Similar a/north causes reporter to deviate from his altitude.

Attributes
ACN	303300
Time
Date	199505
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : jvl airport : ord
State Reference	WI
Altitude	msl bound lower : 9000 msl bound upper : 9000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 150 flight time total : 13000 flight time type : 500
ASRS Report	303300
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance flight crew : became reoriented
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While I was off frequency picking up ATIS, the copilot was flying and accepted a frequency change. After joining him on the new radio frequency, I heard a clearance for a similar call sign. We accepted the clearance and acknowledged. Approach control missed our wrong flight number when reading back the clearance. We started a descent. Approach control called a similar call sign and we caught the potential problem. I called approach to verify our clearance, and the problem became evident. (We had accepted a frequency change and clearance for another flight). Approach control told us to maintain 9000 ft and continue direct ord. We asked if there was a conflict and were told, no. Contributing factors were frequency congestion, similar call signs, one PF and communicating at the same time. Controller very busy and not hearing wrong flight number, accepted the clearance readback. I accept responsibility for this problem happening, but unfortunately it will continue happening as we try to cram too many airplanes into the same airspace.

Original NASA ASRS Text

Title: SIMILAR A/N CAUSES RPTR TO DEVIATE FROM HIS ALT.

Narrative: WHILE I WAS OFF FREQ PICKING UP ATIS, THE COPLT WAS FLYING AND ACCEPTED A FREQ CHANGE. AFTER JOINING HIM ON THE NEW RADIO FREQ, I HEARD A CLRNC FOR A SIMILAR CALL SIGN. WE ACCEPTED THE CLRNC AND ACKNOWLEDGED. APCH CTL MISSED OUR WRONG FLT NUMBER WHEN READING BACK THE CLRNC. WE STARTED A DSCNT. APCH CTL CALLED A SIMILAR CALL SIGN AND WE CAUGHT THE POTENTIAL PROB. I CALLED APCH TO VERIFY OUR CLRNC, AND THE PROB BECAME EVIDENT. (WE HAD ACCEPTED A FREQ CHANGE AND CLRNC FOR ANOTHER FLT). APCH CTL TOLD US TO MAINTAIN 9000 FT AND CONTINUE DIRECT ORD. WE ASKED IF THERE WAS A CONFLICT AND WERE TOLD, NO. CONTRIBUTING FACTORS WERE FREQ CONGESTION, SIMILAR CALL SIGNS, ONE PF AND COMMUNICATING AT THE SAME TIME. CTLR VERY BUSY AND NOT HEARING WRONG FLT NUMBER, ACCEPTED THE CLRNC READBACK. I ACCEPT RESPONSIBILITY FOR THIS PROB HAPPENING, BUT UNFORTUNATELY IT WILL CONTINUE HAPPENING AS WE TRY TO CRAM TOO MANY AIRPLANES INTO THE SAME AIRSPACE.

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.