[Federal Register Volume 64, Number 130 (Thursday, July 8, 1999)]
[Rules and Regulations]
[Pages 36777-36779]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-16745]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE-35-AD; Amendment 39-11216; AD 99-14-06]
RIN 2120-AA64


Airworthiness Directives; MT-Propeller Entwicklung GMBH Models 
MTV-9-B-C and MTV-3-B-C Propellers

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 MT-Propeller Entwicklung GMBH Models MTV-9-B-C and 
MTV-3-B-C propellers. This action requires initial and repetitive 
inspections of Torx head blade root lag screws for torque values and 
breakage, and, if any screws are found broken or with insufficient 
torque, replacement of all screws with new lag screws. In addition, 
this AD requires replacement of certain model Torx head blade root lag 
screws with improved, hexagonal head blade root lag screws. This 
amendment is prompted by reports of broken Torx head blade root lag 
screws. The actions specified in this AD are intended to prevent blade 
root lag screw breakage, which could result in propeller blade 
separation and loss of control of the airplane.

DATES: Effective July 23, 1999.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 23, 1999.
    Comments for inclusion in the Rules Docket must be received on or 
before September 7, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 99-NE-35-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may also be sent 
via the Internet using the following address: ``9-ane-
[email protected]''. Comments sent via the Internet must contain the 
docket number in the subject line.
    The service information referenced in this AD may be obtained from 
MT-Propeller Entwicklung GMBH, Airport Straubing-Wallmuhle, D-94348 
Atting, Germany; telephone (0 94 29) 84 33, fax (0 94 29) 84 32, 
Internet: ``[email protected]''. This information may be examined at 
the FAA, New England Region, Office of the Regional Counsel, 12 New 
England Executive Park, Burlington, MA; or at the Office of the Federal 
Register, 800 North Capitol Street, NW, suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Wayne E. Gaulzetti, Aerospace 
Engineer, Boston Aircraft Certification Office, FAA, Engine and 
Propeller Directorate, 12 New England Executive Park, Burlington, MA 
01803-5299; telephone (781) 238-7156, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: The Luftfahrt-Bundesamt (LBA), which is the 
airworthiness authority for Germany, recently notified the Federal 
Aviation Administration (FAA) that an unsafe condition may exist on MT-
Propeller Entwicklung GMBH Models MTV-9-B-C and MTV-3-B-C propellers. 
The LBA advises that they have received reports of broken Torx head 
blade root lag screws found during routine teardowns. The investigation 
revealed that the screws broke due to insufficient torque. This 
condition, if not corrected, could result in blade root lag screw 
breakage, which could result in propeller blade separation and loss of 
control of the airplane.
    MT-Propeller Entwicklung GMBH has issued Service Bulletin (SB) No. 
17-A, dated March 5, 1999, that specifies procedures for inspections 
for Torx head blade root lag screws for torque values and breakage, and 
replacement of Torx head blade root lag screws, part number (P/N) A-
550-85 (4mm thread pitch), with improved, hexagonal head blade root lag 
screws, P/N A-983-85. The LBA classified this SB as mandatory and 
issued airworthiness directives (ADs) 1999-081/2 and 1999-082/2 in 
order to assure the airworthiness of these propellers in Germany.
    This propeller model is manufactured in 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 propellers of the same type design registered 
in the United States, the AD requires initial and repetitive 
inspections of Torx head blade root lag screws for torque values and 
breakage, and, if any screws are found with insufficient torque or are 
broken, replacement of all screws with new lag screws. In addition, 
this AD requires replacement of Torx head blade root lag screws, P/N A-
550-85 (4mm thread pitch), with improved, hexagonal head blade root lag 
screws, P/N A-983-85. The actions would be required to be accomplished 
in accordance with the SB described previously.
    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

[[Page 36778]]

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 notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 99-NE-35-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 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, 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 the following new 
airworthiness directive:

99-14-06  MT-Propeller Entwicklung GMBH: Amendment 39-11216. Docket 
99-NE-35-AD.

    Applicability: MT-Propeller Entwicklung GMBH Model MTV-9-B-C 
propellers with serial numbers (S/Ns) starting with 98 or less, 
equipped with CL250-27 or CL260-27 blades with S/Ns starting with 
letter ``A'' through ``P'', equipped with Torx head blade root lag 
screws, P/N A-549-85 (3mm thread pitch), or P/N A-550-85 (4mm thread 
pitch); and Model MTV-3-B-C propellers with S/Ns starting with 98 or 
less, equipped with L250-21 blades with S/Ns starting with letter 
``A'' through ``P'', equipped with Torx head blade root lag screws, 
P/N A-549-85 (3mm thread pitch), or A-550-85 (4mm thread pitch). 
These propellers are installed on but not limited to Sukhoi SU-26, 
SU-29, SU-31; Yakovlev YAK-52, YAK-54, YAK-55, and Technoavia SM-92 
airplanes.

    Note 1: This airworthiness directive (AD) applies to each 
propeller 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 propellers 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 (d) 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 blade root lag screw breakage, which could result in 
propeller blade separation and loss of control of the airplane, 
accomplish the following:
    (a) For propellers with Torx head blade root lag screws, P/N A-
549-85 (3mm thread pitch), perform initial and repetitive 
inspections of Torx head blade root lag screws for torque values and 
breakage, and, if necessary, replace with new lag screws, in 
accordance with MT-Propeller Entwicklung GMBH Service Bulletin (SB) 
No. 17-A, dated March 5,1999, as follows:
    (1) Initially inspect within 50 hours time-in-service (TIS), or 
within 2 months after the effective date of this AD, whichever 
occurs first.
    (2) Thereafter, inspect at intervals not to exceed 100 hours 
TIS, or within 12 months, whichever occurs first.
    (3) Prior to further flight, if any Torx head blade root lag 
screws are found broken or with torque less than 64 foot-pounds, 
replace all Torx head blade root lag screws with new lag screws.
    (b) For propellers with Torx head blade root lag screws, P/N A-
550-85 (4mm thread pitch), perform a one-time inspection of Torx 
head blade root lag screws for torque values and breakage, and, if 
necessary, replace with lag screws, in accordance with MT-Propeller 
Entwicklung GMBH SB No. 17-A, dated March 5,1999, as follows:
    (1) Inspect within 50 hours TIS, or within 2 months after the 
effective date of this AD, whichever occurs first.
    (2) Prior to further flight, if any Torx head blade root lag 
screws are found broken or with torque less than 64 foot-pounds, 
replace all Torx head blade root lag screws with improved, hexagonal 
head blade root lag screws, P/N A-983-85.
    (c) For propellers with Torx head blade root lag screws, P/N A-
550-85 (4mm thread pitch), within 100 hours TIS, or within 12 months 
after the effective date of this AD, replace all Torx head blade 
root lag screws, P/N A-550-85, with improved, hexagonal head blade 
root lag screws, P/N A-983-85, in accordance with MT-Propeller 
Entwicklung GMBH SB No. 17-A, dated March 5,1999.
    (d) 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, Boston Aircraft Certification 
Office. Operators shall submit their requests through an appropriate 
FAA Maintenance Inspector, who may add comments and then send it to 
the Manager, Boston Aircraft Certification Office.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the Boston Aircraft Certification 
Office.

    (e) 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 airplane to a location where 
the inspection requirements of this AD can be accomplished.
    (f) The actions required by this AD shall be performed in 
accordance with the following MT-Propeller Entwicklung GMBH SB:

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             Document No.                Pages            Date
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17-A..................................     1-3  March 5, 1999
Total pages: 3.
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    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 MT-Propeller Entwicklung GMBH, 
Airport Straubing-Wallmuhle, D-94348 Atting, Germany; telephone (0 
94 29) 84 33, fax (0 94 29) 84 32, Internet: ``[email protected]''. 
Copies may be inspected at the FAA, New England Region, Office of 
the Regional Counsel, 12 New England Executive Park, Burlington, MA; 
or at the Office of the Federal Register, 800 North Capitol Street, 
NW, suite 700, Washington, DC.
    (g) This amendment becomes effective on July 23, 1999.


[[Page 36779]]


    Issued in Burlington, Massachusetts, on June 23, 1999.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 99-16745 Filed 7-7-99; 8:45 am]
BILLING CODE 4910-13-U