B737-500 crew had multiple system failures in ZOA class east and a airspaces.

Attributes
ACN	501321
Time
Date	200102
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	navaid : rzs.vortac
State Reference	CA
Altitude	msl bound lower : 24000 msl bound upper : 29000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla.artcc artcc : zoa.artcc
Operator	common carrier : air carrier
Make Model Name	B737-500
Operating Under FAR Part	Part 121
Navigation In Use	other Other other vortac
Flight Phase	climbout : vacating altitude
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zla.artcc
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 119
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 220 flight time total : 6800 flight time type : 3800
ASRS Report	501321
Person 2
Experience	flight time last 90 days : 240 flight time total : 9000 flight time type : 6000
ASRS Report	501115
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : eicas failure warnings other controllera other flight crewa other flight crewb
Resolutory Action	controller : provided flight assist controller : issued new clearance
Consequence	faa : reviewed incident with flight crew other other
Supplementary
Problem Areas	Aircraft ATC Human Performance
Primary Problem	Aircraft

Narrative:

This incident chain started shortly after takeoff of the oak-san flight. I was flying the aircraft and after takeoff we got a 'TCASII inoperative, radio altimeter #1, and TCASII display warnings, with ATC asking to check our transponder. The captain checked circuit breakers, recycled all associated circuit breakers and tried #1 and #2 transponder with no effect. ZOA reported that we had no transponder and requested position reports and altitude callouts. ZOA cleared us to FL370, out of FL180, and in the mid 20's. I checked the cabin, and everything was normal. As we passed through FL350, the cabin altitude warning horn went off. The captain altitude indicator showed 10000 ft, the captain asked for a descent, and oak gave us FL290. The captain asked and received clearance to FL240. I initiated a descent, and oxygen masks were donned and communications were established. The analog pressurization system 'automatic fail' light did not come on. The captain ran the QRH -- all checklists and the system worked in the standby mode. During our descent, ZOA (34.55) sent us to lax (26.52), the captain checked in and called out altitude passing and descending to FL240. ZLA acknowledged this and requested a radar fix at rzs VOR. Several mins later, ZLA called out traffic at FL310 and we were at FL240 and 10 NM out of rzs. ZLA was unaware we were at FL240. Center stated that there was no conflict, but I was concerned, because we were in and out of IMC. The captain asked if he needed to call ATC and lax said they were trying to figure out what happened, when an air carrier flight confirmed the ZOA clearance to FL240. On descent in san the 'low idle' light came on, with the throttle at idle. The completion of the flight was normal with no additional incidents. The preflight, discussion with maintenance control, said that the symptoms of the flight point to be partial failure of the air/ground sensor system. I feel we as a crew performed the checklists required and they did not address the situation we had encountered.

Original NASA ASRS Text

Title: B737-500 CREW HAD MULTIPLE SYS FAILURES IN ZOA CLASS E AND A AIRSPACES.

Narrative: THIS INCIDENT CHAIN STARTED SHORTLY AFTER TKOF OF THE OAK-SAN FLT. I WAS FLYING THE ACFT AND AFTER TKOF WE GOT A 'TCASII INOP, RADIO ALTIMETER #1, AND TCASII DISPLAY WARNINGS, WITH ATC ASKING TO CHK OUR XPONDER. THE CAPT CHKED CIRCUIT BREAKERS, RECYCLED ALL ASSOCIATED CIRCUIT BREAKERS AND TRIED #1 AND #2 XPONDER WITH NO EFFECT. ZOA RPTED THAT WE HAD NO XPONDER AND REQUESTED POS RPTS AND ALT CALLOUTS. ZOA CLRED US TO FL370, OUT OF FL180, AND IN THE MID 20'S. I CHKED THE CABIN, AND EVERYTHING WAS NORMAL. AS WE PASSED THROUGH FL350, THE CABIN ALT WARNING HORN WENT OFF. THE CAPT ALT INDICATOR SHOWED 10000 FT, THE CAPT ASKED FOR A DSCNT, AND OAK GAVE US FL290. THE CAPT ASKED AND RECEIVED CLRNC TO FL240. I INITIATED A DSCNT, AND OXYGEN MASKS WERE DONNED AND COMS WERE ESTABLISHED. THE ANALOG PRESSURIZATION SYS 'AUTO FAIL' LIGHT DID NOT COME ON. THE CAPT RAN THE QRH -- ALL CHKLISTS AND THE SYS WORKED IN THE STANDBY MODE. DURING OUR DSCNT, ZOA (34.55) SENT US TO LAX (26.52), THE CAPT CHKED IN AND CALLED OUT ALT PASSING AND DSNDING TO FL240. ZLA ACKNOWLEDGED THIS AND REQUESTED A RADAR FIX AT RZS VOR. SEVERAL MINS LATER, ZLA CALLED OUT TFC AT FL310 AND WE WERE AT FL240 AND 10 NM OUT OF RZS. ZLA WAS UNAWARE WE WERE AT FL240. CTR STATED THAT THERE WAS NO CONFLICT, BUT I WAS CONCERNED, BECAUSE WE WERE IN AND OUT OF IMC. THE CAPT ASKED IF HE NEEDED TO CALL ATC AND LAX SAID THEY WERE TRYING TO FIGURE OUT WHAT HAPPENED, WHEN AN ACR FLT CONFIRMED THE ZOA CLRNC TO FL240. ON DSCNT IN SAN THE 'LOW IDLE' LIGHT CAME ON, WITH THE THROTTLE AT IDLE. THE COMPLETION OF THE FLT WAS NORMAL WITH NO ADDITIONAL INCIDENTS. THE PREFLT, DISCUSSION WITH MAINT CTL, SAID THAT THE SYMPTOMS OF THE FLT POINT TO BE PARTIAL FAILURE OF THE AIR/GND SENSOR SYS. I FEEL WE AS A CREW PERFORMED THE CHKLISTS REQUIRED AND THEY DID NOT ADDRESS THE SIT WE HAD ENCOUNTERED.

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.