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###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. 2003-SW-21-AD; Amendment 39-13424; AD 2004-01-10] 
          - RIN 2120-AA64 

# AGENCY:

Federal Aviation Administration, DOT. 

# ACTION:

Final rule; request for comments. 

# SUMMARY:

This amendment adopts a new airworthiness directive (AD) for Eurocopter Deutschland (Eurocopter) Model MBB-BK-117 A-1, A-3, A-4, B-1, B-2, and C-1 helicopters with a certain tail rotor (TR) transmission or intermediate (INT) gearbox installed. This action requires inspecting the magnetic plug of the TR transmission and INT gearbox for metal particles before the first flight of each day. Replacing an unairworthy TR transmission, INT gearbox, or bearings with airworthy parts is also required within 30 days after the effective date of this AD. This amendment is prompted by a report of production-related cracks on the cage of bearings installed in certain TR transmissions and INT gearboxes. This condition, if not corrected, could result in cracking and separation of the bearing cage, failure of a bearing, failure of the TR transmission or INT gearbox, and subsequent loss of control of the helicopter. 

# DATES:

Effective January 22, 2004. 

Comments for inclusion in the Rules Docket must be received on or before March 8, 2004. 

# ADDRESSES:

                        Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2003-SW-21-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. You may also send comments electronically to the Rules Docket at the following address:                         *9-asw-adcomments@faa.gov.*

# FOR FURTHER INFORMATION CONTACT:

Uday Garadi, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Safety Management Group, Fort Worth, Texas 76193-0110, telephone (817) 222-5123, fax (817) 222-5961. 

# SUPPLEMENTARY INFORMATION:

Luftfahrt-Bundesamt (LBA), the airworthiness authority for the Federal Republic of Germany, notified the FAA that an unsafe condition may exist on Eurocopter Model MBB-BK-117 A-1, A-3, A-4, B-1, B-2, and C-1 helicopters. The LBA advises that Eurocopter has been informed by the manufacturer of the TR transmission and INT gearbox that production-related cracks were found on the bearing cage, which could lead to parts of the cage separating and entering the TR transmission or INT gearbox. 

Eurocopter has issued Alert Service Bulletin No. ASB-MBB-BK117-30-108, Revision 1, dated July 4, 2003, which specifies replacing the TR transmission and INT gearbox or replacing the bearings in the TR transmission and INT gearbox by September 30, 2003. The alert service bulletin also specifies inspecting the magnetic plug before the first flight each day until the subject bearings are replaced. The LBA classified this alert service bulletin as mandatory and issued AD 2003-161, dated April 29, 2003, to ensure the continued airworthiness of these helicopters in the Federal Republic of Germany. 

These helicopter models are manufactured in the Federal Republic of Germany, and are type certificated for operation in the United States under the provisions of 14 CFR 21.29 and the applicable bilateral agreement. Pursuant to the applicable bilateral agreement, the Federal Republic of Germany has kept the FAA informed of the situation described above. The FAA has examined the findings of the Federal Republic of Germany, reviewed all available information, and determined that AD action is necessary for products of these type designs that are certificated for operation in the United States. 

The previously described unsafe condition is likely to exist or develop on other helicopters of these same type designs registered in the United States. Therefore, this AD is being issued to prevent cracking and separation of the bearing cage, failure of a bearing, failure of the TR transmission or INT gearbox, and subsequent loss of control of the helicopter. This AD requires inspecting the magnetic plugs of the TR gearbox and INT gearbox for metal particle deposits before the first flight of each day. If a small amount of fuzz is found on the magnetic plug, the magnetic plug must be cleaned and may be reinstalled. If there is an amount of fuzz that exceeds the amount depicted in “Pos. A” of Figure 1 of this AD, then replacing the INT gearbox, TR transmission, or bearing, part number (P/N) 4639310006, with serial number (S/N) 3246 through 3598, is required within 30 days after the effective date of this AD. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the controllability and structural integrity of the helicopter. Therefore, the inspections and replacement, if necessary, are required before further flight and this AD must be issued immediately. 

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days. 

On July 10, 2002, the FAA issued a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's AD system. The regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. Because we have now included this material in part 39, we no longer need to include it in each individual AD. 

The FAA estimates that this AD will affect 127 helicopters of U.S. registry. It will take approximately 0.5 work hours to inspect both magnetic plugs, and removing and replacing the affected bearings will take approximately 6 work hours to accomplish at an average labor rate of $65 per work hour. Assuming 30 days of inspections, the total cost of inspections will be $123,825. Required parts (3 bearings for each helicopter) will cost approximately $1,147 per helicopter. Based on these assumptions, we estimate the total cost of this AD on U.S. operators to be $319,023. The manufacturer has stated in its alert service bulletin that bearings will be replaced at no cost. Including the warranty coverage, the estimated total cost impact on U.S. operators will be $173,354. 

## Comments Invited 

                    Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire.                           ( print page 872)                        Communications should identify the Rules Docket number and be submitted in triplicate to the address specified under the caption                     **ADDRESSES**                    . All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.                 

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket. 

Commenters wishing the FAA to acknowledge receipt of their mailed comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket No. 2003-SW-21-AD.” The postcard will be date stamped and returned to the commenter. 

The regulations adopted herein will not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132. 

                    The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a “significant regulatory action” under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption                     **ADDRESSES**                    .                 

# List of Subjects in 14 CFR Part 39

      - Air transportation
      - Aircraft
      - Aviation safety
      - Safety

## Adoption of the Amendment 

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: 

# PART 39—AIRWORTHINESS DIRECTIVES 

1. The authority citation for part 39 continues to read as follows: 

Authority:49 U.S.C. 106(g), 40113, 44701. 

§ 39.13 

2. Section 39.13 is amended by adding a new airworthiness directive to read as follows: 

**2004-01-10 Eurocopter Deutschland:**                             Amendment 39-13424. Docket No. 2003-SW-21-AD.                         

*Applicability:*                             Model MBB-BK-117 A-1, A-3, A-4, B-1, B-2, and C-1 helicopters with either:                         

                            (a) Tail rotor (TR) transmission, part number (P/N) 4639003001 or 4639003007, with serial number (S/N) 900 through 932 plus all S/Ns overhauled or repaired after July 15, 2001, and bearing, P/N 4639310006, S/N 3246 through 3598;                             *or*

(b) Intermediate (INT) gearbox, P/N 4639002001 or 4639002005, with S/N 902 through 928 plus all S/Ns overhauled or repaired after July 15, 2001, and bearing, P/N 4639310006 with S/N 3246 through 3598. 

*Compliance:*                             Required as indicated, unless accomplished previously.                         

To prevent cracking, separation of the bearing cage, failure of a bearing, failure of the TR transmission or INT gearbox, and subsequent loss of control of the helicopter, accomplish the following: 

(a) Until you do paragraph (b) of this AD, before the first flight of each day, inspect the magnetic plugs of the TR transmission and INT gearbox for metal particles deposits by reference to Figure 1 of this AD. 
      ( print page 873)    
(1) If you find a small amount of fine fuzz as shown in “Pos. A” of Figure 1 of this AD, clean the magnetic plug and reinstall it after ensuring that the O-ring is correctly positioned and there is no other damage. 

(2) If you find an amount of fuzz as depicted in “Pos. B” or “Pos. C” or metal chip(s) as depicted in “Pos. D” through “Pos. G” or a combination of both fuzz and chips, do paragraph (b) of this AD. 

(b) No later than February 23, 2004, replace bearing, P/N 4639310006 with S/N 3246 through 3598, with an airworthy bearing or replace the affected TR transmission or INT gearbox with an airworthy TR transmission and INT gearbox that does not contain the affected bearing. 

(c) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Contact the Safety Management Group, Rotorcraft Directorate, FAA, for information about previously approved alternative methods of compliance. 

(d) This amendment becomes effective on January 22, 2004. 

# Note:

The subject of this AD is addressed in Luftfahrt-Bundesamt (Federal Republic of Germany) AD 2003-161, dated April 29, 2003. 

Issued in Fort Worth, Texas, on December 31, 2003. 

David A. Downey, 

Manager, Rotorcraft Directorate,  Aircraft Certification Service. 

[FR Doc. 04-267 Filed 1-6-04; 8:45 am] 

BILLING CODE 4910-13-P