A be-200 pilot inadvertently descended too low and receives a TCASII TA.

Attributes
ACN	526210
Time
Date	200109
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	navaid : emp.vortac
State Reference	US
Altitude	msl bound lower : 12500 msl bound upper : 14000
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Controlling Facilities	tower : tbpb.tower
Operator	general aviation : corporate
Make Model Name	Starship Model 2000
Flight Phase	descent : approach descent : intermediate altitude
Route In Use	arrival star : jhawk 4
Flight Plan	IFR
Person 1
Affiliation	company : corporate
Function	flight crew : single pilot
Qualification	pilot : atp pilot : cfi pilot : multi engine
Experience	flight time last 90 days : 55 flight time total : 9530 flight time type : 830
ASRS Report	526210
Events
Anomaly	altitude deviation : overshoot non adherence : clearance non adherence : far
Resolutory Action	controller : issued advisory
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I was about 10 mi southwest of emporia VOR at FL240. My clearance was to fly the jhawk 4 arrival to olathe, johnson county executive airport (ATC). At this point ZKC issued me a descent clearance that I understood as' descend and maintain one two thousand. After leaving FL230 you are cleared direct to johnson county executive airport'. Upon hearing one two thousand, I immediately entered 12000 into the altitude select. I missed the second part of the clearance and had to ask for clarification. I then read back the entire clearance and reported out of FL240. As my descent progressed through 15000 ft, ZKC told me that there was baron traffic at 1 O'clock position and I missed the mi but I noted the traffic on my TCASII at about 1 O'clock position and 4-5 mi. Center said, 'when you get by him I'll have lower.' I admit I missed this cue. I also noted that the traffic was passing well to my right and I tried to locate the baron visually but did not. ZKC requested me to turn immediately left 40 degrees and say altitude. I complied with the turn and reported 12500 ft. At that point I noted the traffic appeared about 7 mi to my right and at no time did I get traffic alert warning. ZKC then advised me that I was to have leveled at 14000 ft.

Original NASA ASRS Text

Title: A BE-200 PLT INADVERTENTLY DSNDED TOO LOW AND RECEIVES A TCASII TA.

Narrative: I WAS ABOUT 10 MI SW OF EMPORIA VOR AT FL240. MY CLRNC WAS TO FLY THE JHAWK 4 ARR TO OLATHE, JOHNSON COUNTY EXECUTIVE ARPT (ATC). AT THIS POINT ZKC ISSUED ME A DSCNT CLRNC THAT I UNDERSTOOD AS' DSND AND MAINTAIN ONE TWO THOUSAND. AFTER LEAVING FL230 YOU ARE CLRED DIRECT TO JOHNSON COUNTY EXECUTIVE ARPT'. UPON HEARING ONE TWO THOUSAND, I IMMEDIATELY ENTERED 12000 INTO THE ALT SELECT. I MISSED THE SECOND PART OF THE CLRNC AND HAD TO ASK FOR CLARIFICATION. I THEN READ BACK THE ENTIRE CLRNC AND REPORTED OUT OF FL240. AS MY DSCNT PROGRESSED THROUGH 15000 FT, ZKC TOLD ME THAT THERE WAS BARON TFC AT 1 O'CLOCK POS AND I MISSED THE MI BUT I NOTED THE TFC ON MY TCASII AT ABOUT 1 O'CLOCK POS AND 4-5 MI. CTR SAID, 'WHEN YOU GET BY HIM I'LL HAVE LOWER.' I ADMIT I MISSED THIS CUE. I ALSO NOTED THAT THE TFC WAS PASSING WELL TO MY R AND I TRIED TO LOCATE THE BARON VISUALLY BUT DID NOT. ZKC REQUESTED ME TO TURN IMMEDIATELY L 40 DEGS AND SAY ALT. I COMPLIED WITH THE TURN AND RPTED 12500 FT. AT THAT POINT I NOTED THE TFC APPEARED ABOUT 7 MI TO MY R AND AT NO TIME DID I GET TFC ALERT WARNING. ZKC THEN ADVISED ME THAT I WAS TO HAVE LEVELED AT 14000 FT.

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.