# Proposed AD FAA-2011-0646: Gulfstream Aerospace LP Model Galaxy and Gulfstream 200 Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2011-20-04
- Products: Gulfstream Aerospace LP
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: June 29, 2011, 76 FR 38062
- Comments due: August 15, 2011
- Became: [AD 2011-20-04](https://openairdocs.org/ad/2011-20-04)
- Docket: FAA-2011-0646 (https://www.regulations.gov/docket/FAA-2011-0646, where comments are filed)
- Project: 2010-NM-224-AD
- FR document: 2011-16314
- Official PDF: https://openairdocs.org/files/sha256/a5/88/a58880bf6b5dab943908fc5f3f2eb5b85e21e81babc3d0217e372e6733b6cb54 (from https://www.govinfo.gov/content/pkg/FR-2011-06-29/pdf/2011-16314.pdf)
- Federal Register: https://www.federalregister.gov/documents/2011/06/29/2011-16314/airworthiness-directives-gulfstream-aerospace-lp-model-galaxy-and-gulfstream-200-airplanes
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/EFDB45D16CF9AA2F862578BE004FFC54.0001
- Page: https://openairdocs.org/proposed/FAA-2011-0646

## Summary

We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:

Cracked nuts * * * were found on aircraft's production line during routine post assembly inspection. Investigation revealed that the cracks resulted from hydrogen embrittlement combined with high hardness. Non-conformity with certified mechanical properties of this fastener can potentially lead to an unsafe condition.

The unsafe condition is cracked nuts in multiple locations (including aileron fittings, rudder tab assembly and mounting structure for power drive units) could result in failure of affected locations and consequent reduced controllability or reduced structural capability of the airplane. The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.

## Notices in this docket

- Jun 29, 2011: Notice of proposed rulemaking (NPRM). (first notice), FR document 2011-16314, comments due Aug 15, 2011 (https://www.federalregister.gov/documents/2011/06/29/2011-16314/airworthiness-directives-gulfstream-aerospace-lp-model-galaxy-and-gulfstream-200-airplanes)

---
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.