Air taxi altitude deviation. Turns off encoder and returns to altitude.

Attributes
ACN	159439
Time
Date	199010
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : 22g
State Reference	OH
Altitude	msl bound lower : 5600 msl bound upper : 6000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : cle
Operator	common carrier : air taxi
Make Model Name	Small Transport, Low Wing, 2 Turboprop Eng
Flight Phase	descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : atp pilot : cfi pilot : commercial pilot : instrument
Experience	flight time last 90 days : 20 flight time total : 3000 flight time type : 700
ASRS Report	159439
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	altitude deviation : overshoot non adherence : clearance non adherence : far
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I was descending and on a vector, I had been cleared to 3 different altitudes and headings in the last 3 mins (approximately). The last altitude was changed from 4000 to stop at 6000'. I reset the altitude alert to 6000' but did not engage the preselect on the autoplt. I was doing cockpit preparation for landing and looked up and saw 5600'. I switched off encoder and returned to 6000'. I had headphones on and did not hear the altitude warning from the alerter. Solutions: 2 pilots, route alerter to headphones. Controller appeared to be playing catch-up as I never achieved any of his goals before he changed them. I was tired also from early trip and personal stress.

Original NASA ASRS Text

Title: AIR TAXI ALT DEVIATION. TURNS OFF ENCODER AND RETURNS TO ALT.

Narrative: I WAS DSNDING AND ON A VECTOR, I HAD BEEN CLRED TO 3 DIFFERENT ALTS AND HDGS IN THE LAST 3 MINS (APPROX). THE LAST ALT WAS CHANGED FROM 4000 TO STOP AT 6000'. I RESET THE ALT ALERT TO 6000' BUT DID NOT ENGAGE THE PRESELECT ON THE AUTOPLT. I WAS DOING COCKPIT PREPARATION FOR LNDG AND LOOKED UP AND SAW 5600'. I SWITCHED OFF ENCODER AND RETURNED TO 6000'. I HAD HEADPHONES ON AND DID NOT HEAR THE ALT WARNING FROM THE ALERTER. SOLUTIONS: 2 PLTS, RTE ALERTER TO HEADPHONES. CTLR APPEARED TO BE PLAYING CATCH-UP AS I NEVER ACHIEVED ANY OF HIS GOALS BEFORE HE CHANGED THEM. I WAS TIRED ALSO FROM EARLY TRIP AND PERSONAL STRESS.

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.