# Airworthiness Directives; Eurocopter Deutschland GMBH Model MBB-BK 117 Helicopters
> **Rule** · Final rule. · Published 2001-01-22 · Effective 2001-02-26 · 66 FR 6453
## Document
- **Document number:** 01-1585
- **Category:** airworthiness
- **Manufacturer:** Eurocopter Deutschland GMBH Model MBB-BK 117
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 66 FR 6453
- **Publication date:** 2001-01-22
- **Effective date:** 2001-02-26
- **FAA docket:** Docket No. 99-SW-67-AD
## Abstract

This amendment supersedes an existing airworthiness directive (AD) that applies to Eurocopter Deutschland GMBH (ECD) Model MBB-BK 117 helicopters. That AD currently requires, before further flight, creating a component log card or equivalent record and determining the calendar age and number of flights on each tension-torsion (TT) strap. This amendment establishes a life limit for certain main rotor TT straps. This amendment is prompted by an accident in which a main rotor blade (blade) separated from an ECD Model MBB-BK 117 helicopter due to fatigue failure of a TT strap. The actions specified by this AD are intended to prevent fatigue failure of a TT strap, loss of a blade, and subsequent loss of control of the helicopter.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2001/01/22/01-1585/airworthiness-directives-eurocopter-deutschland-gmbh-model-mbb-bk-117-helicopters)
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