Altitude excursion after receipt of clearance.

Attributes
ACN	123906
Time
Date	198909
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : tnv
State Reference	TX
Altitude	msl bound lower : 26000 msl bound upper : 27000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other cruise other descent other
Route In Use	arrival other arrival star : star enroute airway : j87
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : cfi pilot : atp
Experience	flight time last 90 days : 200 flight time total : 7500 flight time type : 5000
ASRS Report	123906
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 45 flight time total : 3000 flight time type : 400
ASRS Report	123730
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	Pilot Deviation

Narrative:

At AM38 CDT, sep/fri/89, I was flying an airlines flight from dallas-ft worth to houston intercontinental airport. My position was at 20 mi north of bilee intersection on J-87 at 27,000'. We had been vectored by ZHU to the west for traffic on frequency 134.35, and now we were being turned back to the east to intercept the 305 radial of humble (iah) VOR for the cougar 4 arrival to houston intercontinental. Along with the turn, I heard the controller clear us to FL250. I 'acknowledged the turn and said leaving FL270 for FL250', and began a descent. At 26,400' the controller asked our last assigned altitude. I said we were descending to FL250. He said we were not cleared to FL250 so stop level at 26,000' and level for traffic at 25,000'. I must have misunderstood his original clearance and he must have missed my call out of FL270 for FL250. My copilot was at the controls and I was doing the radio work. Supplemental information from acn 123773: it is my opinion, and I believe the opinion of the other crew members, that the controller who stopped our descent was not the same one who originally issued the STAR clearance, though we were still on the same frequency.

Original NASA ASRS Text

Title: ALT EXCURSION AFTER RECEIPT OF CLRNC.

Narrative: AT AM38 CDT, SEP/FRI/89, I WAS FLYING AN AIRLINES FLT FROM DALLAS-FT WORTH TO HOUSTON INTERCONTINENTAL ARPT. MY POSITION WAS AT 20 MI N OF BILEE INTXN ON J-87 AT 27,000'. WE HAD BEEN VECTORED BY ZHU TO THE W FOR TFC ON FREQ 134.35, AND NOW WE WERE BEING TURNED BACK TO THE E TO INTERCEPT THE 305 RADIAL OF HUMBLE (IAH) VOR FOR THE COUGAR 4 ARRIVAL TO HOUSTON INTERCONTINENTAL. ALONG WITH THE TURN, I HEARD THE CTLR CLEAR US TO FL250. I 'ACKNOWLEDGED THE TURN AND SAID LEAVING FL270 FOR FL250', AND BEGAN A DSCNT. AT 26,400' THE CTLR ASKED OUR LAST ASSIGNED ALT. I SAID WE WERE DESCENDING TO FL250. HE SAID WE WERE NOT CLRED TO FL250 SO STOP LEVEL AT 26,000' AND LEVEL FOR TFC AT 25,000'. I MUST HAVE MISUNDERSTOOD HIS ORIGINAL CLRNC AND HE MUST HAVE MISSED MY CALL OUT OF FL270 FOR FL250. MY COPLT WAS AT THE CONTROLS AND I WAS DOING THE RADIO WORK. SUPPLEMENTAL INFORMATION FROM ACN 123773: IT IS MY OPINION, AND I BELIEVE THE OPINION OF THE OTHER CREW MEMBERS, THAT THE CTLR WHO STOPPED OUR DSCNT WAS NOT THE SAME ONE WHO ORIGINALLY ISSUED THE STAR CLRNC, THOUGH WE WERE STILL ON THE SAME FREQ.

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.