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Casualties unknown

Nose Gear Retraction Failure Following Incorrect Bolt Installation (N4886T)

Hickory, NC, US

On July 1, 1984, a Piper PA-34-200 (registration N4886T) was involved in an aviation accident near Hickory, NC. Investigators recorded the probable cause as: Improper installation of the nose gear centering spring assembly bolt, which was installed head up and secured with a castlenut and cotter key instead of head down with a lock nut as specified in the maintenance manual, causing the bolt to hang up in the gear… This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-07-04Data APIEditorial standards

An aircraft landed with its nose gear retracted; investigation revealed a bolt securing the nose gear centering spring assembly was incorrectly installed, causing interference.

Accident

An aircraft landed with its nose gear retracted. Examination determined that the nose gear was stuck in the wheel well due to an AN4-12 bolt, which secures the nose gear centering spring assembly, becoming hung up in the gear door linkage.

Maintenance and Inspection

An annual inspection had been completed 20 flight hours prior to the accident. During that inspection, the bolt and bushings on the shimmy dampener were replaced. The Piper PA-34 maintenance manual specifies that the correct bolt for this installation is an AN24-20A, to be installed with the bolt head down and secured with a MS20364-428C lock nut. The bolt that caused the hang-up was installed with the bolt head up and secured with a castlenut and cotter key.

Service Bulletin

Piper Service Letter 852, dated September 14, 1978, addressed the potential for improper installation of this bolt and announced the availability of a placard to remind mechanics of the required installation method. The service letter notes that when the bolt is installed incorrectly, nose gear operation can be restricted in the gear-up position. This non-mandatory service letter had not been complied with on the accident aircraft, registered N4886T.

Probable cause

Improper installation of the nose gear centering spring assembly bolt, which was installed head up and secured with a castlenut and cotter key instead of head down with a lock nut as specified in the maintenance manual, causing the bolt to hang up in the gear door linkage and restrict nose gear retraction.
Maintenance error

Frequently asked questions

What happened in the 1 Jul 1984 Piper PA-34-200 accident near Hickory, NC?

An aircraft landed with its nose gear retracted; investigation revealed a bolt securing the nose gear centering spring assembly was incorrectly installed, causing interference.

What aircraft was involved and where did it happen?

The accident on 1 Jul 1984 involved a Piper PA-34-200, registration N4886T, at Hickory, NC.

What was the probable cause of the accident?

Improper installation of the nose gear centering spring assembly bolt, which was installed head up and secured with a castlenut and cotter key instead of head down with a lock nut as specified in the maintenance manual, causing the bolt to hang up in the gear door linkage and restrict nose gear retraction.

More accident analyses

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001214X40185. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.