Air carrier X maintained last assigned altitude after TCASII TA with aircraft Y.

Attributes
ACN	192497
Time
Date	199110
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : bty
State Reference	NV
Altitude	msl bound lower : 26000 msl bound upper : 27000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	arrival other
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 160 flight time total : 9500 flight time type : 500
ASRS Report	192497
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe non adherence : published procedure
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera
Resolutory Action	controller : issued new clearance
Consequence	Other
Miss Distance	horizontal : 3000 vertical : 1000
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other

Narrative:

Air carrier X departed bty VOR on the fuzzy arrival to las and was on the bty 115 degree radial at approximately 20 NM. Level at 27000. Lax center then cleared us to cross fuzzy intersection at 16000. I acknowledged and checked the flight manage computer for our descent point (which was another 14 NM) and noticed on the TCASII that we had traffic at 12 O'clock, 12 mi, 26000 ft, opposite direction. I instructed the first officer to inquire about the traffic. He was unable to do so for about 20 seconds due to conflicting radio transmissions. Before he could inquire, center advised us to maintain 27000. We acknowledged and stated we had traffic on TCASII. Center did not respond. I did not begin my descent because I was not quite to my programmed descent point, but more importantly because of the observed conflict on TCASII. Had I elected to descend when cleared, a definite conflict would have arisen.

Original NASA ASRS Text

Title: ACR X MAINTAINED LAST ASSIGNED ALT AFTER TCASII TA WITH ACFT Y.

Narrative: ACR X DEPARTED BTY VOR ON THE FUZZY ARR TO LAS AND WAS ON THE BTY 115 DEG RADIAL AT APPROX 20 NM. LEVEL AT 27000. LAX CENTER THEN CLRED US TO CROSS FUZZY INTXN AT 16000. I ACKNOWLEDGED AND CHKED THE FLT MANAGE COMPUTER FOR OUR DSCNT POINT (WHICH WAS ANOTHER 14 NM) AND NOTICED ON THE TCASII THAT WE HAD TFC AT 12 O'CLOCK, 12 MI, 26000 FT, OPPOSITE DIRECTION. I INSTRUCTED THE FO TO INQUIRE ABOUT THE TFC. HE WAS UNABLE TO DO SO FOR ABOUT 20 SECONDS DUE TO CONFLICTING RADIO TRANSMISSIONS. BEFORE HE COULD INQUIRE, CENTER ADVISED US TO MAINTAIN 27000. WE ACKNOWLEDGED AND STATED WE HAD TFC ON TCASII. CENTER DID NOT RESPOND. I DID NOT BEGIN MY DSCNT BECAUSE I WAS NOT QUITE TO MY PROGRAMMED DSCNT POINT, BUT MORE IMPORTANTLY BECAUSE OF THE OBSERVED CONFLICT ON TCASII. HAD I ELECTED TO DSND WHEN CLRED, A DEFINITE CONFLICT WOULD HAVE ARISEN.

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.