UNCONTROLLED FLIGHT INTO TERRAIN: SEAT SLIDES BACK
Pilot seats are constructed such that they have a tremendous variance in position. Normally full aft for getting in and out of the plane, and mostly forward for operation of the plane. This is so that the pilot can reach the pedals on the floor and be close to panel controls for operations. The total distance of travel on some planes is as much as 18 inches.
In this unfortunate scenario, a pilot seat can unlock and slide aft during the acceleration of takeoff. This causes the pilot to pull aft briskly on the control yoke or stick. From outside the plane, the aircraft appears to leap skyward in a very sharp climb until it stalls and returns to earth in an unsurvivable crash.
SOLUTION:
Very careful and frequent inspection or seat tracks by both maintenance personnel as well as each PIC in each aircraft during each and every preflight. Be aware of seat tracks with elongated holes where the locking pin could become dislodged during takeoff.
Compare other seat tracks as often as you can so that you can get an idea what good seat tracks look like compared to one with opportunity for a seat slide.
Be very proactive on seat track awareness and mechanism operation. Assure that the pilot seat is properly and firmly locked in place prior to every takeoff, and cannot slide aft.
SAMPLE ACCIDENT REPORT:
The National Transportation Safety Board determines the probable cause(s) of this accident to be: The flight instructor's failure to ensure that her seat was properly secured before initiating the takeoff, which resulted in a subsequent loss of control. Contributing was the lack of an installed secondary seat stop. NTSB Accident Number: ERA16FA141.