BE30 pilot had an altitude undershoot after the autoplt did not capture the selected altitude.

Attributes
ACN	615666
Time
Date	200404
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : zlc.artcc
State Reference	UT
Altitude	msl bound lower : 24000 msl bound upper : 24280
Environment
Flight Conditions	IMC
Weather Elements	Turbulence Rain
Light	Daylight Daylight
Aircraft 1
Controlling Facilities	artcc : zlc.artcc
Operator	general aviation : personal
Make Model Name	Super King Air 300
Operating Under FAR Part	Part 91
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : atp pilot : instrument pilot : multi engine
Experience	flight time last 90 days : 35 flight time total : 2750 flight time type : 50
ASRS Report	615666
Person 2
Affiliation	government : faa
Function	controller : approach
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : undershoot non adherence : published procedure non adherence : far
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance flight crew : overcame equipment problem flight crew : returned to assigned altitude flight crew : became reoriented
Consequence	other
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

Departed slc for sac. While leveling at FL240, the autoplt seemed to have a hard time capturing this altitude and stopping at FL242.8. Before I could reset the autoplt computers to capture my assigned altitude, ATC cleared for a higher altitude. Everything seemed to work properly the rest of my flight. Upon reaching norcal approach about 50 NM short of my destination, I may have inadvertently created a communication error with my n-number, causing me not to respond to subsequent instructions from norcal till I realized the error and corrected it.

Original NASA ASRS Text

Title: BE30 PLT HAD AN ALT UNDERSHOOT AFTER THE AUTOPLT DID NOT CAPTURE THE SELECTED ALT.

Narrative: DEPARTED SLC FOR SAC. WHILE LEVELING AT FL240, THE AUTOPLT SEEMED TO HAVE A HARD TIME CAPTURING THIS ALT AND STOPPING AT FL242.8. BEFORE I COULD RESET THE AUTOPLT COMPUTERS TO CAPTURE MY ASSIGNED ALT, ATC CLRED FOR A HIGHER ALT. EVERYTHING SEEMED TO WORK PROPERLY THE REST OF MY FLT. UPON REACHING NORCAL APCH ABOUT 50 NM SHORT OF MY DEST, I MAY HAVE INADVERTENTLY CREATED A COM ERROR WITH MY N-NUMBER, CAUSING ME NOT TO RESPOND TO SUBSEQUENT INSTRUCTIONS FROM NORCAL TILL I REALIZED THE ERROR AND CORRECTED IT.

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.