Landing and Deceleration
The aircraft touched down on a 2,432-foot runway that had a 224-foot displaced threshold at the approach end, installed due to nearby trees. The pilot reported landing with 25 degrees of flaps, touching down "somewhat down the runway past the threshold." Applying brakes produced little effect; the pilot attributed this to the flaps still generating lift on the wings.
Go-Around Decision
Realizing the aircraft was too far down the runway to safely abort the landing and execute a go-around, the pilot continued the landing roll. The aircraft subsequently departed the end of the runway and struck a ditch.
Aircraft Handling Guidance
The Piper PA-28 owner's handbook states that retracting flaps before applying brakes reduces the likelihood of skidding the tires.