Air carrier medium large transport reported altitude deviation clearance disputed.

Attributes
ACN	96034
Time
Date	198810
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : sjt
State Reference	TX
Altitude	msl bound lower : 31000 msl bound upper : 35000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zhu tracon : suu
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 240 flight time total : 8940 flight time type : 4380
ASRS Report	96034
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : excursion from assigned altitude other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Deviation

Narrative:

Flying at FL310 (filed altitude) from austin to midland on the sjt 102 degree right inbound 80 mi out. Requested FL350 from ZHU. ZHU cleared us to climb and maintain FL350. I used the full call sign on readback and said we were leaving FL310 for FL350. The first officer flying also heard the proper call sign and clearance from ZHU (132.72). Passing through FL330 center called and asked for out altitude. I advised we were passing FL330 for FL350. ZHU at that time said our assigned altitude was FL310. I replied that we requested FL350 and that we had been cleared to climb to that altitude. I then asked what they would like for us to do. Center said to climb and maintain FL350. I replied to climb and maintain FL350 as previously cleared. I feel the reason for the misunderstanding with ZHU was brought by the fact that this controller was working more than 1 center frequency. Even though our frequency (132.72) was not that congested, the other frequency appeared to be because we could hear the controller communicating constantly with aircraft but with very little response from them on our frequency. I have always felt that this is an unsafe situation when a controller doubles up on approach or center frequencys. Not all controllers are capable of handling this type of situation which is obvious with our occurrence that we just experienced.

Original NASA ASRS Text

Title: ACR MLG REPORTED ALT DEVIATION CLRNC DISPUTED.

Narrative: FLYING AT FL310 (FILED ALT) FROM AUSTIN TO MIDLAND ON THE SJT 102 DEG R INBND 80 MI OUT. REQUESTED FL350 FROM ZHU. ZHU CLRED US TO CLB AND MAINTAIN FL350. I USED THE FULL CALL SIGN ON READBACK AND SAID WE WERE LEAVING FL310 FOR FL350. THE F/O FLYING ALSO HEARD THE PROPER CALL SIGN AND CLRNC FROM ZHU (132.72). PASSING THROUGH FL330 CENTER CALLED AND ASKED FOR OUT ALT. I ADVISED WE WERE PASSING FL330 FOR FL350. ZHU AT THAT TIME SAID OUR ASSIGNED ALT WAS FL310. I REPLIED THAT WE REQUESTED FL350 AND THAT WE HAD BEEN CLRED TO CLB TO THAT ALT. I THEN ASKED WHAT THEY WOULD LIKE FOR US TO DO. CENTER SAID TO CLB AND MAINTAIN FL350. I REPLIED TO CLB AND MAINTAIN FL350 AS PREVIOUSLY CLRED. I FEEL THE REASON FOR THE MISUNDERSTANDING WITH ZHU WAS BROUGHT BY THE FACT THAT THIS CTLR WAS WORKING MORE THAN 1 CENTER FREQ. EVEN THOUGH OUR FREQ (132.72) WAS NOT THAT CONGESTED, THE OTHER FREQ APPEARED TO BE BECAUSE WE COULD HEAR THE CTLR COMMUNICATING CONSTANTLY WITH ACFT BUT WITH VERY LITTLE RESPONSE FROM THEM ON OUR FREQ. I HAVE ALWAYS FELT THAT THIS IS AN UNSAFE SITUATION WHEN A CTLR DOUBLES UP ON APCH OR CENTER FREQS. NOT ALL CTLRS ARE CAPABLE OF HANDLING THIS TYPE OF SITUATION WHICH IS OBVIOUS WITH OUR OCCURRENCE THAT WE JUST EXPERIENCED.

Data retrieved from NASA's ASRS site as of August 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.