WX radar inoperative. ATC intrafac coordination. Flight crew declared emergency.

Attributes
ACN	307714
Time
Date	199506
Day	Sat
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : dvc
State Reference	CO
Altitude	msl bound lower : 37000 msl bound upper : 37000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdv
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 190 flight time total : 8000 flight time type : 1300
ASRS Report	307714
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 225 flight time total : 8000 flight time type : 1000
ASRS Report	307808
Events
Anomaly	aircraft equipment problem : less severe inflight encounter : weather other anomaly other other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance flight crew : took evasive action flight crew : declared emergency flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Weather
Air Traffic Incident	Intra Facility Coordination Failure

Narrative:

En route on a normal flight from san jose, ca, to denver, co. Aircraft's on board WX radar failed en route, with frontal thunderstorms between aircraft and denver, over the rocky mountains. After conferring with system aircraft maintenance via radio, and dispatch (via ACARS), and after consulting the flight operations manual, the crew elected to attempt circumnavigation of WX in VMC conditions. Center was advised of our radar failure and intentions. Crew requested and received clearance for a heading toward a gap in the WX, to maintenance FL370. Navigating between 2 cells, a subsequent controller told us to descend to FL350 -- advised controller unable, due to buildup beneath us. Controller then told us to turn right to 190 degrees (straight into the cell to our right) -- advised controller unable to descend or turn for another 15-20 mi, due to WX. Controller said we must descend or turn -- captain elected to exercise emergency authority/authorized to stay out of the thunderstorms and declared an emergency. Aircraft proceeded safely through the WX and landed uneventfully. A lack of communications, both between the center controllers, and between the aircraft and each subsequent controller, probably contributed to this incident: each handoff seemed to require a new statement of our equipment failure and our intentions, while we understood (in error, it seems) that once an in-flight equipment failure was declared to center, each subsequent controller would be advised by the previous controller of that aircraft's status and intentions.

Original NASA ASRS Text

Title: WX RADAR INOP. ATC INTRAFAC COORD. FLC DECLARED EMER.

Narrative: ENRTE ON A NORMAL FLT FROM SAN JOSE, CA, TO DENVER, CO. ACFT'S ON BOARD WX RADAR FAILED ENRTE, WITH FRONTAL TSTMS BTWN ACFT AND DENVER, OVER THE ROCKY MOUNTAINS. AFTER CONFERRING WITH SYS ACFT MAINT VIA RADIO, AND DISPATCH (VIA ACARS), AND AFTER CONSULTING THE FLT OPS MANUAL, THE CREW ELECTED TO ATTEMPT CIRCUMNAVIGATION OF WX IN VMC CONDITIONS. CTR WAS ADVISED OF OUR RADAR FAILURE AND INTENTIONS. CREW REQUESTED AND RECEIVED CLRNC FOR A HDG TOWARD A GAP IN THE WX, TO MAINT FL370. NAVING BTWN 2 CELLS, A SUBSEQUENT CTLR TOLD US TO DSND TO FL350 -- ADVISED CTLR UNABLE, DUE TO BUILDUP BENEATH US. CTLR THEN TOLD US TO TURN R TO 190 DEGS (STRAIGHT INTO THE CELL TO OUR R) -- ADVISED CTLR UNABLE TO DSND OR TURN FOR ANOTHER 15-20 MI, DUE TO WX. CTLR SAID WE MUST DSND OR TURN -- CAPT ELECTED TO EXERCISE EMER AUTH TO STAY OUT OF THE TSTMS AND DECLARED AN EMER. ACFT PROCEEDED SAFELY THROUGH THE WX AND LANDED UNEVENTFULLY. A LACK OF COMS, BOTH BTWN THE CTR CTLRS, AND BTWN THE ACFT AND EACH SUBSEQUENT CTLR, PROBABLY CONTRIBUTED TO THIS INCIDENT: EACH HDOF SEEMED TO REQUIRE A NEW STATEMENT OF OUR EQUIP FAILURE AND OUR INTENTIONS, WHILE WE UNDERSTOOD (IN ERROR, IT SEEMS) THAT ONCE AN INFLT EQUIP FAILURE WAS DECLARED TO CTR, EACH SUBSEQUENT CTLR WOULD BE ADVISED BY THE PREVIOUS CTLR OF THAT ACFT'S STATUS AND INTENTIONS.

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.