E7-25035. Airworthiness Directives; MT-Propeller Entwicklung GmbH Propellers

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Final rule.

SUMMARY:

The FAA is superseding 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 AD requires the same actions. 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.

DATES:

This AD becomes effective January 31, 2008.

ADDRESSES:

You can get the service information identified in this AD from MT-Propeller USA, Inc., 1180 Airport Terminal Drive, Deland, FL 32724; telephone [phone], fax [phone], or visit http://www.mt-propeller.com.

The Docket Operations office is located at Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.

FOR FURTHER INFORMATION CONTACT:

Terry Fahr, Aerospace Engineer, Boston Aircraft Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail [e-mail]; telephone [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

The FAA proposed to amend 14 CFR part 39 with a proposed AD. The proposed AD applies to certain MT-Propeller Entwicklung GmbH variable pitch and fixed pitch propellers manufactured before 1995, which had not been overhauled since April 1994. We published the proposed AD in the Federal Register on December 13, 2006 (71 FR 74878). That action proposed to require:

• Overhauling the propeller blades and performing initial and repetitive visual inspections of affected propeller blades.
• Removing all propeller blades from service with damaged erosion sheath bonding or loose erosion sheaths and installing any missing or damaged polyurethane protective strips.

The proposed AD resulted from the need to clarify the population of affected propellers previously listed in AD 2006-05-05. 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 identifying the affected population as variable pitch and fixed pitch propellers manufactured before 1995 which had not been overhauled since April 1994.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov;​; or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone [phone]) is provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

Comments

We provided the public the opportunity to participate in the development of this AD. We have considered the comment received.

Request To Include Only Propeller Models That Have U.S. Type Certificates

One commenter, the Modification and Replacement Parts Association, requests that we include only those propeller models that have FAA type certificates, and that only those type certificates dated before 1996 be included in the applicability, or that some alternate applicability scheme be employed that is clear and unambiguous. The commenter is assuming that the AD action should be applicable only to propellers that have an FAA type certificate.

We agree and changed the applicability to include only those propeller models that have FAA type certificates, and only those type certificates dated before 1996.

Conclusion

We have carefully reviewed the available data, including the comment received, and determined that air safety and the public interest require adopting the AD with the change described previously. We have determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD.

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 will be affected by this AD. We also estimate that it will take about 2 work-hours to inspect and install the polyurethane protective strip of each affected propeller, and about 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 will cost about $20. Based on these figures, we estimate the total cost of the 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 AD will not have federalism implications under Executive Order 13132. This AD will 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 this AD:

(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.

We prepared a summary of the costs to comply with this AD and placed it in the AD Docket. You may get a copy of this summary at the address listed under ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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. The FAA amends § 39.13 by removing Amendment 39-14502 ( 71 FR 11151, March 6, 2006), and by adding a new airworthiness directive, Amendment 39-15315, to read as follows:

2007-26-13 MT-Propeller Entwicklung GmbH: Amendment 39-15315. Docket No. FAA-2005-20856; Directorate Identifier 2004-NE-25-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective January 31, 2008.

Affected ADs

(b) This AD supersedes AD 2006-05-05, Amendment 39-14502.

Applicability

(c) This AD applies to MT-Propeller Entwicklung GmbH, models MT, MTV-1, MTV-3, MTV-5, MTV-6, MTV-7, MTV-9, MTV-11, MTV-12, MTV-14, MTV-15, MTV-18, and MTV-21 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 within the compliance times specified unless the actions have already been done.

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

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-18	No. E-118, issued March 1994 or later.
MTV-5, MTV-6, MTV-9, MTV-11, MTV-12, MTV-14, MTV-15, MTV-21	No. E-124, issued March 1994 or later.
MTV-3	No. E-148, issued March 1994 or later.

(h) 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.

Initial Visual Inspection of the Propeller Blade Polyurethane Strip

(i) 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

(j) 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

(k) 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

(l) 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

(m) Special flight permits are not authorized.

Related Information

(n) 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.

(o) Contact Terry Fahr, Aerospace Engineer, Boston Aircraft Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail [e-mail]; telephone [phone], fax [phone], for more information about this AD.

Issued in Burlington, Massachusetts, on December 19, 2007.

Peter A. White,

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