Similar call signs air carrier X non adherence to ATC clearance descent from assigned altitude.

Attributes
ACN	290529
Time
Date	199412
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : dxo
State Reference	MI
Altitude	msl bound lower : 12000 msl bound upper : 12000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : dtw
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 300 flight time total : 17500 flight time type : 3600
ASRS Report	290529
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Experience	flight time last 90 days : 210 flight time total : 9000 flight time type : 3000
ASRS Report	290306
Events
Anomaly	altitude deviation : overshoot altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Air carrier X level 12000 ft MSL on descent into detroit metropolitan airport. PF misunderstood clearance altitude and started a descent to 11000 ft MSL. Before 'I' could correct the PF had descended to 11700 ft MSL. I directed him to climb to the clearance altitude of 12000 ft MSL. He questioned the altitude and I recovered the aircraft, started the climb back to 12000 ft MSL and returned to the aircraft to the PF. The PF over corrected and climbed to 12400 ft MSL. I promptly relieved him from the controls and returned the aircraft to 12000 ft MSL. Our clearance altitude. Supplemental information from acn 290306: air carrier X level at 12000 ft MSL captain read back clearance for another aircraft with similar call sign to descend to 11000 ft. First officer was flying at set 11000 ft in altitude window, selected flight change. Captain inquired as to actual call sign for the altitude change. When it was discovered we had answered for another aircraft, we stopped our down deviation just short of 300 ft while correcting our altitude we deviated up just short of 500 ft high. It is a busy time on the radios during a 'hub' arrival. All planes have similar call signs. At the time all aircraft were being given headings, airspeed and altitudes, all at once. We should have listened better.

Original NASA ASRS Text

Title: SIMILAR CALL SIGNS ACR X NON ADHERENCE TO ATC CLRNC DSCNT FROM ASSIGNED ALT.

Narrative: ACR X LEVEL 12000 FT MSL ON DSCNT INTO DETROIT METRO ARPT. PF MISUNDERSTOOD CLRNC ALT AND STARTED A DSCNT TO 11000 FT MSL. BEFORE 'I' COULD CORRECT THE PF HAD DSNDED TO 11700 FT MSL. I DIRECTED HIM TO CLB TO THE CLRNC ALT OF 12000 FT MSL. HE QUESTIONED THE ALT AND I RECOVERED THE ACFT, STARTED THE CLB BACK TO 12000 FT MSL AND RETURNED TO THE ACFT TO THE PF. THE PF OVER CORRECTED AND CLBED TO 12400 FT MSL. I PROMPTLY RELIEVED HIM FROM THE CTLS AND RETURNED THE ACFT TO 12000 FT MSL. OUR CLRNC ALT. SUPPLEMENTAL INFO FROM ACN 290306: ACR X LEVEL AT 12000 FT MSL CAPT READ BACK CLRNC FOR ANOTHER ACFT WITH SIMILAR CALL SIGN TO DSND TO 11000 FT. FO WAS FLYING AT SET 11000 FT IN ALT WINDOW, SELECTED FLT CHANGE. CAPT INQUIRED AS TO ACTUAL CALL SIGN FOR THE ALT CHANGE. WHEN IT WAS DISCOVERED WE HAD ANSWERED FOR ANOTHER ACFT, WE STOPPED OUR DOWN DEV JUST SHORT OF 300 FT WHILE CORRECTING OUR ALT WE DEVIATED UP JUST SHORT OF 500 FT HIGH. IT IS A BUSY TIME ON THE RADIOS DURING A 'HUB' ARR. ALL PLANES HAVE SIMILAR CALL SIGNS. AT THE TIME ALL ACFT WERE BEING GIVEN HDGS, AIRSPD AND ALTS, ALL AT ONCE. WE SHOULD HAVE LISTENED BETTER.

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.