Medium large transport aircraft cleared to descend to 11000 ft by ARTCC radar controller, flight cre...

Attributes
ACN	402110
Time
Date	199805
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : bwi
State Reference	MD
Altitude	msl bound lower : 11000 msl bound upper : 12000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : bwi
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other descent other
Route In Use	enroute airway : zdc
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 210 flight time total : 10000
ASRS Report	402110
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	other anomaly other
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other

Narrative:

Given crossing restr to cross trish intersection at 11000 ft. FMS aircraft and trish intersection not on FMS map. Looked on airway chart to confirm position of trish intersection, entered it in FMS, and began descent. Called balance approach 'out of FL180 for 11000 ft.' balance controller rogered. Leveled at trish intersection at 11000 ft. Controller then asked to confirm altitude. Replied, 'level 11000 ft.' controller said we were cleared to cross trish intersection at 12000 ft. No traffic conflicts noted. Balance controller said to remain at 11000 ft. I called approach control after landing in dca. They said not to worry about it, but I think a NASA report is in order. Were distraction by looking up trish intersection which was not in FMS. Did not immediately dial in crossing altitude in autoplt altitude window. Even though we read back 11000 ft and called 'out of FL180 for 11000 ft,' we did not ask for confirmation or clarification. Thought we had crossed trish intersection at the assigned altitude. Had briefed to be extra cautious with altitude assignments since several pilots had deviated from assigned altitudes in last yr. Not sure what the assigned altitude really was, ie, whether we were wrong or controller was wrong.

Original NASA ASRS Text

Title: MLG ACFT CLRED TO DSND TO 11000 FT BY ARTCC RADAR CTLR, FLC READ BACK ALT AND DSNDED. WHEN CHKING IN WITH TRACON THEY WERE TOLD THEIR ALT WAS SUPPOSED TO BE 12000 FT BUT NO PROB.

Narrative: GIVEN XING RESTR TO CROSS TRISH INTXN AT 11000 FT. FMS ACFT AND TRISH INTXN NOT ON FMS MAP. LOOKED ON AIRWAY CHART TO CONFIRM POS OF TRISH INTXN, ENTERED IT IN FMS, AND BEGAN DSCNT. CALLED BAL APCH 'OUT OF FL180 FOR 11000 FT.' BAL CTLR ROGERED. LEVELED AT TRISH INTXN AT 11000 FT. CTLR THEN ASKED TO CONFIRM ALT. REPLIED, 'LEVEL 11000 FT.' CTLR SAID WE WERE CLRED TO CROSS TRISH INTXN AT 12000 FT. NO TFC CONFLICTS NOTED. BAL CTLR SAID TO REMAIN AT 11000 FT. I CALLED APCH CTL AFTER LNDG IN DCA. THEY SAID NOT TO WORRY ABOUT IT, BUT I THINK A NASA RPT IS IN ORDER. WERE DISTR BY LOOKING UP TRISH INTXN WHICH WAS NOT IN FMS. DID NOT IMMEDIATELY DIAL IN XING ALT IN AUTOPLT ALT WINDOW. EVEN THOUGH WE READ BACK 11000 FT AND CALLED 'OUT OF FL180 FOR 11000 FT,' WE DID NOT ASK FOR CONFIRMATION OR CLARIFICATION. THOUGHT WE HAD CROSSED TRISH INTXN AT THE ASSIGNED ALT. HAD BRIEFED TO BE EXTRA CAUTIOUS WITH ALT ASSIGNMENTS SINCE SEVERAL PLTS HAD DEVIATED FROM ASSIGNED ALTS IN LAST YR. NOT SURE WHAT THE ASSIGNED ALT REALLY WAS, IE, WHETHER WE WERE WRONG OR CTLR WAS WRONG.

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.

Medium large transport aircraft cleared to descend to 11000 ft by ARTCC radar controller, flight crew read back altitude and descended. When checking in with TRACON they were told their altitude was supposed to be 12000 ft but no problem.