MU30 flight crew overshoots assigned altitude on descent within ZKC airspace.

Attributes
ACN	492428
Time
Date	200011
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : cou.airport
State Reference	MO
Altitude	msl bound lower : 7600 msl bound upper : 8000
Environment
Flight Conditions	VMC
Weather Elements	Turbulence
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zkc.artcc
Operator	common carrier : air taxi
Make Model Name	MU-300 Diamond 1/1A
Operating Under FAR Part	Part 135
Flight Phase	descent : approach
Route In Use	approach : visual
Flight Plan	IFR
Person 1
Affiliation	company : air taxi
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 4500 flight time type : 200
ASRS Report	492428
Person 2
Affiliation	company : air taxi
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : multi engine
Experience	flight time last 90 days : 150 flight time total : 1000 flight time type : 75
ASRS Report	492430
Events
Anomaly	altitude deviation : overshoot conflict : airborne less severe non adherence : clearance
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued advisory flight crew : returned to assigned altitude
Supplementary
Problem Areas	Weather Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

On descent into cou, we were with ZKC at 15-20 DME. We were issued a descent to 9000 ft MSL, also a TA 12 O'clock position, 10 mi at 8500 ft MSL. Shortly after, we were issued a clearance to 8000 ft MSL. No further TA's. Going through 7600 ft MSL, about 10 DME, copilot restated 8000 ft MSL clearance. Captain then immediately corrected altitude back to 8000 ft MSL. When correcting through 7800 ft MSL, ATC inquired present altitude. Copilot stated 7800 ft MSL. Shortly after, we were handed off to columbia approach where we were issued a visual approach. Factors involved would be as follows: captain's misunderstanding in descent clearance. Captain's anticipation of tower since we were ending up about 7000 ft AGL, 5-8 DME from airport. Missed '300 ft to go' callout. Also, at higher airspeed, captain's and copilot's altimeters differ as much as 300 ft. So when copilot saw 7900 ft MSL, the captain's side was already 7600 ft MSL. This difference in altimeters is caused by the captain's side using an air data computer, and the copilot's side not having one. Fatigue was also a factor due to multiple legs that day in moderate turbulence, windshear +-10-15 KTS, and crosswind landing components 20-30 KTS.

Original NASA ASRS Text

Title: MU30 FLC OVERSHOOTS ASSIGNED ALT ON DSCNT WITHIN ZKC AIRSPACE.

Narrative: ON DSCNT INTO COU, WE WERE WITH ZKC AT 15-20 DME. WE WERE ISSUED A DSCNT TO 9000 FT MSL, ALSO A TA 12 O'CLOCK POS, 10 MI AT 8500 FT MSL. SHORTLY AFTER, WE WERE ISSUED A CLRNC TO 8000 FT MSL. NO FURTHER TA'S. GOING THROUGH 7600 FT MSL, ABOUT 10 DME, COPLT RESTATED 8000 FT MSL CLRNC. CAPT THEN IMMEDIATELY CORRECTED ALT BACK TO 8000 FT MSL. WHEN CORRECTING THROUGH 7800 FT MSL, ATC INQUIRED PRESENT ALT. COPLT STATED 7800 FT MSL. SHORTLY AFTER, WE WERE HANDED OFF TO COLUMBIA APCH WHERE WE WERE ISSUED A VISUAL APCH. FACTORS INVOLVED WOULD BE AS FOLLOWS: CAPT'S MISUNDERSTANDING IN DSCNT CLRNC. CAPT'S ANTICIPATION OF TWR SINCE WE WERE ENDING UP ABOUT 7000 FT AGL, 5-8 DME FROM ARPT. MISSED '300 FT TO GO' CALLOUT. ALSO, AT HIGHER AIRSPD, CAPT'S AND COPLT'S ALTIMETERS DIFFER AS MUCH AS 300 FT. SO WHEN COPLT SAW 7900 FT MSL, THE CAPT'S SIDE WAS ALREADY 7600 FT MSL. THIS DIFFERENCE IN ALTIMETERS IS CAUSED BY THE CAPT'S SIDE USING AN AIR DATA COMPUTER, AND THE COPLT'S SIDE NOT HAVING ONE. FATIGUE WAS ALSO A FACTOR DUE TO MULTIPLE LEGS THAT DAY IN MODERATE TURB, WINDSHEAR +-10-15 KTS, AND XWIND LNDG COMPONENTS 20-30 KTS.

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.