Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument
Flight Crew Last 90 Days 195; Flight Crew Total 493; Flight Crew Type 225
Situational Awareness; Training / Qualification
Ground Event / Encounter Loss Of Aircraft Control; Ground Excursion Runway
Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification
Human Factors
Changed pattern from Runway 2 to Runway 14; we were already on base by then for Runway 14. Approach setup was fine; we entered the flare fine; landed and then immediately heard the left tire screeching. The student had locked up the left brake. I tried taking controls and pushing on the right rudder; however he was overpowering me. So we ended up skidding off the runway to the left. We did a ground loop and came to a stop. The prop luckily never struck the ground; and the tires were still inflated by the end of it. I quickly shut down the aircraft and shut off the fuel following. Tower asked if we needed assistance; and I said yes.Something that can be done to prevent this is to really make sure to look at your student's setup getting into the plane; ensure that the student has his/her seat adjusted properly and cannot lock his/her leg into place. We were also given strictly a touch and go; so in our case we should have just stuck with a 'Go around'; or 'Low approach'. Something that I can do better as an instructor is to really harp on brakes; and proper foot placement on the rudder. I already use 'Heels on the deck' for takeoff; and can also use it again on landing.
PA-28 instructor pilot reported the student lost directional control on the landing roll after locking up the left brake.