Cessna pilot reported a near midair collision while on base leg.

Attributes
ACN	1639594
Time
Date	201904
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Landing
Route In Use	Visual Approach
Flight Plan	None
Aircraft 2
Make Model Name	Skyhawk 172/Cutlass 172
Flight Phase	Final Approach
Flight Plan	None
Person 1
Function	Single Pilot
Qualification	Flight Crew Instrument Flight Crew Private
Experience	Flight Crew Last 90 Days 13 Flight Crew Total 259 Flight Crew Type 93
Events
Anomaly	Conflict NMAC
Miss Distance	Horizontal 300

Narrative:

I was midfield left downwind for [runway] 20 at ZZZ. Aircraft Y made a report for an 8 mile left base for [runway] 20. A couple of seconds later; aircraft Y reported close base. I then proceeded to announce I was just going to turn base and asked where they were at. As soon as I asked; he was less than 400 feet away on a collision course and made an immediate descending right turn to avoid. I was trying to get in communication with the pilot with no response.

Original NASA ASRS Text

Title: Cessna Pilot reported a NMAC while on base leg.

Narrative: I was midfield left downwind for [Runway] 20 at ZZZ. Aircraft Y made a report for an 8 mile left base for [Runway] 20. A couple of seconds later; Aircraft Y reported close base. I then proceeded to announce I was just going to turn base and asked where they were at. As soon as I asked; he was less than 400 feet away on a collision course and made an immediate descending right turn to avoid. I was trying to get in communication with the pilot with no response.

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.