[Federal Register Volume 73, Number 50 (Thursday, March 13, 2008)]
[Proposed Rules]
[Pages 13515-13518]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-5068]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0287; Directorate Identifier 2006-SW-15-AD]
RIN 2120-AA64


Airworthiness Directives; MD Helicopters, Inc. Model 369A, OH-6A, 
369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, and 369HS Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: This document proposes adopting a new airworthiness directive

[[Page 13516]]

(AD) for MD Helicopters, Inc. (MDHI) Model 369A, OH-6A, 369D, 369E, 
369F, 369FF, 369H, 369HE, 369HM, and 369HS helicopters. The proposed AD 
would require repetitive tap inspections of each tail rotor (T/R) blade 
abrasion strip. This proposal is prompted by an incident in which an 
abrasion strip separated from a T/R blade. The actions specified by the 
proposed AD are intended to prevent disbonding and subsequent 
separation of an abrasion strip from a T/R blade, which could result in 
vibration, loss of the T/R, and subsequent loss of control of the 
helicopter.

DATES: Comments must be received on or before May 12, 2008.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    You may get the Helicopter Technology Company, LLC (HTC) service 
information identified in this proposed AD from, HTC, 12902 South 
Broadway, Los Angeles, California, 90061, telephone (310) 523-2750, fax 
(310) 523-2745, or on the Internet at http://www.helicoptertech.com. 
The service information referenced in Note 2 of this proposed AD may be 
obtained from MD Helicopters Inc., Attn: Customer Support Division, 
4555 E. McDowell Rd., Mail Stop M615, Mesa, Arizona 85215-9734, 
telephone (800) 388-3378, fax (480) 346-6813, or on the Internet at 
http://www.mdhelicopters.com.
    You may examine the comments to this proposed AD in the AD docket 
on the Internet at http://www.regulations.gov.

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: 

Comments Invited

    We invite you to submit any written data, views, or arguments 
regarding this proposed AD. Send your comments to the address listed 
under the caption ADDRESSES. Include the docket number ``FAA-2008-0287, 
Directorate Identifier 2006-SW-15-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact 
with FAA personnel concerning this proposed rulemaking. Using the 
search function of the docket Web site, you can find and read the 
comments to any of our dockets, including the name of the individual 
who sent or signed the comment. You may review the DOT's complete 
Privacy Act Statement in the Federal Register published on April 11, 
2000 (65 FR 19477-78).

Examining the Docket

    You may examine the docket that contains the proposed AD, any 
comments, and other information in person at the Docket Operations 
office between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Operations office (telephone (800) 647-5527) is 
located in Room W12-140 on the ground floor of the West Building at the 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after receipt.

Discussion

    This document proposes adopting a new AD for MDHI Model 369A, OH-
6A, 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, and 369HS helicopters, 
with any of the following T/R blades installed:
     HTC part number (P/N) 500P3100-101 and -103, or MDHI P/N 
369D21640-501, -503, and -505.
     HTC P/N 500P3100-301 and -303, or MDHI P/N 369D21641-501, 
-503, and -505.
     HTC P/N 500P3300-501 and -503, or MDHI P/N 369D21643-501, 
-503, and -505.
     HTC P/N 500P3500-701 and -703, or MDHI P/N 369D21642-501, 
-503, and -505.

    Note: An ``M'' or an ``I'' painted on the root of the T/R blade 
indicates compliance to an Alternate Method of Compliance (AMOC) to 
AD 2003-08-51, (Docket No. 2003-SW-17-AD, Amendment 39-13215 (68 FR 
39449, July 2, 2008), corrected at 68 FR 47447, August 11, 2003, 
issued by the FAA, Los Angeles Aircraft Certification Office (LAACO) 
on June 13, 2003 to HTC. The AMOC addressed shot peening of the 
pitch horn of the T/R assembly.

    The proposed AD would require, within 25 hours time-in-service 
(TIS), and thereafter at intervals not to exceed 25 hours TIS, tap 
inspections of the upper and lower surfaces of each T/R blade abrasion 
strip using a coin (United States 25-cent piece or equivalent), or a 
small brass, mild steel, or aluminum hammer, to detect bonding voids 
that exceed 0.2 square inch in size with a minimum of 1.0 inch between 
voids, at least 75 percent of the bonded area of the abrasion strip 
being free from voids, and no voids at the edge of the abrasion strip. 
Modifying each T/R blade in accordance with FAA-approved data by 
installing a titanium rivet in the tip of the outboard end of each T/R 
blade and painting a ``T'' in the root-end of the T/R blade would be 
considered terminating action for the AD. This proposal is prompted by 
an incident in which an abrasion strip separated from a T/R blade 
during flight. The actions specified by the proposed AD are intended to 
prevent disbonding and subsequent separation of an abrasion strip from 
a T/R blade, which could result in vibration, loss of the T/R, and 
subsequent loss of control of the helicopter.
    We have reviewed the following service information:
     HTC Mandatory SB Notice No. 3100-4R4, dated May 10, 2006, 
which describes procedures for periodic inspection of the abrasion 
strip-to-skin bond integrity on each T/R blade, and modifying each T/R 
blade by installing a titanium rivet, P/N 500P3124-13, in the tip of 
the T/R blade, and painting a ``T'' in the root-end of the T/R blade in 
accordance with applicable engineering drawings or standard repair 
instructions; and
     MD Helicopters Service Bulletin SB369D-203R1, SB369E-
097R1, SB369F-082R1, and SB369H-246R1, dated January 23, 2006, which 
describes procedures for periodic inspections of the T/R abrasion 
strip-to-skin bond integrity and modification of the T/R blade by HTC 
to install a titanium rivet in the tip of the T/R blade.
    This unsafe condition is likely to exist or develop on other 
helicopters of the same type designs. Therefore, the proposed AD would 
require, within 25 hours TIS, unless accomplished previously, and 
thereafter at intervals

[[Page 13517]]

not to exceed 25 hours TIS, tap inspections of the upper and lower 
surfaces of each T/R blade abrasion strip using a coin (United States 
25 cent piece or equivalent) or a small brass, mild steel, or aluminum 
hammer, to detect bonding voids in accordance with Part 1--Inspection 
of the HTC Mandatory Service Bulletin Notice No. 3100-4R4, dated May 
10, 2006. Modifying each T/R blade by installing a titanium rivet, P/N 
500P3124-13, in the tip of the T/R blade and painting a ``T'' in the 
root-end of the T/R blade would be a terminating action for this AD. 
The actions would be required to be accomplished by following the 
specified portions of the HTC service bulletin described previously.
    We estimate that this proposed AD would affect 718 helicopters of 
U.S. registry.
     If operators conduct the repetitive inspections required 
by this AD instead of modifying their T/R blades by installing a 
titanium rivet, the estimated costs per year would be $229,760 per 
year, assuming:
     24 inspections per year per helicopter (600 hours TIS per 
25 hour TIS inspection), * Labor of 5 minutes per T/R blade (10 minutes 
(\1/6\ hour) per helicopter), and
     An average labor rate of $80 per work hour.
     If operators elect to implement the terminating action by 
installing a titanium rivet in each T/R blade, the estimated total cost 
would be $244,120, assuming:
     The cost of removing, reinstalling, and balancing the 2-T/
R blade set for the entire fleet would be $114,880, assuming that it 
would take 2 work hours per helicopter to perform these actions at an 
average labor rate of $80 per work hour, and
     The cost of installing the rivet in each T/R blade in the 
fleet would be $129,240, which includes the cost of $10 per rivet ($20 
per helicopter), 1 work hour per T/R blade (2 work hours per 
helicopter) to install a rivet, at an average labor rate of $80 per 
work hour.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. Additionally, this proposed 
AD would 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.
    For the reasons discussed above, I certify that the proposed 
regulation:
    1. Is not a ``significant regulatory action'' under Executive Order 
12866;
    2. Is not a ``significant rule'' under the 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.
    We prepared a draft economic evaluation of the estimated costs to 
comply with this proposed AD. See the AD Docket to examine the draft 
economic evaluation.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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 adding a new airworthiness directive 
to read as follows:

MD Helicopters, Inc. (MDHI): Docket No. FAA-2008-0287; Directorate 
Identifier 2006-SW-15-AD.

Applicability

    Model 369A, OH-6A, 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, 
and 369HS, certificated in any category, with a tail rotor (T/R) 
blade installed as follows including all serial numbers and those T/
R blades with an ``M'' or an ``I'' painted on the T/R blade root:
     Helicopter Technology Company, LLC (HTC) part number 
(P/N) 500P3100-101 and -103, or MDHI P/N 369D21640-501, -503, and -
505.
     HTC P/N 500P3100-301 and -303, or MDHI P/N 369D21641-
501, -503, and -505.
     HTC P/N 500P3300-501 and -503, or MDHI P/N 369D21643-
501, -503, and -505.
     HTC P/N 500P3500-701 and -703, or MDHI P/N 369D21642-
501, -503, and -505.

    Note 1: An ``M'' or an ``I'' painted on the root of the T/R 
blade indicates compliance to an Alternate Method of Compliance 
(AMOC) to Emergency AD 2003-08-51 (Docket No. 2003-SW-17-AD, 
Amendment 39-13215, April 15, 2003), issued by the FAA, Los Angeles 
Aircraft Certification Office (LAACO) on June 13, 2003 to HTC. The 
AMOC addressed shot peening of the pitch horn of the T/R assembly.

Compliance

    Required as indicated.
    To prevent disbonding and subsequent separation of an abrasion 
strip from a T/R blade, which could result in vibration, loss of the 
T/R, and subsequent loss of control of the helicopter, accomplish 
the following:
    (a) Within 25 hours time-in-service (TIS), unless accomplished 
previously, and thereafter at intervals not to exceed 25 hours TIS, 
inspect the abrasion strip-to-skin bond integrity on each T/R blade 
using a tap test method in accordance with Part 1--Inspection, in 
Helicopter Technology Company, LLC (HTC) Mandatory Service Bulletin 
Notice No. 3100-4R4, dated May 10, 2006 (SB).

    Note 2: MD Helicopters Service Bulletin SB369D-203R1, SB369E-
097R1, SB369F-082R1, and SB369H-246R1, dated January 23, 2006, 
pertain to the subject of this AD.

    (b) Modifying each T/R blade in accordance with FAA-approved 
data by installing a titanium rivet at the outboard end and painting 
the letter ``T'' on the root-end of the T/R blade to indicate the 
modification has been accomplished is considered a terminating 
action for the requirements of this AD.
    (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 Manager, Los Angeles Aircraft Certification Office, FAA, 
ATTN: John Cecil, Aviation Safety Engineer, 3960 Paramount Blvd., 
Lakewood, California 90712-4137, telephone (562) 627-5228, fax (562) 
627-5210, for information about previously approved alternative 
methods of compliance.
    (d) Special flight permits will not be issued.


[[Page 13518]]


    Issued in Fort Worth, Texas, on March 4, 2008.
David A. Downey,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. E8-5068 Filed 3-12-08; 8:45 am]
BILLING CODE 4910-13-P