# Proposed AD FAA-2005-21719: Hamilton Sundstrand Power Systems (formerly Sundstrand Power Systems) Auxiliary Power Units Models T-62T- 46C2, T-62T-46C2A, T-62T-46C3, T-62T-46C7, and T-62T-46C7A

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2005-23-11
- Products: Hamilton Sundstrand
- Product type: Appliance
- Action: Notice of proposed rulemaking (NPRM).
- Published: July 5, 2005, 70 FR 38625
- Comments due: September 6, 2005
- Became: [AD 2005-23-11](https://openairdocs.org/ad/2005-23-11)
- Docket: FAA-2005-21719 (https://www.regulations.gov/docket/FAA-2005-21719, where comments are filed)
- Project: 2005-NE-19-AD
- FR document: 05-13134
- Official PDF: https://openairdocs.org/files/sha256/02/8b/028bc4c950f8b35bff317fa8cc9bba862ab10f406b655c4b0ba2d3530dd341af (from https://www.govinfo.gov/content/pkg/FR-2005-07-05/pdf/05-13134.pdf)
- Federal Register: https://www.federalregister.gov/documents/2005/07/05/05-13134/airworthiness-directives-hamilton-sundstrand-power-systems-formerly-sundstrand-power-systems
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/3A07EA524A51F3B286257035006B48D9.0001
- Page: https://openairdocs.org/proposed/FAA-2005-21719

## Summary

The FAA proposes to adopt a new airworthiness directive (AD). The new AD is for Hamilton Sundstrand Power Systems (formerly Sundstrand Power Systems) auxiliary power units (APUs) models T-62T- 46C2, T-62T-46C2A, T-62T-46C3, T-62T-46C7, and T-62T-46C7A, with compressor impeller assembly, part number (P/N) 4502020 or 4502020A, installed. This proposed AD would require removal from service of those compressor impeller assemblies at reduced service life limits. This proposed AD results from two reports of uncontained failures of compressor impeller assemblies. We are proposing this AD to prevent an uncontained APU failure and damage to the airplane.

## Notices in this docket

- Jul 5, 2005: Notice of proposed rulemaking (NPRM). (first notice), FR document 05-13134, comments due Sep 6, 2005 (https://www.federalregister.gov/documents/2005/07/05/05-13134/airworthiness-directives-hamilton-sundstrand-power-systems-formerly-sundstrand-power-systems)

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