An lj-60 at cruise had both left and right hydraulic pressure annunciator lights illuminate. Hydraul...

Attributes
ACN	731031
Time
Date	200703
Local Time Of Day	1801 To 2400
Place
Locale Reference	navaid : zzz.bcstn
State Reference	US
Altitude	msl single value : 41000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zzz.artcc
Operator	general aviation : corporate
Make Model Name	Learjet 60
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : commercial pilot : atp
Experience	flight time last 90 days : 30 flight time total : 3300 flight time type : 20
ASRS Report	731031
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : hyd. press annunciator other flight crewa
Resolutory Action	flight crew : declared emergency flight crew : landed in emergency condition flight crew : diverted to another airport
Consequence	other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

While at cruise at FL410; the right hydraulic pressure annunciator illuminated. After consulting the checklist; we were still legal to continue to our destination. Shortly thereafter the annunciation extinguished. After a period of time; the left hydraulic pressure annunciator illuminated and stayed light. Sometime later both the left and right hydraulic pressure annunciators illuminated at once. The hydraulic pressure indication was still good. After considering all our options; we opted to divert. This gave us time to burn extra fuel; so we didn't have an overweight landing and got us to our home base with maintenance. Wind conditions and runway length were also ideal. We declared an emergency and stayed at altitude until we calculated a 1500 FPM descent into ZZZ. We ran the checklist twice at altitude; before we did it for real in the approach area. We were able to obtain flaps 20 degrees with the landing gear down. Braking action was normal on the rollout. We were able to taxi to the hangar. Crash; fire; rescue was standing by; but it turned out we didn't need them. Everyone did their job and things turned out the way we train. No far's; to my belief; were violated during this emergency. ATC did not request a report. After landing; inspection found that a hydraulic line ruptured in the right engine nacelle. Hydraulic fluid was everywhere; and shrapnel from the hydraulic line was splattered on the inside of the cowling. Callback conversation with reporter revealed the following information: reporter stated the lear-60 aircraft does not have a hydraulic quantity gauge; whereas the lear-45 does have a full complement of system digital gauges. The lear-60 hydraulic reservoir has a standpipe inside which maintains enough fluid to operate the landing gear and flaps down selection. Reporter noted he was able to go 20 degrees flap and maintain hydraulic pressure. However; when flaps 40 selected all hydraulic pressure was lost. Flaps repositioned to 20 degrees. Aircraft landed safely. Hydraulic flow restrictors do not exist on this model.

Original NASA ASRS Text

Title: AN LJ-60 AT CRUISE HAD BOTH LEFT AND RIGHT HYDRAULIC PRESSURE ANNUNCIATOR LIGHTS ILLUMINATE. HYDRAULIC PRESSURE INDICATION CONTINUED TO SHOW GOOD. EMERGENCY DECLARED.

Narrative: WHILE AT CRUISE AT FL410; THE R HYD PRESSURE ANNUNCIATOR ILLUMINATED. AFTER CONSULTING THE CHKLIST; WE WERE STILL LEGAL TO CONTINUE TO OUR DEST. SHORTLY THEREAFTER THE ANNUNCIATION EXTINGUISHED. AFTER A PERIOD OF TIME; THE L HYD PRESSURE ANNUNCIATOR ILLUMINATED AND STAYED LIGHT. SOMETIME LATER BOTH THE L AND R HYD PRESSURE ANNUNCIATORS ILLUMINATED AT ONCE. THE HYD PRESSURE INDICATION WAS STILL GOOD. AFTER CONSIDERING ALL OUR OPTIONS; WE OPTED TO DIVERT. THIS GAVE US TIME TO BURN EXTRA FUEL; SO WE DIDN'T HAVE AN OVERWT LNDG AND GOT US TO OUR HOME BASE WITH MAINT. WIND CONDITIONS AND RWY LENGTH WERE ALSO IDEAL. WE DECLARED AN EMER AND STAYED AT ALT UNTIL WE CALCULATED A 1500 FPM DSCNT INTO ZZZ. WE RAN THE CHKLIST TWICE AT ALT; BEFORE WE DID IT FOR REAL IN THE APCH AREA. WE WERE ABLE TO OBTAIN FLAPS 20 DEGS WITH THE LNDG GEAR DOWN. BRAKING ACTION WAS NORMAL ON THE ROLLOUT. WE WERE ABLE TO TAXI TO THE HANGAR. CRASH; FIRE; RESCUE WAS STANDING BY; BUT IT TURNED OUT WE DIDN'T NEED THEM. EVERYONE DID THEIR JOB AND THINGS TURNED OUT THE WAY WE TRAIN. NO FAR'S; TO MY BELIEF; WERE VIOLATED DURING THIS EMER. ATC DID NOT REQUEST A RPT. AFTER LNDG; INSPECTION FOUND THAT A HYD LINE RUPTURED IN THE R ENG NACELLE. HYD FLUID WAS EVERYWHERE; AND SHRAPNEL FROM THE HYD LINE WAS SPLATTERED ON THE INSIDE OF THE COWLING. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED THE LEAR-60 ACFT DOES NOT HAVE A HYD QUANTITY GAUGE; WHEREAS THE LEAR-45 DOES HAVE A FULL COMPLEMENT OF SYSTEM DIGITAL GAUGES. THE LEAR-60 HYD RESERVOIR HAS A STANDPIPE INSIDE WHICH MAINTAINS ENOUGH FLUID TO OPERATE THE LANDING GEAR AND FLAPS DOWN SELECTION. REPORTER NOTED HE WAS ABLE TO GO 20 DEGREES FLAP AND MAINTAIN HYD PRESSURE. HOWEVER; WHEN FLAPS 40 SELECTED ALL HYD PRESSURE WAS LOST. FLAPS REPOSITIONED TO 20 DEGREES. ACFT LANDED SAFELY. HYD FLOW RESTRICTORS DO NOT EXIST ON THIS MODEL.

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.

An lj-60 at cruise had both left and right hydraulic pressure annunciator lights illuminate. Hydraulic pressure indication continued to show good. Emergency declared.