The pilot receiving instruction and the flight instructor were conducting an instructional flight in the Piper PA-34-200. During the approach to the airport in Umatilla, Florida, the pilot receiving instruction lowered the landing gear, and the instructor confirmed that the down-and-locked indications were all green.
After touchdown and during the landing roll, the airplane suddenly entered an uncommanded and violent right swerve, which the pilot could not correct with full left brake, rudder, and aileron inputs. The plane departed the runway and hit a drainage ditch.
Post-accident examination of the airplane revealed that the upper and lower torque links of the right main landing gear (MLG) were undamaged and not attached. The attachment hardware was not in place nor recovered.
Examination of the left MLG revealed that the upper and lower torque links remained connected, but a cotter pin was not found installed through the castellated nut and drilled bolt.
A review of the airplane’s maintenance logbooks revealed that, about a month before the accident, the attachment hardware for the left and right torque links was replaced, which included the installation of cotter pins.
The mechanic who signed off the inspection stated that, during subsequent maintenance, both torque links’ cotter pins were removed and that, although the attachment hardware at both torque links was subsequently tightened, neither of the torque link’s cotter pins were installed before the airplane was approved for return to service.
Therefore, it is likely that the right MLG torque link attachment hardware loosened over time due to the lack of a cotter pin and eventually separated from the airplane, which resulted in the torque link becoming disconnected and led to the pilot’s subsequent inability to maintain directional control during landing.
Probable cause: Maintenance personnel’s failure to complete and verify the proper installation of the main landing gear (MLG) torque links’ attachment hardware, which resulted in the right MLG torque link disconnecting and the pilot’s subsequent inability to maintain directional control during the landing roll.
NTSB Identification: ERA18LA178
This June 2018 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Not so much a preflight but an extensive post maintenance inspection.
Statically my Mooney would have performed flawlessly over the last 35 years had it never been touched for maintenance.
The reality is it would have crashed 5 times due to maintenance discrepancies induced during mandatory inspections had i not found the problems before the next flight.
Gotta love FAA mandatory maintenance performed by FAA certified mechanics….for my protection and well being.
So in this case is the liability placed on the maintenance guy only or it’s shared between the maintenance guy and pilot since he probably didn’t do the preflight check given there is no preflight checklist unless I missed that part?
Always do the most comprehensive preflight after returning your acft. to service from maintenance. Unbelievable the many discrepancies that I have found over the years!
Then you might be the next one who lands with a main or nosegear cocked sideways. Whenever you see a castle nut, look for a cotter pin. Period.
I used to do FAA inspections on amateur aircraft. Missing cotter pins was way up the list of common discrepancies.
Like I said, in the real world, this could easily be missed.
A PA-34 is a Seneca, and has retractable gear….no wheel pants to hide anything. A proper preflight would include squatting down and checking the nose and main gear, including the torque links. I don’t have one handy, but I’m sure Piper had published a preflight checklist.
I am just wondering as I am not familiar with that aircraft: would that issue have been noticed during a preflight check?
Would not look for a cotter pin through these nuts on the typical preflight. Even a thorough preflight could easily miss seeing this.
What a shame. It can happen, but after the maintenance, the mechanic should have performed a preflight check (so should have the pilot), and this oversight would/should have been caught.
Maintenance is one thing…. inspection is another.
It happens. I once forgot to place the bolt onto the nut attaching the aileron the its hinge. I flew the airplane that way once, then found my error. I just about p**ped my pants!