Analyzing Failure


On October 9, 2013, in Xenia, Ohio, a Piper PA-46-350P Malibu Mirage sustained a nosewheel failure and departed the runway after landing. There were no injuries.

According to the NTSB, after the pilot lowered the nosewheel to the runway, “the airplane began to pull quickly to the left. He applied right brake and pulled back on the yoke, but the airplane continued to veer off the left side of the runway. The airplane traveled about 500 feet before the nose gear collapsed back into the wheel well, and the airplane’s nose and propeller impacted the ground.”

Investigation revealed the engine mount had fractured in the area of the nose gear actuator feet. The component was the subject of a Mandatory Service Bulletin (SB 1103D) issued by Piper on February 2, 2011, and mandating a 100-hour inspection of the engine mount’s nose gear actuator feet for cracks. This accident occurred about 81 flight hours after a previous inspection under SB 1103D.

Post-accident examination revealed “paint around the engine mount attach feet area was only partially removed and not as specified in the SB.” Microscopic examination revealed “fracture features indicative of fatigue progression in many areas.” Even though the paint removal process was not accomplished per the Piper SB, the fatigue fracture was “in the area where the paint had been removed and should have been detectable during the inspection.” The image on page 8 shows the failed engine mount and where paint was removed to perform the earlier inspection.

Additional images from the NTSB’s Materials Laboratory Division include results obtained from high-magnification optical and scanning electron microscopy. The gray-scale images are from Area E described above and evidence “recontact mechanical damage” in the center view and “fatigue striations” at bottom.

The NTSB’s probable cause determination: “The nose landing gear failure as a result of a fatigue fracture of the engine mount nose gear actuator feet in an area detailed in a service bulletin. Contributing to the accident was maintenance personnel’s inadequate completion of the inspection specified in the service bulletin.”


Please enter your comment!
Please enter your name here