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

[Federal Register Volume 68, Number 127 (Wednesday, July 2, 2003)]
[Rules and Regulations]
[Pages 39449-39452]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-16687]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-SW-17-AD; Amendment 39-13215; AD 2003-08-51]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This document publishes in the Federal Register an amendment 
adopting Airworthiness Directive (AD) 2003-08-51, which was sent 
previously to all known U.S. owners and operators of the specified 
model MD Helicopters, Inc. helicopters by individual letters. This AD 
requires reducing the retirement life of certain tail rotor blades, 
performing a one-time visual inspection of each tail rotor blade pitch 
horn (pitch horn) for a crack or corrosion, and replacing unairworthy 
tail rotor blades with airworthy tail rotor blades. This AD also 
requires revising the Airworthiness Limitations section of the 
helicopter maintenance manual to reflect the reduced retirement life, 
and reporting information to the FAA within 24 hours following the one-
time inspection. The actions specified by this AD are intended to 
prevent a pitch horn from separating from the tail rotor blade, leading 
to an unbalanced condition, vibration, loss of tail rotor pitch 
control, and loss of directional control of the helicopter.

DATES: Effective July 17, 2003, to all persons except those persons to 
whom it was made immediately effective by Emergency AD 2003-08-51, 
issued on April 15, 2003, which contained the requirements of this 
amendment.
    Comments for inclusion in the Rules Docket must be received on or 
before September 2, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 2003-SW-17-AD, 2601 Meacham Blvd., Room 
663, Fort Worth, Texas 76137. You may also send comments electronically 
to the Rules Docket at the following address: [email protected].

FOR FURTHER INFORMATION CONTACT: Fred Guerin, Aviation Safety Engineer, 
FAA, Los Angeles Aircraft Certification Office, Airframe Branch, 3960 
Paramount Blvd., Lakewood, California 90712, telephone (562) 627-5232, 
fax (562) 627-5210.

SUPPLEMENTARY INFORMATION: On April 15, 2003, the FAA issued Emergency 
AD 2003-08-51 for the specified model helicopters, which requires, 
before further flight, reducing the retirement life of certain tail 
rotor blades from 5,140, 5,200, or 10,000 hours time-in-service (TIS) 
to 400 hours TIS, performing a one-time visual inspection of each pitch 
horn for a crack or corrosion, and replacing unairworthy tail rotor 
blades with airworthy tail rotor blades. The Emergency AD also requires 
revising the Airworthiness Limitations section of the helicopter 
maintenance

[[Page 39450]]

manual to reflect the reduced retirement life, and reporting 
information to the FAA within 24 hours following the one-time 
inspection. That action was prompted by two reports of cracked pitch 
horns that failed during flight. In both occurrences, the pilot was 
able to land the helicopter without further incident. Investigation 
revealed that the cause of the failures was a fatigue crack in the 
pitch horns that developed before the tail rotor blade reached its 
retirement life. This condition, if not corrected, could result in a 
pitch horn separating from the tail rotor blade, leading to an 
unbalanced condition, vibration, loss of tail rotor pitch control, and 
loss of directional control of the helicopter.
    Since the unsafe condition described is likely to exist or develop 
on other MD Helicopters, Inc. Model 369A, D, E, H, HE, HM, HS, F, and 
FF helicopters of the same type designs, the FAA issued Emergency AD 
2003-08-51 to prevent a pitch horn from separating from the tail rotor 
blade, leading to an unbalanced condition, vibration, loss of tail 
rotor pitch control, and loss of directional control of the helicopter. 
The AD requires, before further flight, reducing the retirement life of 
certain tail rotor blades from 5,140, 5,200, or 10,000 hours TIS to 400 
hours TIS, performing a one-time visual inspection of each pitch horn 
for a crack or corrosion, and replacing unairworthy tail rotor blades 
with airworthy tail rotor blades. The AD also requires revising the 
Airworthiness Limitations section of the helicopter maintenance manual 
to reflect the reduced retirement life, and reporting information to 
the FAA within 24 hours following the one-time inspection. The short 
compliance time involved is required because the previously described 
critical unsafe condition can adversely affect the structural integrity 
of the helicopter. Therefore, reducing the retirement life of certain 
tail rotor blades; performing a one-time visual inspection of each 
pitch horn; replacing unairworthy tail rotor blades; and revising the 
Airworthiness Limitations section of the helicopter maintenance manual 
to reflect the reduced retirement life are required before further 
flight, and this AD must be issued immediately.
    Since it was found that immediate corrective action was required, 
notice and opportunity for prior public comment thereon were 
impracticable and contrary to the public interest, and good cause 
existed to make the AD effective immediately by individual letters 
issued on April 15, 2003, to all known U.S. owners and operators of MD 
Helicopters, Inc. Model 369A, D, E, H, HE, HM, HS, F, and FF 
helicopters. These conditions still exist, and the AD is hereby 
published in the Federal Register as an amendment to 14 CFR 39.13 to 
make it effective to all persons.
    The Emergency AD contained two typographical errors that are 
corrected in this AD. Paragraph (c) of the Emergency AD stated ``400 
hours TIS'' twice, and the ``or'' in the listing of part numbers should 
have been ``and''.
    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 213 helicopters of U.S. 
registry, and replacing the tail rotor blades will take approximately 2 
work hours per helicopter to accomplish at an average labor rate of $60 
per work hour. Required parts will cost approximately $2,000 per 
helicopter. Based on these figures, we estimate the total cost impact 
of the AD on U.S. operators to be $2,120 per helicopter, or $451,560 to 
replace all the blades in the fleet.

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. 
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-17-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

0
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

0
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]

0
2. Section 39.13 is amended by adding a new airworthiness directive to 
read as follows:

2003-08-51 MD Helicopters, Inc.: Amendment 39-13215. Docket No. 
2003-SW-17-AD.


[[Page 39451]]


    Applicability: Model 369A, D, E, H, HE, HM, HS, F, and FF 
helicopters, with tail rotor blades, part number (P/N) 369D21640-
501, 369D21641-501, 369D21642-501, 369D21643-501, 500P3100-101, 
500P3100-301, 500P3300-501, or 500P3500-701, installed, certificated 
in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent a tail rotor blade pitch horn (pitch horn) from 
separating from the tail rotor blade, leading to an unbalanced 
condition, vibration, loss of tail rotor pitch control, and loss of 
directional control of the helicopter, accomplish the following:
    (a) This airworthiness directive (AD) establishes a new 
retirement life of 400 hours time-in-service (TIS) for the tail 
rotor blades listed in the Applicability section. For helicopters 
with an affected tail rotor blade installed that has 390 through 700 
hours TIS, remove and replace the tail rotor blade with an airworthy 
tail rotor blade within 10 hours TIS.
    (b) Before further flight, perform a one-time visual inspection 
of each pitch horn for a crack or corrosion in the area indicated by 
Note 2 in Figure 1 of this AD. Paint removal in accordance with Note 
1 of Figure 1 of this AD is not required for the visual inspection.
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    (c) Revise the helicopter Airworthiness Limitations section of 
the maintenance manual by making pen-and-ink changes to indicate the 
new retirement life of 400 hours TIS for the tail rotor blades, P/N 
369D21640-501, 369D21641-501, 369D21642-501, 369D21643-501, 
500P3100-101, 500P3100-301, 500P3300-501, and 500P3500-70.
    (d) For helicopters with a tail rotor blade installed that has 
more than 700 hours TIS, a one-time special flight permit to fly it 
to a repair facility may be issued only upon completion of an eddy 
current surface scan of each affected pitch horn (see Figure 1 of 
this AD). Paint removal in accordance with Note 1 of the Figure 1 of 
this AD IS required for the surface scan. If a crack is found,

[[Page 39452]]

remove the tail rotor blade and replace it with an airworthy tail 
rotor blade before further flight.
    (e) Within 24 hours after completing the requirements of this 
Emergency AD, report the information requested in Appendix A for all 
tail rotor blades listed in the Applicability section, including the 
tail rotor blades that were removed as a result of this AD. Report 
the information to: Manager, Los Angeles Aircraft Certification 
Office, ATTN: Fred Guerin, 3960 Paramount Blvd., Lakewood, 
California 90712, telephone (562) 627-5232. Reports may also be 
faxed to (562) 627-5210 or emailed to [email protected].
    (f) Information collection requirements contained in this AD 
have been approved by the Office of Management and Budget (OMB) 
under the provisions of the Paperwork Reduction Act of 1980 (44 
U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-
0056.
    (g) 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 Los Angeles Aircraft Certification Office, Transport 
Airplane Directorate, FAA, for information about previously approved 
alternative methods of compliance.
    (h) This amendment becomes effective on July 17, 2003, to all 
persons except those persons to whom it was made immediately 
effective by Emergency AD 2003-08-51, issued April 15, 2003, which 
contained the requirements of this amendment.

Appendix A--Tail Rotor Blade Inspection (Sample Format)

    Send within 24 hours to:
    Manager, Los Angeles Aircraft Certification Office, ATTN: Fred 
Guerin, 3960 Paramount Blvd., Lakewood, California 90712.
    Fax: (562) 627-5210.
    Email: [email protected].
    Date:
    Operator or Company Name:
    Name of Contact Person:
    Address:
    Telephone:
    Fax:
    Aircraft Serial Number:
    Aircraft Registration Number:
    Estimated average flight hours per year:
    T/R Blade Part Number: Serial Number: Total Time:
    Crack found? (Yes/No): Corrosion Found? (Yes/No)
    T/R Blade Part Number: Serial Number: Total Time:
    Crack found? (Yes/No): Corrosion Found? (Yes/No)
    T/R Blade Part Number: Serial Number: Total Time:
    Crack found? (Yes/No): Corrosion Found? (Yes/No)
    T/R Blade Part Number: Serial Number: Total Time:
    Crack found? (Yes/No): Corrosion Found? (Yes/No)
    Comments/Additional Information:

    Issued in Fort Worth, Texas, on June 3, 2003.
Mark R. Schilling,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 03-16687 Filed 7-1-03; 8:45 am]
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