Airworthiness Directives; DG Flugzeugbau GmbH, Model DG-500MB Sailplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain DG Flugzeugbau GmbH, Model DG-500MB sailplanes. This proposed AD would require you to replace the engine pylon extension/retraction Warner LA10 spindle drive with an improved designed Stross BSA 10 spindle drive and to modify the electrical system following applicable service information. This proposed AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Germany. We are issuing this proposed AD to prevent failure of the Warner LA10 spindle drive, which could result in the engine pylon not rising or lowering. This condition could cause an unstable engine pylon assembly during flight with loss of control of the sailplane.

DATES:

We must receive any comments on this proposed AD by July 9, 2004.

ADDRESSES:

Use one of the following to submit comments on this proposed AD:

• By mail: FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2004-CE-06-AD, 901 Locust, Room 506, Kansas City, Missouri 64106.
• By fax: (816) 329-3771.
• By e-mail: 9-ACE-7-Docket@faa.gov. Comments sent electronically must contain “Docket No. 2004-CE-06-AD” in the subject line. If you send comments electronically as attached electronic files, the files must be formatted in Microsoft Word 97 for Windows or ASCII.

You may get the service information identified in this proposed AD from DG Flugzeugbau, Postbox 41 20, 76625 Bruchsal, Germany; telephone, 49 7257 890; fax, 49 7257 8922.

You may view the AD docket at FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2004-CE-06-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. Office hours are 8 a.m. to 4 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT:

Gregory Davison, Aerospace Engineer, FAA, Small Airplane Directorate, ACE-112, Room 301, 901 Locust, Kansas City, Missouri 64106; telephone: 816-329-4130; facsimile: 816-329-4090.

SUPPLEMENTARY INFORMATION:

Comments Invited

How Do I Comment on This Proposed AD?

We invite you to submit any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. 2004-CE-06-AD” in the subject line of your comments. If you want us to acknowledge receipt of your mailed comments, send us a self-addressed, stamped postcard with the docket number written on it. We will date-stamp your postcard and mail it back to you.

Are There Any Specific Portions of This Proposed AD I Should Pay Attention to?

We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. If you contact us through a nonwritten communication and that contact relates to a substantive part of this proposed AD, we will summarize the contact and place the summary in the docket. We will consider all comments received by the closing date and may amend this proposed AD in light of those comments and contacts.

Discussion

What Events Have Caused This Proposed AD?

The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, recently notified FAA that an unsafe condition may exist on DG Flugzeugbau GmbH, Model DG-500MB sailplanes, all serial numbers up to and including 5E220B15. The LBA reports two separate fatigue failures of the Warner LA10 spindle drive.

What Are the Consequences if the Condition Is Not Corrected?

Failure of the Warner LA10 spindle drive could result in the engine pylon not rising or lowering, which could cause an unstable engine pylon assembly during flight. Failure of the engine pylon assembly during flight could result in loss of control of the sailplane.

Is There Service Information That Applies to This Subject?

DG Flugzeugbau GmbH has issued Technical Note No. 843/18, issue 2, dated June 25, 2003.

What Are the Provisions of This Service Information?

The technical note includes procedures for installing the Stross BSA 10 spindle drive and modifying the electrical system.

What Action Did the LBA Take?

The LBA classified this service bulletin as mandatory and issued Germany AD Number 2003-409, dated December 9, 2003, to ensure the continued airworthiness of these sailplanes in Germany.

Did the LBA Inform the United States Under the Bilateral Airworthiness Agreement?

The DG Flugzeubau Model DG-500MB 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.

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

What Has FAA Decided?

We have examined the LBA's findings, 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 the unsafe condition described previously is likely to exist or develop on other DG Flugzeubau Model DG-500MB sailplanes of the same type design that are registered in the United States, we are proposing AD action to prevent failure of the spindle drive, which could result in the engine pylon not rising or lowering and cause an unstable engine pylon assembly during flight.

What Would This Proposed AD Require?

This proposed AD would require you to replace the Warner LA10 spindle drive with the Stross BSA 10 spindle drive and to modify the electrical system following Technical Note No. 843/18, issue 2, dated June 25, 2003.

How Does the Revision to 14 CFR Part 39 Affect This Proposed AD?

On July 10, 2002, we published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs FAA's AD system. This regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. This material previously was included in each individual AD. Since this material is included in 14 CFR part 39, we will not include it in future AD actions.

Costs of Compliance

How Many Sailplanes Would This Proposed AD Impact?

We estimate that this proposed AD affects 4 sailplanes in the U.S. registry.

What Would be the Cost Impact of This Proposed AD on Owners/Operators of the Affected Sailplanes?

We estimate the following costs to accomplish the proposed replacement and modification that would be required.

Regulatory Findings

Would This Proposed AD Impact Various Entities?

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.

Would This Proposed AD Involve a Significant Rule or Regulatory Action?

For the reasons discussed above, I certify that this proposed AD:

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 summary of the costs to comply with this proposed AD and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include “AD Docket No. 2004-CE-06-AD” in your request.

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.