Airworthiness Directives; DG Flugzeugbau GmbH Models DG-500 Elan Series, DG-500M, and DG-500MB Sailplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes to adopt a new airworthiness directive (AD) that would apply to certain DG Flugzeugbau (DG Flugzeugbau) GmbH Models DG-500 Elan Series, DG-500M, and DG-500MB sailplanes. The proposed AD would require you to visually inspect the elevator control system for proper movement, obtain and incorporate a repair scheme if improper movement is found, and modify and install resin thickened cottonflock reinforcements to the elevator control system as a way to increase the stiffness of the elevator control support stand. The proposed AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for the Federal Republic of Germany. The actions specified by the proposed AD are intended to detect and correct improper movement in the elevator control system and to increase the stiffness of the elevator control support stand. Without accomplishing these actions, the pilot's capability to use full elevator control deflection could be limited, which could require increased force in moving the elevator control with a consequent potentially uncontrolled flight condition.

DATES:

The Federal Aviation Administration (FAA) must receive any comments on this proposed rule on or before October 9, 2000.

ADDRESSES:

Submit comments in triplicate to FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 99-CE-88-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. Comments may be inspected at this location between 8 a.m. and 4 p.m., Monday through Friday, holidays excepted.

Service information that applies to the proposed AD may be obtained from DG Flugzeugbau GmbH, Postbox 41 20, D-76646 Bruchsal, Federal Republic of Germany; telephone: +49 7257-890; facsimile: +49 7257-8922. This information also may be examined at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT:

Mike Kiesov, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 329-4144; facsimile: (816) 329-4090.

SUPPLEMENTARY INFORMATION:

Comments Invited

How Do I Comment on the Proposed AD?

The FAA invites comments on this proposed rule. You may submit whatever written data, views, or arguments you choose. You need to include the rule's docket number and submit your comments in triplicate to the address specified under the caption ADDRESSES. The FAA will consider all comments received on or before the closing date. We may amend the proposed rule in light of comments received. Factual information that supports your ideas and suggestions is extremely helpful in evaluating the effectiveness of the proposed AD action and determining whether we need to take additional rulemaking action.

Are There any Specific Portions of the Proposed AD I Should pay Attention to?

The FAA specifically invites comments on the overall regulatory, economic, environmental, and energy aspects of the proposed rule that might suggest a need to modify the rule. You may examine all comments we receive before and after the closing date of the rule in the Rules Docket. We will file a report in the Rules Docket that summarizes each FAA contact with the public that concerns the substantive parts of the proposed AD.

We are re-examining the writing style we currently use in regulatory documents, in response to the Presidential memorandum of June 1, 1998. That memorandum requires federal agencies to communicate more clearly with the public. We are interested in your comments on whether the style of this document is clearer, and any other suggestions you might have to improve the clarity of FAA communications that affect you. You can get more information about the Presidential memorandum and the plain language initiative at http://www.plainlanguage.gov.

How Can I Be Sure FAA Receives My Comment?

If you want us to acknowledge the receipt of your comments, you must include a self-addressed, stamped postcard. On the postcard, write “Comments to Docket No. 99-CE-88-AD.” We will date stamp and mail the postcard back to you.

Discussion

What Events Have Caused This Proposed AD?

The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for the Federal Republic of Germany, recently notified FAA that an unsafe condition may exist on certain DG Flugzeugbau GmbH Models DG-500 Elan Series, DG-500M, and DG-500MB sailplanes. The LBA reports an incident where a Model DG-500 sailplane experienced notably higher elevator control stiffness during an aerobatic flight. This situation was the result of the outer aluminum tube moving and slipping within the elevator control support stand.

What Are the Consequences If the Condition Is Not Corrected?

If the elevator control support stand permits the outer aluminum tube to move, the pilot's capability to use full elevator control deflection could be limited, which could require increased force in moving the elevator control. This could lead to an uncontrolled flight condition.

Relevant Service Information

Is There Service Information That Applies to This Subject?

DG Flugzeugbau has issued Technical Note (TN) No. 348/12 and 843/12, dated October 6, 1999.

What Are the Provisions of This Service Bulletin?

The service bulletin includes procedures for:

—visually inspecting the elevator control system for proper movement; and

—modifying and installing resin thickened cottonflock reinforcements to the elevator control system as a way to increase the stiffness of the elevator control support stand.

What Action Did the LBA Take?

The LBA classified this service bulletin as mandatory and issued German AD Number 1999-341, dated November 18, 1999, in order to assure the continued airworthiness of these sailplanes in Germany.

Was This in Accordance With the Bilateral Airworthiness Agreement?

These sailplane 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. Pursuant to this bilateral airworthiness agreement, the LBA has kept FAA informed of the situation described above.

The FAA's Determination and an Explanation of the Provisions of the Proposed AD

What Has FAA Decided?

The FAA has examined the findings of the LBA; reviewed all available information, including the service information referenced above; and determined that:

—the unsafe condition referenced in this document exists or could develop on other DG Flugzeugbau GmbH Models DG-500 Elan Series, DG-500M, and DG-500MB sailplanes of the same type design;

—The actions specified in the previously-referenced service information should be accomplished on the affected sailplanes; and

—AD action should be taken in order to correct this unsafe condition.

What Does the Proposed AD Require?

This proposed AD would require you to:

—Visually inspect the elevator control system for proper movement;

—Obtain and incorporate a repair scheme if improper movement is found; and

—Modify and install resin thickened cottonflock reinforcements to the elevator control system as a way to increase the stiffness of the elevator control support stand.

Cost Impact

How Many Sailplanes Does the Proposed AD Impact?

We estimate that the proposed AD affects 10 sailplanes in the U.S. registry.

What Is the Cost Impact of the Proposed AD on Owners/Operators of the Affected Sailplanes?

We estimate the following costs to accomplish the proposed inspection and modification:

Compliance Time of the Proposed AD

What Is the Compliance Time of the Proposed AD?

The compliance time of this proposed AD is to accomplish the inspection “within the next 30 calendar days after the effective date of this AD” and to accomplish the modification “within the next 120 days after the effective date of this AD.”

Why Is the Compliance Time Presented in Calendar Time Instead of Hours Time-in-Service (TIS)?

We have established the compliance in calendar time instead of hours time-in-service (TIS) because the unsafe condition described by the proposed AD is not directly related to sailplane operation. The chance of this situation occurring is the same for a sailplane with 10 hours time-in-service (TIS) as it would be for a sailplane with 500 hours TIS. A calendar time for compliance will assure that the unsafe condition is addressed on all sailplanes in a reasonable time period.

Why are the Compliance Times of the German AD Different Than the Compliance Times in the Proposed AD?

The German AD requires the inspection before next flight and the modification within 45 days of the effective date of the German AD. We do not have justification to require the proposed inspection before next flight. We use compliance times such as this when we have identified an urgent safety of flight situation. We believe that 30 calendar days will give the owners or operators of the affected sailplanes enough time to have the proposed inspection accomplished without compromising the safety of the sailplanes.

The 120-calendar day compliance time for the proposed modification gives the owners/operators of the affected sailplanes enough time to adequately schedule the work to coincide with other maintenance activities.

Regulatory Impact

Does This Proposed AD Impact Various Entities?

The regulations proposed herein 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. Therefore, it is determined that this proposed rule would not have federalism implications under Executive Order 13132.

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

For the reasons discussed above, I certify that this proposed action (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) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action has been placed 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.