PA28 pilot reported that while on final a cessna 172 turned base to final below him.

Attributes
ACN	1491216
Time
Date	201710
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	PA-28R Cherokee Arrow All Series
Operating Under FAR Part	Part 91
Flight Phase	Final Approach
Flight Plan	None
Aircraft 2
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Final Approach
Person 1
Function	Single Pilot Pilot Flying
Qualification	Flight Crew Commercial Flight Crew Flight Instructor Flight Crew Instrument
Experience	Flight Crew Last 90 Days 20 Flight Crew Total 560 Flight Crew Type 20
Events
Anomaly	Conflict NMAC
Miss Distance	Horizontal 100 Vertical 30

Narrative:

Landings practice was in process with a full pattern. All traffic was starting to have a longer than necessary downwind. On my final a cessna 172 approached me on base turning final under my altitude. I noticed them and took immediate corrective action by exiting the pattern to the right. Lack of communication was the largest problem in my opinion.

Original NASA ASRS Text

Title: PA28 pilot reported that while on final a Cessna 172 turned base to final below him.

Narrative: Landings practice was in process with a full pattern. All traffic was starting to have a longer than necessary downwind. On my final a Cessna 172 approached me on base turning final under my altitude. I noticed them and took immediate corrective action by exiting the pattern to the right. Lack of communication was the largest problem in my opinion.

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.