An air carrier flight crew doesn't copy the descent clearance properly and descends early into the Z...

Attributes
ACN	371940
Time
Date	199706
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : dvu
State Reference	CO
Altitude	msl bound lower : 16500 msl bound upper : 19000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdv
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : flight engineer pilot : commercial pilot : atp
Experience	flight time last 90 days : 200 flight time total : 12000 flight time type : 400
ASRS Report	371940
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 240 flight time total : 3500 flight time type : 700
ASRS Report	372415
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	atc equipment other atc equipment : unspecified other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were inbound to den on the larks 1 arrival. Reclred to fly 350 degree heading and maintain FL190. Next, reclred to turn right, direct powdr, powdr 2 arrival, cross powdr at 250 KTS and 11000 ft. Before reading back the clearance on the radio, the first officer (PNF) said to me, 'did you hear that as 11000 ft?' I responded, 'yes.' he then read the clearance back as we both heard it. The controller accepted the readback. As PF, I proceeded toward powdr and began a descent. Passing 16500 ft, the controller queried our altitude. He then instructed us to maintain 17000 ft which we did without further incident. Notes: 1) the powdr 2 arrival procedure advises to expect to cross powdr at 250 KTS or slower and at or below FL190. 2) our call sign was xyaz. There was also an xybz on the frequency at the same time. 3) the controller was very busy. 4) terrain was clearly in sight at all times.

Original NASA ASRS Text

Title: AN ACR FLC DOESN'T COPY THE DSCNT CLRNC PROPERLY AND DSNDS EARLY INTO THE ZDV AREA.

Narrative: WE WERE INBOUND TO DEN ON THE LARKS 1 ARR. RECLRED TO FLY 350 DEG HDG AND MAINTAIN FL190. NEXT, RECLRED TO TURN R, DIRECT POWDR, POWDR 2 ARR, CROSS POWDR AT 250 KTS AND 11000 FT. BEFORE READING BACK THE CLRNC ON THE RADIO, THE FO (PNF) SAID TO ME, 'DID YOU HEAR THAT AS 11000 FT?' I RESPONDED, 'YES.' HE THEN READ THE CLRNC BACK AS WE BOTH HEARD IT. THE CTLR ACCEPTED THE READBACK. AS PF, I PROCEEDED TOWARD POWDR AND BEGAN A DSCNT. PASSING 16500 FT, THE CTLR QUERIED OUR ALT. HE THEN INSTRUCTED US TO MAINTAIN 17000 FT WHICH WE DID WITHOUT FURTHER INCIDENT. NOTES: 1) THE POWDR 2 ARR PROC ADVISES TO EXPECT TO CROSS POWDR AT 250 KTS OR SLOWER AND AT OR BELOW FL190. 2) OUR CALL SIGN WAS XYAZ. THERE WAS ALSO AN XYBZ ON THE FREQ AT THE SAME TIME. 3) THE CTLR WAS VERY BUSY. 4) TERRAIN WAS CLRLY IN SIGHT AT ALL TIMES.

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.

An air carrier flight crew doesn't copy the descent clearance properly and descends early into the ZDV area.