# Proposed AD FAA-2013-0486: MD Helicopters, Inc. (MDHI), Helicopters

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2013-20-16
- Products: MD Helicopters
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: June 14, 2013, 78 FR 35773
- Comments due: August 13, 2013
- Became: [AD 2013-20-16](https://openairdocs.org/ad/2013-20-16)
- Docket: FAA-2013-0486 (https://www.regulations.gov/docket/FAA-2013-0486, where comments are filed)
- Project: 2010-SW-031-AD
- FR document: 2013-14139
- Official PDF: https://openairdocs.org/files/sha256/f7/17/f7178e51377e3cce4925c660e64e89a215cb5cfce9352bef972f0197c0407671 (from https://www.govinfo.gov/content/pkg/FR-2013-06-14/pdf/2013-14139.pdf)
- Federal Register: https://www.federalregister.gov/documents/2013/06/14/2013-14139/airworthiness-directives-md-helicopters-inc-mdhi-helicopters
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/63571402DC99FAF186257B8A00481F78.0001
- Page: https://openairdocs.org/proposed/FAA-2013-0486

## Summary

We propose to adopt a new airworthiness directive (AD) for the MDHI Model MD900 helicopters with certain main rotor blade (MRB) retention bolts (bolts) installed. This proposed AD would require a daily check of the position of each bolt and would also require a daily check and a repetitive inspection for a gap in each bolt. The proposed AD would also require, if necessary, removing and inspecting the bolt for a crack and replacing any cracked bolt with an airworthy bolt. This proposed AD is prompted by multiple reports of in-service bolt failures. The proposed actions are intended to prevent failure of a bolt, which could lead to loss of MRB structural integrity and subsequent loss of control of the helicopter.

## Notices in this docket

- Jun 14, 2013: Notice of proposed rulemaking (NPRM). (first notice), FR document 2013-14139, comments due Aug 13, 2013 (https://www.federalregister.gov/documents/2013/06/14/2013-14139/airworthiness-directives-md-helicopters-inc-mdhi-helicopters)

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