E6-8609. Airworthiness Directives; Stemme GmbH & Co. KG Models S10, S10-V, and S10-VT Sailplanes

AGENCY:

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

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for certain Stemme GmbH & Co. KG Models S10, S10-V, and S10-VT sailplanes. This proposed AD would require you to inspect the connection between the aileron push-rod and the connecting shaft to determine if a safety washer is installed. If there is no safety washer installed, this proposed AD would require you to modify the aileron control assembly. This proposed AD results from mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Germany. We are proposing this AD to prevent a loose bearing in the aileron control lever, which could result in separation of the aileron control system. Separation of the aileron control system could lead to loss of aileron control.

DATES:

We must receive comments on this proposed AD by June 29, 2006.

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.
• Governmentwide 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: [phone].
• 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.

For service information identified in this proposed AD, contact STEMME AG, Flugplatzstraβe F 2, Nr. 7, D-15344 Strausberg, Germany; telephone: + 49.33.41/36 12−0; facsimile: + 49.33.41/36 12−30; e-mail: [e-mail].

FOR FURTHER INFORMATION CONTACT:

Gregory A. Davison, Aerospace Engineer, ACE-112, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: [phone]; facsimile: [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments regarding this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include the docket number, “FAA-2006-24641; Directorate Identifier 2006-CE-27-AD” at the beginning 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 we receive concerning this proposed AD.

Discussion

The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, notified FAA that an unsafe condition may exist on all Stemme GmbH & Co. KG (Stemme) Models S10, S10-V, and S10-VT sailplanes. The LBA reports that, during production, a loose bearing was found on the control lever of a powered Stemme S10 sailplane.

Additional inspections of other levers revealed that a bearing might become loose during operation on the powered sailplane.

The only joint that may disengage because of a loose bearing is the connection between the aileron control rod, part number (P/N) 10SQ-RMB, and the connecting shaft, P/N 10SQ-RMW. All other connections between the push-rods and levers on the affected sailplanes are held in a fork-design that does not allow the joints to disengage because of a loose bearing.

This condition, if not corrected, could result in a loose bearing in the aileron control lever, which could cause separation of the aileron control system. Separation of the aileron control system could lead to loss of aileron control.

Relevant Service Information

We have reviewed Stemme Service Bulletin Document Number: A31-10-069, Am.-Index 01.a, dated September 10, 2004.

The service information describes procedures for:

• Inspecting the bearing of the joint between the push-rod and the connecting shaft for correct position and tight fit;
• Inspecting all connections in the control system with circular caulked hinge or ball bearing to verify that the bearing is in the middle of the part where it is installed;
• Inspecting the joint between the aileron control rod, P/N 10SQ-RMB, and the connecting shaft, P/N 10SQ-RMW, for the installation of a safety washer, P/N DIN 440-06; and
• Modifying the aileron control system if a safety washer is not installed.

Foreign Airworthiness Authority Information

The LBA classified this service bulletin as mandatory and issued German AD Number D-2004-443, dated September 27, 2004, to ensure the continued airworthiness of these sailplanes in Germany. These Stemme Models S10, S10-V, and S10-VT sailplanes 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, the LBA has kept us informed of the situation described above.

FAA's Determination and Requirements of This Proposed AD

We are proposing this AD because we have examined the LBA's findings, evaluated all information and determined the unsafe condition described previously is likely to exist or develop on other products of the same type design that are certificated for operation in the United States.

This proposed AD would require you to inspect the joint between the aileron control rod, P/N 10SQ-RMB, and the connecting shaft, P/N 10SQ-RMW, to determine if a safety washer is installed. If a safety washer is not installed, this proposed AD would require you to modify this area by replacing the joint bolt (P/N LN9037-06042), installing a safety washer (P/N D440-06), and installing washer (P/N 10M-282).

Costs of Compliance

We estimate that this proposed AD would affect 105 sailplanes in the U.S. registry.

We estimate the following costs to do the proposed inspection:

Labor cost	Parts cost	Total cost per sailplane	Total cost on U.S. operators
1 workhour × $80 per hour = $80.	N/A	$80	105 × $80 = $8,400.

We estimate the following costs to do any necessary replacements that would be required based on the results of the proposed inspection. We have no way of determining the number of sailplanes that may need this replacement:

Labor cost	Parts cost	Total cost per sailplane
2 workhours × $80 per hour = $160	$30	$160 + $30 = $190.

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. 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 regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket.

Examining the AD Docket

You may examine the AD docket that contains the proposed AD, the regulatory evaluation, any comments received, and other information on the Internet at http://dms.dot.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone [phone]) is located at the street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

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 FAA 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

[Amended]

2. The FAA amends § 39.13 by adding the following new AD:

Stemme GmbH & Co. KG: Docket No. FAA-2006-24641; Directorate Identifier 2006-CE-27-AD.

Comments Due Date

(a) We must receive comments on this airworthiness directive (AD) action by June 29, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD affects the following sailplane models and serial numbers that are certificated in any category:

Model	Serial No.
S10	10-03 through 10-56.
S10-V	14-001 through 14-030 (including all converted versions 14-003M through 14-056M).
S10-VT	11-001 through 11-089.

Unsafe Condition

(d) This AD results from mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Germany. We are issuing this AD to prevent a loose bearing in the aileron control lever, which could result in separation of the aileron control system. Separation of the aileron control system could lead to loss of aileron control.

Compliance

(e) To address this problem, you must do the following, unless already done:

Actions	Compliance	Procedures
(1) Inspect the joint between the aileron control rod, part number (P/N) 10SQ-RMB (or FAA-approved equivalent part number), and the connecting shaft, P/N 10SQ-RMW (or FAA-approved equivalent part number), to determine if a safety washer, P/N DIN 440-06 (or FAA-approved equivalent part number), is installed.	Within the next 20 hours time-in-service after the effective date of this AD.	Follow Stemme Service Bulletin Document Number: A31-10-069, Am.-Index 01.a, dated September 10, 2004.
(2) If after the inspection required in paragraph (e)(1) of this AD, you can positively determine that a safety washer, P/N DIN 440-06 (or FAA-approved equivalent part number), is installed between the joint in the aileron control rod and the connecting shaft, no further action in required.	Not applicable	Not applicable.
(3) If after the inspection required in paragraph (e)(1) of this AD, you cannot positively determine that a safety washer is installed between the joint in the aileron control rod and the connecting shaft, do the following:	Before further flight after the inspection required in paragraph (e)(1) of this AD.	Follow Stemme Service Bulletin Document Number: A31-10-069, Am.-Index 01.a, dated September 10, 2004.
(i) Install a safety washer, P/N DIN 440-06 (or FAA-approved equivalent part number);
(ii) Replace the existing bolt with bolt, P/N LN9037-06042 (or FAA-approved equivalent part number), from the modification kit; and
(iii) Install washer, P/N 10M-282 (or FAA-approved equivalent part number).
(4) 14 CFR 21.303 allows for replacement parts through parts manufacturer approval (PMA). The phrase “or FAA-approved equivalent part number” in this AD is intended to signify those parts that are PMA parts approved through identicality to the design of the part under the type certificate and replacement parts to correct the unsafe condition under PMA (other than identicality). If parts are installed that are identical to the unsafe parts, then the corrective actions of the AD affect these parts also. In addition, equivalent replacement parts to correct the unsafe condition under PMA (other than identicality) may also be installed provided they meet current airworthiness standards, which include those actions cited in this AD.	Not Applicable	Not Applicable.

Alternative Methods of Compliance (AMOCs)

(f) The Manager, Standards Office, Small Airplane Directorate, FAA, ATTN: Gregory A. Davison, Aerospace Engineer, ACE-112, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: [phone]; facsimile: [phone], has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

Related Information

(g) German AD Number D-2004-443, dated September 27, 2004, and Stemme Service Bulletin Document Number: A31-10-069, Am.-Index 01.a, dated September 10, 2004, also address the subject of this AD. To get copies of the service information referenced in this AD, contact STEMME AG, Flugplatzstraβe F 2, Nr. 7, D-15344 Strausberg, Germany; telephone: + 49.33.41/36 12−0; facsimile: + 49.33.41/36 12−30. To view the AD docket, go to the Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, S.W., Nassif Building, Room PL-401, Washington, DC, or on the Internet at http://dms.dot.gov. The docket number is Docket No. FAA-2006-24641; Directorate Identifier 2006-CE-27-AD.

Issued in Kansas City, Missouri, on May 24, 2006.

David R. Showers,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.