# Airworthiness Directives; McDonnell Douglas Helicopter Systems Model MD-900 Helicopters
> **Rule** · Final rule; request for comments. · Published 1997-06-25 · Effective 1997-07-10 · 62 FR 34163
## Document
- **Document number:** 97-16568
- **Category:** airworthiness
- **Manufacturer:** McDonnell Douglas Helicopter Systems Model MD-900
- **Type:** Rule
- **Action:** Final rule; request for comments.
- **Citation:** 62 FR 34163
- **Publication date:** 1997-06-25
- **Effective date:** 1997-07-10
- **FAA docket:** Docket No. 96-SW-35-AD
## Abstract

This amendment adopts a new airworthiness directive (AD) that is applicable to McDonnell Douglas Helicopter Systems (MDHS) Model MD- 900 helicopters. This action requires applying specified serial numbers to the left and right vertical stabilizer control system (VSCS) bellcrank assemblies, the forward and aft deck-fitting assemblies, and the mid-forward and mid-aft truss strut assemblies; and establishes new life limits for the non-rotating swashplate assembly, the collective drive link assembly, and the self-aligning, spherical/slider main rotor bearing. This amendment is prompted by additional manufacturer's analysis which indicates a need for the reduction of the life limit on several parts and the addition of non-serialized parts to the life- limited parts list. The actions specified in this AD are intended to establish a life limit for various parts and reduce the current life limit on other parts.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1997/06/25/97-16568/airworthiness-directives-mcdonnell-douglas-helicopter-systems-model-md-900-helicopters)
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