AD Amdt-39-13022

[Federal Register Volume 68, Number 13 (Tuesday, January 21, 2003)]
[Rules and Regulations]
[Pages 2687-2689]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 03-1189]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-SW-40-AD; Amendment 39-13022; AD 2002-13-05 R1]
RIN 2120-AA64


Airworthiness Directives; MD Helicopters, Inc. Model 369D, 369E, 
369F, and 369FF Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment revises an airworthiness directive (AD) for the 
specified MD Helicopters, Inc. (MDHI) helicopters that currently 
requires identifying the part number (P/N) of the bolts that attach the 
tail rotor gearbox to the tailboom and replacing any bolt of inadequate 
grip length with an airworthy bolt. That AD also requires adding an 
additional washer if more than four threads protrude from the nutplate. 
This amendment requires the same actions as the existing AD but reduces 
the applicability to only certain tailboom serial numbers and parts 
modified in accordance with either Supplemental Type Certificate (STC) 
SH5055NM or SH4801NM. This amendment also corrects a typographical 
error and clarifies that a slippage mark needs to be reapplied to each 
bolt regardless of the outcome of the required torque test. This 
amendment is prompted by the need to correct and clarify the 
applicability and other portions of the existing AD. The actions 
specified by this AD are intended to prevent loss of a tail rotor 
gearbox due to bolts of inadequate grip length and subsequent loss of 
control of the helicopter.

DATES: Effective February 25, 2003.

FOR FURTHER INFORMATION CONTACT: John Cecil, Aviation Safety Engineer, 
FAA, Los Angeles Aircraft Certification Office, Airframe Branch, 3960 
Paramount Blvd., Lakewood, California 90712-4137, telephone (562) 627-
5228, fax (562) 627-5210.

SUPPLEMENTARY INFORMATION: A proposal to amend 14 CFR part 39 by 
revising AD 2002-13-05, Amendment 39-12793 (67 FR 43227, June 27, 
2002), for the specified MDHI model helicopters with a tailboom 
modified according to either Aerometals STC SH5055NM or SH4801NM, was 
published in the Federal Register on September 24, 2002 (67 FR 185).
    Before issuing AD 2002-13-05, the FAA solicited comments by a 
Notice of Proposed Rulemaking, published in the Federal Register on 
December 27, 2001 (66 FR 66821). A commenter stated that the 
applicability of the AD should be limited to certain part-numbered 
tailbooms with serial number (S/N) 5001-5032 specified in the FAA-
approved Aerometals service bulletin. We did not agree with the 
commenter and, except for minor editorial changes, issued the AD as 
proposed (67 FR 43227, June 27, 2002). Since issuing AD 2002-13-05, we 
have determined that we inappropriately responded to the comment and 
that the commenter's concern was valid. We are now reducing the 
applicability of AD 2002-13-05 to include only certain tailboom S/N's 
and parts that are modified in accordance with either STC SH5055NM or 
SH4801NM. We are also correcting the P/N for the washer to P/N 
AN960D416 in Figure 1 of this AD and clarifying that a slippage mark 
needs to be reapplied to each bolt regardless of the outcome of the 
required torque test.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were received on the 
proposal or the FAA's determination of the cost to the public. The FAA 
has determined that air safety and the public interest require the 
adoption of the rule as proposed.
    The FAA estimates that this AD will affect 500 helicopters of U.S. 
registry. Also, the FAA estimates this AD will require \1/2\ work hour 
per helicopter to determine whether a helicopter has been modified by 
either STC and 1 work hour to inspect and replace the bolts for each of 
approximately 40 helicopters modified by the STC's. The average labor 
rate is $60 per work hour. Required parts will cost approximately $40 
per helicopter. Based on these figures, we estimate the total cost 
impact of the AD on U.S. operators to be $19,000.
    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.
    For the reasons discussed above, I certify that this action (1) Is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) will not have a 
significant economic impact, positive or negative, on a substantial 
number of small entities under the criteria of the Regulatory 
Flexibility Act. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the FAA, Office of the Regional Counsel, Southwest Region, 2601 
Meacham Blvd., Room 663, Fort Worth, Texas.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

[[Page 2688]]

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.


Sec.  39.13  [Amended]

    2. Section 39.13 is amended by removing Amendment 39-12793 (67 FR 
43227, June 27, 2002), and by adding a new airworthiness directive to 
read as follows:

2002-13-05 R1 MD Helicopters, Inc.:\\1/2\\ Amendment 39-13022, 
Docket No. 2001-SW-40-AD. Revises AD 2002-13-05, Amendment 39-12793.

    Applicability: The following MD Helicopters, Inc. helicopter 
models, certificated in any category:

------------------------------------------------------------------------
                                                          Modified In
        Helicopter model                 With           accordance with
------------------------------------------------------------------------
(1) 369D, 369E, 369F, 369FF.....  Tailboom, serial    Aerometals
                                   number (S/N) 5001-  Supplemental Type
                                   5032.               Certificate (STC)
                                                       SH5055NM
(2) 369D and 369E...............  Tail Rotor Gearbox  Aerometals STC
                                   Attach Bolts.       SH4801NM
------------------------------------------------------------------------


    Note 1: This AD applies to each helicopter identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise modified, altered, or repaired in the area subject to the 
requirements of this AD. For helicopters that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (c) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.


    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent loss of the tail rotor gearbox due to attaching bolts 
of inadequate grip length and subsequent loss of control of the 
helicopter, accomplish the following:
    (a) Within 25 hours time-in-service (TIS):
    (1) For each tail rotor gearbox attaching bolt (bolt):
    (i) Determine the part number (P/N).
    (ii) If the P/N cannot be determined or if the bolt is not P/N 
NAS1304-26, before further flight, replace the bolt with bolt, P/N 
NAS1304-26.
    (iii) Torque the bolt to 100-110 in-lbs and apply a slippage 
mark.
    (2) Remove the tailboom control rod and determine the number of 
bolt threads protruding from each nutplate on the internal surface 
of the aft tailboom frame casting, P/N 369D23503, as shown in Figure 
1 of this AD. At least one thread must protrude. If more than four 
threads protrude, add an additional washer, P/N AN960D416, under the 
bolt head. Torque the bolt to 100-110 in-lbs, and reapply a slippage 
mark. See Figure 1:

[[Page 2689]]

[GRAPHIC] [TIFF OMITTED] TR21JA03.000

    (b) Between 2 and 10 hours TIS after accomplishing the 
requirements of paragraph (a) of this AD, inspect the torque on each 
bolt by applying 100 in-lbs. If any bolt movement occurs, retorque 
the bolt to 100-110 in-lbs. Reapply a slippage mark to the bolt 
regardless of the outcome of the torque test. Reinspect the torque 
between 2 and 10 hours TIS thereafter until no bolt movement occurs.

    Note 2: Aerometals Service Bulletin SB-001, dated August 3, 
2000, pertains to the subject of this AD.

    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Los Angeles Aircraft Certification 
Office (LAACO), FAA. Operators shall submit their requests through 
an FAA Principal Maintenance Inspector, who may concur or comment 
and then send it to the Manager, LAACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the LAACO.

    (d) Special flight permits will not be issued.
    (e) This amendment becomes effective on February 25, 2003.


    Issued in Fort Worth, Texas, on January 11, 2003.
David A. Downey,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 03-1189 Filed 1-17-03; 8:45 am]
BILLING CODE 4910-13-U