C172 instructor reported landing long resulting in a runway excursion.

Attributes
ACN	1695392
Time
Date	201910
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Daylight
Aircraft 1
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Landing
Route In Use	None
Flight Plan	None
Person 1
Function	Instructor Pilot Not Flying
Qualification	Flight Crew Commercial Flight Crew Flight Instructor
Experience	Flight Crew Last 90 Days 75 Flight Crew Total 4500 Flight Crew Type 4500
Events
Anomaly	Ground Event / Encounter Loss Of Aircraft Control Ground Excursion Runway

Narrative:

Student could not stop the plane and over ran the end of the runway by about 20 feet. No damage or injury. Should have told student to go-around and since he did not; I should have lifted the flaps to gain more runway stopping action.

Original NASA ASRS Text

Title: C172 instructor reported landing long resulting in a runway excursion.

Narrative: Student could not stop the plane and over ran the end of the runway by about 20 feet. No damage or injury. Should have told student to go-around and since he did not; I should have lifted the flaps to gain more runway stopping action.

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.