02-4587. Airworthiness Directives; MT-Propeller Entwicklung GMBH Models MTV-9-B-C and MTV-3-B-C Propellers

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The Federal Aviation Administration (FAA) proposes to supersede an existing airworthiness directive (AD), applicable to MT-Propeller Entwicklung GMBH models MTV-9-B-C and MTV-3-B-C propellers. That AD currently requires initial and repetitive inspections of Torx head blade root lag screws that are used on certain serial number (SN) propellers and replacing all lag screws on the propeller if any screws are found broken or with insufficient torque. In addition, that AD currently requires replacing certain part number (P/N) Torx head blade root lag screws with improved, hexagonal head blade root lag screws. This proposal would require the expansion of the applicability from certain SN propellers to all propellers with certain SN blades that may contain the suspect Torx head blade root lag screws. This proposal is prompted by FAA awareness that a propeller hub of an affected propeller could be changed, thereby changing the propeller serial number, creating a propeller that is not listed in the AD and that has affected blades and lag screws. The actions specified by the proposed AD are intended to prevent failure of the blade root lag screw, which could result in propeller blade separation and loss of control of the airplane.

DATES:

Comments must be received by April 29, 2002.

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 be inspected at this location, by appointment, between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. Comments may also be sent via the Internet using the following address: “[e-mail]”. Comments sent via the Internet must contain the docket number in the subject line.

The service information referenced in the proposed rule may be obtained from MT-Propeller Entwicklung GMBH, Airport Straubing-Wallmuhle, D-94348 Atting, Germany; telephone [phone], fax [phone], Internet address: “[e-mail]”. This information may be examined, by appointment, at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA.

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 [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed 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 above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action 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.

Availability of NPRM's

Any person may obtain a copy of this NPRM by submitting a request to the 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.

Discussion

On June 23, 1999, the Federal Aviation Administration (FAA) issued airworthiness directive (AD) 99-14-06, Amendment 39-11216 (64 FR 36777, July 8, 1999), to require for certain serial number propellers, 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, that AD requires replacement of certain model Torx head blade root lag screws with improved, hexagonal head blade root lag screws.

Since AD 99-14-06 was issued, a question from a repair facility to the FAA brought to light that if a propeller hub of an affected propeller were to be replaced, the propeller serial number would then be different and, not necessarily on the list of affected propellers in the AD. This would cause affected blades to be missed for inspections. To eliminate this potential for blades not being inspected, this proposal would require the same inspections as AD 99-14-06 but for all model MTV-9-B-C propellers equipped with CL250-27, or CL260-27 blades with S/N's starting with letter “A” through “P” and all model MTV-3-B-C propellers equipped with S/N L250-21 blades with S/N's starting with letter “A” through “P”.

Manufacturer's Service Information

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, 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 (AD's) 1999-081/2 and 1999-082/2 in order to assure the airworthiness of these propellers in Germany.

Bilateral Agreement Information

This propeller model is manufactured in Germany and is type certificated for operation in the United States under the provisions of § 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.

Proposed Requirements of this AD

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, this proposal 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 done in accordance with the SB described previously.

Economic Analysis

There are approximately 250 propellers of the affected design in the worldwide fleet. The FAA estimates that 125 propellers installed on airplanes of U.S. registry would be affected by this proposed AD. The FAA also estimates that it would take approximately 13 work hours per propeller to do the proposed actions, and that the average labor rate is $60 per work hour. Based on these figures, the total cost of the proposed AD on U.S. operators is estimated to be $97,500.

Regulatory Analysis

This proposed rule does not have federalism implications, as defined in Executive Order 13132, because it 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. Accordingly, the FAA has not consulted with state authorities prior to publication of this proposed rule.

For the reasons discussed above, I certify that this 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) if promulgated, will not have a significant economic effect, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting 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

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.

§ 39.13

[Amended]

2. Section 39.13 is amended by removing Amendment 39-11216, (64 FR 36777 July 8, 1999), and by adding a new airworthiness directive:

MT-Propeller Entwicklung GMBH: Docket No. 99-NE-35-AD. Supersedes AD 99-14-06, Amendment 39-11216.

Applicability: This airworthiness directive (AD) is applicable to MT-Propeller Entwicklung GMBH Model MTV-9-B-C propellers equipped with CL250-27 or CL260-27 blades with serial numbers (SN's) starting with letter “A” through “P”, equipped with Torx head blade root lag screws, part number (P/N) A-549-85 (3mm thread pitch), or P/N A-550-85 (4mm thread pitch); and Model MTV-3-B-C propellers, equipped with L250-21 blades with SN's 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). 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 already done.

To prevent blade root lag screw breakage, which could result in propeller blade separation and loss of control of the airplane, do the following:

(a) For propellers with Torx head blade root lag screws, P/N A-549-85 (3mm thread pitch), inspect Torx head blade root lag screws for torque values and breakage 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 two 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) Before further flight, if any lag screws are found broken or with torque less than 64 foot-pounds, replace all lag screws with new lag screws.

(b) For propellers with lag screws, P/N A-550-85 (4mm thread pitch), inspect lag screws for torque values and breakage 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 two months after the effective date of this AD, whichever occurs first.

(2) Before further flight, if any lag screws are found broken or with torque less than 64 foot-pounds, replace all lag screws with improved, hexagonal head blade root lag screws, P/N A-983-85. Torque screws to 58-60 foot-pounds.

(c) Replace lag screws, P/N A-550-85, within 100 hours TIS, or within 12 months after the effective date of this AD, with lag screws, P/N A-983-85, in accordance with MT-Propeller Entwicklung GMBH SB No. 17-A, dated March 5, 1999. Torque screws to 58-60 foot-pounds.

Alternative Methods of Compliance

(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 must 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.

Special Flight Permits

(e) Special flight permits may be issued in accordance §§ 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 requirements of this AD can be done.

Issued in Burlington, Massachusetts, on February 20, 2002.

Jay J. Pardee,

Manager, Engine and Propeller Directorate, Aircraft Certification Service.