AD 49-52-02

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AD Number:
49-52-02
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Bell Model 47B, 47B3, 47D, and 47D1 Series Helicopters
Subject:
Main Rotor Hub Inspection
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
Make:
Scotts-Bell 47 Inc
Model:
47B | 47B3 | 47D | 47D1
Product Type:
Aircraft
Product Subtype:
Rotorcraft
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 49-52-02
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   49-52-02

SUBJECT HEADING:   Airworthiness Directives; Bell Model 47B, 47B3, 47D, and 47D1 Series Helicopters

ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
49-52-02 BELL: Applies to All Models 47B, 47B3, 47D, and 47D1 Series Helicopters.

Compliance required as indicated.

As a result of recent accidents, the following precautionary measures should be taken:

1. The main rotor hub (Bell P/N 47-120-136-1) must be replaced if it has been involved in an accident or sudden stoppage, for any reason, in which the following has occurred:

(a) One or both main rotor blades were damaged to the extent that the steel core shows through the wood at any point.

(b) A drag brace end fitting or the equalizer horn, or both, are damaged or distorted.

(Bell Service Bulletin No. 65, dated August 2, 1949, covers the subject of this portion of the directive.)

2. All aluminum main rotor hubs (Bell P/N 47-120-136-1) must be replaced after 600 hours of operation unless it is necessary to replace them sooner as a result of being affected by the requirements of paragraph 1. In order to assist those operators who possess a part which has over 600 hours accumulated at the time of receipt of this directive, the following latitude in replacing the parts is permitted:

Accumulated Time on Hub at Time of this Directive	Replacement Limit
0-500 hours	At 600 hours
501-800	Within the next 100 hours
801-899	At 900 hours
900 and up	Before the next flight

Hubs with less than 300 hours must be inspected visually (with a 10- to 20-power glass) at 300 hours, in addition to the inspections required by the manufacturers "Erection and Maintenance Manual" for the particular model. During this inspection, specific attention must be directed toward locating fatigue cracks in the shotpeened fillet radius, particularly on the leading edge side. The discovery of cracks in any portion of this radius is cause for immediate replacement of the part. In addition to the execution of the Form FAA 1226, "Malfunctioning and Defects Report," such a discovery should be reported immediately to the Bell Aircraft Corp., together with the number of hours accumulated on the hub, the serial number of the hub, model and serial number of the helicopter on which it was installed, and a statement to indicate whether or not the part had been involved in an accident such as described in paragraph 1.

This supersedes AD 49-35-02.

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