A ZHU amended clearance is issued but not acknowledged by a descending S80 flight crew.

Attributes
ACN	531916
Time
Date	200112
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	intersection : marcs
State Reference	TX
Altitude	msl bound lower : 15500 msl bound upper : 17000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zhu.artcc
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zhu.artcc
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	531916
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	altitude deviation : overshoot conflict : airborne less severe non adherence : published procedure
Independent Detector	atc equipment other atc equipment : radar aircraft equipment : tcas other controllera
Resolutory Action	none taken : detected after the fact
Consequence	faa : investigated faa : reviewed incident with flight crew other
Miss Distance	vertical : 500
Supplementary
Problem Areas	ATC Human Performance Environmental Factor
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

On descent into san antonio, we were given a clearance by houston center to cross marcs intersection at 13000 ft. While descending through FL190, we thought we might have heard our call sign. Radio was very busy at the time. We queried houston center asking if they had called us, but received no response. At about 15500 ft, while still in our descent, houston asked if we were level 17000 ft and that there was traffic near us at 16000 ft. Center told us we had been issued a descent clearance to 17000 ft. We informed center that we had not heard this radio call, nor had we acknowledged it. We did not have the traffic in sight, but did have it on TCAS. TCAS did not go off. We asked for and received a phone number to later talk to a houston center supervisor. Later, while at san antonio, I talked to houston. They informed me that they had reviewed the tapes and determined that the controller working us had failed to get a read back from us and that we were not at fault in any way.

Original NASA ASRS Text

Title: A ZHU AMENDED CLRNC IS ISSUED BUT NOT ACKNOWLEDGED BY A DSNDING S80 FLC.

Narrative: ON DSCNT INTO SAN ANTONIO, WE WERE GIVEN A CLRNC BY HOUSTON CENTER TO CROSS MARCS INTXN AT 13000 FT. WHILE DSNDING THROUGH FL190, WE THOUGHT WE MIGHT HAVE HEARD OUR CALL SIGN. RADIO WAS VERY BUSY AT THE TIME. WE QUERIED HOUSTON CTR ASKING IF THEY HAD CALLED US, BUT RECEIVED NO RESPONSE. AT ABOUT 15500 FT, WHILE STILL IN OUR DSCNT, HOUSTON ASKED IF WE WERE LEVEL 17000 FT AND THAT THERE WAS TFC NEAR US AT 16000 FT. CENTER TOLD US WE HAD BEEN ISSUED A DSCNT CLRNC TO 17000 FT. WE INFORMED CENTER THAT WE HAD NOT HEARD THIS RADIO CALL, NOR HAD WE ACKNOWLEDGED IT. WE DID NOT HAVE THE TFC IN SIGHT, BUT DID HAVE IT ON TCAS. TCAS DID NOT GO OFF. WE ASKED FOR AND RECEIVED A PHONE NUMBER TO LATER TALK TO A HOUSTON CENTER SUPVR. LATER, WHILE AT SAN ANTONIO, I TALKED TO HOUSTON. THEY INFORMED ME THAT THEY HAD REVIEWED THE TAPES AND DETERMINED THAT THE CTLR WORKING US HAD FAILED TO GET A READ BACK FROM US AND THAT WE WERE NOT AT FAULT IN ANY WAY.

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.