was better to have emergency vehicles ready and declared an emergency versus not declaring. The landing was uneventful, so uneventful I wondered if I really needed to declare an emergency. I realized that I associate emergency services (trucks) with declaring an emergency. Even though I questioned whether I really had an emergency, I keep coming back to the same thought -- it's better to over estimate your problem rather than under estimate.

Original NASA ASRS Text

Title: EMB120 HYD EMER LANDS SAFELY AT SFO.

Narrative: WE EXPERIENCED A HYD FAILURE ENRTE TO SFO. THERE ARE 2 HYD SYS AND THIS ONE CTLS THE INBOARD FLAPS AND BRAKES. WE HAD ALMOST ZERO HYD FLUID IN THE RESERVOIR, BUT STILL HAD NORMAL PRESSURE. THE FLT ATTENDANT CONFIRMED A VERY SMALL AMOUNT OF FLUID COMING FROM HYD COMPARTMENT OUT ON THE ENG COMPARTMENT. WE DECIDED TO LOWER LNDG GEAR AND FLAPS EARLY, OVER THE VOR OUTBOUND, TO SEE IF THE FLAPS WOULD WORK. WHEN FLAPS WERE SELECTED, HYD PRESSURE FELL TO ZERO AND NO INBOARD FLAPS. ALTHOUGH THE ACFT IS CAPABLE OF LNDG WITH ONLY OUTBOARD FLAPS AND WE HAD VERY LONG RWYS AT SFO, I DECIDED IT WAS BETTER TO HAVE EMER VEHICLES READY AND DECLARED AN EMER VERSUS NOT DECLARING. THE LNDG WAS UNEVENTFUL, SO UNEVENTFUL I WONDERED IF I REALLY NEEDED TO DECLARE AN EMER. I REALIZED THAT I ASSOCIATE EMER SVCS (TRUCKS) WITH DECLARING AN EMER. EVEN THOUGH I QUESTIONED WHETHER I REALLY HAD AN EMER, I KEEP COMING BACK TO THE SAME THOUGHT -- IT'S BETTER TO OVER ESTIMATE YOUR PROB RATHER THAN UNDER ESTIMATE.

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.