Airworthiness Directives; MT-Propeller Entwicklung GmbH Propellers

Summary:

The FAA proposes to supersede an existing airworthiness directive (AD) for certain MT-Propeller Entwicklung GmbH variable pitch and fixed pitch propellers manufactured before 1995 which had not been overhauled since April 1994. That AD currently requires overhauling the propeller blades and performing initial and repetitive visual inspections of affected propeller blades. That AD also requires removing all propeller blades from service with damaged erosion sheath bonding or loose erosion sheaths and installing any missing or damaged polyurethane protective strips. This proposed AD would require the same actions. This proposed AD results from the need to clarify the population of affected propellers previously listed in AD 2006-05-05. We are proposing this AD to prevent erosion sheath separation leading to damage of the airplane.

Table of Contents

Table of Figures

Addresses:

Use one of the following addresses to comment on this proposed AD.

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.

• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.

• Mail: Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-0001.

• Fax: (202) 493-2251.

• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Contact MT-Propeller USA, Inc., 1180 Airport Terminal Drive, Deland, FL 32724; telephone (386) 736-7762, fax (386) 736-7696 or visit http://www.mt-propeller.com for the service information identified in this proposed AD.

For further information contact:

Frank Walsh, Aerospace Engineer, Boston Aircraft Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-7158, fax (781) 238-7170.

Supplementary information:

Comments Invited

We invite you to send any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2005-20856; Directorate Identifier 2004-NE-25-AD” in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of the DMS Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78) or you may visit http://dms.dot.gov.

Examining the AD Docket

You may examine the docket that contains the proposal, any comments received and any final disposition in person at the DMS Docket Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone (800) 647-5227) is located on the plaza level of the Department of Transportation Nassif Building at the street address stated in ADDRESSES. Comments will be available in the AD docket shortly after the DMS receives them.

Discussion

On February 24, 2006, we issued AD 2006-05-05, Amendment 39-14502 (71 FR 11151, March 6, 2006). That AD requires overhaul of models MT, MTV-1, MTV-2, MTV-3, MTV-5, MTV-6, MTV-7, MTV-9, MTV-10, MTV-11, MTV-12, MTV-14, MTV-15, MTV-17, MTV-18, MTV-20, MTV-21, MTV-22, MTV-24, and MTV-25 propellers with serial numbers (SNs) below 95000, which had not been overhauled since April 1994, within 30 days after the effective date of the AD. That action also required performing initial and repetitive visual inspections of those propeller blades. That action also required removing all propeller blades from service with damaged erosion sheath bonding or loose erosion sheaths and to install any missing or damaged polyurethane protective strips. The European Aviation Safety Agency (EASA), which is the airworthiness authority for the European Union, notified us that an unsafe condition may exist on certain MT-Propeller Entwicklung GmbH propellers.

Actions Since AD 2006-05-05 Was Issued

Since AD 2006-05-05 was issued, MT-Propeller Entwicklung GmbH Propellers and EASA have clarified the population of affected propellers. AD 2006-05-05 described the affected propellers as variable pitch and fixed pitch propellers with serial numbers (SNs) below 95000. Because propellers with SNs starting with 00, 01, 02, 03, 04, 05, and 06, were manufactured in the years 2000, 2001, 2002, 2003, 2004, 2005, and 2006 respectively, some operators are confused as to whether their propeller SN is part of the affected population. For example, propeller SN 00246, manufactured in 2000, would appear to be part of the affected population because the number is below 95000. For clarification, we are proposing to identify the affected population as variable pitch and fixed pitch propellers manufactured before1995 which had not been overhauled since April 1994. Also, since AD 2006-05-05 was issued, we discovered that propeller model MTV-25 was erroneously listed in the AD.

Relevant Service Information

We have reviewed and approved the technical contents of MT-Propeller Service Bulletin (SB) No. 8B, dated March 8, 2006, which lists the affected propeller population as models MT, MTV-1, MTV-2, MTV-3, MTV-5, MTV-6, MTV-7, MTV-9, MTV-10, MTV-11, MTV-12, MTV-14, MTV-15, MTV-17, MTV-18, MTV-20, MTV-21, MTV-22, and MTV-24 propellers, manufactured before 1995 which have not been overhauled since April 1994. This SB describes the visual inspections, removals, and installations proposed by this AD. EASA classified this SB as mandatory and issued AD No. 2006-0345, dated November 14, 2006, in order to ensure the airworthiness of these MT-Propeller Entwicklung GmbH propellers in Europe.

Bilateral Agreement Information

These propeller models are manufactured in Germany and are 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. Under this bilateral airworthiness agreement, EASA kept us informed of the situation described above. We have examined the findings of EASA, 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.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other products of this same type design. We are proposing this AD, which would require you to:

• Overhaul all installed propeller blades of propellers listed in the applicability, within 30 days after the effective date of this AD, unless previously done per AD 2006-05-05.

• Visually inspect certain MT-Propeller Entwicklung GmbH variable pitch and fixed pitch propellers manufactured before 1995.

• Remove from service, certain MT-Propeller Entwicklung GmbH variable pitch and fixed pitch propellers manufactured before 1995 if the propeller blades have damaged erosion sheath bonding or loose erosion sheaths.

• Install polyurethane protective strips onto propeller blades that are missing these strips or have damaged strips.

Costs of Compliance

We estimate that 103 of these MT-Propeller Entwicklung GmbH variable pitch and fixed pitch propellers installed on aircraft of U.S. registry would be affected by this proposed AD. We also estimate that it would take about 2 work-hours to inspect and install the polyurethane protective strip of each affected propeller, and 4 work-hours to remove a propeller requiring overhaul. The average labor rate is $80 per work-hour. Required parts to inspect and install the polyurethane protective strip of each affected propeller would cost about $20. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators, to inspect and install protective strips to be $18,540.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD 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.

For the reasons discussed above, I certify that the 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. Would not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD. See the ADDRESSES section for a location to examine the regulatory evaluation.

List of subjects in 14 cfr part 39

Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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

2. The FAA amends § 39.13 by removing Amendment 39-14502 (71 FR 11151, March 6, 2006) and by adding a new airworthiness directive, to read as follows:

MT-Propeller Entwicklung GmbH: Docket No. FAA-2005-20856; Directorate Identifier 2004-NE-25-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by February 12, 2007.

Affected ADs

(b) This AD supersedes AD 2006-05-05.

Applicability

(c) This AD applies to MT-Propeller Entwicklung GmbH, models MT, MTV-1, MTV-2, MTV-3, MTV-5, MTV-6, MTV-7, MTV-9, MTV-10, MTV-11, MTV-12, MTV-14, MTV-15, MTV-17, MTV-18, MTV-20, MTV-21, MTV-22, and MTV-24 propellers manufactured before 1995 which have not been overhauled since April 1994. These propellers may be installed on, but not limited to, Apex ATL, Apex DR400, EADS Socata Rallye, Extra EA-300, Piper PA-46, Rene Fournier RF4, Sukhoi SU-26, SU-29, and SU-31; Yakovlev YAK-52, YAK-54, and YAK-55; and Technoavia SM-92 airplanes.

Unsafe Condition

(d) This AD results from the need to clarify the population of affected propellers previously listed in AD 2006-05-05. We are issuing this AD to prevent erosion sheath separation leading to damage of the airplane.

Compliance

(e) You are responsible for having the actions required by this AD performed withinthe compliance times specified unless the actions have already been done.

Note 1:

Information about inspection procedures and acceptable limits can be found in Table 1 of this AD.

Overhaul of Propeller Blades

(f) Overhaul all installed propeller blades of propellers listed in the applicability, within 30 days after the effective date of this AD, unless previously done per AD 2006-05-05.

Initial Visual Inspection of the Propeller Blade

(g) During the next preflight inspection or 100-hour inspection, whichever occurs first, after the effective date of this AD, inspect all MT and MTV propellers by doing the following:

(1) Determine if the erosion sheath of any propeller blade is cracked or loose; and

(2) Determine if any propeller blade has other damage out of acceptable limits.

(3) Before the next flight, remove from service those propeller blades with a cracked or loose erosion sheath, or other damage affecting airworthiness.

Table 1.—Service Information
For Propeller Model . . .See Operation and Installation Manual . . .
MT No. E-112, issued Nov. 1993 or later.
MTV-1, MTV-7, MTV-10, MTV-17, MTV-18, MTV-20 No. E-118, issued March 1994 or later
MTV-5, MTV-6, MTV-9, MTV-11, MTV-12, MTV-14, MTV-15, MTV-21, MTV-22, MTV-25 No. E-124, issued March 1994 or later.
MTV-2, MTV-3 No. E-148, issued March 1994 or later.
MTV-24 No. E-309, issued March 1994 or later.

Initial Visual Inspection of the Propeller Blade Polyurethane Strip

(h) During the next pilot's preflight inspection after the effective date of this AD, if the polyurethane protective strip on the leading edge of the inner portion of the blade is found to be damaged or missing, the polyurethane protective strip must be replaced or installed within 10 flight hours. If electrical de-icing boots are installed, no polyurethane protective strips are required.

Repetitive Visual Inspection of the Propeller Blade

(i) If after the effective date of this AD, any propeller blade erosion sheath found to be cracked or loose during the pilot's preflight inspection, or 100-hour inspection, or annual inspection, must be repaired, replaced, or overhauled before the next flight.

Repetitive Visual Inspection of the Propeller Blade Polyurethane Strip

(j) If after the effective date of this AD, any propeller blade polyurethane protective strip found to be damaged or missing during the pilot's preflight inspection, or 100-hour inspection, or annual inspection, must be replaced or installed within 10 flight hours. If electrical de-icing boots are installed, polyurethane protective strips are not required.

Alternative Methods of Compliance

(k) The Manager, Boston Aircraft Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19.

Special Flight Permits

(l) Special flight permits are prohibited.

Related Information

(m) MT-Propeller Entwicklung GmbH, Service Bulletin No. 8B, dated March 8, 2006, pertains to the subject of this AD. European Aviation Safety Agency AD No. 2006-0345, dated November 14, 2006, also addresses the subject of this AD.

Issued in Burlington, Massachusetts, on December 6, 2006. Diane Cook,

Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.

References

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