C150 flight instructor reported an near midair collision with another light aircraft in the vicinity...

Attributes
ACN	1480147
Time
Date	201709
Local Time Of Day	1201-1800
Place
Locale Reference	C81.Airport
State Reference	IL
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Make Model Name	Cessna 150
Operating Under FAR Part	Part 91
Flight Phase	Descent
Aircraft 2
Make Model Name	Golden Eagle 421
Flight Phase	Initial Approach
Person 1
Function	Instructor Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Instrument Flight Crew Flight Instructor
Experience	Flight Crew Last 90 Days 115 Flight Crew Total 8500 Flight Crew Type 250
Events
Anomaly	Conflict NMAC
Miss Distance	Horizontal 100 Vertical 300

Narrative:

[We were] 2 miles west of the campbell airport (C81). I was conducting a training flight in the cessna 150. The sky condition was marginal VFR with scattered and broken clouds at 3;000 feet. I found an opening that allowed us to fly 500 feet below and 2;000 feet horizontal from the clouds. At this time I had observed a cessna 421 at a slight right descending turn; at our approximately 11:30 position and a quarter-mile in distance. By my estimate we passed each other at less than 500 feet. We continued our training flight and landed at C81. As for corrective actions: I will now always contact approach control while doing maneuvers in this area. Highly recommend to flight school owner the installation of ads-B in and out equipment in our training aircraft. Change my personal and flight school policy about flying in marginal VFR conditions.

Original NASA ASRS Text

Title: C150 flight instructor reported an NMAC with another light aircraft in the vicinity of C81 airport.

Narrative: [We were] 2 miles west of the Campbell airport (C81). I was conducting a training flight in the Cessna 150. The sky condition was marginal VFR with scattered and broken clouds at 3;000 feet. I found an opening that allowed us to fly 500 feet below and 2;000 feet horizontal from the clouds. At this time I had observed a Cessna 421 at a slight right descending turn; at our approximately 11:30 position and a quarter-mile in distance. By my estimate we passed each other at less than 500 feet. We continued our training flight and landed at C81. As for corrective actions: I will now always contact Approach Control while doing maneuvers in this area. Highly recommend to flight school owner the installation of ADS-B in and out equipment in our training aircraft. Change my personal and flight school policy about flying in marginal VFR conditions.

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.

C150 flight instructor reported an near midair collision with another light aircraft in the vicinity of C81 airport.