Narrative:

Descending into ZZZ1 out of 16000 ft MSL to 10000 ft smoke came into the cabin; shortly after lost oil pressure; secured the engine and then diverted to ZZZ2. Landed and deplaned the passenger without incident. This problem seems to be mechanical. I think very little could have been done from the pilot point of view to prevent this.

Google
 

Original NASA ASRS Text

Title: FLT CREW OF BE19 SECURE ENGINE AND DIVERT TO NEAREST SUITABLE ARPT AFTER LOSS OF OIL PRESSURE AND SMOKE IN COCKPIT.

Narrative: DSNDING INTO ZZZ1 OUT OF 16000 FT MSL TO 10000 FT SMOKE CAME INTO THE CABIN; SHORTLY AFTER LOST OIL PRESSURE; SECURED THE ENG AND THEN DIVERTED TO ZZZ2. LANDED AND DEPLANED THE PAX WITHOUT INCIDENT. THIS PROB SEEMS TO BE MECHANICAL. I THINK VERY LITTLE COULD HAVE BEEN DONE FROM THE PLT POINT OF VIEW TO PREVENT THIS.

Data retrieved from NASA's ASRS site as of January 2009 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.