Accident Description
During the landing roll, the nose landing gear of the aircraft collapsed. An examination of the nose landing gear determined that the drag link bolt, part number AN4-27, which connects the upper and lower drag link assemblies, was worn and failed, leading to the collapse.
Examination Findings
The inspection revealed that the drag link bolt (AN4-27) had worn and failed. According to the Illustrated Parts Catalog revised November 1982 and subsequent revisions, the specified bolt for this assembly is a NAS464P4-27 bolt, part number 402 940. The change from the AN4-27 bolt to the NAS464P4-27 was reported to be due to a production change.
Service Bulletin
On July 29, 1986, Piper Aircraft issued a service letter advising owners of certain PA-44-180 aircraft of a modification to the nose landing gear. The modification requires, in part, the replacement of the drag link assembly bolt with the NAS bolt.