Altitude overshot on descent.

Attributes
ACN	128538
Time
Date	198911
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : djb
State Reference	OH
Altitude	msl bound lower : 24000 msl bound upper : 28000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zob tower : mac
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	descent other
Route In Use	enroute : on vectors enroute airway : j85
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 10000 flight time type : 3000
ASRS Report	128534
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 5500 flight time type : 150
ASRS Report	128538
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	other

Narrative:

While descending into dtw, we were being vectored for spacing and thought we were cleared down to FL240. I had put FL240 into the awi, so we were quite surprised when center called and said our assigned altitude was FL280. At the time we were through FL270. He cleared us to FL260 immediately. Prior to that, there had been no confusion of the clearance. I don't believe I would have read back FL280 and put FL240 in the awi. We were approaching djb VOR and a common clearance is to cross at FL240. We still don't know if our assigned altitude was FL280. The first officer and I felt FL240 was assigned, and the second officer was on another radio talking to dtw operations and was uncertain.

Original NASA ASRS Text

Title: ALT OVERSHOT ON DESCENT.

Narrative: WHILE DSNDING INTO DTW, WE WERE BEING VECTORED FOR SPACING AND THOUGHT WE WERE CLRED DOWN TO FL240. I HAD PUT FL240 INTO THE AWI, SO WE WERE QUITE SURPRISED WHEN CENTER CALLED AND SAID OUR ASSIGNED ALT WAS FL280. AT THE TIME WE WERE THROUGH FL270. HE CLRED US TO FL260 IMMEDIATELY. PRIOR TO THAT, THERE HAD BEEN NO CONFUSION OF THE CLRNC. I DON'T BELIEVE I WOULD HAVE READ BACK FL280 AND PUT FL240 IN THE AWI. WE WERE APCHING DJB VOR AND A COMMON CLRNC IS TO CROSS AT FL240. WE STILL DON'T KNOW IF OUR ASSIGNED ALT WAS FL280. THE F/O AND I FELT FL240 WAS ASSIGNED, AND THE S/O WAS ON ANOTHER RADIO TALKING TO DTW OPS AND WAS UNCERTAIN.

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.