EMS flight descends to wrong altitude. Controller corrects.

Attributes
ACN	200624
Time
Date	199202
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : phx
State Reference	AZ
Altitude	msl bound lower : 9000 msl bound upper : 10000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : phx
Operator	common carrier : air taxi
Make Model Name	Small Transport, Low Wing, 2 Turboprop Eng
Flight Phase	cruise other descent other
Route In Use	arrival other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : atp pilot : commercial pilot : instrument
Experience	flight time last 90 days : 100 flight time total : 6000 flight time type : 600
ASRS Report	200624
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	altitude deviation : undershoot non adherence : clearance
Independent Detector	other controllera
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I was at 11000 MSL inbound on the fossl 2 arrival into phx. The controller told me to descend to 9000 ft after crossing tonto intersection. Due to distrs in the aircraft with the medical crew, I was too busy to write down the 9000 assigned altitude. After hearing the approach controller assigning (10000 ft after crossing tonto intersection) to other aircraft following me, I thought that I too must have been assigned 10000 ft. I descended to 10000 ft, leveled off, and then was told that I should have descended to 9000 ft MSL. In order to prevent this problem from occurring in the future I will be more vigilant about ignoring crew requests and distrs. I normally write down assigned altitudes or insert the numbers into the altitude alert system. This was the rare occurrence that I did not. Callback conversation with reporter revealed the following information. Callback done for EMS study. Reporter states patient condition is always a consideration. He was distraction due medical personnel questioning about flight progress. Annoyed with himself that he was not more alert in using his normal procedures.

Original NASA ASRS Text

Title: EMS FLT DSNDS TO WRONG ALT. CTLR CORRECTS.

Narrative: I WAS AT 11000 MSL INBOUND ON THE FOSSL 2 ARR INTO PHX. THE CTLR TOLD ME TO DSND TO 9000 FT AFTER XING TONTO INTXN. DUE TO DISTRS IN THE ACFT WITH THE MEDICAL CREW, I WAS TOO BUSY TO WRITE DOWN THE 9000 ASSIGNED ALT. AFTER HEARING THE APCH CTLR ASSIGNING (10000 FT AFTER XING TONTO INTXN) TO OTHER ACFT FOLLOWING ME, I THOUGHT THAT I TOO MUST HAVE BEEN ASSIGNED 10000 FT. I DSNDED TO 10000 FT, LEVELED OFF, AND THEN WAS TOLD THAT I SHOULD HAVE DSNDED TO 9000 FT MSL. IN ORDER TO PREVENT THIS PROBLEM FROM OCCURRING IN THE FUTURE I WILL BE MORE VIGILANT ABOUT IGNORING CREW REQUESTS AND DISTRS. I NORMALLY WRITE DOWN ASSIGNED ALTS OR INSERT THE NUMBERS INTO THE ALT ALERT SYS. THIS WAS THE RARE OCCURRENCE THAT I DID NOT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO. CALLBACK DONE FOR EMS STUDY. RPTR STATES PATIENT CONDITION IS ALWAYS A CONSIDERATION. HE WAS DISTR DUE MEDICAL PERSONNEL QUESTIONING ABOUT FLT PROGRESS. ANNOYED WITH HIMSELF THAT HE WAS NOT MORE ALERT IN USING HIS NORMAL PROCS.

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.