Altitude deviation descent through assigned altitude.

Attributes
ACN	303780
Time
Date	199505
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : dtw
State Reference	MI
Altitude	msl bound lower : 10450 msl bound upper : 11000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : dtw
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : second officer
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 50 flight time total : 6800 flight time type : 25
ASRS Report	303780
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer pilot : atp pilot : commercial
Experience	flight time last 90 days : 150 flight time total : 6500 flight time type : 3500
ASRS Report	304307
Events
Anomaly	altitude deviation : overshoot
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : became reoriented other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Operational Deviation Pilot Deviation

Narrative:

ATC requested descent to 11000 ft and to slow to 250 KTS. Captain read back 'descend to 10000 ft, slow 250 KTS.' ATC did not correct mistake made by captain. First officer queried captain that he wasn't sure of altitude to descend to, but captain reassured first officer that it was 10000 ft. At approximately 10600 ft, ATC advised us to climb back to 11000 ft. Supplemental information from acn 304307: I heard 11000 ft, but the captain heard 10000 ft and set 10000 ft in the altitude alert indicator. I questioned the altitude assignment immediately. The captain said no, he read back 10000 ft, the controller rogered it, so 10000 ft had to be right. The brand new so later admitted to me on the ground he thought he heard 11000 ft. I should have insisted the captain verify the altitude, but I knew such a request would go unheeded. At 10450 ft the controller corrected our deviation and I climbed back to 11000 ft. The captain mumbled, 'guess you were right.' I should have picked up the microphone, and verified the altitude myself. The major factors affecting human performance were fatigue and poor cockpit resource management. The new so was intimidated.

Original NASA ASRS Text

Title: ALTDEV DSCNT THROUGH ASSIGNED ALT.

Narrative: ATC REQUESTED DSCNT TO 11000 FT AND TO SLOW TO 250 KTS. CAPT READ BACK 'DSND TO 10000 FT, SLOW 250 KTS.' ATC DID NOT CORRECT MISTAKE MADE BY CAPT. FO QUERIED CAPT THAT HE WASN'T SURE OF ALT TO DSND TO, BUT CAPT REASSURED FO THAT IT WAS 10000 FT. AT APPROX 10600 FT, ATC ADVISED US TO CLB BACK TO 11000 FT. SUPPLEMENTAL INFO FROM ACN 304307: I HEARD 11000 FT, BUT THE CAPT HEARD 10000 FT AND SET 10000 FT IN THE ALT ALERT INDICATOR. I QUESTIONED THE ALT ASSIGNMENT IMMEDIATELY. THE CAPT SAID NO, HE READ BACK 10000 FT, THE CTLR ROGERED IT, SO 10000 FT HAD TO BE RIGHT. THE BRAND NEW SO LATER ADMITTED TO ME ON THE GND HE THOUGHT HE HEARD 11000 FT. I SHOULD HAVE INSISTED THE CAPT VERIFY THE ALT, BUT I KNEW SUCH A REQUEST WOULD GO UNHEEDED. AT 10450 FT THE CTLR CORRECTED OUR DEV AND I CLBED BACK TO 11000 FT. THE CAPT MUMBLED, 'GUESS YOU WERE RIGHT.' I SHOULD HAVE PICKED UP THE MIKE, AND VERIFIED THE ALT MYSELF. THE MAJOR FACTORS AFFECTING HUMAN PERFORMANCE WERE FATIGUE AND POOR COCKPIT RESOURCE MGMNT. THE NEW SO WAS INTIMIDATED.

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.