Date: 201909
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: Skyhawk 172/Cutlass 172
Operator: FBO
Operating under: Part 91
Mission: Training
Flight phase: Takeoff / Launch
Airspace: Class G ZZZ
ATC / advisory: Tower ZZZ
Reporter organization: FBO
Reporter function: Instructor; Pilot Flying
Reporter qualification: Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Commercial
Human factors: Situational Awareness; Training / Qualification
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Ground Strike - Aircraft; Ground Event / Encounter Loss Of Aircraft Control; Ground Excursion Runway; Inflight Event / Encounter Unstabilized Approach
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Aircraft Damaged; General Maintenance Action
Contributing factors: Company Policy; Human Factors; Procedure
Primary problem: Human Factors

Narrative: My student was flying the pattern at ZZZ; landing RWY XX. Student had controls on short final and was going a little fast (70kts) on short final; he noticed and pulled the power to idle and verified full (30degrees) of flaps. I was shadowing the controls and helped get him into ground effect. Upon touchdown; the mains didn't fully touch down and the airplane was still flying. ZZZ's runway is [fairly short]; and my company doesn't allow touch and go's. Upon the mains fully coming down; I began to fully brake. I didn't retract flaps because I knew at any moment I might need to add full power and didn't want the loss of lift (associated with retracting flaps) to cause a sink or unusual attitude right over the runway. With approximately 400 feet of runway remaining I was still applying full brakes. With approximately 300 ft of runway remaining; we were not reading an airspeed but I estimate it around 40 knots; too fast to make a complete stop but not fast enough to take back off. Right before the threshold numbers (XY) I decided that I would continue to brake (fearing any attempt to try and take back off would lead to a potential stall...I did not know if we were above or below stall speed and the thought of stalling upon take off was something I wanted to avoid. Realizing we didn't have enough usable runway to make a complete stop; I continued to apply full brakes but I'm not sure if one of the brakes locked up or if the brakes were applying uneven braking; but the airplane veered to the right and off the end of the runway and down a slope. I immediately cut the mixture (right about passing RW XY numbers). We went down the hill to the right. Both myself; the instructor; and my student were not injured at all. The airplane came to a stop in the grass and the nose wheel deflated after rolling over a rock; resulting in the propeller to lightly strike the ground (there were small marks on the prop and grass marks). Once going down the hill we both braced and the airplane came to a complete stop at which time I removed the keys; turned the master battery off and assured the fuel cut off valve was pulled.




Synopsis: C172 instructor reported aircraft departed runway during landing roll out.