SR22 pilot reported a loss of oil pressure while on approach.

Narrative:

I was flying an IFR flight. About 10 miles west of [destination] at 3000 feet; I noticed a steady decline in the oil pressure. I thought it might be a sensor at first; but the gauge was steadily declining vs. Jumping around; so I thought there was a potentially serious problem with the plane. At the time; ATC was vectoring me for a visual approach. I knew that I was likely to be brought down towards beach before being turned inland for the final approach. I requested being granted priority handling and they told me to descend to 1600 feet. After a few seconds; I decided that it would be best to get the plane on the ground vs. Continuing south and risk an engine loss over a heavily populated area so I [advised ATC]. I was asked [which runway I wanted]. I took a runway straight in from my position. When I landed; tower informed me that there was a trail of black smoke behind me. I took off with 7 quarts of oil and when I landed I had just over 1; so an engine out scenario was in fact imminent.

Original NASA ASRS Text

Title: SR22 pilot reported a loss of oil pressure while on approach.

Narrative: I was flying an IFR flight. About 10 miles west of [destination] at 3000 feet; I noticed a steady decline in the oil pressure. I thought it might be a sensor at first; but the gauge was steadily declining vs. jumping around; so I thought there was a potentially serious problem with the plane. At the time; ATC was vectoring me for a visual approach. I knew that I was likely to be brought down towards beach before being turned inland for the final approach. I requested being granted priority handling and they told me to descend to 1600 feet. After a few seconds; I decided that it would be best to get the plane on the ground vs. continuing south and risk an engine loss over a heavily populated area so I [advised ATC]. I was asked [which runway I wanted]. I took a runway straight in from my position. When I landed; tower informed me that there was a trail of black smoke behind me. I took off with 7 quarts of oil and when I landed I had just over 1; so an engine out scenario was in fact imminent.

Data retrieved from NASA's ASRS site 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.

Attributes
ACN	1420673
Time
Date	201701
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	SR22
Operating Under FAR Part	Part 91
Flight Phase	Initial Approach
Route In Use	Visual Approach
Flight Plan	IFR
Component
Aircraft Component	Powerplant Lubrication System
Person 1
Function	Pilot Flying
Qualification	Flight Crew Instrument Flight Crew Private
Experience	Flight Crew Last 90 Days 26 Flight Crew Total 173 Flight Crew Type 139
Events
Anomaly	Aircraft Equipment Problem Critical