# Airworthiness Directives; The Boeing Company Model 747-200B, -300, -400, -400D, and -400F Series Airplanes Powered by Pratt and Whitney 4000 or General Electric CF6-80C2 Series Engines
> **Rule** · Final rule. · Published 2011-05-02 · Effective 2011-06-06 · 76 FR 24349
## Document
- **Document number:** 2011-9919
- **Category:** airworthiness
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 76 FR 24349
- **Publication date:** 2011-05-02
- **Effective date:** 2011-06-06
- **FAA docket:** Docket No. FAA-2010-1111
## Abstract

We are adopting a new airworthiness directive (AD) for the products listed above. This AD requires an inspection to determine the part number of the mid-pivot access door and to determine if the correct door is installed, and the installation of a marker on the mid- pivot access door, and if necessary, repetitive ultrasonic inspections for cracking of the mid-pivot bolt assembly and eventual replacement of the mid-pivot bolt assembly. This AD was prompted by a report that the left and right access doors of the spring beam mid-pivot bolt assembly for the No. 1 strut were inadvertently installed in the incorrect position during strut modification. We are issuing this AD to detect and correct incorrectly installed mid-pivot bolt assemblies on the spring beam on the outboard struts. Incorrectly installed bolt assemblies could lead to fatigue cracking and consequent fracturing of the mid-pivot bolt assembly, which could lead to loss of the spring beam load path and the possible separation of a strut and engine from the airplane during flight.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2011/05/02/2011-9919/airworthiness-directives-the-boeing-company-model-747-200b--300--400--400d-and--400f-series)
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