Instructor pilot returning to home airport shutdown an engine as a prcautionary measure.

Attributes
ACN	159166
Time
Date	199010
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : apc airport : 056
State Reference	CA
Altitude	msl bound lower : 1000 msl bound upper : 1000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : apc
Operator	general aviation : personal
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	Other
Function	flight crew : single pilot instruction : instructor
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 120 flight time total : 600 flight time type : 250
ASRS Report	159166
Person 2
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : student pilot : private
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency none taken : unable
Consequence	other
Supplementary
Primary Problem	Aircraft

Narrative:

At the conclusion of a multi-engine flight lesson and the completion of a simulated single engine approach (VOR-a hamilton aaf) my student and I were returning to gross field, novato, ca, (O56). At an altitude of approximately 1000', and about 5 NM east of O56, I noticed a stream of blue smoke flowing underneath the right wing from the right engine nacelle. Due to the mildly rough running engine, the smoke and my concern of an engine fire I elected to make a precautionary engine shutdown and feather. With the engine shut down my student and I proceeded to the napa county airport (apc). As we approached napa airport I climbed the airplane to and maintained 1500'. As I was flying the airplane, I directed my student to contact the napa control tower, declare an emergency and request emergency equipment to standby. The single engine approach and landing to runway 24 at apc was uneventful. No fire was evident on the ground and we taxied to the transient parking unassisted, but with a fire truck escort.

Original NASA ASRS Text

Title: INSTRUCTOR PLT RETURNING TO HOME ARPT SHUTDOWN AN ENGINE AS A PRCAUTIONARY MEASURE.

Narrative: AT THE CONCLUSION OF A MULTI-ENG FLT LESSON AND THE COMPLETION OF A SIMULATED SINGLE ENG APCH (VOR-A HAMILTON AAF) MY STUDENT AND I WERE RETURNING TO GROSS FIELD, NOVATO, CA, (O56). AT AN ALT OF APPROX 1000', AND ABOUT 5 NM E OF O56, I NOTICED A STREAM OF BLUE SMOKE FLOWING UNDERNEATH THE R WING FROM THE R ENG NACELLE. DUE TO THE MILDLY ROUGH RUNNING ENG, THE SMOKE AND MY CONCERN OF AN ENG FIRE I ELECTED TO MAKE A PRECAUTIONARY ENG SHUTDOWN AND FEATHER. WITH THE ENG SHUT DOWN MY STUDENT AND I PROCEEDED TO THE NAPA COUNTY ARPT (APC). AS WE APCHED NAPA ARPT I CLBED THE AIRPLANE TO AND MAINTAINED 1500'. AS I WAS FLYING THE AIRPLANE, I DIRECTED MY STUDENT TO CONTACT THE NAPA CTL TWR, DECLARE AN EMER AND REQUEST EMER EQUIP TO STANDBY. THE SINGLE ENG APCH AND LNDG TO RWY 24 AT APC WAS UNEVENTFUL. NO FIRE WAS EVIDENT ON THE GND AND WE TAXIED TO THE TRANSIENT PARKING UNASSISTED, BUT WITH A FIRE TRUCK ESCORT.

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.