What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(.4)During the landing roll, the agricultural airplane departed the right side of the runway, rolled into soft terrain, and subsequently nosed over to the inverted position. The pilot reported that during the landing roll, his seat became dislodged from the seat track. He further reported that since his left leg is shorter than his right leg, when the seat slid all the way back, it caused his left foot to lose contact with the rudder pedal. Examination of the seat by an FAA inspector revealed that the forward left seat roller housing assembly had spread open to near the width of the seat rail, allowing the seat to dislodge from the locked position. According to the inspector, the airplane's maintenance records indicated that AD 87-20-03 R2 (to assure proper engagement of the seat locking mechanism and to preclude inadvertent seat slippage) had been complied with at the last annual inspection. However, the inspector stated that the AD had not been properly accomplished, since his examination of the seat revealed that it did not meet the locking pin engagement requirements of the AD. Time since the last annual inspection was 249.4 hours. (-23)on August 30, 1999 this commerical pilot lost directional control of his agricultural aircraft during the landing sequence when the pilot seat became dislodged from the seat track and slid all the way back causing the pilots left foot to loose contact with the rudder pedal. The pilot had polio and his left leg is shorter than the right. The aircraft left the runway to the right and rolled a short distance in the soft sand before flipping over on it's back causing substantial damage. During the flip over the seat came off of the seat track completely. The pilot suffered a cracked vertebra and multiple concussions. VFR conditions prevailed for this 14 CFR part 137 flight. Post accident investigation revealed that the part number 0700645-1 housing assembly-seat roller fwd LH had spread open to near the width of the seat rail allowing the seat to dislodge from the locked position. This investigation is over.
As the FAA filed it
(.4)DURING THE LANDING ROLL, THE AGRICULTURAL AIRPLANE DEPARTED THE RIGHT SIDE OF THE RUNWAY, ROLLED INTO SOFT TERRAIN, AND SUBSEQUENTLY NOSED OVER TO THE INVERTED POSITION. THE PILOT REPORTED THAT DURING THE LANDING ROLL, HIS SEAT BECAME DISLODGED FROM THE SEAT TRACK. HE FURTHER REPORTED THAT SINCE HIS LEFT LEG IS SHORTER THAN HIS RIGHT LEG, WHEN THE SEAT SLID ALL THE WAY BACK, IT CAUSED HIS LEFT FOOT TO LOSE CONTACT WITH THE RUDDER PEDAL. EXAMINATION OF THE SEAT BY AN FAA INSPECTOR REVEALED THAT THE FORWARD LEFT SEAT ROLLER HOUSING ASSEMBLY HAD SPREAD OPEN TO NEAR THE WIDTH OF THE SEAT RAIL, ALLOWING THE SEAT TO DISLODGE FROM THE LOCKED POSITION. ACCORDING TO THE INSPECTOR, THE AIRPLANE'S MAINTENANCE RECORDS INDICATED THAT AD 87-20-03 R2 (TO ASSURE PROPER ENGAGEMENT OF THE SEAT LOCKING MECHANISM AND TO PRECLUDE INADVERTENT SEAT SLIPPAGE) HAD BEEN COMPLIED WITH AT THE LAST ANNUAL INSPECTION. HOWEVER, THE INSPECTOR STATED THAT THE AD HAD NOT BEEN PROPERLY ACCOMPLISHED, SINCE HIS EXAMINATION OF THE SEAT REVEALED THAT IT DID NOT MEET THE LOCKING PIN ENGAGEMENT REQUIREMENTS OF THE AD. TIME SINCE THE LAST ANNUAL INSPECTION WAS 249.4 HOURS. (-23)ON AUGUST 30, 1999 THIS COMMERICAL PILOT LOST DIRECTIONAL CONTROL OF HIS AGRICULTURAL AIRCRAFT DURING THE LANDING SEQUENCE WHEN THE PILOT SEAT BECAME DISLODGED FROM THE SEAT TRACK AND SLID ALL THE WAY BACK CAUSING THE PILOTS LEFT FOOT TO LOOSE CONTACT WITH THE RUDDER PEDAL. THE PILOT HAD POLIO AND HIS LEFT LEG IS SHORTER THAN THE RIGHT. THE AIRCRAFT LEFT THE RUNWAY TO THE RIGHT AND ROLLED A SHORT DISTANCE IN THE SOFT SAND BEFORE FLIPPING OVER ON IT'S BACK CAUSING SUBSTANTIAL DAMAGE. DURING THE FLIP OVER THE SEAT CAME OFF OF THE SEAT TRACK COMPLETELY. THE PILOT SUFFERED A CRACKED VERTEBRA AND MULTIPLE CONCUSSIONS. VFR CONDITIONS PREVAILED FOR THIS 14 CFR PART 137 FLIGHT. POST ACCIDENT INVESTIGATION REVEALED THAT THE PART NUMBER 0700645-1 HOUSING ASSEMBLY-SEAT ROLLER FWD LH HAD SPREAD OPEN TO NEAR THE WIDTH OF THE SEAT RAIL ALLOWING THE SEAT TO DISLODGE FROM THE LOCKED POSITION. THIS INVESTIGATION IS OVER.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.