Piper cub instructor pilot reported a runway excursion with the aircraft flipping on its back when h...

Narrative:

The instructor and pilot were returning to the home airport after flying around the area performing landings at 6 various airports. On return; the pilot set up for final to runway xx and made a perfect wheel-landing on the grass runway. Upon landing and roll-out the aircraft started to veer slightly to the left. The pilot was told by instructor to give the aircraft slight right rudder to compensate. The pilot accidently pressed the right brake which sent the right wheel into the soft sandy grass. At this time the pilot also pushed the stick forward which sent the aircraft over. I; the instructor; had no option to recover the aircraft after the pilot accidentally pressed the right brake. I crawled out of the starboard side of the aircraft and turned off the master; starter; and fuel control. I then assisted the pilot out of the aircraft on the starboard side.even though the front cockpit pilot is a very competent commercial pilot he reacted incorrectly and opposite of the instructors' guidance direction which resulted in an incident that the instructor could not recover from. Once the brakes are applied while the aircraft still has momentum on roll-out the pilot (instructor or otherwise) no longer has control.my recommendation as a pilot and instructor in tail-wheel aircraft is that all people in tail-wheel aircraft be instructed to only use the brakes in times of an emergency when there is an obstacle on the ground and the tail wheel is firmly on the ground. The pilot was instructed in this way but it is pertinent that all pilots be taught in this procedure. Incidents can happen (as witnessed from this document) with this training; however; the training will lessen the frequency of such incidents occurring in the future.

Original NASA ASRS Text

Title: Piper Cub instructor pilot reported a runway excursion with the aircraft flipping on its back when his student inadvertently applied right brake when attempting to apply right rudder. Soft sand and forward stick caused the aircraft to flip.

Narrative: The instructor and pilot were returning to the home airport after flying around the area performing landings at 6 various airports. On return; the pilot set up for final to runway XX and made a perfect wheel-landing on the grass runway. Upon landing and roll-out the aircraft started to veer slightly to the left. The pilot was told by instructor to give the aircraft slight right rudder to compensate. The pilot accidently pressed the right brake which sent the right wheel into the soft sandy grass. At this time the pilot also pushed the stick forward which sent the aircraft over. I; the instructor; had no option to recover the aircraft after the pilot accidentally pressed the right brake. I crawled out of the starboard side of the aircraft and turned off the master; starter; and fuel control. I then assisted the pilot out of the aircraft on the starboard side.Even though the front cockpit pilot is a very competent commercial pilot he reacted incorrectly and opposite of the instructors' guidance direction which resulted in an incident that the instructor could not recover from. Once the brakes are applied while the aircraft still has momentum on roll-out the pilot (instructor or otherwise) no longer has control.My recommendation as a pilot and instructor in tail-wheel aircraft is that all people in tail-wheel aircraft be instructed to only use the brakes in times of an emergency when there is an obstacle on the ground and the tail wheel is firmly on the ground. The pilot was instructed in this way but it is pertinent that all pilots be taught in this procedure. Incidents can happen (as witnessed from this document) with this training; however; the training will lessen the frequency of such incidents occurring in the future.

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	1405976
Time
Date	201611
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	J3 Cub
Operating Under FAR Part	Part 91
Flight Phase	Landing
Person 1
Function	Instructor Pilot Not Flying
Qualification	Flight Crew Commercial Flight Crew Flight Instructor Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 75 Flight Crew Total 5825 Flight Crew Type 1200
Events
Anomaly	Ground Event / Encounter Loss Of Aircraft Control Ground Excursion Runway

Piper cub instructor pilot reported a runway excursion with the aircraft flipping on its back when his student inadvertently applied right brake when attempting to apply right rudder. Soft sand and forward stick caused the aircraft to flip.