B737 crew loses communications with ZOA north of bty at FL290.

Attributes
ACN	707998
Time
Date	200608
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : bty.vortac
State Reference	NV
Altitude	msl single value : 29000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zoa.artcc tower : dfw.tower
Operator	common carrier : air carrier
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : level
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 254 flight time type : 10120
ASRS Report	707998
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 215 flight time type : 2400
ASRS Report	707996
Events
Anomaly	other anomaly other other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance flight crew : returned to intended or assigned course other
Supplementary
Problem Areas	ATC Facility ATC Human Performance
Primary Problem	ATC Facility

Narrative:

After departure; was handed of to ZOA and cleared direct to clovis; then another handoff to ZOA. 2 aircraft during the next several mins asked oak to repeat the altitudes they were cleared to. The controller was coming in broken. While en route from bih (bishop) to lidat; oak said to remain on present heading and not to exceed 280 KTS. We could see on TCAS that another aircraft was being vectored in front of us on the arrival. After a while the first officer and I questioned just how much spacing the center was going to get. It was then we both realized we had not heard from center in a while. I knew where we were and that we had restr airspace in front of us. The first officer then tried to contact oak. Then a civil aircraft tried to relay a frequency through center. We could not hear the center's xmissions and the civil aircraft xmissions were very broken. I got on the #2 radio and contacted joshua control and I had no problems contacting them. Joshua was in the process of identing us when dispatch sent us a message with a ZOA frequency of ZZZ. We contacted them and they gave us a 180 degree left turn. Oak said they had tried to contact us on the old frequency and guard. We told them we never heard any of their xmissions and had contacted joshua control. Nothing more was said about it; and they cleared us lidat-bty and the arrival. 1) although initially worried; I'm sure our radios worked fine the entire time. 2) I knew where we were and that we needed to turn soon. 3) I contacted our ATC specialist on arrival in las. Within mins he called back and assured us the oak held no culpability towards our flight. As always; an outstanding job. 4) dispatch (and ACARS) played a quick; efficient role in resolving the problem. Lessons: 1) since we were letting the center build spacing; we didn't question not hearing from them for a longer period of time than we probably should have. 2) since we don't have guard; going to it instead of joshua might have provided a quicker resolution to the problem.

Original NASA ASRS Text

Title: B737 CREW LOSES COMS WITH ZOA N OF BTY AT FL290.

Narrative: AFTER DEP; WAS HANDED OF TO ZOA AND CLRED DIRECT TO CLOVIS; THEN ANOTHER HDOF TO ZOA. 2 ACFT DURING THE NEXT SEVERAL MINS ASKED OAK TO REPEAT THE ALTS THEY WERE CLRED TO. THE CTLR WAS COMING IN BROKEN. WHILE ENRTE FROM BIH (BISHOP) TO LIDAT; OAK SAID TO REMAIN ON PRESENT HDG AND NOT TO EXCEED 280 KTS. WE COULD SEE ON TCAS THAT ANOTHER ACFT WAS BEING VECTORED IN FRONT OF US ON THE ARR. AFTER A WHILE THE FO AND I QUESTIONED JUST HOW MUCH SPACING THE CTR WAS GOING TO GET. IT WAS THEN WE BOTH REALIZED WE HAD NOT HEARD FROM CTR IN A WHILE. I KNEW WHERE WE WERE AND THAT WE HAD RESTR AIRSPACE IN FRONT OF US. THE FO THEN TRIED TO CONTACT OAK. THEN A CIVIL ACFT TRIED TO RELAY A FREQ THROUGH CTR. WE COULD NOT HEAR THE CTR'S XMISSIONS AND THE CIVIL ACFT XMISSIONS WERE VERY BROKEN. I GOT ON THE #2 RADIO AND CONTACTED JOSHUA CTL AND I HAD NO PROBS CONTACTING THEM. JOSHUA WAS IN THE PROCESS OF IDENTING US WHEN DISPATCH SENT US A MESSAGE WITH A ZOA FREQ OF ZZZ. WE CONTACTED THEM AND THEY GAVE US A 180 DEG L TURN. OAK SAID THEY HAD TRIED TO CONTACT US ON THE OLD FREQ AND GUARD. WE TOLD THEM WE NEVER HEARD ANY OF THEIR XMISSIONS AND HAD CONTACTED JOSHUA CTL. NOTHING MORE WAS SAID ABOUT IT; AND THEY CLRED US LIDAT-BTY AND THE ARR. 1) ALTHOUGH INITIALLY WORRIED; I'M SURE OUR RADIOS WORKED FINE THE ENTIRE TIME. 2) I KNEW WHERE WE WERE AND THAT WE NEEDED TO TURN SOON. 3) I CONTACTED OUR ATC SPECIALIST ON ARR IN LAS. WITHIN MINS HE CALLED BACK AND ASSURED US THE OAK HELD NO CULPABILITY TOWARDS OUR FLT. AS ALWAYS; AN OUTSTANDING JOB. 4) DISPATCH (AND ACARS) PLAYED A QUICK; EFFICIENT ROLE IN RESOLVING THE PROB. LESSONS: 1) SINCE WE WERE LETTING THE CTR BUILD SPACING; WE DIDN'T QUESTION NOT HEARING FROM THEM FOR A LONGER PERIOD OF TIME THAN WE PROBABLY SHOULD HAVE. 2) SINCE WE DON'T HAVE GUARD; GOING TO IT INSTEAD OF JOSHUA MIGHT HAVE PROVIDED A QUICKER RESOLUTION TO THE PROB.

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.