Clearance misinterp creates an altitude deviation.

Attributes
ACN	137823
Time
Date	199002
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : rdu
State Reference	NC
Altitude	msl bound lower : 10000 msl bound upper : 11000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc tracon : rdu
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other descent other
Route In Use	arrival other 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 : 180 flight time total : 13000 flight time type : 480
ASRS Report	137823
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 7000 flight time type : 100
ASRS Report	137663
Events
Anomaly	altitude deviation : overshoot non adherence : published procedure other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance none taken : detected after the fact other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	Pilot Deviation Operational Deviation

Narrative:

This incident occurred on the brade arrival into raleigh durham airport. The high altitude controller gave us a crossing restriction over brade intersection. I heard it to be at 10000 and 250 KTS. To the best of my recollection, I read it back as such. The expect clearance over brade is published to cross at 11000 and 250 KTS. I did notice this at the time, but failed to clarify this ambiguity. When handed off to the low sector controller, I reported in giving my altitude at 18000 descending to 10000. This statement was backed up by both the first officer and F/east. After reaching 10000 the error was recognized and I was told to climb back to 11000. There was a short discussion about who was right and who was wrong. Fortunately there were no other aircraft to conflict with us. Another aircraft following us, broke into our conversation and stated that they were given a clearance to cross brade at 10000 and 250 which they challenged and were given a revised clearance to cross at 11000 and 250 KTS. This incident points out the necessity to be ever diligent by both pilots and controllers to listen carefully to readbacks and verify published data.

Original NASA ASRS Text

Title: CLRNC MISINTERP CREATES AN ALT DEVIATION.

Narrative: THIS INCIDENT OCCURRED ON THE BRADE ARR INTO RALEIGH DURHAM ARPT. THE HIGH ALT CTLR GAVE US A XING RESTRICTION OVER BRADE INTXN. I HEARD IT TO BE AT 10000 AND 250 KTS. TO THE BEST OF MY RECOLLECTION, I READ IT BACK AS SUCH. THE EXPECT CLRNC OVER BRADE IS PUBLISHED TO CROSS AT 11000 AND 250 KTS. I DID NOTICE THIS AT THE TIME, BUT FAILED TO CLARIFY THIS AMBIGUITY. WHEN HANDED OFF TO THE LOW SECTOR CTLR, I REPORTED IN GIVING MY ALT AT 18000 DESCENDING TO 10000. THIS STATEMENT WAS BACKED UP BY BOTH THE F/O AND F/E. AFTER REACHING 10000 THE ERROR WAS RECOGNIZED AND I WAS TOLD TO CLIMB BACK TO 11000. THERE WAS A SHORT DISCUSSION ABOUT WHO WAS RIGHT AND WHO WAS WRONG. FORTUNATELY THERE WERE NO OTHER ACFT TO CONFLICT WITH US. ANOTHER ACFT FOLLOWING US, BROKE INTO OUR CONVERSATION AND STATED THAT THEY WERE GIVEN A CLRNC TO CROSS BRADE AT 10000 AND 250 WHICH THEY CHALLENGED AND WERE GIVEN A REVISED CLRNC TO CROSS AT 11000 AND 250 KTS. THIS INCIDENT POINTS OUT THE NECESSITY TO BE EVER DILIGENT BY BOTH PLTS AND CTLRS TO LISTEN CAREFULLY TO READBACKS AND VERIFY PUBLISHED DATA.

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.