[Federal Register Volume 60, Number 30 (Tuesday, February 14, 1995)]
[Rules and Regulations]
[Pages 8288-8290]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-3511]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-SW-05-AD; Amendment 39-9149; AD 95-03-13]


Airworthiness Directives; McDonnell Douglas Helicopter Systems 
and Hughes Helicopters, Inc. Model 369 and OH-6A Series Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), [[Page 8289]] applicable to McDonnell Douglas Helicopter Company 
and Hughes Helicopters, Inc. Model 369 and OH-6A series helicopters 
with certain main rotor (M/R) blade assemblies or certain M/R hub lead-
lag assemblies installed, that currently requires repetitive 
inspections and checks for cracks. This amendment requires the same 
inspections as the superseded AD, but would eliminate pilot checks, 
expand the areas of inspection, and require the application of slippage 
marks on each M/R blade root fitting lug and related bushings. This 
amendment is prompted by additional reports of cracks in the M/R blade 
root fittings, lugs, and adjacent blade skin, and movement of the root 
fitting bushings. The actions specified by this AD are intended to 
prevent failure of a M/R blade assembly or a M/R hub lead-lag link 
assembly, loss of a M/R blade, and subsequent loss of control of the 
helicopter.

DATES: Effective March 21, 1995.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of March 21, 1995.

ADDRESSES: The service information referenced in this AD may be 
obtained from McDonnell Douglas Helicopter Systems, Technical 
Publications, Bldg. 530/B111, 5000 E. McDowell Road, Mesa, Arizona 
85205-9797. This information may be examined at the FAA, Office of the 
Assistant Chief Counsel, 2601 Meacham Blvd., Room 663, Fort Worth, 
Texas; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Mr. Brent Bandley, Aerospace Engineer, 
FAA, Los Angeles Aircraft Certification Office, Transport Airplane 
Directorate, 3960 Paramount Blvd., Lakewood, California 90712, 
telephone (310) 627-5237, fax (310) 627-5210.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 91-17-04, 
Amendment 39-8003 (56 FR 42230, August 27, 1991), which is applicable 
to McDonnell Douglas Helicopter Systems and Hughes Helicopters, Inc. 
Model 369 and OH-6A series helicopters with certain main rotor (M/R) 
blade assemblies or certain M/R hub lead-lag assemblies installed, was 
published in the Federal Register on July 21, 1994 (59 FR 37185). That 
action proposed to require application of a slippage mark on each M/R 
blade root fitting lug and related bushings to detect movement within 
25 hours time-in-service (TIS). In addition, that action proposed to 
require, within 25 hours TIS after the effective date of the AD and 
thereafter at intervals not to exceed 100 hours TIS from the last 
inspection, that the M/R blade assembly be removed and that the M/R 
blade root fittings (root fittings), root fitting lugs, lead-lag lugs, 
the M/R blade skin, and the doublers adjacent to the root fittings be 
inspected for cracks. That action also proposed that the lug bushings 
be inspected for looseness and slippage, and that slippage marks be 
applied if not already present. Visual inspections of the root fittings 
and M/R lead-lag links for cracks and inspection of the bushing 
slippage marks for movement, without removing the M/R blade, were also 
proposed at intervals not to exceed 25 hours TIS.
    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 except for editorial changes and a 
change in the manufacturer's name from McDonnell Douglas Helicopter 
Company to McDonnell Douglas Helicopter Systems. Additionally, the FAA 
has revised the average labor rate from $55 per work hour to $60 per 
work hour, which raises the estimated total cost impact of the AD to 
$1,320,000. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.
    The FAA estimates that 1,000 helicopters of U.S. registry will be 
affected by this AD, that it will take approximately 22 work hours per 
helicopter to accomplish the required actions, and that the average 
labor rate is $60 per work hour. Based on these figures, the total cost 
impact of the AD on U.S. operators is estimated to be $1,320,000.
    The regulations adopted herein will not have substantial direct 
effects 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, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    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 Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, 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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing Amendment 39-8003 (56 FR 
42230, August 27, 1991), and by adding a new airworthiness directive 
(AD), Amendment 39-9149, to read as follows:

95-03-13  McDonnell Douglas Helicopter Systems and Hughes 
Helicopters, Inc.: Amendment 39-9149. Docket No. 94-SW-05-AD. 
Supersedes AD 91-17-04, Amendment 39-8003.

    Applicability: Model 369 and OH-6A series helicopters, with any 
of the following parts installed: (1) Main rotor (M/R) blade 
assembly (blade assembly), part number (P/N) 369A1100-BSC, -501, -
503, -505, -601, or -603; 369D21100-BSC, -503, -505, -507, -509, -
511, -513, or -515; 369D21102-BSC or -501; or (2) M/R hub lead-lag 
link assembly (lead-lag link assembly), P/N 369A1203-BSC, -3, or -
11; 369H1203-BSC, -11, -21, or -31, certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent failure of a M/R blade assembly or a M/R hub lead-lag 
link assembly, loss of a M/R blade, and subsequent loss of control 
of the helicopter, accomplish the following:
    (a) Within 25 hours time-in-service (TIS) after the effective 
date of this AD, and thereafter at intervals not to exceed 100 hours 
TIS from the last inspection, remove each blade assembly from the 
helicopter and accomplish the following:
    (1) Inspect the attachment lugs of the M/R blade root fittings 
(root fittings) and the M/ [[Page 8290]] R lead-lag links (links) 
for cracks and the lug bushings (bushings) for looseness. Conduct 
the inspections in accordance with paragraph (b) of Part I of 
McDonnell Douglas Helicopter Company Service Information Notice HN-
211.4, DN-51.6, EN-42.4, FN-31.4 (SIN), dated January 27, 1993.
    (2) Visually inspect the following for cracks--
    (i) The root fittings around the blade attachment lugs; and,
    (ii) The M/R blade doubler and blade skin adjacent to the root 
fittings.
    (3) Mark the root fittings and bushings with slippage marks in 
accordance with paragraph (e) of Part I of the SIN, dated January 
27, 1993, if the slippage marks are degraded or missing.
    (4) Replace any M/R blades or links found to be cracked or to 
have loose bushings with airworthy parts before further flight.
    (b) Within 25 hours TIS after compliance with the requirements 
of paragraph (a) of this AD, and thereafter at intervals not to 
exceed 25 hours TIS from the last inspection, accomplish the 
following without removing the M/R blade:
    (1) Visually inspect the root fittings and links for cracks or 
loose bushings in accordance with Part II of the SIN, dated January 
27, 1993.
    (2) Replace any M/R blades or links found to be cracked or to 
have loose bushings with airworthy parts before further flight.
    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used when approved by the Manager, Los Angeles Aircraft 
Certification Office, FAA. Operators shall submit their requests 
through an FAA Principal Maintenance Inspector, who may concur or 
comment and then send it to the Manager, Los Angeles Aircraft 
Certification Office.

    Note: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles Aircraft Certification Office.

    (d) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the helicopter to a location where 
the requirements of this AD can be accomplished.
    (e) The inspections and replacements, if necessary, shall be 
done in accordance with McDonnell Douglas Helicopter Company Service 
Information Notice No. HN-211.4, DN-51.6, EN-42.4, FN-31.4, dated 
January 27, 1993. This incorporation by reference was approved by 
the Director of the Federal Register in accordance with 5 U.S.C. 
552(a) and 1 CFR part 51. Copies may be obtained from McDonnell 
Douglas Helicopter Systems, Technical Publications, Bldg. 530/B111, 
5000 E. McDowell Road, Mesa, Arizona 85205-9797. Copies may be 
inspected at the FAA, Office of the Assistant Chief Counsel, 2601 
Meacham Blvd., Room 663, Fort Worth, Texas; or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.
    (f) This amendment becomes effective on March 21, 1995.

    Issued in Fort Worth, Texas, on February 7, 1995.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 95-3511 Filed 2-13-95; 8:45 am]
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