# Leonardo Alert Service Bulletin 139-450

## Copies (5)

Copies the FAA filed in AD dockets on regulations.gov, newest revision first. A newer revision may exist.

- Revision D ("Leonardo Helicopters ASB No. 139-450 Rev D"), 59 pages: PDF https://openairdocs.org/files/sha256/a1/7b/a17b630e58acc9da3656bd9abd7bfe79e9c3bb836f5174fedee7bbfbe60a3751; text https://openairdocs.org/service-documents/leonardo/sb-139-450/file/a17b630e58ac.md. Rights: © Leonardo S.p.A. Filed by the FAA in regulations.gov docket FAA-2020-0283; AD 2021-23-22 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication.
- Revision C ("Leonardo Helicopters ASB No. 139-450 Rev C"), 58 pages: PDF https://openairdocs.org/files/sha256/3b/f2/3bf2445cb83dd4df860172b9b879194374b8edc3d8a25e5aa9e094ba0c293f15; text https://openairdocs.org/service-documents/leonardo/sb-139-450/file/3bf2445cb83d.md. Rights: © Leonardo S.p.A. Filed by the FAA in regulations.gov docket FAA-2020-0283; AD 2021-23-22 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication.
- Finmeccanica Helicopter Division BT 139-450 ("Finmeccanica Helicopter Division BT 139-450"), 49 pages: PDF https://openairdocs.org/files/sha256/b0/8f/b08f152ff9578f737de2907f702aa6af19819ba8265a1f1d3e6eef65fc05a9a1; text https://openairdocs.org/service-documents/leonardo/sb-139-450/file/b08f152ff957.md. Rights: © Leonardo S.p.A. Filed by the FAA in regulations.gov docket FAA-2020-0283; AD 2021-23-22 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication.
- Finmeccanica Helicopter Division BT 139-450 Rev A ("Finmeccanica Helicopter Division BT 139-450 Rev A"), 61 pages: PDF https://openairdocs.org/files/sha256/6f/27/6f27c32325492c190dfae14e907e7f97e5808862bec75c20f65596a4acb3a5eb; text https://openairdocs.org/service-documents/leonardo/sb-139-450/file/6f27c3232549.md. Rights: © Leonardo S.p.A. Filed by the FAA in regulations.gov docket FAA-2020-0283; AD 2021-23-22 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication.
- Leonardo Helicopters BT No. 139-450 Rev B ("Leonardo Helicopters BT No. 139-450 Rev B"), 63 pages: PDF https://openairdocs.org/files/sha256/75/8f/758f55ab3fdd15b741f2c905ca41906007282cf55f5e9cd84301bc396c67c0f3; text https://openairdocs.org/service-documents/leonardo/sb-139-450/file/758f55ab3fdd.md. Rights: © Leonardo S.p.A. Filed by the FAA in regulations.gov docket FAA-2020-0283; AD 2021-23-22 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication.

## Details

- Manufacturer: [Leonardo](https://openairdocs.org/service-documents/leonardo.md)
- Type: Service bulletin (Alert Service Bulletin)
- Number: 139-450
- Latest revision known: 139-450, Revision D, dated May 28, 2019 (OpenAirDocs)
- Page: https://openairdocs.org/service-documents/leonardo/sb-139-450

## ADs that cite it (1) (OpenAirDocs)

Newest first, with the revision each names, as OpenAirDocs read it from the AD's text.

- [AD 2021-23-22](https://openairdocs.org/ad/2021-23-22.md), effective Jan 18, 2022: Revision D

Also cited in [1 proposed AD](https://openairdocs.org/service-documents/leonardo/sb-139-450/proposed.md).

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain, except the copies of manufacturers’ service documents, which belong to their rights holders.