Small transport pilot has altitude deviation while troubleshooting alternator failure.

Attributes
ACN	203905
Time
Date	199203
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : sns
State Reference	CA
Altitude	msl bound lower : 7000 msl bound upper : 7300
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tower : bwi
Operator	general aviation : corporate
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Flight Phase	cruise other
Route In Use	enroute airway : zoa
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 10 flight time total : 3700 flight time type : 4
ASRS Report	203905
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Just as I leveled off at 7000 ft the left alternator failed. I was new to the plane and its system, including the autoplt. Since I needed to run the emergency procedure, I decided to set 'altitude hold' on the autoplt. I didn't -- I hit 'attitude hold' instead. While I was screwing with the alternator, the aircraft climbed to 7300 ft before I noticed the deviation. ZOA never said anything so I don't think I'm in trouble.

Original NASA ASRS Text

Title: SMT PLT HAS ALTDEV WHILE TROUBLESHOOTING ALTERNATOR FAILURE.

Narrative: JUST AS I LEVELED OFF AT 7000 FT THE L ALTERNATOR FAILED. I WAS NEW TO THE PLANE AND ITS SYS, INCLUDING THE AUTOPLT. SINCE I NEEDED TO RUN THE EMER PROC, I DECIDED TO SET 'ALT HOLD' ON THE AUTOPLT. I DIDN'T -- I HIT 'ATTITUDE HOLD' INSTEAD. WHILE I WAS SCREWING WITH THE ALTERNATOR, THE ACFT CLBED TO 7300 FT BEFORE I NOTICED THE DEV. ZOA NEVER SAID ANYTHING SO I DON'T THINK I'M IN TROUBLE.

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.