AD Amdt-39-10246

final rule

Airworthiness Directives; Eurocopter Deutschland GmbH (ECD) (Eurocopter Deutschland) Model MBB-BK 117 A-1, A-3, A-4, B-1, B-2, and C-1 Helicopters

AD Number
Amdt-39-10246
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. 97-SW-45-AD
FR Citation
62 FR 65750
Technical illustration of a helicopter rotor hub assembly
Problem area Rotor system

Applicability

TypeManufacturerModelDetails
aircraft Eurocopter 117 A-1 A-3 A-4 B-1 B-2 C-1 Airworthiness Directives; Eurocopter Deutschland GmbH (ECD) (Eurocopter Deutschland) Model MBB-BK 117 A-1, A-3, A-4, B-1, B-2, and C-1 Helicopters

Unsafe Condition

Cracks in the ribbed area of the main rotor mast flange could result in failure of the flange and subsequent loss of control of the helicopter.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Before further flight, visually inspect the flange's ribbed area for cracks using a 5-power or higher magnifying glass. Repeat inspections at intervals not exceeding 100 hours time-in-service. If cracks are found, replace the cracked main rotor mast with an airworthy one.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Before further flight

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Eurocopter Deutschland Model MBB-BK 117 A-1, A-3, A-4, B-1, B-2, and C-1 helicopters, certificated in any category.

AI-generated summary from the source AD text. Verify against the official source before acting.

Federal Register Abstract

This amendment adopts a new airworthiness directive (AD) that is applicable to Eurocopter Deutschland Model MBB-BK 117 A-1, A-3, A-4, B-1, B-2, and C-1 helicopters. This action requires visual inspections for cracks in the ribbed area of the main rotor mast flange (flange). This amendment is prompted by one report of cracks in a flange. The actions specified in this AD are intended to detect cracks in the flange, which, if not detected, could result in failure of the flange and subsequent loss of control of the helicopter.

Document Text

Show stored source text (verify against official source)
[Federal Register Volume 62, Number 241 (Tuesday, December 16, 1997)]
[Rules and Regulations]
[Pages 65750-65752]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 97-32721]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-SW-45-AD; Amendment 39-10246; AD 97-26-03]
RIN 2120-AA64


Airworthiness Directives; Eurocopter Deutschland GmbH (ECD) 
(Eurocopter Deutschland) Model MBB-BK 117 A-1, A-3, A-4, B-1, B-2, and 
C-1 Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to Eurocopter Deutschland Model MBB-BK 117 A-1, A-3, A-4, 
B-1, B-2, and C-1 helicopters. This action requires visual inspections 
for cracks in the ribbed area of the main rotor mast flange (flange). 
This amendment is prompted by one report of cracks in a flange. The 
actions specified in this AD are intended to detect cracks in the

[[Page 65751]]

flange, which, if not detected, could result in failure of the flange 
and subsequent loss of control of the helicopter.

DATES: Effective December 31, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of December 31, 1997.
    Comments for inclusion in the Rules Docket must be received on or 
before February 17, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 97-SW-45-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137.
    The service information referenced in this AD may be obtained from 
American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, Texas 
75053-4005, telephone (972) 641-3460, fax (972) 641-3527. This 
information may be examined at the FAA, Office of Regional Counsel, 
Southwest Region, 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. Richard Monschke, Aerospace 
Engineer, FAA, Rotorcraft Directorate, Rotorcraft Standards Staff, 2601 
Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5116, (817) 
222-5961.

SUPPLEMENTARY INFORMATION: The Luftfahrt-Bundesamt (LBA), which is the 
airworthiness authority for the Federal Republic of Germany recently 
notified the FAA that an unsafe condition may exist on Eurocopter 
Deutschland Model MBB-BK 117 A-1, A-3, A-4, B-1, B-2, and C-1 
helicopters. The LBA advises that a main rotor mast was found to have 
cracks of critical magnitude in the area of the flange. The cause of 
the cracks is under investigation. Until the cause of the cracks has 
been determined, the flange must be subjected to immediate and 
repetitive visual crack inspections until further notice.
    Eurocopter Deutschland has issued Eurocopter Deutschland GmbH Alert 
Service Bulletin MBB-BK 117 No. ASB-MBB-BK 117-10-114, dated August 27, 
1997, which specifies visually inspecting the area of the holes on the 
underside of the flange for cracks, especially in the ribbed area 
between the holes, and if cracks are found, contacting Eurocopter 
Deutschland before further flight for advice on how to proceed. The LBA 
classified this service bulletin as mandatory and issued LBA AD 97-276, 
effective September 25, 1997, in order to assure the continued 
airworthiness of these helicopters in the Federal Republic of Germany.
    This helicopter model is manufactured in the Federal Republic of 
Germany and is type certificated for operation in the United States 
under the provisions of section 21.29 of the Federal Aviation 
Regulations (14 CFR 21.29) and the applicable bilateral airworthiness 
agreement. Pursuant to this bilateral airworthiness agreement, the LBA 
has kept the FAA informed of the situation described above. The FAA has 
examined the findings of the LBA, reviewed all available information, 
and determined that AD action is necessary for products of this type 
design that are certificated for operation in the United States.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other Eurocopter Deutschland Model MBB-BK 117 A-1, 
A-3, A-4, B-1, B-2, and C-1 helicopters of the same type design 
registered in the United States, this AD is being issued to detect 
cracks in the flange, which, if not detected could result in failure of 
the flange and subsequent loss of control of the helicopter. This AD 
requires, before further flight, a visual inspection of the ribbed area 
of the flange for cracks using a 5-power or higher magnifying glass, 
and thereafter, repeated visual inspections at intervals not to exceed 
100 hours time-in-service. The actions are required to be accomplished 
in accordance with the service bulletin described previously. This 
flange is a part of the main rotor mast assembly and therefore a 
critical component of the flight control system. Due to the criticality 
of the flange to the continued safe flight of the affected helicopters, 
and the required inspection before further flight, this rule must be 
issued immediately to correct an unsafe condition in the affected 
helicopters.
    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.

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, both before and after the closing date for comments, 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 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. 97-SW-45-AD.'' The postcard will be date stamped and 
returned to the commenter.
    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.
    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.

[[Page 65752]]

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. 106(g), 40113, 44701.


Sec. 39.13   [Amended]

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

97-26-03 Eurocopter Deutschland: Amendment 39-10246. Docket No. 97-
SW-45-AD.

    Applicability: Model MBB-BK 117 A-1, A-3, A-4, B-1, B-2, and C-1 
helicopters, certificated in any category.

    Note 1: This AD applies to each helicopter identified in the 
preceding applicability provision, regardless of whether it has been 
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 use the authority 
provided in paragraph (c) to request approval from the FAA. This 
approval may address either no action, if the current configuration 
eliminates the unsafe condition, or different actions necessary to 
address the unsafe condition described in this AD. Such a request 
should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any helicopter from the applicability of this AD.
    Compliance: Required as indicated, unless accomplished 
previously.
    To detects cracks in the main rotor mast flange (flange), which, 
if not detected, could result in failure of the flange and 
subsequent loss of control of the helicopter, accomplish the 
following:
    (a) Before further flight, and thereafter at intervals not to 
exceed 100 hours time-in-service, visually inspect the flange in the 
ribbed area for cracks using a 5-power or higher magnifying glass in 
accordance with paragraphs 2.A.1. and 2.A.2. of the Accomplishment 
Instructions in Eurocopter Deutschland GmbH Alert Service Bulletin 
MBB-BK 117 No. ASB-MBB-BK 117-10-114, dated August 27, 1997.
    (b) If a crack is found as a result of the inspections specified 
in paragraph (a) of this AD, remove the cracked main rotor mast and 
replace it with an airworthy main rotor mast.
    (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, Rotorcraft Standards Staff, 
Rotorcraft Directorate, FAA. Operators shall submit their requests 
through an FAA Principal Maintenance Inspector, who may concur or 
comment and then send it to the Manager, Rotorcraft Standards Staff.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Rotorcraft Standards Staff.

    (d) Special flight permits will not be issued.
    (e) The inspection shall be done in accordance with Eurocopter 
Deutschland GmbH Alert Service Bulletin MBB-BK 117 No. ASB-MBB-BK 
117-10-114, dated August 27, 1997. 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 
American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, 
Texas 75053-4005, telephone (972) 641-3460, fax (972) 641-3527. 
Copies may be inspected at the FAA, Office of Regional Counsel, 
Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 
76137; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.
    (f) This amendment becomes effective on December 31, 1997.

    Note 3: The subject of this AD is addressed in Luftahrt-
Bundesamt (Germany) AD 97-276, effective September 25, 1997.

    Issued in Fort Worth, Texas, on December 5, 1997.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 97-32721 Filed 12-15-97; 8:45 am]
BILLING CODE 4910-13-U

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